A few chemicals require pre-approval by EHS or pre-notification of procurement by the purchaser to EHS. These include explosives (in any amount), pyrophorics, water reactives, toxic materials with an LD50 less than 5 mg/kg, organo-mercury compounds with an LD50 of less than 50 mg/kg or readily absorbed through the skin, and flammable or toxic gases (see the GT Dangerous Gas Safety Program).
Equipment that requires pre notification of EHS includes ethylene oxide/sterilizers, biosafety cabinets, class 3B or 4 lasers, and X-Ray generating equipment.