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A chemical storage cabinet is a purpose-built enclosure that holds laboratory chemicals away from open shelving and, depending on its type, limits fire exposure, contains corrosive spills or keeps incompatible materials apart. The word “chemical” covers several different cabinet classes, and only one of them, the flammable-liquid cabinet, has a federal construction specification in the United States.
This page describes products and general use; it is not medical advice. It is written for lab staff, core-facility users and buyers who need to know which cabinet class a given chemical belongs in.
What it is
A chemical storage cabinet is a closed, lockable cabinet used in a lab or stockroom to store hazardous chemicals by hazard class. The purpose is segregation and protection: keeping flammables from heating up in a fire, keeping acids and bases from reacting with each other, and keeping spills inside a defined volume. Who uses it: researchers, lab managers, stockroom staff and environmental health and safety (EHS) officers.
How it is built
OSHA’s flammable-liquid cabinet rule, 29 CFR 1910.106(d)(3), is the one detailed federal construction standard. A metal cabinet must be made of at least No. 18 gage sheet iron, double-walled with a 1.5-inch air space, with joints riveted, welded or made equally tight, a three-point lock on the door, and a door sill raised at least 2 inches above the floor. The cabinet must limit its internal temperature to no more than 325 °F when subjected to a 10-minute fire test. Wooden cabinets are also permitted if built of plywood at least 1 inch thick. The cabinet must be labelled “Flammable – Keep Fire Away.” (OSHA, read 2026-11-08.)
That rule applies to flammable and combustible liquids only. OSHA’s text contains no matching construction rule for corrosive or oxidizer cabinets, so “corrosive cabinet” is a practice and product class rather than an OSHA-defined specification. For those cabinets, rely on the manufacturer’s documentation and your institution’s EHS office.
Types and variants
| Cabinet class | Typical contents | Key difference | Source |
|---|---|---|---|
| Flammable-liquid cabinet | Flammable and combustible liquids | Defined by 29 CFR 1910.106(d)(3): double-walled, fire-tested, labelled. Max 60 gal of Category 1, 2 and 3 liquids, or 120 gal of Category 4, per cabinet. | OSHA 1910.106 |
| Corrosive (acid/base) cabinet | Acids and bases, stored separately from each other | Not defined by an OSHA construction rule. FSU EH&S recommends segregating acids and bases and keeping them in dedicated corrosive cabinets. | FSU EH&S; Cornell EHS |
| Oxidizing acids within an acid cabinet | Nitric, perchloric and chromic acid | FSU EH&S allows oxidizing acids to share a cabinet with other acids only in secondary containers, in small quantities (1-2 bottles). Cornell EHS says nitric acid needs its own secondary container inside the acid cabinet. | FSU EH&S; Cornell EHS |
| Under-hood or in-lab cabinet | Corrosives | FSU EH&S notes corrosive cabinets can sit under fume hoods, in the lab, or be manufactured units. | FSU EH&S |
Specifications that matter
The only sourced capacity figures are OSHA’s: 60 gallons per cabinet for Category 1, 2 and 3 flammable liquids and 120 gallons for Category 4. Other dimensions vary by manufacturer. For flammable-cabinet capacity, venting and control-area detail, see flammable liquid storage cabinet requirements.
How to choose a cabinet class
- Start with the most severe hazard. Cornell EHS prioritises flammability over corrosivity: a chemical with the GHS flammability pictogram goes in a flammables cabinet, in secondary containment apart from other flammables.
- Separate acids from bases. Cornell EHS says acids and bases are always stored apart. Inorganic and organic acids should also be kept separate (FSU EH&S).
- Check the concentration exception. Cornell EHS stores glacial acetic acid (80% and above) with flammables; below 80% it may go with other acids.
- Size secondary containment. Cornell EHS: it must hold the full contents of the largest container, or at least 10% of the total volume of all containers, whichever is larger. Secondary containment is not required but is highly recommended in properly rated ventilated cabinets with shallow spill pans. Polyethylene resists hydrochloric, sulfuric and nitric acids and bases.
FSU EH&S states its chemical lists are not complete, and each material should be researched individually. Class-by-class compatibility is covered in chemical storage compatibility and segregation rules, and oxidizers in oxidizer storage requirements in the laboratory.
Safe use and handling basics
- Keep the cabinet for storage only and follow the hazard-class rules above.
- Use secondary containment inside the cabinet; see secondary containment requirements.
- Avoid storing acids under sinks or on metal shelving; segregation charts from UWM and the University of Kentucky advise against it.
- For the hazards of corrosives themselves, see corrosive chemicals: lab hazards and handling.
Common mistakes
- Assuming every “chemical cabinet” meets the OSHA flammable-cabinet specification. That specification covers flammable and combustible liquids only.
- Storing a flammable corrosive by its corrosivity alone; Cornell EHS puts flammability first.
- Placing acids and bases in the same cabinet or tray.
- Storing nitric acid with other acids without its own secondary container.
FAQ
Does OSHA define a corrosive storage cabinet?
No. The cabinet construction paragraph of 29 CFR 1910.106(d)(3) covers flammable and combustible liquids. Corrosive cabinets follow manufacturer specifications and EHS guidance.
How much can one flammable cabinet hold?
Up to 60 gallons of Category 1, 2 and 3 liquids or 120 gallons of Category 4 liquids (OSHA 1910.106(d)(3)).
Can acids and bases share a cabinet?
Cornell EHS and FSU EH&S both say to keep them separate.
Sources
- OSHA, 29 CFR 1910.106, flammable liquids: osha.gov (read 2026-11-08).
- Florida State University EH&S, Corrosive Storage Guidelines: safety.fsu.edu (read 2026-11-08).
- Cornell EHS, Chemical Segregation FAQ (March 2026): ehs.cornell.edu (read 2026-11-08).
