OSHA-Compliant First Aid Kit Stocking Guide

A workplace first aid kit that satisfies an OSHA inspector and a workplace first aid kit that actually helps someone during an emergency are not automatically the same thing. OSHA’s own standard says almost nothing about what has to be in the box; the specificity comes from a voluntary consensus standard, ANSI/ISEA Z308.1, that OSHA treats as an acceptable benchmark rather than a legal mandate. Buyers who don’t understand that distinction end up either under-stocked (a token kit that technically exists but can’t handle a real cut or burn) or over-buying supplies the standard never actually requires. This guide separates the two layers — what 29 CFR 1910.151 legally requires, and what ANSI/ISEA Z308.1 recommends as a specific, purchasable standard — and gives a practical framework for sizing, classifying, and maintaining a compliant kit.

What OSHA 29 CFR 1910.151 actually requires

OSHA’s general industry first aid standard, 29 CFR 1910.151, is short and deliberately non-prescriptive. Paragraph (b) states that where a workplace is not in near proximity to an infirmary, clinic, or hospital for the treatment of injured employees, the employer must have a person or persons trained to render first aid, and that “adequate first aid supplies shall be readily available.” That’s the entire supply requirement in the regulatory text itself — no item list, no quantity table, no mention of ANSI or Z308.1 by name.

Two things follow from that wording, and both matter for a buying decision:

“Adequate” is not defined by OSHA in the standard. OSHA leaves the judgment of what constitutes adequate supplies to the employer, based on the actual hazards of that specific workplace — not a fixed national checklist.
OSHA does not mandate ANSI/ISEA Z308.1. In its own compliance guidance (Best Practices Guide: Fundamentals of a Workplace First-Aid Program, OSHA 3317), OSHA describes the ANSI Z308.1 minimum-contents standard as “a specific example of the minimal contents of a workplace first-aid kit,” notes the kits described in it are “suitable for small businesses,” and tells larger operations to determine independently how many kits they need and whether to augment them — language that treats Z308.1 as a reference point for what “adequate” can look like, not a box-ticking requirement in itself.

In practice, this is exactly how OSHA enforces it: a compliance officer citing an employer under 1910.151(b) for inadequate supplies will typically point to the gap between what the workplace’s actual injury history/hazard profile calls for and what was on hand — and ANSI Z308.1 compliance is the most common, most defensible way employers close that gap, precisely because it’s a named, purchasable, third-party-verifiable standard rather than a subjective judgment call made after the fact.

ANSI/ISEA Z308.1: the standard that actually defines kit contents

ANSI/ISEA Z308.1, Minimum Requirements for Workplace First Aid Kits and Supplies, is maintained by the International Safety Equipment Association (ISEA) and accredited through ANSI. It’s the document manufacturers actually build kits against, and the one a “compliant” or “OSHA-compliant” claim on a first aid kit’s packaging is almost always referencing. The current edition in force is Z308.1-2021.

The standard organizes kits along two independent axes: a class (how much and what variety of supply) and a container type (how the kit is built and where it can be used). A compliant kit needs both specified correctly for the environment it’s going into — picking the right class in the wrong container (or vice versa) is a common buying mistake.

Class A vs. Class B

	Class A	Class B
Intended for	Workplaces where the expected injuries are the common, lower-severity kind — minor cuts, small burns, splinters, sprains.	Workplaces with a broader or more severe hazard profile — more employees, heavier equipment, chemical exposure, or a mix of injury types.
Supply mix	Covers the same required item categories as Class B, at the standard’s baseline quantities.	Same required item categories, at higher minimum quantities and, for several categories, larger or more varied item sizes.
Typical fit	Offices, retail, most light general-industry sites.	Manufacturing, construction, warehousing, higher-headcount or multi-shift sites, anywhere the risk assessment turns up more than the routine minor-injury profile.

Both classes are built around the same set of required item categories — wound cleaning/antiseptic, adhesive bandages, gauze pads and roller gauze, adhesive tape, a burn treatment, an eye covering/wash item, a trauma/compress pad, and several others — the difference is quantity and, in some categories, size, not which categories are covered at all. Because the exact per-category counts are revised between editions, don’t rely on a summary (including this one) for the literal numbers when you’re checking a specific SKU against the standard: a compliant kit from a reputable manufacturer will carry a printed “Meets ANSI/ISEA Z308.1-2021, Class A” (or B) label and a supply list on the packaging or spec sheet — check that against the edition year, not just the class letter, since pre-2021 stock is still in circulation and isn’t necessarily wrong, just built to an older count.

Container Types I–IV

Type governs how the kit is built and where it’s allowed to be used, independent of class:

Type I — indoor use, mounted/stationary. Not designed to be carried around or to resist impact, moisture, or corrosion.
Type II — indoor use, portable. Meets basic impact resistance so it can be moved between locations or carried to the scene of an incident.
Type III — indoor or outdoor use, portable, with added resistance to moisture, dust, and corrosion for a mobile or semi-exposed environment.
Type IV — indoor or outdoor use, portable, with the full package of impact, moisture, dust, and corrosion resistance for the harshest environments (field sites, vehicles, outdoor industrial settings).

A Class B kit in a Type I container is a real, standard-compliant combination for a fixed indoor manufacturing floor. The same Class B supply set in a Type IV container is the right call for a mobile field crew or an EMS/fleet vehicle. Buying decisions should specify both, not just “Class A” or “Class B” alone.

Sizing a kit program: what actually drives the decision

This is the part most stocking guides get wrong: neither OSHA nor ANSI/ISEA Z308.1 publishes a formula tying kit count or class to a specific employee headcount. There is no “one kit per 25 employees” rule in either document — that figure, when you see it on a vendor page, is a rule of thumb someone is applying, not a citation to the standard. What both frameworks actually require is a documented judgment call, made by the employer, based on:

The workplace’s actual hazard and injury profile — use OSHA 300 log history, workers’ comp claims, and a walk-through hazard assessment (the same exercise that drives your written PPE hazard assessment) to identify what kinds of injuries are plausible, not hypothetical.
Headcount and shift structure — more people working simultaneously, especially across multiple shifts or in a facility large enough that one kit can’t be reached quickly from every work area, is the practical reason to add kits or move to Class B, even though it isn’t tied to a published ratio.
Travel distance and response time — ANSI/ISEA Z358.1, the companion standard for eyewash and safety shower placement, is explicit about a roughly 10-second/55-foot reachability benchmark for a different hazard class; Z308.1 doesn’t set an equivalent hard number for first aid kits, but the same logic — a kit that takes several minutes to reach is not “readily available” in the sense 1910.151(b) uses the term — is the standard practical test employers apply.
Facility layout and isolation — multiple buildings, floors, or physically separated work areas each generally need their own kit rather than one central kit for the whole site, regardless of total headcount.
EMS response time — a rural or remote site with a long ambulance ETA is exactly the scenario 1910.151(b)’s “near proximity” language is built around, and typically justifies both a higher kit class and on-site trained first aid responders, not just more supplies.

A practical way to apply this without inventing a false headcount formula: treat facility profile as a set of qualifying questions, not a lookup table.

Facility profile	What typically follows
Single small office or retail site, one shift, low-hazard work	One Class A, Type I or II kit, centrally located, is often defensible — document the hazard assessment that supports it.
Mid-size site with mechanical, chemical, or manual-handling hazards	Class B kits, placed so no work area requires an extended walk to reach one; consider an AED program alongside first aid supplies.
Large or multi-building campus, multiple shifts	Multiple Class B kits distributed by building/floor rather than headcount, each independently stocked and inspected; trained first-aid responders per shift.
Field, mobile, or outdoor work, remote from EMS	Type III/IV weather- and corrosion-resistant containers, higher supply class, and a documented EMS response-time estimate per the OSHA 3317 guidance above.

Treat that table as illustrative planning logic, not a compliance formula — the only thing that actually satisfies 1910.151(b) is a real, documented assessment of your own workplace.

Checklist: what a compliant kit needs, beyond “buy a labeled kit”

Confirm the edition year. Look for “ANSI/ISEA Z308.1-2021” (or whatever the current edition is at purchase time) printed on the kit or its spec sheet, not just “ANSI compliant.”
Confirm the class matches your hazard assessment, not just what was cheapest or in stock.
Confirm the container type matches the environment it will actually live in (indoor/fixed vs. outdoor/mobile).
Assign an owner. OSHA’s own guidance recommends giving one specific person responsibility for choosing supply types/amounts and keeping the kit stocked — an unowned kit degrades fast.
Set a restocking and inspection cadence. Z308.1 doesn’t set a universal interval, but at minimum, check after every use and on a fixed schedule (monthly is common practice); track expiration dates on items that carry one, like some antiseptics and burn gels.
Decide whether to augment beyond the standard. An AED, a bleeding-control/hemorrhage kit, or naloxone are common additions many employers layer on top of a Z308.1-compliant kit based on their own risk profile — none of these are Z308.1 requirements, they’re separate purchasing decisions.
Train someone to use it. A kit alone doesn’t satisfy 1910.151(a)’s trained-responder requirement where the “near proximity” exception doesn’t apply — supplies and training are two separate line items, not one.
Write it down. A short written first aid program — hazard assessment, kit locations, class/type chosen and why, restocking owner, training roster — is what actually demonstrates “adequate” if it’s ever questioned; the kit itself is only half the record.

Common mistakes buyers make

Buying one small Class A kit for a facility that clearly needs Class B, usually because nobody ran the hazard assessment that would have surfaced the gap.
Assuming “OSHA compliant” printed on packaging means OSHA reviewed or certified the product. OSHA doesn’t certify first aid kits; “OSHA compliant” language on a kit is a manufacturer’s claim that it meets ANSI/ISEA Z308.1, which OSHA in turn treats as a reasonable benchmark — not a direct OSHA endorsement.
Treating the kit as the whole program. Supplies without a trained responder, without a restocking owner, and without documentation don’t satisfy 1910.151(b) as durably as the same kit backed by all three.
Never rotating expired contents. A compliant kit on delivery day that hasn’t been checked in eight months is not a compliant kit anymore, even though nothing about the box changed.

Frequently asked questions

Does OSHA require ANSI/ISEA Z308.1-compliant kits by law?

No. OSHA’s own standard, 29 CFR 1910.151(b), requires only “adequate first aid supplies” without naming ANSI Z308.1. OSHA’s compliance guidance describes Z308.1 as a specific, usable example of what adequate can look like, and Z308.1 compliance is the most common way employers document that they met the “adequate” bar — but it isn’t independently incorporated into the regulatory text as a mandatory standard.

What’s the real difference between Class A and Class B kits?

Both cover the same required categories of first aid supplies. Class B carries higher minimum quantities (and, in some categories, larger item sizes) because it’s built for workplaces with a broader or higher-severity injury profile than Class A’s baseline assumption of common, lower-severity injuries.

How many first aid kits does my workplace need?

Neither OSHA nor ANSI/ISEA Z308.1 ties the number to a specific headcount ratio. The number depends on your documented hazard assessment, facility layout, shift structure, and how quickly a kit can actually be reached from every work area — not a fixed employees-per-kit formula.

Do I need a separate AED or bleeding-control kit?

Those aren’t part of the ANSI/ISEA Z308.1 first aid kit requirement. They’re separate purchasing and program decisions many employers layer on top of a compliant first aid kit, based on their own workplace risk assessment.

How often should a workplace first aid kit be restocked or inspected?

Neither standard sets one universal interval. Common practice is a fixed periodic check (monthly is typical), plus a check after every use, with someone specifically assigned ownership of the kit so restocking doesn’t rely on whoever happens to notice it’s low.

Where to source this

Once you know the class, container type, and quantity your risk assessment calls for, LAC (lac.us) — CASRAI’s sister medical-supply business — stocks a range of workplace first aid kits and refill supplies. Browse LAC’s first aid kits category to compare kit classes, container types, and sizes against the requirements outlined above before you buy.

Building an OSHA-Compliant Workplace First Aid Kit: A Stocking Guide

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