Safety Toes
ASTM F2413 Explained: What the Label Inside Your Boot Certifies
Four lines of small print, decoded — including what they do not promise.

I and C. Everything else on the label — Mt, EH, SD, Cd, PR — is an optional designation the maker has chosen to certify against, printed on its own line.Reading the label
The marking is three or four lines, stitched or printed inside the boot:
- Line 1 — the standard designation and year, for example
ASTM F2413-18. - Line 2 — gender (
MorF) followed by the mandatoryIandCdesignations for impact and compression. - Lines 3 and 4 — the optional protections the boot has been certified for.
A boot marked ASTM F2413-18 M I/C EH is a men's boot meeting the current impact and compression requirements with electrical hazard protection. A boot marked ASTM F2413-18 M I/75 C/75 EH from an earlier print run means the same thing.
Why the numbers disappeared
Older labels carried a numeric suffix — I/75, C/75, and a lower Class 50 tier. The 2018 edition removed the Class 50 tier entirely, making 75 foot-pounds of impact and 2,500 pounds of compression the only level the standard recognizes. With nothing left to distinguish, the suffix became redundant and was dropped. The protection did not change; only the notation did.
This is why a boot marked I/C is not weaker than one marked I/75 C/75. If anyone tells you otherwise, they are reading a 2005-era label convention onto a modern boot.
The two mandatory designations
| Code | What it certifies |
|---|---|
| I — Impact | The toe cap withstands a 75 foot-pound impact without collapsing onto the foot. |
| C — Compression | The toe area withstands compression from a rolling object of up to 2,500 pounds, while maintaining a minimum interior clearance — 0.5 inches in men's footwear and 0.468 inches in women's. |
The clearance requirement is the part worth knowing. It is the direct answer to the old story about safety caps severing toes: the standard specifically tests that the cap holds a gap open above the foot under full compression load.
The optional designations
| Code | Protection | When it matters |
|---|---|---|
| Mt | Metatarsal impact resistance — the guard withstands a 75 foot-pound impact to the instep while limiting the force transmitted to the metatarsal region. | Anywhere something can land on the top of your foot: foundries, heavy materials handling, drum and pipe work. |
| EH | Electrical hazard — outsole and heel insulate the wearer, tested at 18,000 V, 60 Hz, one minute, dry, with leakage under 1.0 mA. | Electricians, linemen, anyone near energized circuits. Secondary protection only. |
| SD | Static dissipative — bleeds charge at a controlled rate. ASTM lists SD10, SD35 and SD100 levels. | Electronics, cleanrooms, anywhere static damages the work rather than the worker. |
| Cd | Conductive — dissipates static rapidly by conducting it to ground. The opposite of EH. | Explosives and munitions handling. Never near live circuits. |
| PR | Puncture resistance — an integral plate between the insole and outsole. | Demolition, framing, anywhere nails and swarf are underfoot. |
How OSHA uses the standard
OSHA does not certify boots. 29 CFR 1910.136(a) puts the duty on the employer: they must ensure each affected employee uses protective footwear where there is a danger of foot injuries from falling or rolling objects, objects piercing the sole, or an electrical hazard.
1910.136(b) then says what counts as compliant footwear, and incorporates three consensus standards by reference: ASTM F-2412-2005 and F-2413-2005, ANSI Z41-1999, and ANSI Z41-1991. It also allows footwear the employer can demonstrate is at least as effective as one of those.
Two consequences follow. First, “OSHA-approved boots” is not a thing — OSHA approves no footwear, it accepts standards. Second, which optional codes you need is decided by your employer's hazard assessment, not by the boot. If the assessment identifies an instep-impact hazard, the employer can require Mt-rated footwear, and your preference does not enter into it.
What the standard does not protect you from
This is the section most explainers skip, and it is the most useful one.
- Anything above the toe cap and outside the guard. The sides of your foot, your ankle and your lower leg are protected by leather and nothing else unless you buy height.
- Slipping. Slip resistance is a separate standard — ASTM F3445 — with its own designation. A boot can be fully F2413 rated and have no slip rating at all.
- Water, cold and heat. None of them appear in F2413. A steel cap tells you nothing about whether the boot keeps water out.
- Fatigue and long-term musculoskeletal load. The standard measures a single catastrophic event. The thing most likely to actually hurt you over a career is standing on concrete for thirty years, and no ASTM code addresses it.
- A boot that no longer performs. The rating describes the boot as manufactured. A worn outsole is a compromised EH rating, and a cap that has taken a serious hit should be retired.
Three questions the label does not answer
The designation tells you what a boot was certified to do, not whether you need it. Three questions come up constantly and each has its own page: are steel toe boots required by OSHA (no — the rule names hazards, not materials), are steel toe boots slip resistant (not unless the outsole carries its own ASTM F3445 rating), and carbon fiber toe vs composite toe (same rating, different cap thickness).
Two things outside this standard
The label tells you what was certified, which means it also tells you what was not. A boot with no toe designation at all is a different category — best soft toe work boots covers when that is legitimate. And the EH clause in this standard is routinely confused with a separate class of equipment: dielectric boots vs EH-rated keeps the two apart.
Two of the codes above come up often enough to have their own pages: what EH rated means goes through the electrical-hazard test in full, and what composite toe means covers the cap material that passes the same impact and compression thresholds as steel.
No product recommendations on this page, deliberately: A standards explainer, not a shopping page. Attaching picks here would turn a reference into a disguised roundup.
Frequently asked questions
Are steel toe boots required by OSHA?
OSHA 29 CFR 1910.136(a) requires the employer to ensure protective footwear is used where there is a danger of foot injury from falling or rolling objects, objects piercing the sole, or an electrical hazard. It does not require steel specifically — 1910.136(b) accepts footwear built to ASTM F2412/F2413 or ANSI Z41, so composite and alloy caps comply identically.
What does the C in ASTM F2413-18 M/I/C mean?
C is compression resistance. The toe area must withstand compression from a rolling object of up to 2,500 pounds while maintaining a minimum interior clearance of 0.5 inches in men's footwear and 0.468 inches in women's, so the cap cannot collapse onto the foot.
Metatarsal boots meaning?
A metatarsal boot carries an Mt designation, meaning it has a guard over the instep certified to withstand a 75 foot-pound impact while limiting the force transmitted to the metatarsal bones. The toe cap protects only the toes; the Mt guard covers the bones behind them, which a toe cap does nothing for.
Is ASTM F2413-18 still current?
You will see both F2413-18 and the newer F2413-24 on boots being sold today, because manufacturers certify on their own production cycles — Red Wing's King Toe 2240 and Wolverine's Rancher wellington both carry F2413-24 markings. The impact and compression requirements are the same single level in both.
Sources
- ASTM F2413 protective footwear standard — technical summary — Label format, the mandatory I and C designations, and each optional code
- What changed in ASTM F2413-18 — Why the Class 50 tier and the numeric suffix disappeared from the marking
- OSHA 29 CFR 1910.136 — Foot protection — The federal rule itself: when protective footwear is required, and which consensus standards it accepts
- ASTM F2413 safety footwear ratings explained — The 18,000-volt / 60 Hz / one-minute EH test condition, stated in full
Read next
Best EH-Rated Work Boots
The EH code in practice, and an honest account of its limits.
Metatarsal Guard Boots
What Mt covers, and internal versus external guards.
Steel Toe vs Composite Toe
Both clear the same bar — here is what actually separates them.
Best Slip-Resistant Work Boots
Slip resistance is a different standard entirely — ASTM F3445.
Work Boots vs Hiking Boots
What a boot without this certification is missing.
Work Boots vs Combat Boots
Military boots are specified to a different standard entirely.
Best Steel Toe Boots Under $100
The price band where unmarked boots are most common.
Best Puncture-Resistant Work Boots
The optional PR code in practice, and the handful of boots that carry it.