Dimethyl phosphite

Dimethyl phosphite (CAS 868-85-9, EC 212-783-8) is a phosphorus-based organic compound also referred to as dimethyl phosphonate, dimethoxyphosphineoxide, and (CH3O)2PHO. It carries no E-code designation and is classified under HS code 29209013. It belongs to the organic acids category and is handled as a colourless liquid with a mild odour.

In water treatment, dimethyl phosphite functions as a pH buffer by donating or accepting protons to stabilise process streams within target ranges. In polymer and plastics manufacturing, it acts as an antioxidant and stabiliser, interrupting oxidative chain reactions that degrade polymer matrices. Pharmaceutical and agrochemical producers also use it as a reactive intermediate and catalyst in synthesis processes.

Dimethyl phosphite is supplied in technical and synthesis grades and is subject to REACH registration requirements within the European Union. Standard packaging includes drums and intermediate bulk containers. Buyers should confirm purity specifications and SDS documentation prior to procurement to meet applicable regulatory obligations.