If your safety shoes are marked S1PL or S1PS rather than plain S1P, nothing has gone wrong with the label. The extra letter records which test nail the puncture-resistant insert was tested against, and it only appears on shoes with a non-metallic insert.
This guide explains the three puncture codes under EN ISO 20345, why the 2022 revision split non-metallic inserts into two categories, and how to read your own label. It also covers one widespread myth about these codes that we have a direct interest in correcting, because it applies to our own shoes.
P means a metallic insert. PL and PS both mean a non-metallic insert, tested with a 4.5mm nail and a 3mm nail respectively. All three have to withstand the same 1,100 newton force.
What the P, PL and PS Codes Actually Mean
Under EN ISO 20345:2022, a safety shoe earns a puncture-resistance marking when its midsole insert survives a standard penetration test at a minimum force of 1,100 newtons. That threshold is the same for every code. What changes is the insert material and the shape of the nail used to test it.
| Code | Insert material | Test nail diameter | Minimum force |
|---|---|---|---|
| P | Metallic, usually a steel plate | 4.5mm truncated point | 1,100 N |
| PL | Non-metallic, usually a textile or composite insert | 4.5mm, the larger point | 1,100 N |
| PS | Non-metallic, usually a textile or composite insert | 3.0mm, the smaller point | 1,100 N |
The letters are simple mnemonics once you see them written out: L for the large nail, S for the small nail. Both attach only to non-metallic inserts, which is why you will never see "S1PL" on a shoe with a steel midsole plate.
Why Non-Metallic Inserts Needed Their Own Codes
Before the 2022 revision, a shoe with a steel plate and a shoe with a textile insert could both be marked simply "P," even though the two materials fail in different ways.
A steel plate is a continuous sheet. A nail that meets it is stopped by the sheet regardless of how fine the point is. A non-metallic insert is typically a woven or layered structure, and a fine point can sometimes push between the fibres and pass through without the material itself actually breaking. The insert holds up perfectly well against a blunt 4.5mm nail and still lets a thin needle-like object through.
That's the gap the PL and PS codes close. Rather than letting one marking cover both outcomes, the standard now records which nail the insert was actually tested against, so the buyer can judge whether that test matches the hazard on their own floor.
Is PS Better Protection Than PL?
Against fine, sharp objects, yes. A PS-marked insert has passed a test with a narrower point, which concentrates the same force into a smaller area and is harder for the material to resist. If your workplace has thin wire, staples, needles, or fine metal swarf on the floor, PS is the more relevant certification.
For most everyday workplaces, though, the honest answer is that the difference rarely decides anything. The hazards that actually cause underfoot injuries in warehouses, workshops and indoor trade work are nails, screws, box staples and glass fragments, which the 4.5mm test represents reasonably well. Employers specifying footwear for those environments generally treat PL as adequate, and PL is by far the more common marking on shoes sold into UK light-duty roles.
It's also worth keeping the codes in proportion. No insert of any code removes the risk of a puncture injury. Certification means the insert passed a defined laboratory test at a defined force, not that it will stop every object in every real-world situation, at any angle, at any point on the sole, throughout the life of the shoe.
How Metallic and Non-Metallic Inserts Compare
The choice between P and PL/PS is not only about the test nail. The two insert types behave differently in daily wear, and each has genuine trade-offs.
| Metallic insert (P) | Non-metallic insert (PL or PS) | |
|---|---|---|
| Typical material | Stainless or carbon steel plate | Woven aramid textile or composite laminate |
| Weight | Heavier | Lighter |
| Flexibility | Stiffer underfoot | More flexible, moves closer to the foot |
| Sole coverage | Often less than the full footprint, limited by plate shape | Can usually be cut closer to the full footprint |
| Thermal conduction | Conducts cold and heat more readily | Conducts less readily |
| Corrosion | Can corrode if the sole is damaged and moisture reaches it | Does not rust |
| Fine-point resistance | Continuous sheet, unaffected by point size | Depends on the code, PS covers the finer point |
Neither is universally superior. Steel gives you point-size independence and a long track record. Non-metallic gives you lower weight, more flexibility and often better sole coverage. We look at this trade-off in more depth in our comparison of Kevlar and steel midsoles.
The Metal Detector Myth, and Why It Matters to Us
The most common misunderstanding about PL and PS codes is that they mean the shoe is metal-free and will pass through a metal detector. They don't. The codes describe the midsole insert only. They say nothing about the toe cap, the eyelets, the shank, or any other component.
This matters to us directly, because it applies to our own products. XNEXZ PulseX and StrideX are both certified with a non-metallic anti-penetration insert, which is exactly why they carry the PL marking. But both models use a metallic aluminium toe cap, recorded as such on the certificate. A metal detector will find that toe cap. If your workplace genuinely requires fully metal-free footwear, for airport security screening, certain food-processing lines, or magnetic-sensitive environments, PulseX and StrideX are not suitable, and no amount of PL marking changes that.
If you need a fully metal-free shoe, look for one with a composite toe cap alongside the non-metallic insert. Our guide to aluminium, composite and steel toe caps explains which materials are and aren't detectable.
What XNEXZ Actually Carries
On the current EU type examination certificate, issued by CTC (Notified Body 0075) on 10 April 2026 under EN ISO 20345:2022+A1:2024, both PulseX and StrideX are listed under the category S1PL FO SR.
Read left to right, that means: S1 base protection, puncture resistance through a non-metallic insert tested with the 4.5mm nail (PL), a fuel-and-oil-resistant outsole (FO), and slip resistance (SR). The certificate records the insert nature as non-metallic and the toe cap nature as metallic. It records no water resistance, no heat resistance, and no metatarsal protection, so we don't claim any of those.
We publish the full marking rather than shortening it to "S1P" because the extra letters are the part that tells you which test was actually run. If you want the wider context on what S1P covers and where its limits sit, that's in our complete UK guide to S1P safety shoes.
How to Read Your Own Shoe's Label
The marking is usually printed on the tongue label, the inside collar, or a stamp on the insole. Work through it in this order:
- Find the base rating first. S1, S2, S3 and so on tell you the core protection package before any add-on codes.
- Look for P, PL or PS immediately after it. No letter at all means no certified puncture resistance in that shoe.
- Check what follows. FO, SR, HRO, CI, WR and similar codes are separate optional properties, each tested independently.
- Match it against your employer's PPE requirement. If the risk assessment specifies PS and your shoes are marked PL, the shoes do not meet the requirement, however good they otherwise are.
If the label has worn off and you can't confirm the marking, treat the shoe as uncertified for that property until you can check the manufacturer's documentation. Under the UK's PPE at Work Regulations 2022, it's your employer's duty to specify and verify the correct footwear rating for your role.
Two Worked Examples
Warehouse picker on a dry unit floor
The realistic underfoot hazards are box staples, banding wire off-cuts and the occasional dropped fixing. Nothing routinely on the floor is finer than a standard staple leg.
A PL-marked shoe covers this well. Specifying PS would add a certification the role never actually calls on.
Workshop with fine metal swarf
Machining produces thin, sharp metal shavings that can sit upright on the floor and are considerably finer than a 4.5mm nail. This is exactly the hazard the smaller test point was introduced to represent.
PS is the more relevant marking here, and the employer's risk assessment should say so explicitly rather than leaving it to the wearer to judge.
Suitable For / Choose Differently
PL marking, such as PulseX or StrideX, may suit
- Warehouse pickers, packers and forklift operators
- Painters, decorators and interior fit-out teams
- Car mechanics and garage workers
- Delivery and depot staff working mostly indoors
- Facilities and light-maintenance teams
- Retail stockroom workers
Look for a different specification if
- Fine wire, needles or metal swarf are present: look for PS
- Your risk assessment names a specific code: follow it exactly
- You need genuinely metal-free footwear: composite toe cap plus non-metallic insert
- The floor is wet as well as sharp: S3 rather than S1P
- The work is construction, groundworks or demolition: higher-rated footwear
The Honest Verdict
PL and PS are not marketing tiers, and neither one is a premium version of the other. They're a record of which test nail the insert faced, introduced so that buyers could stop guessing what a plain "P" on a non-metallic insert actually covered.
For most everyday indoor work, PL is the appropriate and widely accepted marking. For environments with genuinely fine sharp hazards, PS earns its place. The one thing neither code does is make a shoe metal-free, and that's the misunderstanding most worth clearing up before you buy.
Try XNEXZ Where It Genuinely Fits
If your workplace accepts S1P footwear with a PL-marked insert and a metallic toe cap, we'd like you to try PulseX or StrideX on a real shift and tell us honestly how the fit, comfort and daily performance hold up. We're a new brand earning trust through real feedback, not claims.
Frequently Asked Questions
What does S1PL mean on a safety shoe?
S1PL means S1 base protection plus a non-metallic puncture-resistant insert tested with the larger 4.5mm nail. The L identifies the test nail size, not a lower grade of protection.
What is the difference between PL and PS?
Both mark a non-metallic insert tested at 1,100 newtons. PL uses a 4.5mm test point and PS uses a narrower 3mm point, which concentrates the same force into a smaller area and is the more demanding of the two tests.
Does a PL or PS marking mean the shoe is metal-free?
No. The code describes the midsole insert only. The toe cap, eyelets and other components may still be metallic. Check the toe cap material separately if you need footwear that passes a metal detector.
Is PS worth paying more for?
Only if your workplace actually has fine sharp hazards such as wire, needles or metal swarf. For typical nails, screws and staples in indoor light-duty work, PL is generally accepted and adequate. Your employer's risk assessment should make the call.
Why doesn't a steel midsole get a PL or PS code?
Because a steel plate is a continuous sheet, its resistance doesn't change with the size of the nail point. The two-code split was created specifically to distinguish between test outcomes for woven and composite inserts, which can behave differently against a finer point.
Which code do XNEXZ shoes carry?
PulseX and StrideX are both certified S1PL FO SR under EN ISO 20345:2022+A1:2024. The insert is non-metallic and tested with the 4.5mm nail, while the toe cap is metallic aluminium.
Can a shoe carry both PL and PS?
In practice you'll see one code on the marking. An insert that passes the smaller 3mm nail test is marked PS, which is the more demanding of the two, so there's no need to also state PL alongside it.
