Acid chlorides, coco

Short-term toxicity to fish

Description of key information

With high probability acutely not harmful.
Hydrolysis product HCl: Acutely toxic for fish (pH-dependent).

Additional information

Regarding the information requirements of REACH, for this tonnage band a study with fish is not required.

 

Disregarded study with acid chlorides, coco:

The substance was tested in a static system according to OECD 203 in a GLP guideline study using Danio rerio as test species (BASF, 1998; report no. 17F0239/965038). The nominal test substance concentrations exceeded the water solubility (46.4 to 1000 mg/L). The test solutions were milky and the test substance was flocculated with increase in test concentration. The test substance concentrations were analytically verified in filtered and unfiltered samples. The 96 -h LC50 was ca. 100 mg/L (based on nominal concentrations), ca. 27 mg/L (based on geometric mean measured concentrations in unfiltered samples) and ca. 9 mg/L (based on geometric mean measured concentrations in filtered samples). However, the results are likely affected by the low oxygen content measured after 24 h in the aquaria containing the test substance solutions (nominal concentrations of >= 46.4 mg/L), which was clearly below the required level of 60% of the maximum saturation level (ASV). Hence, the study is not valid and not considered in the evaluation of the acute fish toxicity.

Therefore, the assessment of the acute toxicity to fish is conducted on weights of evidence (WoE) based on the following experimental data:

Lauroyl chloride:

The toxicity of lauroyl chloride (CAS 112-16-3) to O. mykiss was tested according to OECD 203. The 96-h LC50 was determined to be 191 mg/L (nominal, not neutralised; BASF 1987; report no. 12F0214/875173). Lauroyl chloride decomposes rapidly in water to form lauric acid (CAS 143-07-7) and hydrochloric acid. Therefore the test organisms were mainly exposed to the hydrolysis product lauric acid. The test item concentrations were not analytically verified. From the second day on, undissolved test material was visible on the water surface increasing with test concentration. This was probably due to the formation of lauric acid which is less water soluble. The lethal concentration lies therefore above the water solubility limit of lauric acid.

 

Palmitoyl chloride:

There is a fish study available for palmitoyl chloride (BASF AG, 1998). Palmitoyl chloride hydrolyses rapidly in water therefore fish are mainly exposed to its hydrolysis product, palmitic acid.

Test concentrations were clearly above the solubility limit of palmitoyl chloride and palmitic acid as insoluble test material was visible and the test solutions were cloudy. Test concentrations were analytically verified. No toxic effects within the range of water solubility were observed. The 96 -h LC50 was determined to be 115 mg/L.

 

Octanoyl chloride:

The acute toxicity on fish was studied according to OECD 203 with Danio rerio under static conditions (BASF AG, 1998). The test item was octanoyl chloride, which is expected to hydrolyse rapidly. The test item concentrations were analytically verified, but are based on the hydrolysis product octanoic acid. The test item concentrations initially agreed within the precision of the method with the expected concentrations, although the results of the two highest concentrations were inhomogeneous. Mortality occurred only in the two highest test solutions in the first hour of exposure (215 and 464 mg/L, nominal). Therefore, the LC50 was calculated based on the initially measured concentrations: 96-h LC50 = 157 mg/L.

Structurally similar substances:

Neodecanoyl chloride (CAS 40292 -82 -8):

The substance was tested according to OECD 203 (1992) under GLP conditions with Brachydanio rerio. The 96 -h LC50 was 138 mg/L (BASF AG, 1999).

Isooctadecanoyl chloride (CAS 78851 -82 -8):

In a BASF study conducted in 2005 the toxicity of the test substance on the zebra fish was determined in a limit test. The LC50 based on nominal concentrations was > 100 mg/L. However, in this test the analytical concentration verification resulted in test item concentrations below the limit of quantification. This was determined already in samples taken at the start of the study. Whether the test substance loss was already completed at the start of the test or during the time till analysis could not be determined. It is expected, that the test substance is of very poor water solubility. Dissolved test substance will rapidly hydrolyse to the corresponding acid which in turn is also of very low solubility.

 

Hydrolysis product hydrochloric acid (HCl):

HCl was tested in a semi-static acute toxicity test according to OECD 203 with Cyprinus carpio. The 96-h LC50 was 4.92 mg/L (acid equivalent to pH 4.3; OECD, 2002).

 

Based on the data available for its major components and structurally similar substances, it can be concluded that the substance acid chlorides, coco (CAS 68187-89-3) is with high probability acutely not harmful to fish.

The acute toxicity of the hydrolysis product hydrochloric acid to fish is pH-dependent.