2,2'-azobis[2-methylpropionamidine] dihydrochloride

Endpoint summary

Additional information

For the endpoints short-term toxicity to fish and invertebrates a static and a semi-static study is available. Due to the instablity of the substance and the missing analytical monitoring in the static studies the observed, respectively not observed, effects cannot be equivocally assigned to the substance itself, the transformation products from abiotic processes or a mixture from both. In the semi-static study exposing fish a threshold value of 570 mg/L is calculated. In the static study no effects in all test concentrations are observed. Based on these observations a low acute toxicity of the substance itself and its transformation products is concluded.

In the studies exposing Daphnia magna threshold values of EC50 (48 h) 3.5 mg/L (semi-static) and 4.84 mg/L (static) for aquatic invertebrates are determined. Based on these findings an increased acute toxicity to invertebrates through the transformation products cannot be determined. In the long-term study on toxicity on reproduction of Daphnia no effects on reproduction, parental growth and survival up to a concentration of 2.7 mg/L (TWA) could be observed. Exposure to a TWM concentration of 8.2 mg/L induced significant inhibition of the reproductive capacity of the parental daphnids. This effect is attributable to complete mortality of the parental daphnids at this concentration. Based on the observations a value of EC10 (21d) 3.5 mg/L for reproduction is determined.

For the endpoint toxicity to algae a static study is available only. As analytical monitoring is missing in the study the key component for the observable effect on the inhibition of growth cannot be unequivocally assessed. In the study a threshold value EC50 (72h) of 0.5 mg/L is observed. Additionally, a semi-static long-term study exposing Lemna minor is available indicating a significantly less sensitivity of higher aquatic plants to the substance.

 

Summarizing the available information it can be concluded that aquatic invertebrates and unicellular algae are significantly more sensitive to the toxic effects of the substance itself and/or its transformation products compared to fish and higher aquatic plants. Additionally, the toxicity of the substance and its transformation products seems to be similar. Therefore, the available information are considered to be sufficient for the assessment and no further assessment of the transformation products is necessary.

 

Although the trigger component for the effects observed in the static algae study is unequivocally assignable, this value is used in the further assessment and for the classification and labelling of the substance.