Oxydiethylene bis(chloroformate)

Short-term toxicity to fish

Description of key information

Parent compound: acutely toxic to fish.
Hydrolysis product diethylene glycol: With high probability acutely not harmful to fish.
Hydrolysis product HCl: Acutely toxic to fish (pH dependent).

Additional information

Parent compound:

The effect of DIBIS (CAS 106 -75 -2) to fish was tested in an acute toxicity test following the national industial standard DIN 38412 -15 which is similar to OECD 203. The test species was Leuciscus idus, the test conditions were static. Test concentrations were not analytically verified. The test solutions were prepared using acetone as solvent. The 96 -h LC50 was determined to be 1.78 mg/L (nominal; BASF AG, 1987; report no. 10F0531/875206). Toxic effects were most likely caused by the substance itself and not pH effect due to the hydrolysis product HCl as the pH of the test solutions remained close to the pH of the control solutions.

Hydrolysis product diethylene glycol (DEG, CAS 111 -46 -6):

The acute toxicity of DEG was tested in an acute toxicity study according to AMPHA Standard methods. The test species was Pimephales promelas. The test was performed under flow through conditions with analytical verification of test item concentrations. The 96 -h LC50 was determined to be 75200 mg/L (meas.; Geiger et al., 1990).

The low toxicity is supported by the results from a guideline study (Environment Canada EPS 1/RM/9, 1990/1996) with Oncorhynchus mykiss as test species. The fish were exposed to a series of 5 test concentrations and a control in a static approach. The 96 -h LC50 was 66000 mg/L (nominal, analytically verified; PTAC, 2006). This study was selected as supporting study as the study is not reported in such detail as the study by Geiger et al. (1990).

Based on the Substance Evaluation within CoRAP (ECHA, 2016), the highest sensitivity was observed in Dicentrarchus labrax (saltwater species): 96 -h EC50 = 40300 mg/L.

Hydrolysis product HCl (CAS 7647 -01 -0): The acute toxicity of hydochloric acid was studied accordding to OECD 203 using Cyprinus carpio as test species. The 96 -h LC50 was determined to be 4.92 mg/L (acid equivalent to pH 4.3; OECD, 2002).

For the hydrolysis product carbon dioxide no fish toxicity data are available.

Since oxidiethylene bischloroformate hydrolyses rapidly to diethylene glycol and the pH remained within acceptable limits, the clearly higher toxicity compared to diethylene glycol must be due to the reactivity of unhydrolysed oxidiethylene bischloroformate at the beginning of the test. The higher toxicity may be explained by reactions with nucleophiles (such as -NH2, -SH and –OH) on biological macromolecules.

Species	Results	Remarks	Reference
Leuciscus idus	96-h LC50 = 1.78 mg/L (nominal)	DIN 38412-15; Parent compound (DIBIS); reliability 2	BASF AG (1987)
Pimephales promelas	96-h LC50 = 75200 mg/L (meas.)	equivalent or similar to OECD 203; hydrolysis product (DEG); reliability 2	Geiger et al. (1990)
Cyprinus carpio	96-h LC50 = 4.92 mg/L (acid equivalent to pH 4.3)	OECD 202; hydrolysis product (HCl); reliability 2	OECD (2002)