Most safety trainers sold as "waterproof" are not certified waterproof at all. The marking that proves an assembled shoe keeps water out is WR, found in the S6 and S7 classes, and even that is tested in water just 20 mm above the point where the upper meets the sole.
So the better question is not "which trainer is waterproof", it is "how wet does my work actually get". A splash, a rainy delivery round, a wet kitchen floor and a flooded yard each need a different answer, and some of those answers are not trainers at all.
Why Waterproof Rarely Means What You Think
"Waterproof" is not a word the safety standard uses. EN ISO 20345 has two separate water tests, and product pages blur them together, along with a third category of claims that were never tested at all.
The four real levels of water protection
From no water test at all to footwear with no seams to leak through.
Words that prove nothing on their own"Water repellent", "water resistant", "weatherproof", "all weather" and "with a waterproof membrane" are descriptions, not certifications. Unless S2, S3, S4, S5, S6, S7, WPA or WR appears in the marking, no water test is being claimed.
Upper Tested Versus Whole Shoe Tested
This is the single most useful distinction in the whole topic, and it is the one most buyers never hear. The two water markings test different things, and only one of them looks at the shoe you will actually wear.
WPA and WR side by side
Both are real tests. They answer different questions.
WPA, in S2 and S3
WR, in S6 and S7
An S3 trainer with a water resistant upper can still let water in through the tongue gusset, a stitched seam or the sole join, because none of those were in the WPA test.
If you are weighing up the classes themselves, we have set out the honest difference between S2 and S1P and when S1P is not enough and S3 takes over in separate guides.
Inside The Whole Shoe Water Test
WR is the marking that comes closest to what most people mean by waterproof, so it is worth knowing exactly what it involves. The laboratory can use either of two methods.
- The machine method. The shoe is mounted in a flexing machine that bends the toe through about 22 degrees at 60 flexes a minute, standing in water set 20 mm above the featherline, the line where upper meets sole. It runs for 80 minutes, roughly 4,800 steps.
- The walking method. Alternatively, a person walks up and down a shallow trough of water 9 to 10 metres long for 100 lengths, which works out at around 5,000 steps per shoe.
- The inside is checked. After either method, the inside of the shoe is examined for water. Under the 2011 edition, a wet area of up to 3 cm² was still a pass. Under the 2022 edition, no water penetration may be detected at all.
That 20 mm figure is the one to remember. WR proves a shoe keeps water out when it is flexed in water reaching 20 mm up the side of the upper, roughly the width of a thumb.
It does not prove anything about water that reaches the collar, the laces or the top of the tongue, and on a low cut trainer that point is not very far up.
The 2022 Change That Made Waterproof Mean Waterproof
The current edition of the standard made two changes that matter to anyone shopping for wet weather footwear.
- WR got stricter. The old allowance of a 3 cm² wet patch inside the shoe was removed. A WR shoe certified to the 2022 edition must show no water penetration.
- New classes were created. S6 is S2 plus WR, and S7 is S3 plus WR. For the first time, "certified to keep water out" has its own class code rather than being an optional letter tacked on the end.
- The old marking was renamed. WRU, the upper water test, became WPA. The test covers the same ground, but the new name is clearer about what it measures: water penetration and absorption of the upper.
There is a catch. Manufacturers have a transition period running until the end of 2027, so shoes certified to both editions are on sale side by side.
An S3 certified in 2019 and an S3 certified in 2024 can look identical on the box. We broke down how S6 and S7 differ under the new rules in more detail if you are comparing specific classes.
The Problem No Membrane Can Fix
Every shoe has a top edge, and water above it goes in regardless of the marking. The standard itself recognises this by describing footwear in five height designs, from a low shoe to a thigh boot.
| Design | What it is | Water it can realistically handle |
|---|---|---|
| A | Low shoe, including safety trainers | Wet ground, rain and shallow splashes |
| B | Ankle boot | Puddles that stay well below the ankle |
| C | Half knee boot | Standing water up to mid calf |
| D | Knee boot, the classic wellington | Deeper standing water and wash down areas |
| E | Thigh boot | Wading and specialist wet work |
This is why the phrase "waterproof safety trainer" is slightly self defeating. Even a perfect WR certificate on a low cut shoe only helps until the water reaches the collar, and a low collar is part of what makes a trainer a trainer.
If your work involves water that deep, the shape of the footwear matters more than the membrane inside it, which is a trade off we explored when comparing safety trainers against boots.
What To Buy Instead, By Situation
The right answer depends on how often you get wet, how deep the water gets and whether your feet stay in it. The UK averages 159 days a year with at least 1 mm of rain, according to Met Office climate averages, so for outdoor workers this is not an occasional question.
| Your situation | What to buy | Why |
|---|---|---|
| Indoors all day, a short walk from the car park | S1P is usually fine | A few minutes of rain rarely justifies giving up breathability for a whole shift |
| In and out of vans, depots and yards in all weather | S3 trainer, or S7 if the ground is often wet | WPA handles rain on the upper, WR handles wet ground and shallow puddles |
| Wet floors indoors, such as kitchens and food prep | A closed, wipeable upper with SR slip marking | On wet tile the danger is slipping, not soaking |
| Outdoors most of the day on wet ground and grass | S7 ankle boot | Whole shoe water resistance plus a higher collar |
| Standing water, wash down, farm or drainage work | S5 wellington, Class II | Moulded in one piece, with the height to match the water |
| Wading or working in water above the calf | Specialist knee or thigh boots | No trainer or ankle boot is designed for this |
Notice the third row. Many people searching for waterproof safety trainers work in kitchens or wet processing areas, where the real hazard is the floor rather than the water. Grip on wet surfaces is its own subject, and we covered what the slip rating letters actually mean separately.
What You Give Up For Water Protection
Every step up the water ladder costs something. The materials and membranes that stop liquid water getting in also slow down the water vapour trying to get out.
| Option | Keeps rain off | Keeps puddles out | Breathability |
|---|---|---|---|
| Mesh S1P trainer | No | No | Highest, the upper is built to vent |
| S3 trainer, WPA | Yes, the upper material | Not certified | Lower, the upper has to resist water |
| S7 shoe or boot, WR | Yes | Yes, to the tested depth | Depends on the membrane, usually lower again |
| S5 wellington | Yes | Yes, to boot height | Lowest, moulded rubber and polymer do not breathe |
That trade off works in both directions. A fully water resistant shoe worn indoors on a warm shift can leave feet wetter from sweat than a mesh shoe would from a short rain shower. We explained how breathable safety shoes move sweat out in our guide to mesh uppers, and it is the other half of this decision.
How To Check A Waterproof Claim Before You Buy
- Find the class code, not the adjective. Look for S6, S7, S4, S5 or WR in the marking. If the page says "waterproof" but the class is S1P or S3, the whole shoe was not tested for water.
- Check which edition it was certified to. EN ISO 20345:2022 WR means no water inside. A 2011 certificate allowed a small wet patch. The year appears after the standard number.
- Read the label on the shoe itself. The classification must be marked on the footwear, usually inside the tongue. If the label and the website disagree, trust the label.
- Measure your water against the collar. Think about the deepest water you actually stand in, then compare it with the height of the shoe. No marking helps above the top edge.
- Ask what you give up. Heavier construction, a warmer foot and less flexibility are normal costs of water protection. Make sure you need it enough to pay them every day.
The Honest Verdict
A truly waterproof safety trainer is a narrower product than the search results suggest. The WR marking is real, it got tougher in 2022, and a small number of low cut S6 and S7 shoes now carry it. But it is tested at 20 mm above the sole join, and a low collar limits what any trainer can do once water gets deeper.
For most workers the better move is to match the footwear to the wettest part of the day. Rain on the upper points to S3. Wet ground points to S7. Standing water points to an S5 wellington. And a wet kitchen floor points to grip, not waterproofing. Your employer's risk assessment should always have the final word.
Xnexz PulseX and StrideX are S1P shoes with breathable mesh and microfiber uppers, so they carry no water rating and are not the right pick for wet outdoor work. If your day involves rain, puddles or standing water, choose an S3, S7 or S5 from an established specialist instead.
Frequently Asked Questions
Are there any truly waterproof safety trainers?
A small number of low cut shoes carry S6 or S7, which means the whole shoe passed the WR water test. Even then, the test uses water only 20 mm above the sole join, and water above the collar will still get in.
Is S3 waterproof?
No. S3 includes WPA, which tests a sample of the upper material for water penetration and absorption. The assembled shoe, including its seams and tongue, is not tested. For whole shoe water resistance, look for S7.
What is the difference between WPA and WR?
WPA tests the upper material for 60 minutes and allows no more than 0.2 g of water through. WR tests the complete shoe in water for 80 minutes, or across 100 lengths of a trough, and under the 2022 edition no water may reach the inside.
What do S6 and S7 mean?
They are classes introduced in EN ISO 20345:2022. S6 is S2 plus whole shoe water resistance, and S7 is S3 plus whole shoe water resistance. S7 therefore also includes a puncture resistant midsole and a cleated outsole.
Does a waterproof membrane make a shoe waterproof?
A membrane can help, but it is not a certification. Only the WR marking, or the S6 and S7 classes, proves the assembled shoe kept water out under test. Without that marking, a membrane claim is unverified.
What should I wear for standing water?
A Class II safety wellington, marked S4 or S5, is usually the right choice. It is moulded in one piece with no stitched seams, and its height matches water that would pour straight over a trainer.
Do waterproof safety shoes make feet sweat more?
Usually, yes. Materials that stop liquid water getting in also slow down the water vapour trying to get out. That is why fully water resistant footwear can feel warm and damp on a long indoor shift.
Are old S3 certificates still valid?
Yes, during the transition period that runs to the end of 2027. That means shoes certified to the 2011 and 2022 editions are on sale together, so check the year shown after the standard number on the label.
For Dry Indoor Shifts, Try Xnexz
If your work is mostly indoors on dry floors and your workplace accepts S1P, try Xnexz in a real shift. Then tell us honestly how the fit, comfort and breathability hold up, and what we should improve.
