1,2,3-Propanetriol, mono- and diformates

Short-term toxicity to fish

Description of key information

LC50 (96 h), ethylene glycol diformate: 42 mg/L for Oncorhynchus mykiss (nominal; OECD 203), corresponding to 42.8-52.7 mg/L 1,2,3-propanetriol, mono- and diformates.

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Effect concentration:

42.8 mg/L

Additional information

One experimental study investigating the short-term toxicity of ethylene diformate (CAS 629-15-2) to fish is available (Harris, 2013). The study was performed according to OECD 203 under GLP conditions using the rainbow trout Oncorhynchus mykiss. A range-finding study with three concentrations up to 100 mg/L resulted in complete mortality at 100 mg/L. Thus, the definite study was performed with five different concentrations up to 100 mg/L under semi-static conditions. The substance was found to hydrolyse in test medium with an approximate half-life of 11 h. The analytical measurement with gas chromatography (GC) revealed a decline in test concentration. Therefore, the possible effects of the parent substance and the hydrolysis products were tested in this study. After an exposure of 96 h, an LC50 of 42 mg/L and a NOEC of 32 mg/L resulted. Given that complete hydrolysis of the parent test item did not occur, and that toxicity cannot be attributed to the parent test item, the degradation product, or a mixture of the two, it was considered appropriate to calculate the results based on nominal parent test item concentrations only.

The result for ethylene glycol diformate is used for the assessment of the substance 1,2,3-propanetriol, mono- and diformates in a read-across approach (for details and justification please refer to the read-across report).

The LC50 of 42 mg/L ethylene glycol diformate (M= 118.1 g/mole) corresponds to 42.8-52.7 mg/L 1,2,3-propanetriol, mono- and diformates (M = 120.1-148.11 g/mole).

In addition, available data on sodium formate are used as supporting information for the following reasons:

1,2,3-propanetriol, mono- and diformates is used as an acidity regulator in textile treatment baths. Due to rapid hydrolysis release of this substance to wastewater (and further to the environment) is essentially zero. The substance is added to treatment baths of basic pH, and consequently shifts the pH to neutral or slightly acidic values. In the technical process (textile treatment) the substance reacts completely, yielding glycerol and formic acid/formate. The relevant breakdown product to be considered in the risk assessment hence is formic acid in dissociation equilibrium with formate. Glycerol is of no environmental concern and does not require to be assessed. Also the formate ion is not environmentally hazardous as demonstrated by the acute 96-h LC₀ for Pimephales promelas of 1000 mg/L. In the relevant pH range (approximately neutral) the equilibrium is shifted towards the free formate. Use of data on sodium formate is therefore justified.