1. Formaldehyde is numbered 830 12 in the Catalogue of Hazardous Chemicals, belonging to 8 categories and 3 hazardous chemicals. Formaldehyde is a colorless aqueous solution or gas, which has a pungent smell and is easily soluble in water and ether. Formaldehyde is a strong reducing agent, and its vapor forms an explosive mixture with air, which will cause combustion and explosion when exposed to open fire and high heat. General commodities will add 10% ~ 12% methanol as polymerization inhibitor, otherwise polymerization will occur.

2. The chemical properties of formaldehyde are very active. Under the catalysis of metal or metal oxide, it is easily reduced to methanol; When oxidized, formic acid or carbon dioxide and water are produced. Formaldehyde is a strong reducing agent, which is more reducing when it is weakly alkaline, and can be slowly oxidized into formic acid in air.