4-chlorobutyryl chloride

Short-term toxicity to aquatic invertebrates

Description of key information

Parent compound 4-chlorobutyryl chloride: No data available.
Hydrolysis product 4-chlorobutyric acid: No data available.
Because there are no data available for the parent compound and its hydrolysis product, the short-term toxicity to aquatic invertebrates is assessed on the results of the structurally similar substance isobutyric acid (weight-of-evidence approach).
Isobutyric acid: Acutely harmful to aquatic invertebrates.
Hydrolysis product HCL: Acutely very toxic for aquatic invertebrates (pH-dependent).

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

51.25 mg/L

Additional information

Parent compound 4 -chlorobutyryl chloride and hydrolysis product 4 -chlorobutyric acid:

No data are available for 4 -chlorobutyryl chloride (CAS 4635 -59 -0). The substance rapidly decomposes in water and form HCl (CAS 7647 -01 -0) and 4 -chlorobutyric acid (CAS 627 -00 -9). No experimental data are available for both substances, therefore the short-term toxicity to aquatic invertebrates is assessed on the basis of a weight-of-evidence approach which considers is based on the analogue substances 3 -chloropropionic acid (CAS 107 -94 -8), butyric acid (CAS 107 -92 -6) and isobutyric acid (CAS 79 -31 -2).

3 -Chloropropionic acid:

The available data are not valid. The short-term toxicity to Daphnia magna was tested after 24 h of exposure instead of 48 h, which is the standard exposure according to recent guidelines. Nevertheless, the data will be used in a weight-of-evidence approach to demonstrate the pH-influence of the acid on the mobility of the Daphnids. The 24 -h EC50 was determined to be 109 mg/L. After neutralisation the 24 -h EC50 was 1366 mg/L (Trénel & Kühn, 1982).

Butyric acid:

For butyric acid no valid experimental data are available. Results as cited in Onitsuka et al. (1989) and Bringmann & Kuhn (1982) are not suitable since exposure duration is 24h instead of 48h. Nevertheless, the study of Bringmann & Kuhn can be used to show that the toxicity of butyric acid to Daphnia magna is likely influenced by pH effects due to pH-shift. Tested under not neutralized conditions the observed 24 -h EC50 was determined to be 55 mg/L. When the test medium was neutralized the obtained 24 -h EC50 was 1950 mg/L.

Isobutyric acid:

With the structurally similar substance isobutyric acid (CAS 79 -31 -2) the acute Daphnia toxicity was tested in a non-GLP study following the German Industrial Standard DIN 38412, part 11 (similar to OECD 202). The EC50 (48-h) was reported as 51.25 mg/L (BASF, 1989,1/0244/2/89-0244/89).

In a weight-of-evidence approach based on the results summmarised above, 4 -chlorobutyryl chloride and its hydrolysis product 4 -chlorobutyric acid are expected to be acutely not harmful to aquatic invertebrates after pH-adjustment. Nevertheless, the assessment will be based on the lowest valid EC50 of 51.25 mg/L.

Hydrolysis producthydrochloric acid (HCl):

The hydrolysis product hydrochloric acid (HCl) was tested in a semi-static acute toxicity test according to OECD 202 withDaphnia magna. The 48-h EC50was 0.492 mg/L (acid equivalent to pH 5.3; OECD, 2002).