Most likely, your earliest exposure to “formaldehyde” involved some sort of biological specimen, preserved in a clear liquid. This liquid was probably identified as “formaldehyde.” And, if you were in elementary school or junior high, you didn’t give it a second thought.
But, if you were to study organic chemistry, you would learn that formaldehyde is the simplest aldehyde, and is a gas at room temperature. So…just what is this clear liquid?
The clear liquid is formalin–an aqueous solution of formaldehyde, with methanol added to prevent polymerization. Here is a typical formulation:
|COMPONENT||CHEMICAL FORMULA||PERCENT BY WEIGHT|
|Formaldehyde||HCHO||36.5 – 38.0|
|Methanol||CH3OH||10.0 – 15.0|
|Water||H2O||47.0 – 53.5|
This solution is also used as a disinfectant. Notably, the solution gives off some gaseous formaldehyde, and areas of human occupancy containing formalin should be monitored.