.beta.-Alanine:pyruvate aminotransferase

Short-term toxicity to aquatic invertebrates

Description of key information

 EC50 values for daphnids ranged from 450 to greater than 1,000 mg/L.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

450 mg/L

Additional information

The results of aquatic toxicity tests that have been conducted on enzyme preparation by others demonstrate that they are not very toxic to aquatic organisms including daphnids. For example, HERA (HERA, 2005. Human and Environmental Risk Assessment on ingredients of household cleaning products) conducted a risk assessment on three very different classes of enzymes( enzyme preparations of alpha amylase, cellulase and lipase) commonly found in household products. EC50 values for daphnids ranged from 450 to greater than 1,000 mg/L.

In 2002, an extensive review on enzymes was published entitled Collection of Information on Enzymes. The review was supported by the Directorate General Environment of the European Commission and conducted by the Austrian Federal Environment Agency. Based on the studies reviewed, the report concluded that “enzymes seem unlikely to be dangerous to the aquatic environment due to their ready biodegradability and the low effects on aquatic life”. Although the data base and number of enzymes reviewed were limited, the pattern of toxicity was clear and the authors were able to reach the above conclusion based on the studies reviewed. There are several mitigating factors which indicate that both aquatic toxicity due to the presence of enzymes is unlikely to occur and that any observed toxicity could be the result of physical effects due to the complex composition of enzyme preparations which are classified at UVCB substances (Unknown or Variable Composition). The use aquatic toxicity studies with daphnids in general are problematic for testing with large complex macromolecules like enzymes. This is particularly true for the testing of enzyme preparations which are mixtures and not pure substances. Daphnids are very sensitive to osmotic stress and other physical factors in their environment quite unrelated to any toxicological properties of the substance in question. Previous use of daphnids for testing complex mixtures such as leachates have resulted in the need to modify the testing protocol to buffer for pH and other physical factors in the test material media. Round robin studies had to be performed to adapt the test protocol and still the results have been the subject of interpretation and misinterpretation. The acute toxicity with daphnids is not a good test model for enzyme preparations.

Reference: HERA Human and environmental risk assessment on ingredients of household cleaning products - alpha-amylases, cellulases and lipases. 2005.