Registration Dossier

Diss Factsheets

Ecotoxicological information

Toxicity to aquatic algae and cyanobacteria

Currently viewing:

Administrative data

Link to relevant study record(s)

Description of key information

Acute very toxic for aquatic algae.

Key value for chemical safety assessment

Additional information

Two growth inhibition tests on freshwater algae were performed. In the first test the inhibitory effect of glutaraldehyde 50% on cell multiplication of unicellular green algae was determined according to Directive 92/69/EEC, C.3. The ErC50 of glutaraldehyde to Scenedesmus suspicatus after 72 hours exposure was assigned as 0.6 mg a.i./L referring to the active ingredient;. The effect on biomass of test organism showed an EC50 value of 0.375 mg a.i./L (BASF AG 97/0329/60/1).

The second algae growth inhibition test was performed according to DIN 38412, part 9 (BASF AG 01/88/0011). The ErC50 of glutaraldehyde to Scenedesmus subspicatus was determined as 0.61 mg a.i./L after 72 hours exposure, indicating that glutaraldehyde is toxic to green algae. The NOEC was < 0.0391 mg a.i./L and confirmed the toxicity values obtained in the first study. Concerning the lack of analytical controls the second non-GLP study has a lower validity.

In a review article by Leung (2001) data on the toxicity of glutaraldehyde on algae, especially on marine algae Skeletonema costatum were published. The results of a guideline study performed according to ISO 10253 investigating effects of glutaraldehyde on growth rate and biomass can be regarded as reliable as the test performance is scientifically acceptable: Algae were exposed to glutaraldehyde for 72 hours and daily samples were taken for determining the cell density by direct counting. The average growth rate was determined from the straight section of the growth curve. The ErC50 and EbC50 of glutaraldehyde to Skeletonema costatum was determined as 0.92 mg a.i./L and 0.61 mg a.i./L respectively. The NOEC was determined at 0.33 mg a.i./L.

Regarding the aquatic toxicity of glutaraldehyde algae were evaluated to be the most sensitive organism. In conclusion, glutaraldehyde is highly toxic to algae, whereas the sensitivity of marine and freshwater algae to glutaraldehyde can be considered as similar.