4. Combustion appliances: Many garages contain a furnace, water heater or gas powered clothes dryer. If you read the label on a water heater it will tell you that, if it is in a location where combustible materials are stored, the pilot and flames should be a minimum of 18 inches above the floor. Though modern water heaters have a sealed combustion chamber, many older water heaters remain in use. The same logic holds true for other appliances. The pilot and flames on most furnaces are, by design, 18 inches or more above the floor, but gas clothes dryers are not. If either your water heater or gas clothes dryer are installed on the floor of your garage, you should have them raised to comply with the 18 inch rule.
5. Electrical: Since the late 1970s, building codes in most areas of the Southeast have required that electrical receptacles in garages be protected with ground fault circuit interrupters (GFCI). In most cases these receptacles are easily recognizable by the two buttons on the receptacle that say "test" and "reset." Even if your house was constructed prior to this requirement, installation of GFCI receptacles in garages is recommended.
6. Carbon monoxide: Carbon monoxide gas is a by-product of combustion; it is tasteless, odorless and deadly. For this reason, never leave a car running in the garage, even with the door open. Never cook on a grill in the garage, and if your power happens to go out, never run a gas generator in the garage.