Phthalates
Phthalates are a class of industrial chemicals used to increase the flexibility, transparency, durability, and longevity of plastics. Phthalates were first introduced in the 1920s, with increased popularity upon being used as a component in polyvinylchloride (PVC) beginning in 1931. Phthalates are produced by reacting phthalic anhydride with an alcohol. Although there is no bond present between the phthalate and plastic, the phthalate is physically bound to the plastic during the manufacturing process. The most widely used phthalates are di(2-ethylhexyl) phthalate (DEHP), diisodecyl phthalate (DIDP), and diisononyl phthalate (DINP). DEHP is the dominant plasticizer in PVC, while benzylbutylphthalate (BBP) is used in the manufacture of foamed PVC, commonly used as a flooring material.
Phthalates are easily released into the environment, thus, people are commonly exposed to phthalates. The main route of human exposure is through diet, as phthalates can easily leach and evaporate into food or the atmosphere; however, human exposure also occurs through inhalation and dermal contact. A study conducted by the Centers for Disease Control and Prevention showed that most people have metabolites of phthalates in their urine. There have been concerns of antiandrogenic effects due to phthalate exposure. Infants and children are particularly susceptible to phthalate exposure through personal care products and mouthing toys. They exhibit a greater adverse effect upon exposure due to their increased dosage per unit body surface area, metabolic capabilities, and developing endocrine and reproductive systems.1
The European Union has restricted the use of some phthalates in children’s toys since 1999. DEHP, BBP, and di-n-butyl phthalate (DBP) are restricted for all toys; DINP, DIDP, and di-n-octyl phthalate (DNOP) are restricted only in toys that can be taken into the mouth. In August 2008, the United States Congress passed the Consumer Product Safety Improvement Act (CPSIA), which has since become public law. The CPSIA bans the use of DEHP, DBP, and BBP in amounts greater than 0.1% in all children’s toys and some child care products. Congress has also banned, on an interim basis, DINP, DNOP, and DIDP. The Consumer Product Safety Commission (CPSC) has proposed that the ban on DINP be made permanent. The CPSC has also recommended banning diisobutyl phthalate, di-n-pentyl phthalate, di-n-hexyl phthalate, and dicyclohexyl phthalate.2
References
1. Sathyanarayana, S.; Karr, C.J.; Lozano, P.; et al. 2008. Baby care products: possible sources of infant phthalate exposure. Pediatrics, 121(2), e260-8. PMID: 18245401
2. Advisers Call for New Controls on Phthalates. 2014. Chemical and Engineering News, 23. Read more.
Phthalates, Related Plasticizers, and Metabolites