Identity, Properties, Uses and Sources of Release

This substance is named 2,2'-methylenebis[6-(1,1-dimethylethyl)-4-methylphenol] on Canada’s DSL. Its Chemical Abstracts Service (CAS) Registry Number is 119-47-1. It has a number of other names, including 6,6-di-tert-butyl-2,2'-methylenedi-p-cresol and 2,2'-methylene-bis(4-methyl-6-tert-butyl-phenol), from which the acronym MBMBP is derived. MBMBP is a phenolic antioxidant with a molecular weight of 340.51. It has a low vapour pressure (calculated as 4.7 × 10⁻¹¹ Pa; OECD, 2001), low water solubility (0.02 mg/L; OECD, 2001) and a high octanol/water partition coefficient (log K_ow = 6.25; OECD, 2001).

Although MBMBP is considered a high production volume substance globally (OECD, 2004), a survey conducted pursuant to Section 71 of CEPA 1999 indicated that during the year 2000, between 10 and 100 tonnes of MBMBP at a concentration higher than 1% were imported into Canada. In addition, companies reported either importing or manufacturing MBMBP at a concentration lower than 1% and in a quantity meeting the reporting threshold of 100 kg. MBMBP was not reported as being manufactured at a concentration higher than 1% in Canada (Environment Canada, 2001). The principal use of MBMBP is as an antioxidant in plastics such as acrylonitrile-butadiene-styrene copolymer, polypropylene and polyacetal. It is also used in industry as a stabilizer in styrenic and olefin polymers and polyoxymethylene homopolymers and copolymers and as an antioxidant in rubber, latex and adhesives (HSDB, 1999).