ANSI First Aid Kit Types I, II, III & IV Explained (2026 Guide)

What do ANSI first aid kit Types I, II, III and IV mean?

Published August 16, 2026

Short answer: Type I through Type IV are ANSI/ISEA Z308.1's container ratings — how tough and how portable the box is — and they are completely independent of Class A and Class B, which describe the contents. Type I is a mounted indoor cabinet, Type II a portable indoor kit, Type III a portable water-resistant kit for mobile and outdoor use, and Type IV a waterproof, impact-resistant case for harsh environments, as summarized in ANSI/ISEA materials. Every kit therefore carries two designations: a class for what is inside, and a type for what it is inside of.

Class ≠ Type: the distinction that answers most questions

Most confusion about first aid kit labeling comes from reading the two systems as one. They answer different questions:

The two combine freely: a Class A fill can ship in a Type I wall cabinet or a Type III field case, and a Class B fill can sit in either. Choose the class from the hazard profile — our ANSI Class A vs Class B first aid kits comparison covers that call — and the type from where the kit will live.

The four container types, one by one

One caution when comparing sources: the exact test wording behind these ratings lives in the standard itself, ANSI/ISEA Z308.1-2021, and published summaries paraphrase it differently — a few older summaries do not describe Type IV at all. When a purchase decision hinges on the container spec, the listing's stated type and the manufacturer's documentation are what to verify, and the standard is the authority.

Which container type for which workplace

Fixed indoor work: Type I, and the wall does the compliance work

For an office, plant floor, or kitchen, a Type I station is the default because a mounted, visible cabinet is the easiest way to pass 1910.151(b)'s readily-available test — nobody relocates it, nobody buries it. Formats and shelf capacities are compared in our best first aid cabinets guide, and the first aid cabinets collection carries the stocked stations.

Vehicles and field duty: Type III is the floor

A kit that rides in a cab or works outdoors needs at minimum the water resistance and mountability of a Type III case — moisture is the silent killer of sterile stock. On construction vehicles the container question stops being preference: 29 CFR 1926.50(d)(2) requires kit contents in a weatherproof container with individually sealed packages, the same concern the Type III and IV ratings address, though the regulation predates and does not cite the type system. The vehicle first aid kits collection is built around that duty.

Harsh environments: Type IV earns its price

Crews that throw the kit in a gang box, boat, or truck bed need the gasketed, impact-resistant tier. The cheap failure mode is buying a Type IV case and restocking it with loose, unsealed supplies — the container rating protects unit-packaged contents, not bulk ones, so restock from unit-packaged first aid kit refills. For extended-care depth on remote work, the outdoor first aid kits collection sizes kits to the delay to definitive care.

How to read a kit listing that mixes class and type

A listing like "ANSI/ISEA Z308.1-2021 Class B, Type III" decodes as: Class B contents (the higher-quantity fill with a splint and a tourniquet) inside a portable, water-resistant, mountable case. A listing that states only a class tells you nothing about the container; one that states only a type tells you nothing about the fill. Some cabinets list dual ratings such as "Type I & II" — a fixed-station format the maker also rates for indoor carrying. And because OSHA approves neither classes nor types, a "2021 OSHA Approved" badge on a listing is marketing shorthand for "stocked to the current standard," not a certification — the same caution flagged in our OSHA first aid kit requirements explainer. When the class-and-type pair is right for your site, the buying options live in workplace first aid kits and OSHA first aid kits; if you have not settled the pair yet, the first aid kit selector maps setting, headcount and hazards to both in five questions.

Frequently asked questions

What is the difference between first aid kit Class and Type?

Class (A or B) rates the contents — item types and minimum quantities. Type (I–IV) rates the container — portability, mounting, and environmental resistance. They are independent axes, and every workplace kit decision is really both decisions.

What is a Type I first aid kit?

A stationary indoor container — the wall-mounted cabinet format — intended to stay mounted rather than be carried, with minimal exposure to rough handling or weather, as summarized from ANSI/ISEA materials.

What is a Type II first aid kit?

A portable indoor kit: built to be carried between indoor locations where damage to the contents is unlikely. Think a handled kit moving around a facility rather than riding in a truck.

What is a Type III first aid kit?

A portable kit for mobile and outdoor settings — water-resistant and equipped with a means to mount, for environments where damage is possible but not probable. It is the sensible floor for any vehicle kit.

What is a Type IV first aid kit?

The harsh-environment tier: waterproof and impact-resistant, built for rough handling on construction, utility, marine and remote work. Note that some older published summaries omit Type IV — the current standard is the authority.

Does OSHA require a specific container type?

No — OSHA names neither classes nor types. The nearest regulatory cousin is construction's 1926.50(d)(2), which requires a weatherproof container with individually sealed packages; a Type III or IV case is a natural way to satisfy that concern, but the regulation does not cite the ANSI type system.

Can a Class A kit come in any container type?

Yes. Class and type combine freely — Class A contents ship in everything from Type I cabinets to Type IV hard cases. The class follows the hazard profile; the type follows the storage and transport reality.

What does a dual rating like Type I and II mean on a cabinet?

The maker rates the container for both duties: a fixed station format that is also acceptable for indoor portability. It is common on commercial cabinets and changes nothing about the fill class.

Is a Type IV case worth it for a work truck?

If the kit rides loose in a bed, gang box, or trailer, yes — impact resistance is what keeps sealed packages sealed. For an in-cab kit, a Type III case usually covers the duty; heat, not water, is the in-cab enemy, and that argues for disciplined date checks either way.

Do container types affect what OSHA inspects?

Indirectly. Inspectors evaluate whether supplies are adequate and readily available under 1910.151(b) — a container that let the contents get soaked or crushed fails that test regardless of its label, and on construction jobs the weatherproof duty in 1926.50(d)(2) is explicit.

Which type should a restaurant kitchen use?

Type I — a mounted cabinet clear of the cook line, because kitchens are fixed indoor workplaces where visibility and a known location matter more than portability. The fill question matters more there: burn coverage and blue detectable bandages, covered in our best workplace first aid kits guide.

Which type do construction crews need?

Per-crew portable kits in Type III or IV cases plus a fixed kit at the trailer. Construction also carries the hard inspection cadence — checked before each job and at least weekly on the job — walked through in our first aid kit inspection checklist.

Does a tougher container change the inspection schedule?

No. The cadence follows the workplace — weekly on construction jobs, monthly by convention elsewhere — not the box. A Type IV case protects contents between checks; it does not substitute for them.

Where is the type stated on a kit?

On the listing or the label, usually alongside the class — "Class B, Type III." If a listing states neither, treat the kit as unrated: fine for a desk drawer at home, not a defensible basis for a workplace program.

Do refill packs have a container type?

No — types rate containers, and refills are contents. What matters for refills is unit packaging (sealed packages per item) so the container's rating keeps meaning something after a restock.

Further reading on this site

• ANSI Class A vs Class B first aid kits — the contents half of the two-part decision.
• First aid kit selector — maps setting, headcount and hazards to a class and format in five questions.
• OSHA first aid kit requirements — what 1910.151 and 1926.50 actually obligate.
• Best first aid cabinets — the Type I format, compared by capacity and fill class.
• First aid kits — complete kits with published class and type ratings.
• First aid kit inspection checklist — the maintenance duty no container rating replaces.

Why trust WC Safety

WC Safety is an independent, affiliate-supported review site. It is not a retailer: it holds no inventory, takes no orders, and earns only from qualifying purchases through clearly marked links — which never changes what a product is rated to do. Container-type definitions on this page are summarized from ANSI/ISEA materials and industry references and are labeled as summaries; the standard itself, ANSI/ISEA Z308.1-2021, is the authority, and where published summaries disagree — including whether Type IV is described at all — this page says so rather than papering over it. We run no laboratory and perform no testing of our own.

Our methodology

Researched and written by Steven Eaton, editor of WC Safety. Steven holds no safety certification and does not test products; this page reports what the standard and its published summaries say, with the gaps in that record marked. Last reviewed August 2026.