The Society of the Plastics Industry, Inc., ad hoc Bisphenol A Task Group determined that freshwater and saltwater environmental effects testing on bisphenol A should be conducted. This decision was based upon the nation's high production capacity for bisphenol A, which is manufactured at many sites, its potential for entering the environment in substantial quantities and the general lack of relevant ecological effects data. The freshwater test results were as follows: the 96‐h EC50 algal toxicity to Selenastrum capricornutum was 2.7 mg/L based on cell count, and 3.1 mg/L based on cell volume; the 48‐h EC50 to the invertebrate Daphnia magna was 10 (9.2–11) mg/L; and the 96‐h LC50s to the fathead minnow, Pimephales promelas, was 4.7 (4.0–5.5) mg/L in a static test and 4.6 (3.6 to 5.4) mg/L in a flow‐through test. The saltwater test results were as follows: the 96‐h EC50 algal toxicity to the diatom Skeletonema costatum was 1.0 mg/L based on cell count and relative fluorescence, and 1.8 mg/L based on chlorophyll a content; the 96‐h LC50 to the mysid Mysidopsis bahia was 1.1 (0.92 to 1.2) mg/L; and the 96‐h LC50 to the Atlantic silverside, Menidia menidia, was 9.4 (8.3 to 11) mg/L. According to current U.S. Environmental Protection Agency standard evaluation procedures, bisphenol A was moderately to slightly toxic to the fish and invertebrates tested, with LC50 or EC50 values of from 1.1 to 10 mg/L. These data did not trigger freshwater or saltwater chronic tests. The acute toxicity data together with the fact that bisphenol A rapidly biodegrades in surface waters indicate a low potential for chronic exposure or toxicity.

Some hydrophobic chemicals may reach plateau levels in fish only after several months of continuous exposure. Therefore, an accelerate•l test procedure, based on kinetics, was developed using an isomer of PCB's (polychlorinated biphenyls): 2,2',4,4'-tetrachlorobiphenyl. The rates of uptake and clearance of 2,2',4,4'•tetrachlorobiphenyl were determined by analysis of rainbow trout (Salmo gairdneri Richardson). These trout were exposed to 1.6 and 9.0 gg/liter for five days and then transferred to fresh water. A nonlinear regression analysis was used to estimate the rate constants for uptake and clearance, and the bioconcentration factor at steady-state was calculated from the rate constants. For 2,2',4,4'-tetrachlorobiphenyl, the bioconcentration factor at steady-state was 9550 q-1610 in trout muscle.The accuracy of the bioconcentration factor determined by this accelerated test procedure was compared with experimental observations in a 42-day test. The concentration of 2,2',4,4'-tetrachlorobiphenyl in trout muscle was 82 ___ 20/•g/g after 42 days continuous exposure to 14/•g/liter. This was in good agreement with 92 q-18 /•g/g predicted from the accelerated procedure. The 42-day level was about 43% of the theoretical steady-state for 2,2',4,4'•tetrachlorobiphenyl in trout muscle. Therefore, this accelerated procedure can provide information about the potential of a chemical to bioconcentrate in fish in a much shorter period of time than can be provided by previously described methods.The objective of this investigation was the development of an accelerated test procedure for measuring the bioconcentration potential of chemicals in fish. The bioconcentration factor is expressed as the ratio of the concentration in the fish (at steady-state) to the

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The toxicity of ammonia to the juvenile stages of the bluegill (Lepomis macrochirus) and the walleye (Stizostedion vitreum), and to the embryo, larval and juvenile stages of the fathead minnow (Pimephales promelas) was determined in support of the development of a site-specific water quality standard for ammonia in the Tittabawassee River at Midland, Michigan. There was little difference among the acute toxicities of ammonia (expressed as un-ionized ammonia nitrogen NH -N) to the three species tested, with 96-h LC50 values of 1.04, 1.06 and 1.50 mg NH -N/L for the bluegill, walleye and fathead minnow, respectively. Evaluation of the chronic data showed no concentration-related effects for hatching success and growth. However, there was a significant (α = 0.05) decrease in number of normal larvae at hatch and in larval survival at 0.26 mg NH -N/L and higher. The maximum acceptable toxicant concentration fell between 0.17 and 0.26 mg NH -N/L, or 0.21 mg NH -N/L when expressed as the geometric mean of these values. Both the acute and chronic values derived during this study are similar to those reported in the literature, indicating that, in this case, Tittabawassee River water quality did not influence the toxicity of ammonia to the species tested.