Registration Dossier

Environmental fate & pathways

Endpoint summary

Administrative data

Description of key information

Additional information

When released into the atmosphere, formaldehyde may be degraded by direct or indirect phototransformation. Reaction with the hydroxyl radical is considered to be the most important photooxidation process. The atmospheric half-life of formaldehyde, based on hydroxyl radical reaction rate constants, is calculated to be 1.7 days.

When released to water and to a minor degree to soil, biological activites by bacteria will eliminate formaldehyde rapidly as based on results of biodegradability tests. Therefore, phototransformation in water or soil are expected to be of minor importance. Furthermore, studies on the phototransformation in water or soil are not required for a registration under REACH. Formaldehyde undergoes, essentially complete hydration to yield the gem-diol, methylene glycol. Equilibrium almost totally favours the glycol; less than 0.04% by weight of unhydrated formaldehyde is found in highly concentrated solutions (WHO, 2002; Environment Canada, 2001).