OSHA First Aid Kit Requirements: What ANSI/ISEA Z308.1-2021 Actually Means for Your Workplace

Published: August 1, 2026 · By Anne Johnson

What OSHA Actually Requires

29 CFR 1910.151, OSHA's medical services and first aid standard, is deliberately vague on paper: it requires that “adequate first aid supplies shall be readily available” but doesn’t list specific contents in the enforceable text. Employers looking for something concrete to comply with usually end up at the standard’s non-mandatory Appendix A, which points to ANSI/ISEA Z308.1 as the source OSHA itself recommends for minimum kit contents. ANSI Z308.1 was never formally adopted into the OSHA regulation, but in practice it’s the benchmark inspectors and safety consultants use to judge whether “adequate” supplies are actually present.

Class A vs Class B: What's the Difference

The 2021 revision of ANSI/ISEA Z308.1 organizes workplace kits into two classes based on the type of environment they’re built for:

• Class A kits: sized for common workplace injuries in lower-risk settings – offices, retail, light warehousing. Contents focus on treating minor cuts, abrasions, and strains for a small number of people.
• Class B kits: built for higher-risk or higher-headcount environments. They include everything in a Class A kit but in larger quantities, plus two items Class A kits don’t require: a splint and a tourniquet.

One change that applies across both classes: the 2021 revision added an emergency foil blanket as a required item in both Class A and Class B kits, where earlier versions of the standard didn’t require one in either.

Container Types: I Through IV

Separately from the class system, ANSI Z308.1 also defines four container types based on how and where the kit will physically be used:

• Type I: stationary, indoor, fixed-mount kits not expected to face rough handling – a wall-mounted office kit.
• Type II: portable, indoor kits with minimal exposure risk – typically toolbox-style cases.
• Type III: portable, indoor or outdoor kits with a water-resistant seal, often mounted in vehicles.
• Type IV: portable, outdoor kits built to withstand rough handling – waterproof and impact-resistant, meant for construction sites and remote work locations.

A kit's full compliance designation combines both: a construction crew typically needs a Class B, Type IV kit, while a small office is usually well covered by a Class A, Type I or Type II kit.

Where Employers Get This Wrong

The most common gap isn’t a missing kit – it’s an outdated one. Kits purchased before 2021 often lack the tourniquet and splint now required in Class B kits, or the foil blanket now required in both classes. The second most common issue is a mismatch between class and environment: a Class A kit stocked for a construction crew, or a heavy-duty Type IV case bolted to an office wall where it will never need that level of durability.

Building a Compliant Kit

The safest approach is to match class to risk level and headcount first, then match container type to how and where the kit will actually be stored or carried. Browse OSHA-compliant first aid kits or see our ANSI-compliant first aid kits built to the current 2021 Class A/B and Type I–IV specifications.

FAQ

Is ANSI Z308.1 legally required by OSHA?

No. OSHA references it as non-mandatory guidance in Appendix A to 1910.151, not as an enforceable requirement. In practice, though, it's the standard most inspectors and safety consultants use to evaluate whether a workplace's first aid supplies are "adequate."

What's the practical difference between a Class A and Class B kit?

Class B kits contain everything a Class A kit does, in larger quantities, plus a splint and tourniquet that Class A kits don't require. Class B is intended for higher-risk or higher-headcount environments.

Do I need to replace a first aid kit that meets the older ANSI 2015 standard?

Not automatically, but a pre-2021 kit is likely missing the tourniquet and splint now required in Class B kits and the foil blanket now required in both classes - worth checking against the current contents list before your next restock.