Methyl formate

Short-term toxicity to fish

Description of key information

The parent compound methyl formate along with its hydrolysis products formic acid and methanol are with high probability acutely not harmful to fish.

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Dose descriptor:

LC50

Remarks:

Methyl formate (CAS 107-31-3)

Effect concentration:

115 mg/L

Fresh water fish

Dose descriptor:

LC50

Remarks:

Hydrolysis product formic acid (CAS 64-18-6)

Effect concentration:

130 mg/L

Fresh water fish

Dose descriptor:

LC50

Remarks:

Hydrolysis product methanol (CAS 67-56-1)

Effect concentration:

15 400 mg/L

Marine water fish

Marine water fish

Dose descriptor:

LC50

Remarks:

Hydrolysis product formic acid (CAS 64-18-6)

Effect concentration:

1 700 mg/L

Additional information

Parent compound (CAS 107-31-3)

As determined in a static acute toxicity test following the German Industrial Standard DIN 38 412 part 15 using Leuciscus idus as test species the LC50 (96h) is estimated to be 115 mg/L, related to the nominal concentrations (BASF AG, 1989, rep. no.: 10F0797/88506, 1989).

Moreover, according to the available hydrolysis study for the substance, Methyl formates' susceptibility to hydrolysis increases with pH as well as with temperature. The hydrolysis half-life ranges from 410 h at pH 4 and 20 °C to less than 1 hour at pH 9 and 25 °C (OECD 111, BASF SE, 2010). Therefore, it can be concluded, that under environmentally relevant conditions (pH 7-9) the rapid hydrolysis will be the major fate process of the methyl formate due to the short half-life in aqueous solution. Therefore, this estimate may be of low relevance. Thus, the assessment of the short-term toxicity of the substance is also based on the available experimental data for the hydrolytic products: formic acid and methanol.

 

Hydrolysis product formic acid (CAS 64-18-6):

In a GLP guideline study according to OECD TG 203 using Danio rerio as test organism an LC50 (96h) of 130 mg/L was determined, related to the analytically verified nominal concentrations of ammonium formate (Fraunhofer, 2005, KEM-001/4-11).

Moreover, following a national British guideline using the marine species Scophthalmus maximus (turbot)) a GLP study was conducted with potassium formate. After 96 hours of exposure, a LC50 of 1700 mg/L was estimated, related to the nominal concentrations (Huntington, 1992, SLL 217(I)/920037).

The ammonium formate as well as the potassium formate are salts of the hydrolysis product formic acid. Formic acid changes the pH of the test solutions towards acidic conditions. When using ammonium and potassium salts as test substances, the pH is not affected. Therefore, both substances are suitable to investigate the sensitivity of fish towards formic acid under pH-neutralised conditions.

Hydrolysis product methanol (CAS 67-56-1):

In the key study conducted under flow-through conditions with Lepomis macrochirus the 96 -h LC50 was 15400 mg/L based on analytically verified concentrations (Poirer, 1986).

Overall, based on the available experimental data it can be concluded, that the parent compound methyl formate along with its hydrolysis products formic acid and methanol are with high probability acutely not harmful to fish.