It is used as preservative in food, paints and cosmetics. Used as an antiseptic in medicine, disinfectant in funeral home, used in making RDX. To improve the yield of fuels it is used in petroleum and natural gas industries. It is also used in the manufacture of ink.
Formalin has been used as a tissue preservative in operating rooms and pathology laboratories for a long time. Formalin is a solution of about 4% formaldehyde and water (known as 10% NBF) and is ubiquitous in clinical laboratories, pathology laboratories, and in operating rooms.