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Flammable Storage in Shops

Flammable liquids give off vapors that can travel across a room to a spark. Where and how you store them matters more than how much you own.

Why do flammable liquids need special storage?

It is the vapor, not the liquid, that ignites. Gasoline, many solvents, brake cleaner, paint thinner and some aerosols release vapors that can drift along the floor to a pilot light, a switch, a hot surface or a static spark. Vapors from some products are heavier than air and collect low in a building.

That is why the shop is a poor place for open or loosely capped containers. Good storage keeps vapors contained, keeps ignition sources away and limits how much fuel could feed a fire.

What counts as flammable in a typical shop?

Think beyond the fuel can. Paint, stain, thinner, degreasers, starting fluid, penetrating oil, some adhesives, propane cylinders, welding gases and aerosol cans may all carry fire warnings. Read the label and the safety data sheet, which the manufacturer provides, to see what the product is and how it should be stored.

Safety data sheets are the right place to find product-specific storage notes. Ask the seller for one if you do not have it, and keep them in a binder or folder that anyone in the shop can reach.

If you have older cans with faded labels, treat them as unknown and ask your county hazardous waste program how to dispose of them. Unknown liquids should not be poured out, burned or mixed with other products.

Where should containers be kept?

Official guidance and fire codes address cabinets, containers, quantities and distances, and the numbers depend on the product and on local code. Do not rely on a rule of thumb from a neighbor. Ask your local fire marshal or insurer what applies to your building, and read the manufacturer's label.

In principle, keep fuel in approved, labeled containers made for that fuel, closed when not in use, away from heaters, welding, grinding and electrical panels, and away from the main exit path. Keep the stored amount as small as the work allows.

Storage near doors can block your exit if there is a fire, while storage next to a water heater, furnace or welder invites trouble. A separate outbuilding, a ventilated spot away from the main work area, or a purpose-made cabinet are options to discuss with your fire marshal.

• Use containers made for the product, not repurposed food or drink bottles.
• Label everything, including anything you pour into a second container.
• Keep lids closed and containers upright.
• Keep ignition sources and hot work away from the storage area.

How do I handle spills and leaks?

Check storage areas on a regular schedule for dampness, odor, bulging cans and rust. Small leaks often go unnoticed until someone strikes a spark. Follow the product's safety data sheet for cleanup, and do not use an ignition source or run a fan or tool that could spark in a space with strong vapors.

If you smell fuel strongly or cannot control a spill, ventilate if it is safe, keep people out and ask your fire department for advice. In an emergency, leave the building and call 911.

What about fuel for equipment and heaters?

Fueling tractors, generators, saws and heaters inside a shop mixes vapors with every other hazard in the building. Hot engines and fuel do not belong together. Let equipment cool before fueling, as the owner's manual directs, and fuel outdoors or where the manual and local rules allow.

Portable heaters and fuel-burning appliances have their own manufacturer instructions about fuel type, clearance and ventilation. Follow those instructions closely and never improvise.

How do I teach everyone the same rules?

Put the rules where people work and say them out loud when new workers or teens start. Walk them to the storage spot, show the label system and explain why. Include who to tell when something is leaking or a container is damaged.

Review the storage area at least once a year, and again when you add products. Throw away what you no longer use through the hazardous waste program your county offers rather than letting it age on the shelf.

What should I do about propane and welding gas?

Pressurized cylinders have their own handling rules from the supplier and from official sources. In principle, keep them upright and secured, with valve caps on when not in use, protected from impact and heat and kept away from ignition sources. The cylinder label and your gas supplier's instructions govern the details.

Do not store cylinders where a vehicle could strike them, and do not try to repair a leaking cylinder or valve yourself. Move people away, ventilate if it is safe and call your supplier or 911.

Last reviewed: November 12, 2026. Written by the Farm Safety Editorial Team. See our editorial policy.