Ethanol

Short-term toxicity to fish

Description of key information

P. Promelas (96hr LC50 values): >0.1, 13.8, 14.2, 15.3 g/l
S gairdneri: 11.2 (24hr LC50), 13.0g/l (96hr)
O. latipes (200hr, EC0, developmental effects): 3.9mg/l.  EC50 for same end point in range 12-16g/l.

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Effect concentration:

11 200 mg/L

Additional information

In a 96 hour acute toxicity study for which information is available via a reliable secondary compilation of experimental derived data, rainbow trout (Salmo gairdneri) were exposed to ethanol at nominal concentrations up to and above 15g/l. An LC50 of 13g/l was established. In a 24 hour flow through acute toxicity range finder study which was designed to identify the most benign vehicle for fish toxicity testing, the same species were exposed to ethanol up to doses of 25000mg/l. An LC50 of 11,200mg/l was calculated. Based on the results of this study, ethanol would be not be classified toxic to the environment according to the classification system of the EU. It should be noted that the test duration is shorter than normally required although data from other studies suggests that the toxicity does not increase significantly between 24 and 96hrs. This study is not regarded as the key study but the result is used to derive the LC50 for this species.

In a well reported 96 hour acute toxicity study, fathead minnows (Pimephales promelas) were exposed to ethanol from two different sources and using two analytical methods. In a 96 hour acute toxicity screening study for which detailed information is available, fathead minnows (Pimephales promelas) were exposed to ethanol simultaneously with a number of other species at a nominal concentration of 100mg/l. No deaths were observed. Based on the results of this study, ethanol would be not be classified toxic to the environment according to the classification system of the EU. The study is not suitable for deriving a PNEC. In a 96 hour static acute toxicity test using the same species, fish were exposed to ethanol up to doses of 30000mg/l. An LC50 of 13,480mg/l was calculated.  In a 96 hour acute toxicity screening study for which detailed information is available, fathead minnows were exposed to ethanol simultaneously with a number of other species at a nominal concentration of 100mg/l. No deaths were observed.  This study is supportive of the other results but cannot be used to derive an LC50 for risk assessment use.

In a study designed to assess the potential of using fish as a screening test for reproductive toxicity, Medaka (O. latipes) embryos were exposed to ethanol for a period of 200hrs over a wide range of concentrations. Developmental effects were seen at higher concentrations but a no effect level of 3900mg/l was established.

All the available data is consistent in demonstrating that the LC50 for fish is in excess of 10,000mg/l and ethanol is practically non toxic to fish.