Sodium nonyl sulphate

Biodegradation in water: screening tests

Description of key information

Readily biodegradable according to OECD criteria: 92% after 30 days (OECD 301 D)

Key value for chemical safety assessment

Biodegradation in water:

readily biodegradable

Additional information

Since no reliable biodegradation test with C9AS Na (CAS 1072-15-7) is available, in accordance to Regulation (EC) No. 1907/2006 Annex XI, 1.5, a read-across to another structurally related category member was conducted. Read-across data from C10AS Na (CAS 142-87-0) were used, since the C10 homologue will represent the worst case scenario for the C9 homologue.

The key, non-GLP study assessing biodegradation of C10AS Na (CAS 142-87-0) was performed according to OECD guideline 301 D (Richterich 2001). Effluent of the sewage treatment plant handling predominantly domestic sewage was used as inoculum. The initial concentrations of the test substance were 2 mg/L and 5 mg/L. Biodegradation of 98% measured as oxygen demand was observed after 30 days at the initial concentration of 2 mg/L and 92% at the concentration of 5 mg/L. The test substance was biodegraded by more than 60% in both cases within five days. Based on these results it can be concluded that C10AS Na (CAS 142-87-0) is readily biodegradable. This result was confirmed by a supporting non-GLP study performed according to OECD 301 E guideline (Sanchez Leal et al. 1991). Biodegradation reached ca. 90% after 8 days of testing. Based on the above data it can be concluded that C10AS Na (CAS 142-87-0) is readily biodegradable according to OECD criteria.

Due to structural and property similarities with the tested category member, it can be concluded that the above results apply also to C9AS Na (CAS 1072-15-7).