Registration Dossier

Environmental fate & pathways

Endpoint summary

Administrative data

Description of key information

Bioaccumulation: aquatic/sediment

The bioaccumulation potential of the test substance in eastern oyster, grass shrimp and bluegill sunfish were assessed in four individual studies. The test substance did not bioaccumulate appreciable in any of the species tested (BCF <1). This is in line with the logPow value of the substance. The logPow depends on the pH and did not exceed 1.3.

Additional information

Bioaccumulation: aquatic/sediment

Key study: Bioconcentration potential of bluegill sunfish (American Cyanamid Company, 200437, 2007)

The bioconcentration potential of the test substance by bluegill sunfish (Lepomis macrochirus) was evaluated in a dynamic 36-day test, consisting of a 28-day exposure period followed by an 8-day depuration period according to OECD Guideline 305. Under flow-through conditions, the bluegill sunfish were exposed to 14C-labeled test substance at nominal concentrations of 0.0026 and 0.0087 ppm (in acetone) and a control group receiving dilution water and co-solvent only.

No mortality, abnormal behavior, or abnormal physical appearance was observed in the control or test substance treatments during the exposure or depuration periods. Mean total radioactive residues (TRR) concentrations of 14C-labeled test substance in the 0.0026 ppm water samples ranged from 0.00245 to 0.00274 ppm (mean±SD: 0.00255±0.000100 ppm) during the 28-day exposure period. Mean TRR concentrations of 14C-labeled test substance in the 0.0087 ppm water samples ranged from 0.00860 to 0.00904 ppm (mean±SD: 0.00878±0.000143) during the 28-day exposure period. HPLC analysis of the 0.0087 ppm water samples indicated that the unchanged parent test substance was the only component in the water samples. During the 8 day depuration period, no 14C-labeled test substance residues were detected above the minimum of quantifiable limit (MQL). Mean measured TRR concentrations of 14C-labeled test substance in edible and non-edible fish tissue samples from both treatment groups remained below MQL during the 28-day exposure period and the 8 day depuration period. Therefore, steady state BCF, distribution of the test substance between edible and non-edible portions, uptake and depuration rate constants, and characterisation/identification of the significant metabolites could not be established since the test substance did not bioaccumulate in tissue during the 28-day exposure period.

In conclusion, the test substance does not bioaccumulate in the tissue of bluegill sunfish. The ratio of TRR in the tissue to the TRR in water, a measure of the bioconcentration factor (BCF), remained <1 during the 28 day exposure period.

 

Supporting studies

Bioconcentration potential of bluegill sunfish (American Cyanamid Company, 32819, 1985)

In addition, a second bioconcentration study with bluegill sunfish (Lepomis macrochirus) is available. A flow-through proportional diluter system was used to maintain a mean measured water concentration of 1.0 (±0.023) mg/L for a 28-day exposure period. All mean measured tissue concentrations of fillet, whole fish and viscera, during the uptake phase, were less than the radioassay MQL of 0.54 mg/kg, 0.55 mg/kg and 0.57 mg/kg, respectively. These MQL tissue levels correspond to bioconcentration factors (BCF) of <0.54, <0.55 and 0.57. This data suggests that there was no active or passive transport of the parent 14C-labeled test substance across gill membrane as indicated by the bioconcentration factors of <1. There was no evidence of any change in bioconcentration during the 14-day depuration phase since all tissue concentrations were below MQL.

 

Bioconcentation potential of eastern oyster and grass shrimp (American Cyanamid Company, 954-93-165, 1996; 954-93-164, 1995)

The bioaccumulation potential of the eastern oyster (Crassostrea virginica) and grass shrimp (Paleomonetes pugio) were evaluated in two separate flow-through studies equivalent to OECD Guideline 305. Both tests consist of a 28 day exposure period, and a 14 day depuration period. The oysters and shrimp were exposed to 14C-labeled test substance at a nominal concentration of 0.25 mg/L and a control group with dilution water only. The overall results for the two test species, oyster and shrimp, were essentially the same. The test substance did not bioaccumulate in oysters or shrimp (BCF <1).

Additionally, a field study is available (American Cyanamid Company, RES 99-059, 1999) in which the magnitude of dissipation of the test substance in non-target organisms is determined. The test substance did not bioaccumulate appreciable in bluegill, tilapia, catfish and crayfish.