ABSTRACT
A review of the published and available unpublished literature on the effects of surfactants in microcosm, mesocosm, and field tests was conducted. Nine surfactants were assessed under a variety of experimental conditions. These included 5 cationic, 2 anionic, and 2 nonionic materials. A total of 26 higher tier tests were reviewed, including 24 microcosm, 4 mesocosm, and 1 field experiment. Comparisons of higher tier effects were made with chronic single species toxicity results in all cases. The anionic surfactant, dodecyl linear alkyl benzene sulfonate (LAS), and the cationic surfactant, dodecyl trimethyl ammonium chloride (TMAC), were the most frequently tested surfactants available to this review. A comparison of statistical extrapolation techniques described in the published literature using single species chronic noobserved-effect-concentrations (NOEC) for LAS and TMAC with mesocosm and field tests demonstrated that all the statistical extrapolations using single species chronic NOECs were conservative. The United States Environmental Protection Agency (USEPA) “concern level” approach (USEPA, 1984) was the most conservative for TMAC (factor of 64 difference between single species extrapolation vs mesocosm) and the Sloof et al. (1986) method was the most conservative for LAS (factor of 73 difference between single species extrapolation versus mesocosm). However, the USEPA “concern level” approach gives precedence to higher tier test NOECs when available. This is consistent with the current state-of-the-science in surfactant effects assessment.
