California’s Office of Environmental Health Hazard Assessment (OEHHA) has adopted it proposed Maximum Allowable Dose Level (MADL) for Benzyl Butyl Phthalate (BBP), a phthalate plasticizer.
BBP was listed as a developmental toxicant under Proposition 65 in December 2005 after it was formally identified the National Toxicology Program’s Center for Evaluation of Risks to Human Reproduction (NTP-CERHR), which found BBP to be reproductive toxicants in its 2003 final report.
OEHHA’s MADL for BBP is 1,200 micrograms per day based on an oral route of exposure. The MADL will take effect on October 1, 2013.
BBP is used as a plasticizer for polyvinyl chloride, polyvinyl acetate, rubbers, cellulose plastics and polyurethane. End application include PVC floorings and wall coverings, artificial leather, PVC foams, films, sealing and adhesive systems based on polyurethane or polysulphide, PVAC based adhesives and paint binders. It is also used in the manufacture of food conveyor belts, automotive trim, and traffic cones.
The Ferro Corporation, which describes itself as a “major manufacturer of BBP,” last year called the No Observable Effect Level (NOEL) used by OEHHA to calculate its’ proposed MADL as “overly conservative.” The company criticized OEHHA’s reliance on a hypothesis testing study, which it said was “inappropriate for regulatory risk management when robust risk assessment studies are available.”
Because BBP is a constituent of several materials commonly found in consumer products, the new MADL may cause increased enforcement activity for this chemical.