Lysozyme (chicken egg white)

Short-term toxicity to aquatic invertebrates

Description of key information

Expected non-toxic to aquatic invertebrates.

Additional information

No specific information exists on the short-term toxicity of Lysozyme to aquatic invertebrates.

However considering that Lysozymeis naturally occurring in many organisms, including aquatic organisms^[6] it is expected to be non-toxic for aquatic life.

Below are reported some data available in the HERA documentation on Cellulase, Lipase and Subtilisins (Protease) in order to support this consideration.

- Cellulase: IC50 Daphnia magna at 24 and 48-h > 1000 mg active enzyme protein (aep)/L. At 0.6 g/L no immobilized daphnia were observed ^{[1 -2]}

- Lipase: IC50 Daphnia magna at 24-h > 1000 mg aep/L. Analysis of samples revealed a significant loss of enzyme activity during the 24 h period. The mean value for enzyme activity was 82% after 2 h and 76% after 24 h. ^{[1 -2]}

- Maxatese P: EC50 on Gammarus salinus at 24 -h: 200 mg/L (probably not based on aep) ^{[3 -4]}

- Subtilisin (Maxatase P): EC50 on Tubifex sp. at 24 -h: 50 mg/L (probably not based on aep ^{[3 -4]}

- Subtilisin: Daphnia Magna EC50 at 48-h: 160 mg/L (probably not based on aep) ^{[3 -5]}

The existing data on the acute toxicity to aquatic invertebrates of enzymes reported values of the E(I)C50 in a range between 50 - 1000 mg/L.

Data by Mann (1971^[4]) and Schöberl and Huber (1988^[5]) are not conducted in compliance of the standard test methods, thus they were evaluated by HERA as not reliable and, hence, not suitable for the aquatic toxicity assessment.

Nevertheless, in general the available data are in agreement to describe enzymes as non-toxic to aquatic invertebrates.

In conclusion, on the basis of the comparison with other enzymes, Lysozyme may be considered as non-toxic to aquatic invertebrates. Since data available are not specific for Lysozyme, it is preferred to make a qualitative assessment.

Reference

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

[2] Greenough RJ, Everett DJ (1991) Safety evaluation of alkaline cellulase. Food and Chemical Toxicology 29: 781-785.

[3] HERA Human and environmental risk assessment on ingredients of household cleaning products - Subtilisins (Proteases). Edition 2.0. 2007.

[4] Mann H (1971) Untersuchungen über die Wirkung von Waschmittelenzymen auf Fische und andere Wasserorganismen. Archive der Fischerwissenschaft 22; 146-154.**

[5] Schöberl P and Huber L, (1988) Ökologisch relevante Daten von nichttensidischen Inhaltsstoffen in Wasch- und Reinigungsmitteln. Tenside Detergents 3/4: 86-107 **

[6] Oystein Lie, Oystein Evensen, Anita Sorensen, Ellen Froysadal. Study on lysozyme activity in some fish species. Dis. aquat. Org. 6: 1-5, 1989

**Reported as Klimisch 4 in the HERA document.