Polyformaldehyde (or polyformaldehyde; Polyacetal), a polymer of formaldehyde (high molecular weight polyformaldehyde), with a general structural length of eight to one hundred units. Long chain polyformaldehyde is commonly made in heat-resistant plastics, also known as polyformaldehyde plastic (POE, DuPont produced Derlin). Paraformaldehyde decomposes quickly and releases a slightly smelly formaldehyde. Polyformaldehyde can be used for smoking disinfection, sterilization, and can also be used to prepare pure formaldehyde (can be formalin). When formaldehyde solution is stored at low temperature, it will slowly form polyformaldehyde, which will precipitate out as white insoluble matter.