The handle of pressure cookers s made of plastic because it should be made a non-conductor of heat. The plastic used there is the first man-made plastic, which is bakelite. Bakelite, or polyoxy benzyl methyl englycolanhydri de, is an early plastic. It is a thermosetting phenol formaldehyde resin, formed from a condensation reaction of phenol with formaldehyde. Its chemical formula is (C6H6O⋅CH2O)n