Benzotriazole

Endpoint summary

Description of key information

For the assessment of 1H-Benzotriazole a complete dataset for the aquatic environment is available. In total, 10 short-term studies with fish, invertebrates and algae as well as 5 studies on long-term effects on all three trophic levels are reported. in addition, the toxicity to microorganisms was investigated in three studies.
The calculation of the PNECs is based on the long-term effect value of an OECD 211 study exposing D. galeata and an OECD 209 study exposing activated sludge. Potential endocrine disrupting effects were examined in a sexual development study with fish. In the study no endocrine effect was observed up to the maximal test concentration of 11.0 mg/L.

Additional information

The effect concentrations in the short-term fish studies (OECD 203 and 236) are in the range of 170-180 mg/L with one FET study showing significantly less effect concentrations. This study could not be fully evaluated due to missing information. The initial phase of the OECD 234 long-term fish study convers the endpoints of a standard OECD 210 long-term fish test. From the observations a NOEC of 1.07 mg/L based on the post-hatch survival was calculated.
In the short term tests with aquatic invertebrates effect concentrations in the range of 91-137 mg/L were observed for tests exposing D. magna. In one study D. galeata was exposed to BTA showing an effect concentration of 15.8 mg/L. As this species is significantly smaller than D. magna this difference is considered as reason for the lower effect concentration. A similar situation can be seen in the long-term studies with invertebrates. The calculated effect concentration for D. magna is about 25 mg/L (second study showed no effects due to lower selected concentration range), and the effect concnetration in D. galeata is calculated at 0.97 mg/L.
In studies with algae the short-term values range from 97-231 mg/L and the long-term values were observed in the range of 1.18 to 58 mg/L. In addition, a study with higher aquatic plants (L. minor) is available showing an EC10 (7d) of 3.94 mg/L.
Based on the available effect concentrations all trophic levels are considered to be similar sensitive to 1H-Benzotriazole, respectively no specific mode of action was identified. The short-term effects are above 10 mg/L (D. galeata), respectively in the range of 100 mg/L or above (fish, D. magna, algae). The long term effects value are in the range of 1 mg/L. In conclusion, 1H-Benzotriazole is considered moderately toxic for aquatic organisms. The same conclusion can be made for microorganisms in STPs considering the results from the available tests.