Paraformaldehyde is a white, crystalline solid that is a polymeric form of formaldehyde, consisting of linear chains of formaldehyde molecules. It is produced through the polymerization of formaldehyde gas, typically under heat and specific conditions. Paraformaldehyde is soluble in water and can be depolymerized back into formaldehyde when heated or treated with acids or bases. It is commonly used in various industrial applications, including the production of resins, such as phenolic and urea-formaldehyde resins, which are utilized in adhesives, coatings, and composite materials. Additionally, paraformaldehyde serves as a disinfectant and preservative in laboratories and medical settings due to its effective antimicrobial properties. It is also employed in histology for tissue fixation.