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Environmental fate & pathways

Biodegradation in water: screening tests

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Description of key information

The test substance is readily biodegradable

Key value for chemical safety assessment

Biodegradation in water:
readily biodegradable

Additional information

Ready biodegradability tests for several alkyl sulfates are available. Based on the results of screening tests for biodegradation in water it can be concluded that alkyl sulfates with carbon chain length of C8-C18 are readily biodegradable according to OECD criteria (OECD SIDS 2007).

Since no reliable biodegradability tests are available for C12-13AS Na (CAS 1231880-35 -5), in accordance to Regulation (EC) No. 1907/2006 Annex XI, 1.5 a read-across to another structurally related category members was conducted. Read-across data on the following substances was used: CAS 91783-232 and CAS 68585-47-7.

In a study conducted by Busetto (1993, Sasol) the biodegradation of the CAS-No. 91783 -23 -2 was tested in an OECD 301 E study. This mixture consists of C12 and C13 alkyl sulfates and is hence comparable to the test substance (typical composition 38 - 78% C12 and 22 - 62% C13, linear and branched). In the test CAS-No. 91783 -23 -2 was found to be readily biodegradable. This result is supported by an OECD 301 B study using CAS-No 68585 -47 -7 (Schaefer, 2005, Sasol) which is also used for a read-across. Mineralisation in this study was 75.7% after 28 days of exposure.

Further in a test on the inherent biodegradability of alkyl sulfates according to OECD guideline 302 A (SCAS test; Neven, 1991, Procter & Gamble) the C12, C13 mixture (CAS 91783 -23 -2) was tested. After 21 days of exposure 95.3% of the DOC were removed.

Due to structural and property similarities with the tested category members it can be concluded that C12 -13AS Na (CAS 1231880 -35 -5) can be considered as readily biodegradable.