Glutaral

Biodegradation in water: screening tests

Description of key information

Glutaraldehyde is readily biodegradable and it has a potential to biodegrade in the marine environment.

Key value for chemical safety assessment

Biodegradation in water:

readily biodegradable

Additional information

The ready biodegradability of glutaraldehyde 50% was tested in the DOC Die Away-Test (ISO 7827) according to OECD 301A (new version). The biodegradation of 20 mg/l DOC of the test substance was monitored for 28 days. 90-100% of the initial glutaraldehyde (20 mg/L DOC) was eliminated from water after 28 days (BASFAG 93/0406/21/1). Glutaraldehyde fulfilled the pass criteria in this test for ready biodegradability, which include the concept of the 10-days window. In conclusion, as neither toxicity nor abiotic degradation was observed in the controls at the concentration tested and further, the reference substance fulfilled the validity criteria, glutaraldehyde can be regarded as readily biodegradable in the test system used.

The biodegradability of glutaraldehyde 50% in marine water was investigated according to the marine CO2-Evolution Test (ISO 16221 comparable to OECD Guideline 306); the inoculum was seawater from the North Sea (BASFAG 01/0411/32/1). The biodegradation of glutaraldehyde was evaluated at an initial concentration of 32 mg/L. A previous test carried out with 100 mg/L, has shown clear toxic effects in the inhibition assay. The CO2 evolution was considered as parameter indicative of marine biodegradation; the degree of marine biodegradation was expressed as CO2 of the theoretical CO2 (ThCO2). At an initial test concentration of 32 mg test substance/L equivalent to 10 mg/L TOC, the degree of biodegradation ranged from 90 to 100% at the end of incubation period (70 days). There were no indications for abiotic elimination processes: therefore, glutaraldehyde can be regarded as ultimate biodegradable under marine water conditions.