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 2-chlorobutane was tested in a closed bottle test to show 14% biodegradation after 28 days, recalculated. However, in this test the positive control sodium benzoate only achieved 40% biodegradation within 28 days which is fairly low, indictaive of low inoculum activity. The substance did not show an inhibitory effect on the inoculum in this test. Hence, this test of of limited suitability and inherent biodegradability may be assumed.
This is supported by the hydrolysis test of sec-butylchloride, which forms with a half life of approx. 60 hours at 27 °C butan-2-ol as the direct hydrolysis product being readily biodegradable. Thus it can be assumed that 2-Chlorobutane abiotically hydrolyses to 2-butanol which is radiply biodegraded.

Key value for chemical safety assessment

Biodegradation in water:
inherently biodegradable

Additional information

The substance 2-Chlorobutane was tested in an OECD 301D closed bottle test and found to be not readily biodegradable (14% biodegradation after 28 days, recalculated). However, in this test the positive control sodium benzoate only achieved 40% biodegradation within 28 days which is fairly low. The substance did not show an inhibitory effect on the inoculum in this test.

However, it should be noted that Butan-2-ol (sec-butylalcohol) is readily biodegradable. Butan-2-ol is the direct hydrolysis product of sec-butylchloride, which forms as shown in the hydrolysis test according to OECD 111 with a half life of approx. 60 hours at 27 °C in the environmentally relevant pH range of 5 -9. Thus it can be assumed that 2-Chlorobutane abiotically hydrolyses to 2-butanol which is radiply biodegraded.