Paraformaldehyde is a polymer of formaldehyde. Formed by the evaporation of an aqueous solution of formaldehyde. Insoluble in water. Uses include - fungicides, bactericides, adhesives and disinfectants. Packaged in a wide mouth polyethylene jar with screw cap. This material is shipped in compliance with USPS Publication 52 as an ORM-D. Shipping .50.