Assessing the Chronic Aquatic Toxicity of Phthalate Ester Plasticizers

Phthalic acid esters (PAE) are a class of chemicals varying greatly in terms of uses, properties, and toxicity. C1 to C4 PAE are used in non-vinyl commercial products and pharmaceuticals. C8 to C10 PAE are additives imparting flexibility to vinyl resins. The purpose of the present study is to assess chronic effects of PAE on aquatic organisms. Studies show that populations of fish and invertebrates may be adversely affected by exposure to C1 to C4 PAE, but are not adversely affected by exposure to C8 or higher PAE. Secondary endpoints, including molecular, biochemical, and/or histological responses to chemical exposure, do not appear to predict effects related to primary endpoints of survival, growth and development, or reproductive fitness. A previously published risk assessment for C1 to C4 PAE demonstrated low risks in North American and Western European surface waters. Risk assessments conducted by authorities in Europe with di-2-ethylhexyl-, di-isononyl-, and di-isodecyl phthalates have concluded no risks to aquatic organisms due to aqueous solubility constraints, low expected surface water concentrations, and metabolic biotransformation capabilities of aquatic organisms. The present review of chronic aquatic toxicity data, which includes data from studies performed subsequent to the risk assessments, confirms these earlier conclusions.