Reaction mass of ethanol and propan-2-ol

Long-term toxicity to aquatic invertebrates

Description of key information

Ethanol:
Ceriodaphnia dubia: EC50, 10 day (adult, mortality) = 1806mg/l.  NOEC (reproduction, 10 day) = 9.6mg/l 
Daphnia Magna: EC50, 10 day (adult, mortality) = 454mg/l.  NOEC (reproduction, 10 day) = 9.6mg/l.  NOEC (reproduction, 21 days) >10mg/l.
Palaemonetes pugio LC50 4 day (acute invertebrate embryo lethality) = 12.07g/l 
Palaemonetes pugio LC50 10 day (invertebrate embryo lethality) = 3.63g/l, 0.53g/l.  NOEC (developmental effects) = 79mg/l 

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

10 mg/L

Marine water invertebrates

Marine water invertebrates

Effect concentration:

79 mg/L

Additional information

There are no data available for the reaction mass. A reliable NOEC value was derived for ethanol in a 21 -day study and was considered to be >10 mg/l. This value will be taken forward to the risk assessment, representing a worst case value for the reaction mass. For saltwater species the lowest NOEC value was 79 mg/l fro shrimp (developmental delay).

Ethanol:

In a very well reported invertebrate reproduction study, Daphnia magna were exposed to ethanol over a period of approximately 10 days, sufficient for the production of 3 broods of offspring. An LC50 of 454mg/l was reported for the adults but a much lower NOEC of 9.6mg/l was reported for the reproduction test, based on criteria of total progeny, number of broods and mean brood size. In the same study, Ceriodaphnia dubia were similarly exposed. An LC50 of 1806mg/l was reported for the adults and the same NOEC of 9.6mg/l as for the D magna and based on the same findings.  A very low NOEC of 2mg/l was reported for the Ceriodaphnia adults, but it was unclear what exact end points were used for this or why this figure was vastly lower than the LC50. For this reason, the NOEC for this study is based on the reproduction end point.

In a study to assess the sensitivity of the grass shrimp developmental cycle to the ethanol, a 4 day assay, was used to determine the acute toxicity of embryos from the daggerblade grass shrimp (Palaemonetes pugio) to ethanol. This test (known as SEATOX) included exposure through the development prior to hatch and through the time of hatch, which is regarded as a critical life stage of these embryos and this species. The LC50 obtained was 12.07g/l, which suggests that Ethanol is not acutely toxic to invertebrate embryos.

In two studies to assess the sensitivity of the grass shrimp developing embryos to ethanol, embryos from the daggerblade grass shrimp were exposed to the test substance from the tissue cap stage embryo stage (day 3 - late gastrula) through to 2 days post hatch, a total of 12 days exposure in a test known as the "Shrimp embryo teratogenesis assay - Palaemonid" or SETAP.  In the first study, the LC50 obtained based on mortality was 3.63g/l, which suggests that ethanol is not acutely toxic to invertebrate embryos. However, the NOEC based on developmental toxicity, in this case developmental delay, was 79mg/l. In the second study, the reported LC50 for embryo mortality was 0.53g/l.  A NOEC was not reported.

In a 21 day daphnia reproduction study that used ethanol as a vehicle, a single concentration of 0.001% ethanol (approximately 10mg/l) had no adverse effects on any of the reproductive parameters monitored for the daphnia magna test species.