Isovaleryl chloride

Toxicity to aquatic algae and cyanobacteria

Description of key information

Parent compoun isovaleryl chloride: No data available.
Hydrolysis product isovaleric acid: No data available.
Because there are no data available for the parent compound and its hydrolysis product, the toxicity to aquatic algae and cyanobacteria is assessed
on the results of the structurally similar substance isobutyric acid.
Isobutyric acid: Acutely harmful to aquatic algae and cyanobacteria.
Hydrolysis product HCL: Acutely very toxic for algae and cyanobacteria (pH-dependent).

Key value for chemical safety assessment

EC50 for freshwater algae:

50.6 mg/L

EC10 or NOEC for freshwater algae:

31.7 mg/L

Additional information

Parent compound isovaleryl chloride and hydrolysis product isovaleric acid:

Isovaleryl chloride (CAS 108 -12 -3) rapidly decomposes in water and forms HCl (CAS 7647 -01 -0) and isovaleric acid (CAS 503 -74 -2). Since there are neither experimental data available for isovaleryl chloride nor for its hydrolysis product isovaleric acid, toxicity to aquatic algae and cyanobacteria is assessed on read across to the structurally similar substances isobutyric acid (CAS 79 -31 -2) and valeric acid (CAS 109 -52 -4).

Structurally similar substances:

The toxicity of isobutyric acid to the algae Scenedesmus subspicatus was tested according to German Industrial Standard Guideline DIN 38412 part 9. The 72 -h E_rC₅₀ was determined to be 53.9 mg/L and the NOEC was 31.3 mg/L (nominal, not neutralized; BASF, 1990/2011, report no. 2/0244/89). Based on the results of the read across substance isobutyric acid, the test substance isovaleryl chloride is assessed to be acutely harmful to aquatic algae and cyanobacteria.

The analogue substance propionic acid (CAS 79 -09 -4) was tested on Desmodesmus subspicatus in a study following the German Industrial Standard DIN 38412, part 9 (similar to OECD 201). The 72 -h ErC10 and ErC50 values were determined to be 31.92 and 48.7 mg/L, respectively (BASF, 1987; report no. 1103/87).

The analogue substance 2 -ethylhexanoic acid (CAS 149 -57 -5) was also studied under similar conditions. The corresponding ErC10 and ErC50 values were 31.94 and 49.28 mg/L, respectively (BASF, 1989; report no. 2/0949/88).

The geometric mean of the ErC10 and ErC50 of the three studies is 31.7 and 50.6 mg/L, respectively.

These results are supported by company data published in the ECHA REACH dossier for valeric acid:

The toxicity of the hydrolysis product valeric acid (CAS 109 -52 -4) to Pseudokirchnerella subcapitata was determined according to OECD 201 (Alga, Growth Inhibition Test). Based on growth rate and initial measured concentrations, the 72 -h EC₅₀ was 29.3 mg/L. The NOEC was 12.6 mg/L (ECHA, 2011).

Hydrolysis product hydrochloric acid (HCl):

The hydrolysis product hydrochloric acid (HCl) was tested in an algae growth inhibition test according to OECD 201 with Pseudokirchneriella subcapitata. The 72-h ErC₅₀was 0.492 mg/L (acid equivalent to pH 5.3), the 72 -h NOEC was 0.097 (acid equivalent to pH 6; OECD, 2002).