Registration Dossier

Environmental fate & pathways

Biodegradation in water: screening tests

Currently viewing:

Administrative data

Link to relevant study record(s)

Description of key information

The substance was found to be ready biodegradable during testing.

Key value for chemical safety assessment

Biodegradation in water:
readily biodegradable

Additional information

In a key study, the test item D-Panthenol was investigated for its ready biodegradability in a "28-Day DOC Die-Away Test" according to the Commission Regulation (EC) No 440/2008, C.4-A, the Commission Directive 92/69EEC, C.4-A and the OECD Guideline for Testing of Chemicals, No. 301 A (1992). In accordance with the testing guidelines the test was ended after 21 days since the biodegradation curves of the test and the reference item had reached a plateau over at least three determinations.

In the test flasks, containing the test item D-Panthenol and activated sludge (inoculum), the mean concentrations of dissolved organic carbon (DOC) rapidly decreased by 97% of the initial values within the test period of 21 days. Therefore, D-Panthenol was found to be biodegradable under the test conditions. Moreover, the pass level for ready biodegradability (70 % removal of DOC in a 10-day window within a 28-day period) was reached.

The test item D-Panthenol is therefore readily biodegradable under the test conditions. The reference item sodium benzoate was completely (> 90 %) biodegraded within seven days of exposure, thus confirming suitability of the activated sludge.   In the toxicity control, containing the test item, the reference item sodium benzoate and activated sludge (inoculum), the initial DOC decreased by 97% within 14 days of exposure. Thus, according to the test guidelines the test item was not inhibitory to activated sludge at the tested concentration of 54 mg/L because degradation was >35% within 14 days (Harlan, 2011).

In a supporting study evaluating the inherent biodegradability in the Zahns-Wellens/EMPA test according to OECD guideline 302 B, the test substance D-Panthenol had a much shorter adaption-phase as compared to the reference substance diethylene glycol. The degree of biodegradation for D-Panthenol at the end of the test after 15 days was 100 %. The plateau-phase was reached after 12 days. The length of the degradation-phase of the reference substance was in the same range as the one of the test substance.

The physico-chemical degradation of D-Panthenol (without inoculum) was 0 % after 28 days. In the control experiment the reference substance, diethylene glycol, was biodegraded by 100 % after 15 days (DOC comparison). Thus, the used inherent biodegradability test (Zahn-Wellens test) shows evidence for ultimate biodegradation of D-Panthenol (DSM, 1991).