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PPE and safety standards

PPE markings are compressed to the point of being a code: EN 388 4X42D, S3 SRC, Class 2, FFP3. Each of those is doing real work, and mis-reading one is how the wrong kit ends up on site. These entries explain what each marking governs, and - because standards get revised - which specifications are quoting a version that no longer exists.

High-visibility clothing

EN ISO 20471

The standard for high-visibility clothing for professional use. It sets three classes based on the minimum areas of fluorescent background material and retroreflective material in the garment, Class 3 being the highest.

Buying note. Class is a property of the garment, and it can be achieved by combining garments only where the manufacturer has certified the combination. A Class 2 vest over Class 1 trousers does not reliably make Class 3 - if a spec says Class 3, buy a Class 3 item or a certified set.

Class 1 (hi-vis)

The lowest of the three EN ISO 20471 classes, with the smallest minimum areas of background and retroreflective material. Typically trousers or a light over-vest.

Buying note. Class 1 is rarely acceptable as standalone upper-body wear on an infrastructure site. It usually turns up as part of a set, and buying it as a cheap vest substitute is the most common way a site fails a PPE inspection.

Class 2 (hi-vis)

The middle EN ISO 20471 class. In practice the typical hi-vis waistcoat or short-sleeved vest.

Buying note. Class 2 is the general construction default and is often what a site means when it just says “hi-vis”. It is usually not enough where traffic is moving at speed or in poor light - check whether the site rule distinguishes day and night working before standardising on it.

Class 3 (hi-vis)

The highest EN ISO 20471 class, requiring the greatest areas of background and retroreflective material. Normally a long-sleeved jacket, or a certified coat-and-trouser combination.

Buying note. Class 3 needs sleeves - that is the practical consequence of the area requirement. A sleeveless garment cannot reach Class 3 on its own, so a summer specification asking for Class 3 in a vest is asking for something that does not exist.

Retroreflective material

The silver tape that returns light towards its source, making the wearer visible in headlights and torchlight. Distinct from the fluorescent background material, which works in daylight.

Buying note. Retroreflective performance is what laundering destroys first, and it fails invisibly - the garment still looks bright in daylight while its night-time performance has gone. Check wash cycle limits on the label and treat them as a replacement schedule, not a suggestion.

Fluorescent background material

The fluorescent yellow, orange-red or red fabric that provides daytime conspicuity by re-emitting ultraviolet light in the visible range.

Buying note. Fluorescence degrades with UV exposure and washing, which is why a two-year-old vest looks tired rather than bright. It is also why colour matters for matching: a faded replacement next to new stock is visibly a different garment, which sites read as non-conformance.

RIS-3279-TOM

The Rail Industry Standard covering high-visibility clothing for the GB rail industry, published by RSSB. It is the reason rail hi-vis is orange rather than yellow, and it replaced the former Railway Group Standard GO/RT3279.

Buying note. This is the single most common cross-sector specification error: general construction hi-vis is yellow, rail hi-vis on or near the line is orange, and they are not interchangeable. Note the category too: Rail Industry Standards are called up by contract rather than being mandatory across the mainline the way a Railway Group Standard is, so what binds you is what the client specification says. If a crew works across both, they need both - see orange or yellow hi-vis.

Safety footwear

EN ISO 20345 was revised in 2022 and the markings changed. Both older- and newer-marked stock is legitimately in circulation, which is why several entries below give two answers.

EN ISO 20345

The standard for safety footwear. Its defining requirement is a toe cap that withstands a 200-joule impact - that is what makes footwear “safety” rather than protective or occupational. The S-ratings stack further protections on top.

Buying note. The 2022 revision changed the markings substantially: new S6 and S7 classes, new penetration codes, and the withdrawal of the SRA/SRB/SRC slip grades. A specification written before 2022 may quote codes that no longer exist - read the boot’s own marking, not just the S-number.

SB

The basic level under EN ISO 20345: a 200-joule toe cap and the fundamental requirements, without the additional protections the numbered S-ratings add.

Buying note. SB alone is very rarely what a site wants. If a quote comes back unusually cheap against an S3 specification, check whether it is SB with a couple of extras rather than a true S3.

S1 and S1P

S1 adds a closed seat region, antistatic properties and an energy-absorbing heel to the base requirements. S1P adds penetration resistance to that. Under the 2011 edition S1 also carried fuel-oil resistance; the 2022 edition dropped it from the S-classifications and made it the optional FO marking.

Buying note. S1 has no water resistance, so it belongs indoors. The gap between S1P and S3 is essentially the water-resistant upper and cleated outsole - which is exactly what outdoor site work needs, so substituting S1P for S3 outdoors will not pass.

S2

S1 plus a water-resistant upper. Suited to damp and outdoor work where underfoot penetration is not the main hazard.

Buying note. S2 is the rating most often mistakenly bought against an S3 specification, because the boots look identical. The difference is the penetration-resistant midsole, which you cannot see. Check the marking, not the boot.

S3

S2 plus a penetration-resistant midsole and a cleated outsole - water resistance, underfoot protection, grip and the 200-joule toe cap together.

Buying note. S3 is the general site default because it covers the hazards a construction or infrastructure site presents without listing them individually. Detail is in S3 safety boots explained.

S5

An all-moulded rubber or polymeric boot - a safety wellington - with penetration resistance and a cleated outsole, for very wet and dirty conditions.

Buying note. S5 is bought for groundworks, concrete and washdown areas where a leather boot would be destroyed. The trade-off is comfort over a long shift; sites that issue S5 as a blanket standard usually end up issuing S3 as well.

S6 and S7

Classes introduced by the 2022 revision: S6 is S2 with the stricter WR whole-boot water resistance, and S7 is S3 with WR.

Buying note. If a specification predates 2022 it cannot ask for S6 or S7, because they did not exist - but they may be exactly what the site actually wants where the old spec said “S3, waterproof”. Worth raising rather than substituting silently.

P, PL and PS

The 2022 penetration-resistance markings. P is a metallic insert tested with a 4.5 mm nail; PL a non-metallic insert tested with a 4.5 mm nail; PS a non-metallic insert tested with a 3.0 mm nail.

Buying note. PS is the demanding one - the smaller nail concentrates more pressure. Non-metallic midsoles cover more of the sole area than a steel plate and do not conduct cold, but if your site risk is fine debris rather than large nails, PS is the marking to ask for rather than assuming PL is equivalent.

Slip resistance: SR, and the old SRA/SRB/SRC

Under the 2022 revision a basic slip test is mandatory for all safety footwear, and the optional SR marking indicates a further test on ceramic tile with glycerol. The former SRA, SRB and SRC grades are withdrawn.

Buying note. A specification saying “S3 SRC” can no longer be matched exactly by current production. Read it as S3 with slip resistance and check the marking on the boot. Anyone still offering you SRC as a current grade is selling old stock or working from an old catalogue.

WR and WPA

Water markings. WR is whole-boot water resistance with no penetration permitted under test; WPA covers water penetration and absorption at the upper, allowing some breathability.

Buying note. WR is genuinely waterproof and correspondingly less breathable. For standing water and washdown, WR. For long shifts outdoors in ordinary British weather, WPA is often the more comfortable and sufficient choice - and cheaper.

SC, LG and FO

SC marks an abrasion-resistant scuff cap over the toe. LG marks a ladder-grip outsole profile. FO marks fuel and oil resistance of the outsole.

Buying note. FO is the one to watch: under the 2011 edition it was required for the S-classifications from S1 upward, and under 2022 it is optional, marked only where it has been tested. So a like-for-like replacement boot may quietly lack a property the old one had. If oil resistance matters, ask for FO explicitly now.

Penetration-resistant midsole

The layer between insole and outsole that resists a nail or sharp object driven up through the sole. Either a steel plate or a non-metallic textile composite.

Buying note. Steel plates do not cover the full sole area - there is an unprotected margin at the edges. Composite midsoles generally cover more, weigh less and do not conduct cold, which is why they dominate new specifications despite costing more.

Toe cap: steel or composite

The 200-joule impact protection over the toes, in steel, aluminium or a non-metallic composite. All three meet the same impact requirement when certified.

Buying note. Composite is lighter, non-conductive, does not carry cold and does not trigger metal detectors - which matters in airports, secure sites and food environments. Steel is thinner for the same protection, so a steel toe cap gives a slimmer profile. Neither is “stronger”; they are certified to the same level.

Metatarsal protection (M)

Additional protection over the instep and metatarsal bones, above and behind the toe cap. Marked M.

Buying note. Specified where heavy objects are handled at low level - steel erection, foundry, heavy plant yards. It changes the shape of the boot noticeably, so if you are introducing it, order samples for fitting before committing to a site-wide roll-out.

HRO, CI and ESD

HRO is a heat-resistant outsole tested against brief contact with hot surfaces. CI is cold insulation of the sole complex. ESD denotes controlled electrostatic dissipation, tighter than standard antistatic.

Buying note. ESD and antistatic are not the same thing and are not interchangeable. Electronics, cleanroom and some rail signalling environments specify ESD with a defined resistance range; ordinary antistatic safety footwear will fail that requirement.

Head, eye and hearing protection

EN 397

The standard for industrial safety helmets - the conventional hard hat. Covers shock absorption and penetration resistance, with optional requirements for low temperature, electrical insulation, lateral deformation and molten metal splash.

Buying note. EN 397 helmets are designed to release under load at the chin strap, so the helmet comes off rather than the wearer being strangled by a snag. That is exactly the wrong behaviour at height, which is why height work uses EN 12492 instead.

EN 12492

Originally the mountaineering helmet standard, now widely used for work at height. Adds side, front and rear impact requirements and a chin-strap retention system that holds under load.

Buying note. The distinguishing feature is the retention system: an EN 12492 helmet stays on when the wearer falls or inverts. If a method statement involves height, rope access or confined space, an EN 397 hard hat is very likely the wrong item.

EN 812

The standard for industrial bump caps - protection against striking the head on stationary objects, and against abrasion and laceration.

Buying note. A bump cap is not a hard hat and offers no protection from falling objects. Substituting one for a helmet because it is more comfortable in a low-headroom workshop is a real and recurring mistake. Where falling objects are possible, EN 397 or EN 12492, without exception.

Helmet replacement interval

The manufacturer’s stated service life for a helmet shell and harness, usually printed or moulded inside the shell alongside a manufacture date.

Buying note. The date inside the shell is the one that counts, not the date of purchase - a helmet sitting in a store is ageing. Any helmet that has taken a significant impact is scrap even if it looks undamaged, because the shell absorbs energy by deforming microscopically.

EN 166

The general standard for personal eye protection. Markings cover optical class, mechanical strength, and resistance to specific hazards such as liquids, dust, molten metal and short-circuit arc.

Buying note. Two markings are worth insisting on for site use: K for resistance to surface damage by fine particles, and N for resistance to fogging. Fogging is the single biggest reason eye protection gets pushed up onto a forehead, at which point its rating is irrelevant.

Impact grades F, B and A

Eye protection impact ratings by the speed of the test projectile: F low energy, B medium energy, A high energy. S denotes increased robustness below F.

Buying note. The grade must be on both the lens and the frame to apply to the assembly - a B-rated lens in an F-rated frame is an F-rated product. Grinding and cutting work generally needs at least B, and face shields rather than spectacles.

EN 352

The hearing protector standards: EN 352-1 for earmuffs, -2 for earplugs and -3 for helmet-mounted defenders.

Buying note. Helmet-mounted defenders are only certified with the specific helmets they were tested against. Mixing a defender from one manufacturer onto another’s helmet voids the certification, which is easy to do accidentally when replacing helmets mid-project.

SNR and HML

Attenuation ratings. SNR is a single-number estimate of noise reduction across the spectrum; HML splits it into high, medium and low frequency figures.

Buying note. Over-protection is a genuine hazard, not a safe default. Too much attenuation isolates the wearer from reversing alarms, shouted warnings and machinery changing note. Where noise is moderate, aim for protection to a safe level, not the highest SNR on the shelf.

Respiratory protection

RPE

Respiratory protective equipment - the collective term for masks, respirators and powered or supplied-air systems that protect the wearer from airborne contaminants.

Buying note. RPE is the PPE category where getting it wrong is least visible and most serious, because the harm is cumulative rather than immediate. It is also the category where selection must follow the COSHH assessment: the contaminant determines the filter, and no catalogue category can substitute for that.

EN 149

The standard for filtering half masks protecting against particles - the familiar disposable respirator. Three classes, FFP1, FFP2 and FFP3, in ascending order of filtering efficiency.

Buying note. FFP masks protect against particles only, not gases or vapours. Solvent, paint and fuel work needs a filter cartridge respirator, and reaching for an FFP3 because it is “the best one” provides no protection at all against a vapour.

Full guide: Face fit testing

FFP3

The highest of the three EN 149 classes, with the greatest filtering efficiency and lowest permitted inward leakage.

Buying note. FFP3 is commonly specified for silica dust, which is the reason it appears on so many construction COSHH assessments. It only achieves its rating on a face it actually seals against - which is what face fit testing exists to establish.

Full guide: Face fit testing

Face fit testing

A test confirming that a specific tight-fitting mask seals against a specific wearer’s face. Qualitative testing uses a taste or smell agent; quantitative testing counts particles inside and outside the mask.

Buying note. Fit testing is per person and per model - passing on one manufacturer’s FFP3 says nothing about another’s. This is the practical argument against switching respirator brand on price mid-project: the saving is smaller than the cost of re-testing the workforce.

Full guide: Face fit testing

Facial hair and seal

Tight-fitting RPE requires an unbroken seal against the skin. Stubble or a beard crossing the sealing surface prevents that seal forming.

Buying note. This is a procurement question as much as a personnel one. Where facial hair cannot or will not be removed, the answer is loose-fitting powered RPE with a hood or visor, which does not rely on a face seal. Budget for it rather than discovering it at fit testing.

Assigned protection factor (APF)

A number expressing how much a class of RPE reduces the wearer’s exposure - the ratio of contaminant outside the mask to contaminant inside it, when correctly fitted and worn.

Buying note. APF is what lets you check whether the selected RPE is adequate for a measured exposure: required APF is roughly the measured concentration divided by the exposure limit. If nobody has measured, nobody can say whether the mask is sufficient.

Hand and body protection

EN 388

The standard for gloves against mechanical risk. The familiar four digits are abrasion, blade cut, tear and puncture. The 2016 revision added a fifth character, A to F, for cut resistance measured by the TDM test, and an optional sixth, P, for impact protection.

Buying note. An X in any position means the test was not applicable or not performed - it is not a zero and not a pass. Reading 4X42D as though the second digit were poor performance is a common misinterpretation.

Full guide: EN 388 cut resistance

TDM cut levels A–F

The cut resistance scale added by the 2016 revision of EN 388, measured by the ISO 13997 TDM test and running from A (lowest) to F (highest). It sits alongside the older coup test, which remains the third digit of the four-figure code.

Buying note. The two scales coexist, which is what causes the confusion. Where a material blunts the blade - HPPE, glass or steel fibre, so most genuinely cut-resistant gloves - the coup result is reported as X and the TDM letter carries the rating instead. So a specification asking for “cut level 5” may well be answered by a glove whose third digit is X. There is no official conversion between the numeric and lettered scales - different blades, loads and geometry - so never substitute on an assumed equivalence. Ask the specifier which test they mean, in writing.

Full guide: EN 388 cut resistance

EN 407

The standard for gloves protecting against thermal risks - flammability, contact heat, convective heat, radiant heat, and small and large splashes of molten metal.

Buying note. Heat-resistant does not mean flame-resistant, and neither implies the other. Check which of the six properties the glove is actually rated for; a glove excellent at contact heat can perform poorly against molten splash.

EN 511

The standard for gloves against cold, rating convective cold, contact cold and water permeability.

Buying note. The water permeability digit is the one that decides winter comfort. A thermally excellent glove that wets through is worse than a thinner waterproof one after twenty minutes outdoors, which is why cold-weather glove complaints usually trace to that digit.

EN ISO 374

The standard for gloves protecting against chemicals and micro-organisms, with performance expressed as breakthrough time against specified test chemicals.

Buying note. Chemical gloves are selected against the named substance, from the safety data sheet, and against a breakthrough time longer than the task. A glove rated for one solvent may fail quickly against another; “chemical resistant” on its own means nothing.

EN ISO 13688

The general requirements standard for protective clothing - sizing, innocuousness, ageing, compatibility and marking. It underpins the hazard-specific clothing standards rather than standing alone.

Buying note. You will see it listed alongside another standard on a garment label. On its own it is not a protection claim, so a garment marked only EN ISO 13688 offers no specific protection whatever the marketing says.

EN ISO 11611

Protective clothing for welding and allied processes, in two classes according to the welding technique and level of spatter and radiant heat.

Buying note. Welding clothing and general flame-retardant clothing are different specifications, and a garment certified to one is not automatically suitable for the other. Where a permit calls for hot works, check which standard it names.

EN ISO 11612

Protective clothing against heat and flame, with lettered codes for limited flame spread and for convective, radiant, molten aluminium and molten iron heat.

Buying note. Look at the letter codes rather than the standard number. Two garments both marked EN ISO 11612 can protect against quite different hazards, and the codes are how you tell them apart.

EN 1149

The series covering electrostatic properties of protective clothing, most commonly cited as EN 1149-5 for material and design requirements in electrostatic dissipative garments.

Buying note. Required where a spark could ignite a flammable atmosphere - fuel handling, some tunnelling and confined-space work, petrochemical sites. Antistatic performance depends on the garment being worn closed and earthed through footwear; an open jacket over a synthetic fleece defeats it.

EN 13034 (Type 6)

Protective clothing against liquid chemicals, Type 6 - the lowest level, offering limited protective performance against a light spray or accidental splash rather than sustained contact.

Buying note. Type 6 is for incidental splash. It is not immersion protection and not sustained-contact protection. Disposable coveralls marketed for “chemical” work are very often Type 5/6, which is a much lower bar than the phrase suggests.

EN 343

Protective clothing against rain, rating water penetration resistance and water vapour resistance (breathability) in classes, with higher numbers better in both cases.

Buying note. The two figures pull against each other, and the breathability one is the one people ignore. A garment with top water resistance and poor breathability makes the wearer wet from the inside over a long shift, which is why expensive waterproofs get left in the van.

Full guide: EN 343 waterproof clothing

Arc flash protection

Protection against the thermal effects of an electric arc, assessed by open-arc or box tests and expressed as an arc rating for the garment or assembly.

Buying note. Arc rating is a property of the whole clothing system, not one layer. A rated outer worn over a synthetic base layer is dangerous - the base layer can melt. If you specify arc-rated outerwear, specify the base layers too.

Height and water

EN 361

The standard for full body harnesses used in fall arrest - the only form of body holding device permitted for arresting a fall.

Buying note. A work-positioning belt or a sit harness is not a fall arrest harness and will cause serious injury if used as one. Harnesses also need documented pre-use checks and periodic inspection; buy them with an inspection regime, not just a price.

Full guide: Fall arrest vs work restraint

Fall arrest vs work restraint

Work restraint physically prevents the wearer reaching a position from which they could fall. Fall arrest permits the fall and then stops it, within a calculated clearance distance.

Buying note. Restraint is always preferable where the work allows it, because nothing has to work correctly under load. Fall arrest requires enough clearance below for the lanyard, the energy absorber’s extension and the wearer’s height - on low-level work there is frequently not enough, and the system cannot function.

Full guide: Fall arrest vs work restraint

EN 354 and EN 355

EN 354 covers lanyards; EN 355 covers energy absorbers, which limit the force transmitted to the body when a fall is arrested.

Buying note. A plain EN 354 lanyard with no energy absorber is a restraint component, not a fall arrest component. Connecting one to an anchor above a drop is a serious and surprisingly common error.

Full guide: Fall arrest vs work restraint

EN ISO 12402

The series for personal flotation devices, graded by buoyancy: 50 N buoyancy aids, and 100 N, 150 N and 275 N lifejackets.

Buying note. The distinction that matters is self-righting. A 50 N buoyancy aid will not turn an unconscious wearer face-up; 150 N is the usual working minimum on open water, and 275 N is specified where heavy clothing or tools would otherwise defeat the jacket. Automatic inflation cylinders need periodic checking - that is an ongoing consumable, not a one-off buy.

Standards, schemes and regulations are described here as general buyer education. Nothing on this page is a claim that any TES-supplied product is certified to a particular standard, or that TES holds a scheme it is not listed as holding on our accreditations. Where a marking matters commercially, check the product’s own certification and the wording of your own specification.

The rest of the glossary

Procurement & compliance - PQQs, assurance schemes, site paperwork and stock arrangements.

Fixings, fasteners & threads - Property classes, thread forms, coatings, stainless grades and anchors.

Tools, abrasives & consumables - Drill shanks, abrasive discs, socket drives and workshop chemicals.

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