Paraformaldehyde is a white, solid polymer of formaldehyde with the pungent, characteristic formaldehyde odour. Paraformaldehyde is composed of varying molecular weight polymers of polyoxymethylene glycols. The combined water is the terminating agent for the paraformaldehyde chains. Paraformaldehyde is slightly soluble in alcohols and insoluble in ethers, hydrocarbons and carbon tetrachloride. It is relatively insoluble in cold water, but soluble in hot water with depolymerization. The solubility and rate of solution of paraformaldehyde in water are greatly influenced by pH and temperature. Both acidic and alkaline pHs and higher temperatures accelerate the rate of solution. Once dissolved, the paraformaldehyde solution behaves like the methanol-free formaldehyde solution of the same concentration. Paraformaldehyde reacts chemically as formaldehyde at a rate determined by its rate of depolymerization under the conditions of use.