Reaction mass of ethanol and propan-2-ol

Short-term toxicity to fish

Description of key information

Ethanol:
P. Promelas (96hr LC50 values): >0.1, 13.8, 14.2, 15.3 g/l
S gairdneri(): 11.2 (24hr), 13.0g/l (96hr)
Isopropanol:
The substance was not acutely toxic to freshwater fish when tested according to the methods defined by the US Environmental Protection Agency Committee on Methods for Toxicity Tests with Aquatic Organisms, the substance was determined to possess a 96-hour LC50 in freshwater fish ranging between 9640 and 10000 mg/L

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Effect concentration:

9 640 mg/L

Additional information

There are no data available for the reaction mass. However there are several studies available for both constituents. The lowest reliable LC50 value is coming from a study with isopropanol (LC50 = 9640 mg/l) and is considered to represent a worst-case value for the reaction mass. This value will be taken forward to the risk assessment.

Ethanol:

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 testin, 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 using 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.

All the available data is consistent in demonstrating that the LC50 for fish is in excess of 10,000mg/l

Isopropanol:

Three studies addressing short-term toxicity to fish are presented in the dossier. 

Short-term toxicity to fish.001 – 1983 – key: Acute toxicity to the freshwater fishPimephales promelas(Fathead minnow) was assessed according to the methods defined by the US Environmental Protection Agency Committee on Methods for Toxicity Tests with Aquatic Organisms not according to GLP (pre-dates GLP requirements). The study was conducted under flow through conditions under the use of proportional diluters with 4 fish per concentration (individual test concentrations not reported) for 96 hours. Temperature was maintained at 25 ± 1°C and the concentrations were measured in each tank throughout the test. The percentage of dead fish was recorded at 1, 3, 6, 12, 24, 48, 72 and 96 hours. The following validity criteria were met: dissolved oxygen concentrations remained above 60% of the air saturation value at the end of the test; and the pH of the control and of the test solution did not vary by more than one unit during the course of the test. Mortality of the controls was not reported and although concentrations were measured throughout the test, individual nominal and measured concentrations were not reported. Two separate tests resulted in 96 hour LC50s of 10,000 mg/L and 9640 mg/L.

Short-term toxicity to fish.003 – Golden orf - 1978: Acute toxicity to the freshwater fishLeuciscus idus melanotus(Golden orf) was assessed according to Deutsche Einheitsverfahren zur Wasser-, Abwasser- und Schlammuntersuchung. L 15: Fischtest (Bestimmung der Wirkung von Wasserinhaltsstoffen auf Fische) not according GLP (pre-dates GLP). The fish were exposed to the substance under static conditions for 48 hours. The 48 – hour LC50 was determined to range between 8970 and 9280 mg/L. This lower toxicity over a shorter exposure period is in keeping with the result of the key study.

Short-term toxicity to fish.002 - Goldfish - 1973: Acute toxicity to the freshwater fishCarassius auratus(Goldfish) was assessed according to OECD guideline 203 (Fish, acute toxicity test) not according GLP (pre-dates GLP). The fish were exposed to the substance under static conditions for 24 hours.  The median tolerance limit (TLm: the concentration at which 50% animals survive) at 24 hours was reported to be >5000 mg/L. Detailed information was not provided in the report however, the results are in line with the key study. Therefore, result from a non reliable study however supports the results from the 2 reliable studies presented above.