In forensic laboratory settings there are a few materials of note that present physical hazards. Diethyl ether is extremely flammable and is often one of the most dangerous fire hazards often found in the laboratory (both legitimate and clandestine). This is due to its high volatility and extremely low flash point. Electrical arcs from equipment motors and switches or from static electricity discharges may ignite ether vapors. Most flammable liquids have vapors that are heavier than air and may travel surprisingly long distances to an ignition source and flash back. Never use a household-type refrigerator to store flammable liquids (ethers, alcohols, etc). In the event of a container spill or leak an explosive concentration can quickly develop with ignition occuring when the unit cycles. Every year or two there is a new story of a university lab destroyed as a result of a refrigerator fire. Ethers, tetrahydrofuran, dioxane, and several other flammable solvents have the additional hazard of forming unstable peroxides over time, especially with exposure to air. When sufficiently concentrated (e.g. around a container cap or through distillation) detonation can occur. Because of their tendency to form peroxides on contact with air, date containers upon receipt and at the time they are opened. Many organizations require peroxide formers to be either disposed of, or tested, within three to six months after opening. If unopened, they should always be disposed of by the expiration date on the container.

Flammable and combustible liquids (including organic acids) are best stored in Factory Mutual (FM) approved flammable liquid storage cabinets or in a specially designed flammable liquid storage room. There are often local and state requirements or fire codes that limit quantities of flammable liquids and other classes of chemicals within portions of a building and within the building as a whole. Chemical compatibility is critical when storing chemicals. Inadvertent mixing of incompatible chemicals may result in fire, explosion or evolution of extremely toxic gases.

From: Chemical Safety in the Forensic Lab by The Safety Guys