Registration Dossier

Environmental fate & pathways

Endpoint summary

Administrative data

Description of key information

Additional information

In two reliable OECD 305E studies (Brachydanio rerio and Lepomis macrochirus) the BCF is ca. 600 for the parent compound (L. macrochirus, Van Dijk 1996 and B. rerio, Butte 1999). In the study with L. macrochirus it was observed that AHTN was rapidly transformed into more polar metabolites that were readily excreted (38-50% per day). The metabolites were water soluble (low log Kow).

Bioaccumulation factors estimated based on a rather large set of measured concentrations in fish and shellfish in field studies range between 50 and 670 with incidentally a higher value of 1421 for eel (summarised in the EU Risk Assessment Report 2008). Thus the BCF of both the parent AHTN and its biotransformation products were below the B-criterion of 2,000, and this is confirmed by the results of field studies.

 

In soil AHTN did not significantly bioaccumulate into earthworms (BSAF was 0.1 - 1.0) (Kinney 2008, not in EU RAR)

 

The EU Risk Assessment Report for AHTN (2008) also reviewed field data on biomagnification. In seven field studies on food chain accumulation including aquatic mammals and sharks as well as water birds around the northern hemisphere, The test item was included in the chemical analyses. In general low concentrations were detected in fish and mussel tissues (range 0.1 mg/kg lipids) and the concentrations of the test item in the predators were at or below the detection limits. It was concluded from these studies that no trend on increasing the test item concentrations at higher trophic levels could be detected (EU RAR 2008, § 3.1.7.2). So bioaccumulation of the test item in the food chain does not occur.