State of the Science Report for MBMBP

Identity, Uses and Sources of Exposure

MBMBP is produced by the reaction of 2-tert-butyl-p-cresol with formaldehyde through a carbonyl condensation. It is used in industry as a stabilizer in styrenic and olefin polymers and polyoxymethylene homopolymers and copolymers and as an antioxidant in acrylonitrile-butadiene-styrene copolymer, polypropylene, polyacetal, rubber, latex and adhesives ( NLM, 1998). A survey conducted pursuant to section 71 of the Canadian Environmental Protection Act, 1999 (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. Results of the Section 71 survey (Environment Canada, 2001) indicate that the pattern of use in Canada is similar to that reported elsewhere (OECD, 2003a): namely, as an adhesive and an antioxidant. No data have been identified to indicate the levels of MBMBP present in consumer products. However, given the physical and chemical properties of MBMBP, consumer products are not expected to contribute significantly to the exposure of the general Canadian population to this substance.