Formaldehyde Health and Safety Guide - Health and Safety Guide 57

Formaldehyde is a flammable, colourless, reactive, and readily polymerized gas at normal temperature and pressure. The heat of combustion for formaldehyde gas is 4.47 kcal/g. It forms explosive mixtures with air and oxygen at atmospheric pressure. Flammability is reported to range from 12.5 to 80% by volume, a 65-70% formaldehyde—air mixture being the most readily flammable.