Registration Dossier

Environmental fate & pathways

Bioaccumulation: aquatic / sediment

Currently viewing:

Administrative data

Link to relevant study record(s)

Description of key information

A fish dietary bioaccumulation study was performed under OECD 305 guidelines (OECD 2013) to determine the tissue elimination rate constant (k_depuration) for the test substances in rainbow trout (Oncorhynchus mykiss).  Data collected in this study were used to derive the elimination half-life (t½), the assimilation efficiency (α), the biomagnification factor (BMF) and the lipid-normalized biomagnification factor (BMF_L) for the test substance.  The study included a 12-day uptake phase and 21-day depuration phase.  This OECD 305 fish dietary fish bioaccumulation test is especially suitable for determining the bioaccumulation potential of substances with very low water solubility such as the test substance.

The mean concentration of the test substances in the fish tissue at the end of the uptake phase  (mean feed conc. of 630 ppm) was determined to be 1.0 µg/g.  Mean lipid content of tissues collected at Day 12 Uptake and Day 21 Depuration was determined to be 2.93%.  No statistically significant differences were observed in mortality or growth rate for the treatment groups when compared to the control group.  

The test substance had lipid-normalized biomagnification factor of 0.04, an assimilation efficiency of 0.79%, and the elimination half-life was 22 days.

The assimilation efficiencies (α) value for the test substance indicates uptake of the test substances.  More importantly, the depuration kinetic rate constant and elimination half-lives (22 days) indicate that the test substance is effectively cleared from the fish (50% clearance within about 22 days), most likely as a result of metabolism.  The experimental lipid-normalized BMF value (0.04) indicates that the test substance is not expected to biomagnify or bioaccumulate in rainbow trout under the conditions of the OECD 305 fish dietary bioaccumulation test (Burkhard, et al. 2011).  

QSAR model results further support this conclusion. The test substance has a low potential to bioconcentrate or bioaccumulate, based on a calculated BCF value of 0.893 and calculated BAF values of 0.893 -0.9475 for the major components from EPI Suite  v4.0.

Key value for chemical safety assessment

Additional information