Phthalates (pronounced or in British English /ˈ(f)θaleɪts/), or
phthalate esters, are
esters of
phthalic acid and are mainly used as
plasticizers (substances added to
plastics to increase their flexibility, transparency, durability, and longevity). Phthalates are manufactured by reacting phthalic anhydride with alcohol(s) that range from methanol and ethanol (C1/C2) up to tridecyl alcohol (C13), either as a straight chain or with some branching. They are divided into two distinct groups, with very different applications, toxicological properties, and classification, based on the number of carbon atoms in their alcohol chain. They are used primarily to soften
polyvinyl chloride (PVC). Lower-molecular-weight phthalates (3-6 carbon atoms in their backbone) are being gradually replaced in many products in the
United States,
Canada, and
European Union over health concerns. They are replaced by high-molecular-weight phthalates (those with more than 6 carbons in their backbone, which gives them increased permanency and durability). In 2010, the market was still dominated by high-phthalate plasticizers; however, due to legal provisions and growing environmental awareness and perceptions, producers are increasingly forced to use non-phthalate plasticizers.