Formaldehyde is an organic chemical with the chemical formula HCHO or CH? o？ [1], molecular weight 30.03? [2], also known as ant aldehyde. ? [1] is a colorless irritating gas, which is irritating to human eyes and nose. The relative density of gas is 1.067 (air = 1), and the density of liquid is 0.8 15g/cm? (-20℃)。 Melting point -92℃, boiling point-65438 09.5℃. Soluble in water and ethanol. The highest concentration of aqueous solution can reach 55%, generally 35%-40%, generally 37%. It is called formaldehyde water, commonly known as formalin.
It is reducible, especially in alkaline solution. Can burn, steam and air form an explosive mixture, the explosion limit is 7%-73% (volume), and the ignition point is about 300℃. ?
It can be prepared by dehydrogenation or oxidation of methanol under the catalysis of metals such as silver and copper, and can also be separated from oxidation products of hydrocarbons. It can be used as raw materials for phenolic resin, urea-formaldehyde resin, vinylon, urotropine, pentaerythritol, dyes, pesticides and disinfectants. Industrial formaldehyde solution generally contains 37% formaldehyde and 15% polymerization inhibitor methanol, and its boiling point is 10 1℃.
2017101On October 27th, the list of carcinogens published by the International Agency for Research on Cancer of the World Health Organization included formaldehyde in the list of carcinogens. On July 23rd, 20 19, formaldehyde was listed in the List of Toxic and Harmful Water Pollutants (the first batch).