Vinyl chloroacetate

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

other: Expert Assessment

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: An expert assessment was performed based on the literature data of the degradation products of VCA

Justification for type of information:

An experimental study to determine the toxicity of VCA to aquatic invertebrates was not considered necessary, nor scientifically justified, since the registered substance is expected to undergo rapid abiotic transformation upon contact with water. Therefore the degradation products of VCA were assessed instead in order to calculate an EC50 value for VCA.

Qualifier:

no guideline required

Principles of method if other than guideline:

An expert assessment was performed based on literature data on the degradation products of VCA.

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

ca. 98.56 mg/L

Remarks on result:

other: Expert assessment based on literature data on the degradation products

Validity criteria fulfilled:

not applicable

Conclusions:

It is not scientifically necessary to perform a study on the toxicity of VCA to aquatic invertebrates, since it hydrolyses rapidly in water to form Chloroacetic acid and Acetaldehyde. The aquatic toxicity of VCA is expected to be driven by the toxicity of these degradation products. The 48 hour EC 50 for VCA was calculated to be 98.56 mg/L which is the lowest calculated EC50 value based on the existing literature data across both degradation products.

Executive summary:

VCA has been found to hydrolyse rapidly (t1/2 12 hrs) upon contact with water to give two main degradation products: Chloroacetic acid (CAS 79-11-8 / EC 201-178-4) and Acetaldehyde (CAS 75-07- 0 / EC 200-836-8). Subsequently, the toxicity of VCA to aquatic invertebrates was determined by means of expert assessment, based on the ecotoxicity of its degradation products, for which substantial literature data is already available. A literature search was conducted to obtain a value for the toxicity of Chloroacetic acid and Acetaldehyde to aquatic invertebrates. Considering the uses of VCA, it is the toxicity to freshwater species that was considered.

The lowest calculated EC50 value was taken from across both degradation products, in order to take the most conservative approach. Chloroacetic acid was found to be the degradation product with the lowest EC50. For the purpose of the assessment it was assumed that VCA hydrolyses entirely into the two degradation products. The 48 hour EC50 value for chloroacetic acid is 77 mg/L. To produce this amount of chloroacetic acid, 98.56 mg/ mg/L VCA must be hydrolysed. Therefore, it can be concluded that the 48 hour EC50 for the toxicity of VCA to aquatic invertebrates is 98.56 mg/L.

Description of key information

It is not scientifically necessary to perform a study on the toxicity of VCA to aquatic invertebrates, since it hydrolyses rapidly in water to form Chloroacetic acid and Acetaldehyde. The 48 hour EC50 for the toxicity of VCA to aquatic invertebrates was calculated to be 98.56 mg/L based on the amount of VCA required to produce 77 mg/L of chloroacetic acid. This value is the lowest calculated EC50 value found across the two degradation products.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

98.56 mg/L