33 Laboratory Safety Manual Environmental Health and Safety • Perchloric acid use may result in the formation of explosive perchloric acid salts. Perchloric acid procedures must only be performed in approved laboratory fume hoods. Explosives Explosives may be divided into two categories: chemicals designed and produced for use as an explosive, and chemicals that may become explosive due to dehydration, age, or contamination. Examples include ammunition, dry picric acid, and trinitrotoluene (TNT). Follow procedures outlined in Potentially Explosive Chemicals: Guidelines for Safe Storage and Handling. • Obtain approval from EH&S prior to purchasing, using, and synthesizing explosives in the laboratory. • Store away from other chemicals in a secure cabinet or magazine. • Keep wetted or otherwise stabilized. • Use and store away from sources of heat, friction, or static electricity. • Use barriers such as blast shields, barricades, and guards to protect personnel and equipment. • Use of eye protection and flame-resistant lab coats are required. Never wear synthetic clothing (such as: polyester or nylon) as it may ignite causing severe burns. Wear heavy leather or kevlar gloves and a face shield that protects the throat when in a hazardous or exposed position. Refer to information from the chemical manufacturer for additional PPE requirements. Flammables Flammable materials burn readily in the presence of an ignition source. Flammable liquids have a flash point of less than or equal to 60ºC (140ºF). Vapor from these liquids can reach remote ignition sources, causing flashback fires. • Isolate ignition sources, including hot surfaces, electrical equipment, and static electricity from flammable materials. • Store flammables away from oxidizers and strong acids. • Ensure proper bonding and grounding when transferring flammable liquids from a container or drum. • Implement additional safety precautions when heating flammable liquids, particularly when heating to or above their flash points.