Registration Dossier
Registration Dossier
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EC number: 201-187-3 | CAS number: 79-22-1
Short-term toxicity to fish
Administrative data
Link to relevant study record(s)
Description of key information
Parent compound: Acutely toxic to fish.
Hydrolysis product methanol: With high probability acutely not harmful to fish.
Hydrolysis product HCl: Acutely toxic to fish (pH dependent).
Key value for chemical safety assessment
Additional information
The parent compound methyl chloroformate hydrolyses rapidly to methanol (CAS 67-56-1), HCL (CAS 7647 -01 -0) and CO2 (CAS 124 -38 -9).
Parent compound: 96-h LC50 = 4.5 mg/L (Hoechst AG, 1981);
Hydrolysis product methanol: 96 -h LC50 ≥ 15400 mg/L (OECD, 2004);
Hydrolysis product HCl: 96 -h LC50 = 4.92 mg/L (OECD, 2002). These data have not been taken into consideration to evaluate aquatic toxicity as observed effects are caused by a pH-shift in the test medium.
Since methyl chloroformate hydrolyses rapidly to methanol (DT50 < 10 min at 25 °C and pH 7) and the pH in the key study test remained within acceptable limits, the clearly higher toxicity compared to methanol must be due to the reactivity of unhydrolysed methyl chloroformate 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 |
LC50 (96 h) = 4.5 mg/L (nominal), static fish acute toxicity test (similar to German Industrial Standard DIN 38412, part 15) |
reliability: 2, key study |
Hoechst AG, 1981 |
several species with Lepomis macrochirus being the most sensitive |
LC50 (96 h) ≥ 15400 mg/L (nominal), fish acute toxicity test, flow-through, with analytical monitoring |
Hydrolysis product methanol; reliability: 2, key study |
OECD, 2004 |
| Cyprinus carpio | LC50 (96 h) = 4.92 mg/L (acid equivalent to pH 4.3), semi-static, with analytical monitoring, OECD TG 203 |
Hydrolysis product HCl; reliability: 2, key study |
OECD, 2002 |
| Oncorhynchus mykiss | LC50 (96 h) = 7.45 mg/L (acid equivalent to pH 4.12), fish acute toxicity test |
Hydrolysis product HCl; reliability: 2, supp. study |
OECD, 2002 |
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