Paraformaldehyde is a kind of white amorphous powder.It has the smell similar to Formaldehyde.It is the Formaldehyde linear polymer and has no fixed melting point. Paraformaldehyde will decompose when heated. Melting point is 120 ~ 170 ℃. Soluble in hot water and release formaldehyde, soluble in cold water, soluble in caustic and alkali carbonate solution, insoluble in alcohol and ether, the high degree of polymer is insoluble in water. Formaldehyde-like reactions such as chloromethylation, acetal formation with alcohols and the like can occur. For synthetic resins, adhesives, medicine, fungicides, pesticides, disinfectants and so on.