Breathable Safety Shoes: Why Your Feet Still Sweat
A mesh upper works by giving sweat vapour an open path out of the shoe. Warm, humid air around your foot moves toward the cooler, drier air outside, and every step flexes the upper and pushes some of that air out through the mesh and the collar. That is the whole mechanism, and it has limits. Mesh moves vapour, not puddles, it lets water in as easily as it lets air out, and the rest of the shoe decides as much as the upper does. Here is what the safety standard actually measures, and how to tell whether a shoe will breathe on a real shift. What Breathable Actually Means In A Safety Shoe In everyday language, breathable means "does not feel hot". In the safety standard it means something far more specific: a sample of the upper material has been measured for how much water vapour it lets through in a set time, and it has cleared a minimum figure. 0.8Minimum upper permeability, mg per cmΒ² per hour 2.0Minimum lining permeability, same units 25%Most of the upper that may be non breathable 24 to 48 hTime a shoe needs to dry out fully The unit reads as milligrams of water vapour, per square centimetre of material, per hour. A square centimetre is roughly the size of a fingernail, so the upper minimum is less than a milligram of vapour through each fingernail sized patch every hour. That sounds tiny, but it is spread across the whole upper and runs for the whole shift. Two things follow from this. First, "breathable" is a pass mark, not a ranking, so two shoes that both meet the standard can feel very different at hour eight. Second, the figure describes a material, not a finished shoe, which is a gap we will come back to. If you want the ground floor first, we have a separate explainer onΒ what a mesh upper is and how it is constructed. This article is about what happens once it is on your foot. Where Your Feet Actually Sweat Most people assume the sole of the foot is the sweatiest part. The research says otherwise, and it changes how you should think about mesh. A study published in the International Journal of Clothing Science and Technology mapped sweating across the feet of 32 people, using two independent laboratory methods. Its findings are directly relevant to anyone choosing footwear: The top of the foot sweated substantially more than the sole. The dorsal surface, the part a mesh upper covers, is where most of the output came from. The highest local rates were at the inner ankle. The collar and heel counter area sits right over it. Sweating across the sole was uniform. No single hot spot, just a steady, even output across the whole plantar surface. Men produced more than twice the sweat of women at the same relative work rate, which is one reason two colleagues can report completely different experiences in the same shoe. The researchers concluded that footwear should follow a body mapping principle, using different materials on different parts of the foot. That is exactly the logic of a mesh upper: put the most open material over the area producing the most vapour. It is also why the sole side of the shoe is handled so differently, as the next section shows. Three Routes Moisture Takes Out Of A Shoe Sweat does not leave a shoe by one route. It takes three, and a well designed shoe uses all of them. How moisture leaves a safety shoe Each route handles a different part of the foot and works at a different speed. Through the upper How it worksVapour drifts from humid air inside to drier air outside ServesThe top of the foot, where output is highest Helped byOpen mesh, thin linings, few overlays Steady, all shift Out of the collar How it worksEach step flexes the shoe and pushes humid air out ServesThe whole foot, especially the ankle area Helped byCorrect fit and regular movement Fast, while you walk Into the insole How it worksAbsorbs sweat now and releases it later ServesThe sole, which the outsole seals below Helped byRemoving the insole to dry overnight Emptied between shifts The second route is the one people forget. Walking turns the shoe into a small bellows, and a study in Scientific Reports that tracked in shoe conditions found that bacterial growth on the skin rose with temperature and humidity inside the shoe, and fell as the ventilation rate went up. It was a small study, three men over twelve days, but the direction is clear: moving air matters as much as the material it moves through. That has a practical consequence for workers who stand still. A picker walking the aisles all shift gets constant pumping. A worker at a fixed station gets very little, so the upper and the insole carry nearly all the load. How The Standard Tests Breathability EN ISO 20345 sets the requirement, and the companion standard ISO 20344 sets the method. The procedure is simple, and knowing it helps you read the result properly. The material is flexed first. Specimens are pre conditioned on a flexing machine, so the test reflects material that has already been bent the way a shoe bends, not a pristine sheet. A sample is sealed over a jar of desiccant. A disc of the upper material is fixed over the neck of a holder containing silica gel, which pulls moisture through the material. It runs in controlled air. The holders turn on a rotating table in a conditioned room at 23 C and 50 percent relative humidity, for a period of roughly seven to eight hours. The gain in weight is the answer. The holders are weighed before and after. The extra weight is water vapour that passed through the material, and that becomes the permeability figure. Absorption is measured too. A separate test records how much vapour the material soaks up, and the two figures are combined into a water vapour coefficient, which must reach 15 mg per cmΒ² for the upper. What the test does not doIt never tests the finished shoe. There is no foot, no sock, no toe cap, no walking and no sweat. It tells you the material can breathe. Whether the assembled shoe does depends on everything else built around it. Every Layer Has To Breathe, Not Just The Mesh Sweat does not meet the mesh first. It has to pass through the sock, then the lining, then any foam padding, and only then the outer mesh. The whole stack is only as open as its tightest layer, which is why the standard sets its own minimums for the inner layers too. Layer What the standard requires Why it matters Upper Permeability of at least 0.8 mg/cmΒ²/h, and a coefficient of at least 15 mg/cmΒ² The outer exit for vapour from the top of the foot Lining Permeability of at least 2.0 mg/cmΒ²/h, and a coefficient of at least 20 mg/cmΒ² Sits against the sock, so it must be two and a half times more open than the upper Insole Absorbs at least 70 mg/cmΒ², then gives back at least 80 percent of it Handles the sole, where the outsole blocks any exit below Sock Not covered by the standard Often the tightest layer in the whole stack, and entirely your choice That last row is the one most people overlook. A thick cotton sock can hold moisture against the skin no matter how open the upper is. Wicking synthetic or wool blend socks move it outward so the rest of the stack can do its job. The toe cap is the other fixed barrier. Aluminium, steel and composite caps do not pass vapour at all, so the mesh stretched over the front of the shoe cannot breathe through the cap beneath it. Designers accept this because the protection is not negotiable, and because the mapping research puts the heaviest sweat output higher up the foot, around the instep and ankle. The 2022 Rule That Caught Out Heavy Overlays Look closely at many modern safety trainers and the "mesh" upper is partly covered in welded plastic cages, printed films, rubber toe bumpers and logos. All of those are useful for durability and looks. None of them breathe. The 2022 edition of the standard started counting them. How much of an upper may be non breathable Share of the upper covered by non vapour permeable material, EN ISO 20345:2022. 10% 25% 100% Up to 10 percentAccepted. The normal upper minimum of 0.8 applies. Between 10 and 25 percentAccepted, but the breathable parts must now reach 2.0, two and a half times the normal minimum, to make up for the covered area. Above 25 percentThe upper does not meet the requirement. This is one of the more useful changes in the current edition, and it gets very little attention. It means a heavily caged shoe has to earn its certification with a much more open mesh underneath. It also gives you a quick visual check in the shop: the more of the upper you can see through, the less work each remaining patch of mesh has to do. We covered the rest of the revision in our guide to what changed between the 2011 and 2022 editions. What Mesh Cannot Do The same openness that lets vapour out lets other things in. This is not a flaw in any particular shoe. It is simply physics, and it decides where a mesh upper belongs. It does not keep water out. An S1P upper is not tested for water penetration at all. The S2 class adds a test where the upper is flexed in water for 60 minutes and may let through no more than 0.2 g, which is why we set out the honest difference between S2 and S1P before anyone buys mesh for wet work. It does not stop liquids. Hot spills, cleaning chemicals and oils pass through open textile faster than through leather or coated materials. It does not resist sparks or hot surfaces. Synthetic mesh can be marked or melted by heat that leather would shrug off, and an outsole heat marking says nothing about the upper, as our breakdown of what the HRO marking does and does not cover explains. It does not keep fine dust out. Plaster, sawdust and grit can work through an open knit and collect inside the shoe. It does not dry you out when you stand still. Without the pumping effect of walking, mesh relies on slow diffusion alone. Where A Mesh Upper Makes Sense And Where It Does Not Put the physics together and the fit decision becomes fairly clear. Mesh earns its place where the main problem is heat and sweat on dry floors. It is the wrong upper where the main problem is water, heat or splashes from outside. A mesh upper tends to suit Choose a different upper Warehouse picking and packing on dry floors Wet outdoor work, standing water, rain and mud Delivery drivers and depot staff Welding, grinding, hot cutting or foundry work Indoor facilities and light maintenance Regular chemical handling or wash down areas Retail stockrooms and back of house Heavy construction, groundworks and demolition Indoor fit out and decorating, where S1P is accepted Kitchens with frequent hot spills onto the foot Your employer's risk assessment always has the final word. If it calls for water resistance, a higher class or a specialist standard, that requirement outranks comfort. For a fuller side by side on durability, protection and feel, we compared how mesh and leather uppers compare overall in a separate guide. How To Get The Most From A Breathable Shoe A breathable upper is half the job. How you wear and rest the shoe decides the other half, and none of these steps cost anything. Wear wicking socks. Swap thick cotton for synthetic or wool blends that move moisture away from the skin, so the lining and upper have something to work with. Rotate two pairs if you can. The Royal College of Podiatry advises that shoes take 24 to 48 hours to dry out properly and recommends alternating pairs daily. Open the shoe up after a shift. Take the insoles out, loosen the laces and open the shoe fully, so the insole can release what it absorbed. Dry gently. For speed, the same guidance suggests a hairdryer on a cold setting rather than direct heat. Get the fit right. A shoe that grips the foot correctly flexes with you and pumps air on every step. A sloppy fit causes rubbing, and damp skin rubs more readily, which is how blisters start. Moisture and friction work together. Damp skin is more prone to friction damage, and the Royal College of Podiatry notes that fungal infections such as athlete's foot thrive in the warm, dark and sweaty environment of feet inside shoes and trainers. A breathable upper reduces that environment, it does not remove it. We looked at the wider picture in what happens to your feet over a ten hour shift. The Honest Verdict Mesh uppers work, and the reasons are simple physics: an open path for vapour over the part of the foot that sweats most, plus the pumping action of every step. The standard sets a real floor for that performance, and the 2022 edition closed a loophole by counting non breathable overlays against the upper. But breathability is a system, not a material. The sock, the lining, the insole, the toe cap, the fit and whether you are walking or standing all change the result, and the certificate only ever tested a flexed sample of fabric over a jar of silica gel. Judge a breathable shoe by the whole stack, and choose mesh for dry, warm, active work rather than for water, heat or splashes. Xnexz PulseX and StrideX use a breathable mesh and microfiber upper intended to reduce heat build-up on dry indoor floors. They are S1P shoes, not water resistant, so they are not the right pick for wet outdoor work. Frequently Asked Questions How does a mesh upper make a safety shoe breathable? It gives water vapour an open path out. Humid air around the foot moves toward drier air outside, and each step flexes the shoe and pushes some of that air out through the mesh and the collar. The insole absorbs sweat from the sole and releases it later. Are mesh safety shoes waterproof? No. The openness that lets vapour out also lets water in. S1P uppers are not tested for water penetration, while S2 adds a 60 minute flexing test in water. For wet work, look at S2, S3 or the newer S6 and S7 classes. What does the safety standard require for breathability? EN ISO 20345 requires the upper to have a water vapour permeability of at least 0.8 mg/cmΒ²/h and a coefficient of at least 15 mg/cmΒ². The lining must reach 2.0 and 20, and the insole must absorb at least 70 mg/cmΒ² and release at least 80 percent of it. Why do my feet still sweat in mesh safety shoes? Because the upper is only one layer. Thick cotton socks, a tight lining, a large area of plastic overlays or standing still for long periods can all slow the process. The top of the foot also produces more sweat than the sole, so output can be high. Does the toe cap stop the shoe breathing? Over the toes, yes. Aluminium, steel and composite toe caps do not pass vapour, so the front of the shoe breathes less than the rest. Research suggests the heaviest sweat output sits higher up the foot, around the instep and inner ankle. What changed about breathability in the 2022 standard? It began counting non breathable materials on the upper. Up to 10 percent is accepted under the normal rule. Between 10 and 25 percent, the breathable parts must reach 2.0 mg/cmΒ²/h. Above 25 percent, the upper fails. How long do safety shoes take to dry out? The Royal College of Podiatry advises that shoes take 24 to 48 hours to dry out properly, and recommends alternating pairs daily. Removing the insoles and loosening the laces after each shift helps. Is mesh suitable for kitchen or hospitality work? Sometimes, where S1P is accepted and hot spills onto the foot are rare. Where spills are frequent, a more closed and liquid resistant upper is the safer choice. Your employer's risk assessment should decide. Breathable S1P For Dry, Busy Shifts If your workplace accepts S1P and your day is spent moving on dry indoor floors, try Xnexz in a real shift. Then tell us honestly how the fit, comfort and breathability hold up, and what we should improve. Browse S1P safety shoes Mesh vs leather guide Β
Breathable Safety Shoes: Why Your Feet Still Sweat
A mesh upper works by giving sweat vapour an open path out of the shoe. Warm, humid air around your foot moves toward the cooler, drier air outside, and every step flexes the upper and pushes some of that air out through the mesh and the collar. That is the whole mechanism, and it has limits. Mesh moves vapour, not puddles, it lets water in as easily as it lets air out, and the rest of the shoe decides as much as the upper does. Here is what the safety standard actually measures, and how to tell whether a shoe will breathe on a real shift. What Breathable Actually Means In A Safety Shoe In everyday language, breathable means "does not feel hot". In the safety standard it means something far more specific: a sample of the upper material has been measured for how much water vapour it lets through in a set time, and it has cleared a minimum figure. 0.8Minimum upper permeability, mg per cmΒ² per hour 2.0Minimum lining permeability, same units 25%Most of the upper that may be non breathable 24 to 48 hTime a shoe needs to dry out fully The unit reads as milligrams of water vapour, per square centimetre of material, per hour. A square centimetre is roughly the size of a fingernail, so the upper minimum is less than a milligram of vapour through each fingernail sized patch every hour. That sounds tiny, but it is spread across the whole upper and runs for the whole shift. Two things follow from this. First, "breathable" is a pass mark, not a ranking, so two shoes that both meet the standard can feel very different at hour eight. Second, the figure describes a material, not a finished shoe, which is a gap we will come back to. If you want the ground floor first, we have a separate explainer onΒ what a mesh upper is and how it is constructed. This article is about what happens once it is on your foot. Where Your Feet Actually Sweat Most people assume the sole of the foot is the sweatiest part. The research says otherwise, and it changes how you should think about mesh. A study published in the International Journal of Clothing Science and Technology mapped sweating across the feet of 32 people, using two independent laboratory methods. Its findings are directly relevant to anyone choosing footwear: The top of the foot sweated substantially more than the sole. The dorsal surface, the part a mesh upper covers, is where most of the output came from. The highest local rates were at the inner ankle. The collar and heel counter area sits right over it. Sweating across the sole was uniform. No single hot spot, just a steady, even output across the whole plantar surface. Men produced more than twice the sweat of women at the same relative work rate, which is one reason two colleagues can report completely different experiences in the same shoe. The researchers concluded that footwear should follow a body mapping principle, using different materials on different parts of the foot. That is exactly the logic of a mesh upper: put the most open material over the area producing the most vapour. It is also why the sole side of the shoe is handled so differently, as the next section shows. Three Routes Moisture Takes Out Of A Shoe Sweat does not leave a shoe by one route. It takes three, and a well designed shoe uses all of them. How moisture leaves a safety shoe Each route handles a different part of the foot and works at a different speed. Through the upper How it worksVapour drifts from humid air inside to drier air outside ServesThe top of the foot, where output is highest Helped byOpen mesh, thin linings, few overlays Steady, all shift Out of the collar How it worksEach step flexes the shoe and pushes humid air out ServesThe whole foot, especially the ankle area Helped byCorrect fit and regular movement Fast, while you walk Into the insole How it worksAbsorbs sweat now and releases it later ServesThe sole, which the outsole seals below Helped byRemoving the insole to dry overnight Emptied between shifts The second route is the one people forget. Walking turns the shoe into a small bellows, and a study in Scientific Reports that tracked in shoe conditions found that bacterial growth on the skin rose with temperature and humidity inside the shoe, and fell as the ventilation rate went up. It was a small study, three men over twelve days, but the direction is clear: moving air matters as much as the material it moves through. That has a practical consequence for workers who stand still. A picker walking the aisles all shift gets constant pumping. A worker at a fixed station gets very little, so the upper and the insole carry nearly all the load. How The Standard Tests Breathability EN ISO 20345 sets the requirement, and the companion standard ISO 20344 sets the method. The procedure is simple, and knowing it helps you read the result properly. The material is flexed first. Specimens are pre conditioned on a flexing machine, so the test reflects material that has already been bent the way a shoe bends, not a pristine sheet. A sample is sealed over a jar of desiccant. A disc of the upper material is fixed over the neck of a holder containing silica gel, which pulls moisture through the material. It runs in controlled air. The holders turn on a rotating table in a conditioned room at 23 C and 50 percent relative humidity, for a period of roughly seven to eight hours. The gain in weight is the answer. The holders are weighed before and after. The extra weight is water vapour that passed through the material, and that becomes the permeability figure. Absorption is measured too. A separate test records how much vapour the material soaks up, and the two figures are combined into a water vapour coefficient, which must reach 15 mg per cmΒ² for the upper. What the test does not doIt never tests the finished shoe. There is no foot, no sock, no toe cap, no walking and no sweat. It tells you the material can breathe. Whether the assembled shoe does depends on everything else built around it. Every Layer Has To Breathe, Not Just The Mesh Sweat does not meet the mesh first. It has to pass through the sock, then the lining, then any foam padding, and only then the outer mesh. The whole stack is only as open as its tightest layer, which is why the standard sets its own minimums for the inner layers too. Layer What the standard requires Why it matters Upper Permeability of at least 0.8 mg/cmΒ²/h, and a coefficient of at least 15 mg/cmΒ² The outer exit for vapour from the top of the foot Lining Permeability of at least 2.0 mg/cmΒ²/h, and a coefficient of at least 20 mg/cmΒ² Sits against the sock, so it must be two and a half times more open than the upper Insole Absorbs at least 70 mg/cmΒ², then gives back at least 80 percent of it Handles the sole, where the outsole blocks any exit below Sock Not covered by the standard Often the tightest layer in the whole stack, and entirely your choice That last row is the one most people overlook. A thick cotton sock can hold moisture against the skin no matter how open the upper is. Wicking synthetic or wool blend socks move it outward so the rest of the stack can do its job. The toe cap is the other fixed barrier. Aluminium, steel and composite caps do not pass vapour at all, so the mesh stretched over the front of the shoe cannot breathe through the cap beneath it. Designers accept this because the protection is not negotiable, and because the mapping research puts the heaviest sweat output higher up the foot, around the instep and ankle. The 2022 Rule That Caught Out Heavy Overlays Look closely at many modern safety trainers and the "mesh" upper is partly covered in welded plastic cages, printed films, rubber toe bumpers and logos. All of those are useful for durability and looks. None of them breathe. The 2022 edition of the standard started counting them. How much of an upper may be non breathable Share of the upper covered by non vapour permeable material, EN ISO 20345:2022. 10% 25% 100% Up to 10 percentAccepted. The normal upper minimum of 0.8 applies. Between 10 and 25 percentAccepted, but the breathable parts must now reach 2.0, two and a half times the normal minimum, to make up for the covered area. Above 25 percentThe upper does not meet the requirement. This is one of the more useful changes in the current edition, and it gets very little attention. It means a heavily caged shoe has to earn its certification with a much more open mesh underneath. It also gives you a quick visual check in the shop: the more of the upper you can see through, the less work each remaining patch of mesh has to do. We covered the rest of the revision in our guide to what changed between the 2011 and 2022 editions. What Mesh Cannot Do The same openness that lets vapour out lets other things in. This is not a flaw in any particular shoe. It is simply physics, and it decides where a mesh upper belongs. It does not keep water out. An S1P upper is not tested for water penetration at all. The S2 class adds a test where the upper is flexed in water for 60 minutes and may let through no more than 0.2 g, which is why we set out the honest difference between S2 and S1P before anyone buys mesh for wet work. It does not stop liquids. Hot spills, cleaning chemicals and oils pass through open textile faster than through leather or coated materials. It does not resist sparks or hot surfaces. Synthetic mesh can be marked or melted by heat that leather would shrug off, and an outsole heat marking says nothing about the upper, as our breakdown of what the HRO marking does and does not cover explains. It does not keep fine dust out. Plaster, sawdust and grit can work through an open knit and collect inside the shoe. It does not dry you out when you stand still. Without the pumping effect of walking, mesh relies on slow diffusion alone. Where A Mesh Upper Makes Sense And Where It Does Not Put the physics together and the fit decision becomes fairly clear. Mesh earns its place where the main problem is heat and sweat on dry floors. It is the wrong upper where the main problem is water, heat or splashes from outside. A mesh upper tends to suit Choose a different upper Warehouse picking and packing on dry floors Wet outdoor work, standing water, rain and mud Delivery drivers and depot staff Welding, grinding, hot cutting or foundry work Indoor facilities and light maintenance Regular chemical handling or wash down areas Retail stockrooms and back of house Heavy construction, groundworks and demolition Indoor fit out and decorating, where S1P is accepted Kitchens with frequent hot spills onto the foot Your employer's risk assessment always has the final word. If it calls for water resistance, a higher class or a specialist standard, that requirement outranks comfort. For a fuller side by side on durability, protection and feel, we compared how mesh and leather uppers compare overall in a separate guide. How To Get The Most From A Breathable Shoe A breathable upper is half the job. How you wear and rest the shoe decides the other half, and none of these steps cost anything. Wear wicking socks. Swap thick cotton for synthetic or wool blends that move moisture away from the skin, so the lining and upper have something to work with. Rotate two pairs if you can. The Royal College of Podiatry advises that shoes take 24 to 48 hours to dry out properly and recommends alternating pairs daily. Open the shoe up after a shift. Take the insoles out, loosen the laces and open the shoe fully, so the insole can release what it absorbed. Dry gently. For speed, the same guidance suggests a hairdryer on a cold setting rather than direct heat. Get the fit right. A shoe that grips the foot correctly flexes with you and pumps air on every step. A sloppy fit causes rubbing, and damp skin rubs more readily, which is how blisters start. Moisture and friction work together. Damp skin is more prone to friction damage, and the Royal College of Podiatry notes that fungal infections such as athlete's foot thrive in the warm, dark and sweaty environment of feet inside shoes and trainers. A breathable upper reduces that environment, it does not remove it. We looked at the wider picture in what happens to your feet over a ten hour shift. The Honest Verdict Mesh uppers work, and the reasons are simple physics: an open path for vapour over the part of the foot that sweats most, plus the pumping action of every step. The standard sets a real floor for that performance, and the 2022 edition closed a loophole by counting non breathable overlays against the upper. But breathability is a system, not a material. The sock, the lining, the insole, the toe cap, the fit and whether you are walking or standing all change the result, and the certificate only ever tested a flexed sample of fabric over a jar of silica gel. Judge a breathable shoe by the whole stack, and choose mesh for dry, warm, active work rather than for water, heat or splashes. Xnexz PulseX and StrideX use a breathable mesh and microfiber upper intended to reduce heat build-up on dry indoor floors. They are S1P shoes, not water resistant, so they are not the right pick for wet outdoor work. Frequently Asked Questions How does a mesh upper make a safety shoe breathable? It gives water vapour an open path out. Humid air around the foot moves toward drier air outside, and each step flexes the shoe and pushes some of that air out through the mesh and the collar. The insole absorbs sweat from the sole and releases it later. Are mesh safety shoes waterproof? No. The openness that lets vapour out also lets water in. S1P uppers are not tested for water penetration, while S2 adds a 60 minute flexing test in water. For wet work, look at S2, S3 or the newer S6 and S7 classes. What does the safety standard require for breathability? EN ISO 20345 requires the upper to have a water vapour permeability of at least 0.8 mg/cmΒ²/h and a coefficient of at least 15 mg/cmΒ². The lining must reach 2.0 and 20, and the insole must absorb at least 70 mg/cmΒ² and release at least 80 percent of it. Why do my feet still sweat in mesh safety shoes? Because the upper is only one layer. Thick cotton socks, a tight lining, a large area of plastic overlays or standing still for long periods can all slow the process. The top of the foot also produces more sweat than the sole, so output can be high. Does the toe cap stop the shoe breathing? Over the toes, yes. Aluminium, steel and composite toe caps do not pass vapour, so the front of the shoe breathes less than the rest. Research suggests the heaviest sweat output sits higher up the foot, around the instep and inner ankle. What changed about breathability in the 2022 standard? It began counting non breathable materials on the upper. Up to 10 percent is accepted under the normal rule. Between 10 and 25 percent, the breathable parts must reach 2.0 mg/cmΒ²/h. Above 25 percent, the upper fails. How long do safety shoes take to dry out? The Royal College of Podiatry advises that shoes take 24 to 48 hours to dry out properly, and recommends alternating pairs daily. Removing the insoles and loosening the laces after each shift helps. Is mesh suitable for kitchen or hospitality work? Sometimes, where S1P is accepted and hot spills onto the foot are rare. Where spills are frequent, a more closed and liquid resistant upper is the safer choice. Your employer's risk assessment should decide. Breathable S1P For Dry, Busy Shifts If your workplace accepts S1P and your day is spent moving on dry indoor floors, try Xnexz in a real shift. Then tell us honestly how the fit, comfort and breathability hold up, and what we should improve. Browse S1P safety shoes Mesh vs leather guide Β
HRO Safety Shoes: It Is 60 Seconds, Not 30 Minutes
HRO stands for heat resistant outsole, and it certifies one narrow thing: a small patch cut from the sole survived contact with a surface at 300 C for 60 seconds without melting, deforming or cracking. That is a genuine, useful test. It is also far narrower than the phrase "heat resistant safety shoes" suggests, because it says nothing about the upper, nothing about how hot the inside of the shoe gets, and nothing about standing on a hot floor for an hour. Knowing exactly what the letters cover is what stops a worker buying the wrong protection. Where HRO Sits In The Marking System HRO is not a class on its own. It is an additional requirement that a manufacturer can choose to test for and add after the main classification, which is why you see it written as S1P HRO or S3 HRO SRC rather than on its own. The class tells you the base package, and the letters after it tell you what extras were certified on top. That structure matters for two reasons. First, HRO is optional, so a shoe without those three letters has not failed the test, it has simply never been submitted for it. Second, HRO can sit on almost any class, so seeing HRO tells you nothing about whether the shoe also has a puncture resistant midsole or a water resistant upper. If you want the whole map of what each code covers, we laid out the full run of safety shoe ratings from SB to S7 in a separate guide. The one sentence versionThe class code describes the shoe. HRO describes a piece of the sole, tested on its own, against one specific type of heat. Inside The Hot Contact Test The method sits in ISO 20344, the companion standard that holds the test procedures for EN ISO 20345, under the clause for determination of resistance to hot contact. Laboratories run it on purpose built equipment, and the numbers are tighter than the marketing language around them. 300 CContact temperature, held exactly 60 sHow long the contact lasts 13 NForce pressing the head down 10 mmMandrel the sole is bent around A strip is cut out of the sole. The specimen is roughly 30 mm by 70 mm, taken from the outsole, with any cleats or tread blocks removed so the surface presented to the heat is flat. The heated head is brought to temperature. An electrically heated head with a square contact face of about 25.5 mm is warmed until it passes 300 C, then the heating stops and it is allowed to settle back down to exactly 300 C before it touches anything. Foil goes over the specimen. A piece of aluminium foil is laid across the test piece so that molten or degraded material does not weld itself to the equipment. Contact is held for 60 seconds. The arm lowers and applies a pressure of 20 kPa across that small contact face, which works out at roughly 13 newtons, about the weight of a bag of sugar. The piece cools, then gets bent. After the foil is removed the specimen cools for around ten minutes, and it is then inspected and bent around a steel mandrel of 10 mm diameter. The pass is visual and dimensional. There must be no melting, no separation of layers, no cracking when it is flexed, and the piece must still be within the dimensional limits the standard allows. Only then does the shoe earn HRO. Two details in that sequence do a lot of quiet work. The bend around the mandrel is there because a sole can look perfectly fine after heating and then crack the moment it flexes, which is exactly what a sole does on every step. And the contact face is small, about the size of a large postage stamp, sitting on a flat strip of material rather than on a finished shoe. The Two Numbers Product Pages Get Wrong Search for heat resistant safety shoes and you will find the test described in several mutually incompatible ways. Two errors come up again and again, and both make the marking sound stronger than it is. What you will often read What the test method actually says "Withstands 300 C for 30 minutes" or "for an hour" Contact is held for 60 seconds. Not 30 minutes, not an hour. A minute of contact is the whole exposure. "Rated for working in 300 C environments" It is a contact test on a sole specimen, not an environmental or ambient rating. Nothing measures the air around the shoe. "Heat resistant, so it is fire resistant" Flame resistance is a different property under a different standard. HRO involves no flame at all. "The sole is tested on the finished shoe" A flat specimen is cut from the sole and tested on an anvil. The assembled shoe does not go into the rig. None of this makes HRO worthless. A sole that comes through a minute at 300 C and then bends around a 10 mm bar without cracking is made of something serious. It just means the claim is precise, and precision is what you need when a risk assessment is involved. HRO, HI And CI Are Three Different Promises This is where most of the confusion actually lives. Three temperature related codes exist in EN ISO 20345, they are tested in completely different ways, and they answer completely different questions. Code Question it answers Test conditions Pass criteria HRO Will the outsole survive touching something hot? 300 C contact on a sole specimen for 60 seconds No melting, no delamination, no cracking when bent HI Will heat travel through the sole to my foot? Footwear stood in a sand bath at 150 C for 30 minutes Temperature inside, on top of the insole, rises no more than 22 C CI Will cold travel through the sole to my foot? Footwear held in a chamber at minus 17 C for 30 minutes Temperature inside falls no more than 10 C Read that table twice and the practical consequence becomes obvious. A shoe can carry HRO and still let your foot cook, because nothing in the HRO test measures what reaches the inside. The sole survives, which protects the shoe. HI is the code that protects the foot. A worker who is going to stand on hot surfaces rather than briefly step across them needs HI, and ideally both. It is also worth knowing that HI was tightened in the current edition of the standard, which added explicit failure criteria for delamination and visible deformation rather than relying on the temperature figure alone. That is one of a long list of revisions, and we covered the bigger picture in our breakdown of what changed between the 2011 and 2022 editions. Where 300 C Sits Against Real Working Heat Three hundred degrees sounds enormous until you put it on a scale with the temperatures that actually appear in industrial work. The chart below is drawn to a single linear scale so the gaps are honest rather than flattering. Working temperatures against the HRO test point All bars on one linear scale, zero to 1400 C. Newly laid asphalt, cool enough to open to traffic50 C Where PU outsole material begins to degrade faster80 C The HI heat insulation test, sand bath150 C UK hot rolled asphalt at delivery to site160 C The HRO hot contact test300 C Molten aluminium, foundry work700 C Molten iron, foundry work1400 C Two things jump out. The HRO test comfortably clears the temperature of freshly delivered asphalt, which is reassuring for anyone who occasionally has to cross it. And it sits at roughly a fifth of the temperature of molten iron, which tells you immediately that HRO was never designed for foundry work. Clearing the temperature is not the same as being suitableHot asphalt is below 300 C, but it is also sticky, it clogs tread, and the exposure lasts far longer than sixty seconds. Passing the contact test does not make a shoe the right choice for a full shift on a paving crew. The Outsole Material Decides Whether HRO Is Possible HRO is not something a manufacturer adds to a shoe. It is a property of the compound the sole is made from, and the material families used in safety footwear behave very differently once heat is involved. Two outsole families, two different jobs Why one can realistically pass HRO and the other rarely tries. Nitrile and heat grade rubber Heat behaviourCompounded to hold its shape and structure at around 300 CHRO realistic WeightHeavier, because rubber is simply the denser material Underfoot feelFirm and supportive rather than soft and springy Typical useFoundries, heavy engineering, hot work, roofing The usual route to an HRO marking PU and EVA foam soles Heat behaviourPU degrades noticeably faster above roughly 80 CHRO unlikely WeightPU can be up to around 30 percent lighter than rubber Underfoot feelSofter, with more cushioning on hard flat floors Typical useWarehouses, depots, light trade, indoor maintenance Built for comfort on cool floors This is the honest trade off, and no amount of clever engineering removes it. The compound that survives a minute at 300 C is heavier and firmer than the foam that makes a twelve hour shift on concrete bearable. If you have ever compared how PU and rubber outsoles differ on grip, the same material logic applies to heat, only more sharply. EVA sits at the far end of that spectrum. It is a foam, it is light, and it is popular in midsoles precisely because it is soft, but heat is the thing it handles least well of all. We went through where EVA outsoles do well and where they give up in more detail, and hot contact is firmly in the second category. Five Things HRO Does Not Cover The marking is specific, so its silences are specific too. If a job involves any of the following, HRO on the box is not the answer you are looking for. Heat reaching your foot. That is HI, tested at 150 C for thirty minutes with a limit on how much the inside warms up. HRO measures the sole's survival, not your comfort or your skin. The upper. Nothing in the HRO test touches the mesh, the microfiber, the leather, the stitching or the laces. A shoe can hold HRO and still have an upper that is damaged by sparks. Flame. There is no ignition, no burner and no flame anywhere in the procedure. Heat resistant and flame resistant are different words for good reason. Molten metal splash. Liquid metal lands, sticks and keeps burning. A static contact test at 300 C does not model that at all. Long exposure. Sixty seconds is sixty seconds. Standing on a hot surface for an hour is a different physical problem, and it is the one HI is designed for. When You Need EN ISO 20349 Instead Once molten metal, welding spatter or sustained radiant heat enters the picture, EN ISO 20345 stops being the right standard, whatever letters are printed after the class. Footwear for those environments is certified to EN ISO 20349, which is a separate standard written specifically for foundry and welding work. Marking Standard What it is built for HRO EN ISO 20345, optional extra Brief contact between the outsole and a hot surface HI EN ISO 20345, optional extra Limiting how much heat travels through to the foot WG EN ISO 20349-2 Welding and allied processes, including sparks and contact heat Al EN ISO 20349-1 Molten aluminium splash, in the region of 700 C Fe EN ISO 20349-1 Molten iron splash, in the region of 1400 C Footwear built to EN ISO 20349 generally carries an HRO sole as part of the package, but the reverse is never true. HRO on an EN ISO 20345 shoe does not quietly give you foundry protection, and no honest retailer should imply that it does. Who Actually Needs HRO On Their Shoes Before paying for the marking, it is worth being clear about whether your working day contains the hazard it was written for. The question is not "does it ever get warm at work", it is "does the sole of my shoe make brief contact with something genuinely hot". HRO earns its place HRO is usually not the deciding factor Roofing and felt work with hot bitumen Warehouse picking, packing and order fulfilment Road surfacing and asphalt crews, alongside HI Delivery drivers and depot staff Foundry and heavy metal work, under EN ISO 20349 Retail stockroom and general facilities work Welding bays and hot cutting areas, under EN ISO 20349 Painting, decorating and interior fit out Glass, ceramics and furnace adjacent roles Healthcare, care homes and lab support work Some kitchen and bakery roles near ovens and fryers Office based and light maintenance roles Kitchens are the interesting middle case. A commercial kitchen has real heat hazards, but the ones that hurt people are usually spills onto the top of the foot and slips on wet tile rather than the outsole touching a 300 C surface, which is why our guidance on kitchen and hospitality footwear puts grip and closure ahead of the heat markings for most roles. Ask your head chef and your risk assessment, not a product page. How To Check An HRO Claim Before You Buy Marketing copy is not certification. These four checks take about two minutes and will tell you whether the claim is real. Find the marking, not the adjective. Look for HRO printed in the classification string on the shoe's own label or in the technical specification, for example S3 HRO SR. A product page that only says "heat resistant sole" in prose has told you nothing certifiable. Check the marking is on the shoe itself. EN ISO 20345 requires the classification to be marked on the footwear. If the label inside the tongue or collar does not carry HRO, the website claim is the one that is wrong. Ask for the EU type examination certificate. A notified body issues it, it lists the tested properties, and a supplier who cannot produce it for a safety critical claim is a supplier worth questioning. Match the code to the actual hazard. If the hazard is heat soaking through the sole, you want HI. If it is molten metal, you want EN ISO 20349. HRO answers one question, and it is the narrow one. The Honest Verdict HRO is a real, measurable, independently tested property, and it is worth having when the hazard matches. A sole that takes 300 C for a minute and then bends around a 10 mm mandrel without a crack is not a marketing flourish, it is a compound choice with consequences for weight, cost and cushioning. What HRO is not is a general heat badge. It does not keep your foot cool, it does not resist flame, it does not survive molten metal, and it does not describe the upper. Most workers reading this do not need it, and for the ones who do, HRO alone is rarely enough on its own. The right answer is almost always HRO plus HI, or a shoe certified to EN ISO 20349, chosen against a written risk assessment rather than a product description. For everyone else, the markings that shape your day are the ordinary ones. Grip, fit, weight and closure decide how a shift feels far more often than any temperature code does. Xnexz PulseX and StrideX are S1P shoes built around comfort on indoor floors, so they do not carry HRO, and we would rather say that plainly than let the word "durable" do quiet work. If hot contact is on your risk assessment, choose a nitrile soled HRO shoe from a specialist instead. Frequently Asked Questions What does HRO mean on safety shoes? HRO means heat resistant outsole. It certifies that a specimen cut from the sole withstood contact with a surface at 300 C for 60 seconds without melting, separating into layers or cracking when bent around a 10 mm mandrel afterwards. Is 300 C tested for 60 seconds or 30 minutes? Sixty seconds. The 30 minute figure that appears on some retail pages belongs to the HI heat insulation test, which is run at 150 C for half an hour. Mixing the two up makes HRO sound far broader than it is. Are HRO shoes fire resistant? No. There is no flame in the HRO test at any point, and heat resistance and flame resistance are separate properties assessed in different ways. Footwear for work with genuine fire risk is specified under different standards entirely. What is the difference between HRO and HI? HRO protects the sole, HI protects the foot. HRO asks whether the outsole survives touching something hot. HI asks how much heat travels up through the sole complex, allowing no more than a 22 C rise inside after 30 minutes on a 150 C sand bath. Can an S1P shoe carry HRO? Yes in principle, because HRO is an additional requirement that can sit on any classification. In practice it is far more common on S3 boots, because the nitrile rubber compounds that pass the test are usually paired with the heavier constructions used in hot work. Do I need HRO for working on hot asphalt? HRO helps, because UK hot rolled asphalt is delivered around 160 C, below the test temperature. It is not sufficient on its own though, since the exposure lasts far longer than a minute and heat soaks upward. Look for HI as well, and follow your employer's specification. Why do so few lightweight safety trainers have HRO? Because the materials that make a shoe feel light and cushioned are the ones heat treats worst. PU degrades faster above roughly 80 C and EVA is a foam, while the nitrile compounds that pass at 300 C are denser, firmer and heavier underfoot. Does HRO cover molten metal splash? No. Molten metal is covered by EN ISO 20349, which uses Al for aluminium at around 700 C and Fe for iron at around 1400 C. Those temperatures are well beyond the HRO contact test, and the hazard behaves completely differently. Where is the HRO marking printed? On the footwear itself, usually on a label inside the tongue or the collar, as part of the classification string such as S3 HRO SR. If it appears only in website copy and not on the shoe, treat the claim as unverified. S1P Comfort For Indoor Shifts, Stated Honestly If your risk assessment calls for HRO, buy HRO from a specialist. If it calls for S1P and your day is spent on indoor floors, try Xnexz in a real shift and tell us honestly how the fit, comfort and grip hold up. Browse S1P safety shoes Read the full ratings guide Β
HRO Safety Shoes: It Is 60 Seconds, Not 30 Minutes
HRO stands for heat resistant outsole, and it certifies one narrow thing: a small patch cut from the sole survived contact with a surface at 300 C for 60 seconds without melting, deforming or cracking. That is a genuine, useful test. It is also far narrower than the phrase "heat resistant safety shoes" suggests, because it says nothing about the upper, nothing about how hot the inside of the shoe gets, and nothing about standing on a hot floor for an hour. Knowing exactly what the letters cover is what stops a worker buying the wrong protection. Where HRO Sits In The Marking System HRO is not a class on its own. It is an additional requirement that a manufacturer can choose to test for and add after the main classification, which is why you see it written as S1P HRO or S3 HRO SRC rather than on its own. The class tells you the base package, and the letters after it tell you what extras were certified on top. That structure matters for two reasons. First, HRO is optional, so a shoe without those three letters has not failed the test, it has simply never been submitted for it. Second, HRO can sit on almost any class, so seeing HRO tells you nothing about whether the shoe also has a puncture resistant midsole or a water resistant upper. If you want the whole map of what each code covers, we laid out the full run of safety shoe ratings from SB to S7 in a separate guide. The one sentence versionThe class code describes the shoe. HRO describes a piece of the sole, tested on its own, against one specific type of heat. Inside The Hot Contact Test The method sits in ISO 20344, the companion standard that holds the test procedures for EN ISO 20345, under the clause for determination of resistance to hot contact. Laboratories run it on purpose built equipment, and the numbers are tighter than the marketing language around them. 300 CContact temperature, held exactly 60 sHow long the contact lasts 13 NForce pressing the head down 10 mmMandrel the sole is bent around A strip is cut out of the sole. The specimen is roughly 30 mm by 70 mm, taken from the outsole, with any cleats or tread blocks removed so the surface presented to the heat is flat. The heated head is brought to temperature. An electrically heated head with a square contact face of about 25.5 mm is warmed until it passes 300 C, then the heating stops and it is allowed to settle back down to exactly 300 C before it touches anything. Foil goes over the specimen. A piece of aluminium foil is laid across the test piece so that molten or degraded material does not weld itself to the equipment. Contact is held for 60 seconds. The arm lowers and applies a pressure of 20 kPa across that small contact face, which works out at roughly 13 newtons, about the weight of a bag of sugar. The piece cools, then gets bent. After the foil is removed the specimen cools for around ten minutes, and it is then inspected and bent around a steel mandrel of 10 mm diameter. The pass is visual and dimensional. There must be no melting, no separation of layers, no cracking when it is flexed, and the piece must still be within the dimensional limits the standard allows. Only then does the shoe earn HRO. Two details in that sequence do a lot of quiet work. The bend around the mandrel is there because a sole can look perfectly fine after heating and then crack the moment it flexes, which is exactly what a sole does on every step. And the contact face is small, about the size of a large postage stamp, sitting on a flat strip of material rather than on a finished shoe. The Two Numbers Product Pages Get Wrong Search for heat resistant safety shoes and you will find the test described in several mutually incompatible ways. Two errors come up again and again, and both make the marking sound stronger than it is. What you will often read What the test method actually says "Withstands 300 C for 30 minutes" or "for an hour" Contact is held for 60 seconds. Not 30 minutes, not an hour. A minute of contact is the whole exposure. "Rated for working in 300 C environments" It is a contact test on a sole specimen, not an environmental or ambient rating. Nothing measures the air around the shoe. "Heat resistant, so it is fire resistant" Flame resistance is a different property under a different standard. HRO involves no flame at all. "The sole is tested on the finished shoe" A flat specimen is cut from the sole and tested on an anvil. The assembled shoe does not go into the rig. None of this makes HRO worthless. A sole that comes through a minute at 300 C and then bends around a 10 mm bar without cracking is made of something serious. It just means the claim is precise, and precision is what you need when a risk assessment is involved. HRO, HI And CI Are Three Different Promises This is where most of the confusion actually lives. Three temperature related codes exist in EN ISO 20345, they are tested in completely different ways, and they answer completely different questions. Code Question it answers Test conditions Pass criteria HRO Will the outsole survive touching something hot? 300 C contact on a sole specimen for 60 seconds No melting, no delamination, no cracking when bent HI Will heat travel through the sole to my foot? Footwear stood in a sand bath at 150 C for 30 minutes Temperature inside, on top of the insole, rises no more than 22 C CI Will cold travel through the sole to my foot? Footwear held in a chamber at minus 17 C for 30 minutes Temperature inside falls no more than 10 C Read that table twice and the practical consequence becomes obvious. A shoe can carry HRO and still let your foot cook, because nothing in the HRO test measures what reaches the inside. The sole survives, which protects the shoe. HI is the code that protects the foot. A worker who is going to stand on hot surfaces rather than briefly step across them needs HI, and ideally both. It is also worth knowing that HI was tightened in the current edition of the standard, which added explicit failure criteria for delamination and visible deformation rather than relying on the temperature figure alone. That is one of a long list of revisions, and we covered the bigger picture in our breakdown of what changed between the 2011 and 2022 editions. Where 300 C Sits Against Real Working Heat Three hundred degrees sounds enormous until you put it on a scale with the temperatures that actually appear in industrial work. The chart below is drawn to a single linear scale so the gaps are honest rather than flattering. Working temperatures against the HRO test point All bars on one linear scale, zero to 1400 C. Newly laid asphalt, cool enough to open to traffic50 C Where PU outsole material begins to degrade faster80 C The HI heat insulation test, sand bath150 C UK hot rolled asphalt at delivery to site160 C The HRO hot contact test300 C Molten aluminium, foundry work700 C Molten iron, foundry work1400 C Two things jump out. The HRO test comfortably clears the temperature of freshly delivered asphalt, which is reassuring for anyone who occasionally has to cross it. And it sits at roughly a fifth of the temperature of molten iron, which tells you immediately that HRO was never designed for foundry work. Clearing the temperature is not the same as being suitableHot asphalt is below 300 C, but it is also sticky, it clogs tread, and the exposure lasts far longer than sixty seconds. Passing the contact test does not make a shoe the right choice for a full shift on a paving crew. The Outsole Material Decides Whether HRO Is Possible HRO is not something a manufacturer adds to a shoe. It is a property of the compound the sole is made from, and the material families used in safety footwear behave very differently once heat is involved. Two outsole families, two different jobs Why one can realistically pass HRO and the other rarely tries. Nitrile and heat grade rubber Heat behaviourCompounded to hold its shape and structure at around 300 CHRO realistic WeightHeavier, because rubber is simply the denser material Underfoot feelFirm and supportive rather than soft and springy Typical useFoundries, heavy engineering, hot work, roofing The usual route to an HRO marking PU and EVA foam soles Heat behaviourPU degrades noticeably faster above roughly 80 CHRO unlikely WeightPU can be up to around 30 percent lighter than rubber Underfoot feelSofter, with more cushioning on hard flat floors Typical useWarehouses, depots, light trade, indoor maintenance Built for comfort on cool floors This is the honest trade off, and no amount of clever engineering removes it. The compound that survives a minute at 300 C is heavier and firmer than the foam that makes a twelve hour shift on concrete bearable. If you have ever compared how PU and rubber outsoles differ on grip, the same material logic applies to heat, only more sharply. EVA sits at the far end of that spectrum. It is a foam, it is light, and it is popular in midsoles precisely because it is soft, but heat is the thing it handles least well of all. We went through where EVA outsoles do well and where they give up in more detail, and hot contact is firmly in the second category. Five Things HRO Does Not Cover The marking is specific, so its silences are specific too. If a job involves any of the following, HRO on the box is not the answer you are looking for. Heat reaching your foot. That is HI, tested at 150 C for thirty minutes with a limit on how much the inside warms up. HRO measures the sole's survival, not your comfort or your skin. The upper. Nothing in the HRO test touches the mesh, the microfiber, the leather, the stitching or the laces. A shoe can hold HRO and still have an upper that is damaged by sparks. Flame. There is no ignition, no burner and no flame anywhere in the procedure. Heat resistant and flame resistant are different words for good reason. Molten metal splash. Liquid metal lands, sticks and keeps burning. A static contact test at 300 C does not model that at all. Long exposure. Sixty seconds is sixty seconds. Standing on a hot surface for an hour is a different physical problem, and it is the one HI is designed for. When You Need EN ISO 20349 Instead Once molten metal, welding spatter or sustained radiant heat enters the picture, EN ISO 20345 stops being the right standard, whatever letters are printed after the class. Footwear for those environments is certified to EN ISO 20349, which is a separate standard written specifically for foundry and welding work. Marking Standard What it is built for HRO EN ISO 20345, optional extra Brief contact between the outsole and a hot surface HI EN ISO 20345, optional extra Limiting how much heat travels through to the foot WG EN ISO 20349-2 Welding and allied processes, including sparks and contact heat Al EN ISO 20349-1 Molten aluminium splash, in the region of 700 C Fe EN ISO 20349-1 Molten iron splash, in the region of 1400 C Footwear built to EN ISO 20349 generally carries an HRO sole as part of the package, but the reverse is never true. HRO on an EN ISO 20345 shoe does not quietly give you foundry protection, and no honest retailer should imply that it does. Who Actually Needs HRO On Their Shoes Before paying for the marking, it is worth being clear about whether your working day contains the hazard it was written for. The question is not "does it ever get warm at work", it is "does the sole of my shoe make brief contact with something genuinely hot". HRO earns its place HRO is usually not the deciding factor Roofing and felt work with hot bitumen Warehouse picking, packing and order fulfilment Road surfacing and asphalt crews, alongside HI Delivery drivers and depot staff Foundry and heavy metal work, under EN ISO 20349 Retail stockroom and general facilities work Welding bays and hot cutting areas, under EN ISO 20349 Painting, decorating and interior fit out Glass, ceramics and furnace adjacent roles Healthcare, care homes and lab support work Some kitchen and bakery roles near ovens and fryers Office based and light maintenance roles Kitchens are the interesting middle case. A commercial kitchen has real heat hazards, but the ones that hurt people are usually spills onto the top of the foot and slips on wet tile rather than the outsole touching a 300 C surface, which is why our guidance on kitchen and hospitality footwear puts grip and closure ahead of the heat markings for most roles. Ask your head chef and your risk assessment, not a product page. How To Check An HRO Claim Before You Buy Marketing copy is not certification. These four checks take about two minutes and will tell you whether the claim is real. Find the marking, not the adjective. Look for HRO printed in the classification string on the shoe's own label or in the technical specification, for example S3 HRO SR. A product page that only says "heat resistant sole" in prose has told you nothing certifiable. Check the marking is on the shoe itself. EN ISO 20345 requires the classification to be marked on the footwear. If the label inside the tongue or collar does not carry HRO, the website claim is the one that is wrong. Ask for the EU type examination certificate. A notified body issues it, it lists the tested properties, and a supplier who cannot produce it for a safety critical claim is a supplier worth questioning. Match the code to the actual hazard. If the hazard is heat soaking through the sole, you want HI. If it is molten metal, you want EN ISO 20349. HRO answers one question, and it is the narrow one. The Honest Verdict HRO is a real, measurable, independently tested property, and it is worth having when the hazard matches. A sole that takes 300 C for a minute and then bends around a 10 mm mandrel without a crack is not a marketing flourish, it is a compound choice with consequences for weight, cost and cushioning. What HRO is not is a general heat badge. It does not keep your foot cool, it does not resist flame, it does not survive molten metal, and it does not describe the upper. Most workers reading this do not need it, and for the ones who do, HRO alone is rarely enough on its own. The right answer is almost always HRO plus HI, or a shoe certified to EN ISO 20349, chosen against a written risk assessment rather than a product description. For everyone else, the markings that shape your day are the ordinary ones. Grip, fit, weight and closure decide how a shift feels far more often than any temperature code does. Xnexz PulseX and StrideX are S1P shoes built around comfort on indoor floors, so they do not carry HRO, and we would rather say that plainly than let the word "durable" do quiet work. If hot contact is on your risk assessment, choose a nitrile soled HRO shoe from a specialist instead. Frequently Asked Questions What does HRO mean on safety shoes? HRO means heat resistant outsole. It certifies that a specimen cut from the sole withstood contact with a surface at 300 C for 60 seconds without melting, separating into layers or cracking when bent around a 10 mm mandrel afterwards. Is 300 C tested for 60 seconds or 30 minutes? Sixty seconds. The 30 minute figure that appears on some retail pages belongs to the HI heat insulation test, which is run at 150 C for half an hour. Mixing the two up makes HRO sound far broader than it is. Are HRO shoes fire resistant? No. There is no flame in the HRO test at any point, and heat resistance and flame resistance are separate properties assessed in different ways. Footwear for work with genuine fire risk is specified under different standards entirely. What is the difference between HRO and HI? HRO protects the sole, HI protects the foot. HRO asks whether the outsole survives touching something hot. HI asks how much heat travels up through the sole complex, allowing no more than a 22 C rise inside after 30 minutes on a 150 C sand bath. Can an S1P shoe carry HRO? Yes in principle, because HRO is an additional requirement that can sit on any classification. In practice it is far more common on S3 boots, because the nitrile rubber compounds that pass the test are usually paired with the heavier constructions used in hot work. Do I need HRO for working on hot asphalt? HRO helps, because UK hot rolled asphalt is delivered around 160 C, below the test temperature. It is not sufficient on its own though, since the exposure lasts far longer than a minute and heat soaks upward. Look for HI as well, and follow your employer's specification. Why do so few lightweight safety trainers have HRO? Because the materials that make a shoe feel light and cushioned are the ones heat treats worst. PU degrades faster above roughly 80 C and EVA is a foam, while the nitrile compounds that pass at 300 C are denser, firmer and heavier underfoot. Does HRO cover molten metal splash? No. Molten metal is covered by EN ISO 20349, which uses Al for aluminium at around 700 C and Fe for iron at around 1400 C. Those temperatures are well beyond the HRO contact test, and the hazard behaves completely differently. Where is the HRO marking printed? On the footwear itself, usually on a label inside the tongue or the collar, as part of the classification string such as S3 HRO SR. If it appears only in website copy and not on the shoe, treat the claim as unverified. S1P Comfort For Indoor Shifts, Stated Honestly If your risk assessment calls for HRO, buy HRO from a specialist. If it calls for S1P and your day is spent on indoor floors, try Xnexz in a real shift and tell us honestly how the fit, comfort and grip hold up. Browse S1P safety shoes Read the full ratings guide Β
Energy Absorbing Heels: What "E" Actually Means
The E on a safety shoe stands for energy absorption of the seat region, which is the standard's term for the heel. It means one specific thing: in a laboratory, that heel absorbed at least 20 joules when it was compressed. That is the whole claim. It is not a comfort rating, it is not a measure of how the shoe feels at hour nine, and it is not a score you can compare between two models, because a heel that absorbed 21 joules and one that absorbed 45 carry exactly the same letter. Understanding what the test actually does is the fastest way to stop over-reading the marking and start looking at the things that genuinely decide how a shoe feels underfoot. What the E Marking Actually Certifies Like antistatic performance, energy absorption is written into the base requirements of the main safety classes rather than sold as an extra. If your shoe is S1 or above, it has been through this test. Class Energy absorbing heel What else the class brings SB No, unless separately marked E The 200J toe cap and basic requirements only S1 Yes Closed heel region and antistatic performance S1P Yes S1 plus a perforation-resistant midsole S2 Yes S1 plus water resistance of the upper S3 Yes S2 plus perforation resistance and a cleated outsole S6 and S7 Yes The newer waterproof constructions SB is the exception again, which is why it keeps catching people out. A basic SB shoe covers the toe and little else, as we set out in what SB means and what it does not cover. Everything from S1 upward includes the energy absorbing heel by definition, so a product page that advertises it as a special feature is telling you something the class code already guaranteed. Inside the Test, Step by Step The method is more brutal and more specific than the phrase "shock absorbing" suggests. 20 JMinimum energy absorbed to pass 5,000 NForce the heel is compressed to 10 mm/minSpeed the load is applied 1 JPrecision the result is reported to A shaped punch goes inside the shoe. Testing uses a set of backpart punches made from standardised lasts, and the one matching the shoe's size is selected so the load is spread the way a real heel would spread it. It is brought down onto the centre of the heel. The punch contacts the inside of the shoe at the middle of the heel area, so the whole sole structure beneath it takes the load. The load is applied slowly. Compression runs at a rate of 10 mm per minute, which is a deliberate, controlled squeeze rather than an impact. It continues until 5,000 newtons. That is the end point, and the sole is compressed all the way there. The energy is the area under the curve. Absorbed energy is calculated by integrating the load deflection curve between 50 N and 5,000 N, reported to the nearest joule, and it must not be less than 20 J. Why it is measured as energy, not softness Energy is force multiplied by the distance the sole compresses. A thick soft sole that squashes a long way can absorb the same energy as a firmer sole that compresses less but resists harder. That is why two shoes that feel completely different underfoot can produce similar numbers, and why the figure alone cannot tell you which one you will prefer. Why 5,000 Newtons Is Not a Footstep This is the part worth sitting with, because it reframes the whole marking. Gait research puts the peak vertical ground reaction force in normal walking at around 107 per cent of body weight during the loading phase just after heel contact, with the force through a stride typically moving between roughly 80 and 120 per cent of body weight. For an 85 kg worker, body weight is about 834 newtons, so the peak is somewhere near 890 newtons. The test compresses the heel to 5,000 newtons. That is roughly five to six times the peak force of a normal walking step, applied once, slowly, to a brand new shoe. The test and the workday are different events Both matter, but only one of them is certified. The laboratory test LoadUp to 5,000 N Speed10 mm per minute RepetitionsOnce Condition of shoeNew A severe single squeeze Your actual shift LoadAround 107% of body weight SpeedFast impact, milliseconds RepetitionsThousands per day Condition of shoeProgressively worn Mild loads, endless repetition So the test proves the heel structure has real capacity. It answers the question "can this sole soak up a heavy load without bottoming out", and that is genuinely worth knowing. What it does not do, and was never designed to do, is model a ten hour shift. Fatigue is a story about thousands of small repeated loads, and this is a single large one. What the E Marking Does Not Tell You Four limits are worth being clear about, because most of the disappointment around cushioning comes from expecting the letter to cover them. It is a threshold, not a score. 20 J is a floor. A shoe scraping past it and a shoe comfortably beyond it both print the same E. The marking cannot rank two products. It is measured on a new shoe. Certification captures a moment. Nothing in that letter describes what the heel is doing after six months of daily compression. It says nothing about the forefoot. The test is the seat region only. If you stand still for long periods, a good deal of your loading is through the ball of the foot, which is not part of this assessment at all. It is not a comfort claim. Comfort depends on fit, volume, insole, upper, weight and how your particular foot loads. Energy absorption is one input among many, and the standard makes no promise about how anything will feel. The honest way to read it Treat E as a floor that has been cleared, not as a feature that has been won. It tells you the heel is not hollow and not brittle. It cannot tell you whether this shoe suits your feet, and no marking can. Where the Cushioning Actually Comes From The letter is certified, but the feel comes from the midsole material sitting between your heel and the ground. That is the part worth reading on a spec sheet. Material How it behaves underfoot The trade-off Polyurethane (PU) Resilient and supportive, holds its structure well over a long day Denser than EVA, and susceptible to breakdown with age and moisture EVA Very light and soft on first wear, which is why it feels immediately comfortable Compresses permanently over time, so the cushioning fades PU and EVA combined EVA for lightness with a PU or rubber layer for durability and grip More complex construction, and the two layers age at different rates TPU inserts Used in the heel for structure and energy return rather than softness Adds firmness, which not everyone wants under the heel If you are weighing up the two you will meet most often, PU and EVA outsoles compared goes through the differences properly, and what workers should know about EVA covers the softness-versus-longevity question on its own. How Heel Cushioning Fades The certificate does not expire. The cushioning does. This is the single most useful thing to understand about the E marking, and nothing on the box mentions it. Compression set. Foams do not fully rebound after being squashed thousands of times. The cells collapse gradually and the midsole thins, which is why an old sole can look intact and feel dead. Material breakdown. Polyurethane degrades over time in the presence of moisture, a slow chemical process that continues whether the shoe is worn or sitting in a cupboard. Uneven loading. Most people wear one edge of the heel faster, so cushioning becomes asymmetric long before the sole looks worn out. None of this is a defect. It is what foam does. The practical consequence is that heel comfort should be judged by how the shoe feels now rather than by a letter printed when it was new, and a pair that has gone flat is worth replacing even if the toe cap and upper are fine. The wider cost of getting this wrong is something we looked at in the hidden cost of heavy safety shoes, and the physical side in what happens to your feet after ten hours. The Insole Is Part of What Gets Tested One detail follows directly from the method. The punch presses against the inside of the shoe, which means everything sitting in the heel at that moment forms part of what is being compressed, including the removable insole the shoe was supplied with. That has a practical consequence people rarely think about. Throw away the original insole and drop in a thin flat replacement, and the heel you are standing on is no longer quite the one that was certified. It may well still be fine, and for many people a better-fitting insole is a clear improvement, but it is worth knowing that the tested configuration is the shoe as it came out of the box rather than the shoe as you have modified it. Five Questions Worth Asking Is the shoe S1 or above? If so, the energy absorbing heel is already included and does not need to be sold to you as a bonus. Do you walk or do you stand? Walkers load the heel repeatedly. Standers load the forefoot, which this test never touches, so heel cushioning is less of the story for them. What is the midsole made of? The material tells you more about how the shoe will age than the certification does. How old is your current pair? If the heel feels flat, it probably is, regardless of what the shoe passed when new. Does it actually fit? A heel that slips wastes cushioning, because the foot is moving relative to the sole rather than loading it cleanly. The Honest Verdict The E marking is a real, measurable property with a precise test behind it, and it deserves neither the shrug it usually gets nor the weight marketing puts on it. It certifies that a new heel absorbed at least 20 joules under a slow compression to 5,000 newtons. That proves capacity. It does not promise comfort, it cannot rank two shoes against each other, and it says nothing about month six. The useful takeaway is narrow but genuinely practical. Stop shopping for the letter, because every S1 shoe has it. Shop instead for the midsole material, the fit, and how old your current pair is, because those are the three things that actually change how the end of a shift feels. On ours: the Xnexz PulseX and StrideX are certified EN ISO 20345 S1P, so the shock-absorbing heel is part of that certification, exactly as it is on every other S1P shoe on the market. We are not going to claim that makes your feet feel different at hour ten, because the standard does not measure that and we would be guessing. What we would rather do is hear from you after a real week in them. Full detail on the code is in what S1P certification actually covers. If S1P Is Accepted Where You Work Try Xnexz in a real workday and tell us honestly how the cushioning, fit and comfort hold up over a full week, and what we should improve. If your site needs a higher rating or specialist protection, buy what your safety officer specifies. That comes first. View the PulseX View the StrideX Frequently Asked Questions What does E mean on safety shoes? E means energy absorption of the seat region, which is the heel. To carry it, the heel must absorb at least 20 joules when compressed in a laboratory test. It is a minimum threshold rather than a comfort score. Do all S1P safety shoes have an energy absorbing heel? Yes. Energy absorption is part of the S1 base requirement, so it carries through S1P, S2, S3 and the newer S6 and S7 classes. SB is the exception, since a basic SB shoe only covers the toe cap and basic requirements unless separately marked E. How is the energy absorbing heel tested? A shaped backpart punch sized to the footwear is pressed into the inside of the heel and the sole is compressed at 10 mm per minute until the force reaches 5,000 newtons. Absorbed energy is calculated by integrating the load deflection curve between 50 N and 5,000 N and must be at least 20 joules. Is 20 joules a lot? It is a floor, not a target. Some soles clear it narrowly and others exceed it comfortably, and both print the same E marking. Because the standard reports only pass or fail, the letter cannot be used to compare two shoes against each other. Does an energy absorbing heel reduce fatigue? The standard makes no claim about fatigue, and neither should a seller. The test is a single slow compression on a new shoe, whereas fatigue comes from thousands of repeated loads over a shift. Cushioning is one factor among fit, weight, insole and the surface you work on. Does the cushioning wear out? Yes. Midsole foams take a permanent compression set over time, polyurethane degrades slowly in the presence of moisture, and most people wear one edge of the heel faster than the other. The certification describes a new shoe and does not expire, but the cushioning genuinely fades. Does the E marking cover the forefoot? No. The test applies to the seat region, meaning the heel, only. If your work involves long periods standing still, much of your loading goes through the ball of the foot, which this marking does not assess. Β
Energy Absorbing Heels: What "E" Actually Means
The E on a safety shoe stands for energy absorption of the seat region, which is the standard's term for the heel. It means one specific thing: in a laboratory, that heel absorbed at least 20 joules when it was compressed. That is the whole claim. It is not a comfort rating, it is not a measure of how the shoe feels at hour nine, and it is not a score you can compare between two models, because a heel that absorbed 21 joules and one that absorbed 45 carry exactly the same letter. Understanding what the test actually does is the fastest way to stop over-reading the marking and start looking at the things that genuinely decide how a shoe feels underfoot. What the E Marking Actually Certifies Like antistatic performance, energy absorption is written into the base requirements of the main safety classes rather than sold as an extra. If your shoe is S1 or above, it has been through this test. Class Energy absorbing heel What else the class brings SB No, unless separately marked E The 200J toe cap and basic requirements only S1 Yes Closed heel region and antistatic performance S1P Yes S1 plus a perforation-resistant midsole S2 Yes S1 plus water resistance of the upper S3 Yes S2 plus perforation resistance and a cleated outsole S6 and S7 Yes The newer waterproof constructions SB is the exception again, which is why it keeps catching people out. A basic SB shoe covers the toe and little else, as we set out in what SB means and what it does not cover. Everything from S1 upward includes the energy absorbing heel by definition, so a product page that advertises it as a special feature is telling you something the class code already guaranteed. Inside the Test, Step by Step The method is more brutal and more specific than the phrase "shock absorbing" suggests. 20 JMinimum energy absorbed to pass 5,000 NForce the heel is compressed to 10 mm/minSpeed the load is applied 1 JPrecision the result is reported to A shaped punch goes inside the shoe. Testing uses a set of backpart punches made from standardised lasts, and the one matching the shoe's size is selected so the load is spread the way a real heel would spread it. It is brought down onto the centre of the heel. The punch contacts the inside of the shoe at the middle of the heel area, so the whole sole structure beneath it takes the load. The load is applied slowly. Compression runs at a rate of 10 mm per minute, which is a deliberate, controlled squeeze rather than an impact. It continues until 5,000 newtons. That is the end point, and the sole is compressed all the way there. The energy is the area under the curve. Absorbed energy is calculated by integrating the load deflection curve between 50 N and 5,000 N, reported to the nearest joule, and it must not be less than 20 J. Why it is measured as energy, not softness Energy is force multiplied by the distance the sole compresses. A thick soft sole that squashes a long way can absorb the same energy as a firmer sole that compresses less but resists harder. That is why two shoes that feel completely different underfoot can produce similar numbers, and why the figure alone cannot tell you which one you will prefer. Why 5,000 Newtons Is Not a Footstep This is the part worth sitting with, because it reframes the whole marking. Gait research puts the peak vertical ground reaction force in normal walking at around 107 per cent of body weight during the loading phase just after heel contact, with the force through a stride typically moving between roughly 80 and 120 per cent of body weight. For an 85 kg worker, body weight is about 834 newtons, so the peak is somewhere near 890 newtons. The test compresses the heel to 5,000 newtons. That is roughly five to six times the peak force of a normal walking step, applied once, slowly, to a brand new shoe. The test and the workday are different events Both matter, but only one of them is certified. The laboratory test LoadUp to 5,000 N Speed10 mm per minute RepetitionsOnce Condition of shoeNew A severe single squeeze Your actual shift LoadAround 107% of body weight SpeedFast impact, milliseconds RepetitionsThousands per day Condition of shoeProgressively worn Mild loads, endless repetition So the test proves the heel structure has real capacity. It answers the question "can this sole soak up a heavy load without bottoming out", and that is genuinely worth knowing. What it does not do, and was never designed to do, is model a ten hour shift. Fatigue is a story about thousands of small repeated loads, and this is a single large one. What the E Marking Does Not Tell You Four limits are worth being clear about, because most of the disappointment around cushioning comes from expecting the letter to cover them. It is a threshold, not a score. 20 J is a floor. A shoe scraping past it and a shoe comfortably beyond it both print the same E. The marking cannot rank two products. It is measured on a new shoe. Certification captures a moment. Nothing in that letter describes what the heel is doing after six months of daily compression. It says nothing about the forefoot. The test is the seat region only. If you stand still for long periods, a good deal of your loading is through the ball of the foot, which is not part of this assessment at all. It is not a comfort claim. Comfort depends on fit, volume, insole, upper, weight and how your particular foot loads. Energy absorption is one input among many, and the standard makes no promise about how anything will feel. The honest way to read it Treat E as a floor that has been cleared, not as a feature that has been won. It tells you the heel is not hollow and not brittle. It cannot tell you whether this shoe suits your feet, and no marking can. Where the Cushioning Actually Comes From The letter is certified, but the feel comes from the midsole material sitting between your heel and the ground. That is the part worth reading on a spec sheet. Material How it behaves underfoot The trade-off Polyurethane (PU) Resilient and supportive, holds its structure well over a long day Denser than EVA, and susceptible to breakdown with age and moisture EVA Very light and soft on first wear, which is why it feels immediately comfortable Compresses permanently over time, so the cushioning fades PU and EVA combined EVA for lightness with a PU or rubber layer for durability and grip More complex construction, and the two layers age at different rates TPU inserts Used in the heel for structure and energy return rather than softness Adds firmness, which not everyone wants under the heel If you are weighing up the two you will meet most often, PU and EVA outsoles compared goes through the differences properly, and what workers should know about EVA covers the softness-versus-longevity question on its own. How Heel Cushioning Fades The certificate does not expire. The cushioning does. This is the single most useful thing to understand about the E marking, and nothing on the box mentions it. Compression set. Foams do not fully rebound after being squashed thousands of times. The cells collapse gradually and the midsole thins, which is why an old sole can look intact and feel dead. Material breakdown. Polyurethane degrades over time in the presence of moisture, a slow chemical process that continues whether the shoe is worn or sitting in a cupboard. Uneven loading. Most people wear one edge of the heel faster, so cushioning becomes asymmetric long before the sole looks worn out. None of this is a defect. It is what foam does. The practical consequence is that heel comfort should be judged by how the shoe feels now rather than by a letter printed when it was new, and a pair that has gone flat is worth replacing even if the toe cap and upper are fine. The wider cost of getting this wrong is something we looked at in the hidden cost of heavy safety shoes, and the physical side in what happens to your feet after ten hours. The Insole Is Part of What Gets Tested One detail follows directly from the method. The punch presses against the inside of the shoe, which means everything sitting in the heel at that moment forms part of what is being compressed, including the removable insole the shoe was supplied with. That has a practical consequence people rarely think about. Throw away the original insole and drop in a thin flat replacement, and the heel you are standing on is no longer quite the one that was certified. It may well still be fine, and for many people a better-fitting insole is a clear improvement, but it is worth knowing that the tested configuration is the shoe as it came out of the box rather than the shoe as you have modified it. Five Questions Worth Asking Is the shoe S1 or above? If so, the energy absorbing heel is already included and does not need to be sold to you as a bonus. Do you walk or do you stand? Walkers load the heel repeatedly. Standers load the forefoot, which this test never touches, so heel cushioning is less of the story for them. What is the midsole made of? The material tells you more about how the shoe will age than the certification does. How old is your current pair? If the heel feels flat, it probably is, regardless of what the shoe passed when new. Does it actually fit? A heel that slips wastes cushioning, because the foot is moving relative to the sole rather than loading it cleanly. The Honest Verdict The E marking is a real, measurable property with a precise test behind it, and it deserves neither the shrug it usually gets nor the weight marketing puts on it. It certifies that a new heel absorbed at least 20 joules under a slow compression to 5,000 newtons. That proves capacity. It does not promise comfort, it cannot rank two shoes against each other, and it says nothing about month six. The useful takeaway is narrow but genuinely practical. Stop shopping for the letter, because every S1 shoe has it. Shop instead for the midsole material, the fit, and how old your current pair is, because those are the three things that actually change how the end of a shift feels. On ours: the Xnexz PulseX and StrideX are certified EN ISO 20345 S1P, so the shock-absorbing heel is part of that certification, exactly as it is on every other S1P shoe on the market. We are not going to claim that makes your feet feel different at hour ten, because the standard does not measure that and we would be guessing. What we would rather do is hear from you after a real week in them. Full detail on the code is in what S1P certification actually covers. If S1P Is Accepted Where You Work Try Xnexz in a real workday and tell us honestly how the cushioning, fit and comfort hold up over a full week, and what we should improve. If your site needs a higher rating or specialist protection, buy what your safety officer specifies. That comes first. View the PulseX View the StrideX Frequently Asked Questions What does E mean on safety shoes? E means energy absorption of the seat region, which is the heel. To carry it, the heel must absorb at least 20 joules when compressed in a laboratory test. It is a minimum threshold rather than a comfort score. Do all S1P safety shoes have an energy absorbing heel? Yes. Energy absorption is part of the S1 base requirement, so it carries through S1P, S2, S3 and the newer S6 and S7 classes. SB is the exception, since a basic SB shoe only covers the toe cap and basic requirements unless separately marked E. How is the energy absorbing heel tested? A shaped backpart punch sized to the footwear is pressed into the inside of the heel and the sole is compressed at 10 mm per minute until the force reaches 5,000 newtons. Absorbed energy is calculated by integrating the load deflection curve between 50 N and 5,000 N and must be at least 20 joules. Is 20 joules a lot? It is a floor, not a target. Some soles clear it narrowly and others exceed it comfortably, and both print the same E marking. Because the standard reports only pass or fail, the letter cannot be used to compare two shoes against each other. Does an energy absorbing heel reduce fatigue? The standard makes no claim about fatigue, and neither should a seller. The test is a single slow compression on a new shoe, whereas fatigue comes from thousands of repeated loads over a shift. Cushioning is one factor among fit, weight, insole and the surface you work on. Does the cushioning wear out? Yes. Midsole foams take a permanent compression set over time, polyurethane degrades slowly in the presence of moisture, and most people wear one edge of the heel faster than the other. The certification describes a new shoe and does not expire, but the cushioning genuinely fades. Does the E marking cover the forefoot? No. The test applies to the seat region, meaning the heel, only. If your work involves long periods standing still, much of your loading goes through the ball of the foot, which this marking does not assess. Β
