tert-butyl acrylate

Short-term toxicity to fish

Description of key information

Tert-butyl acrylate is acutely toxic to freshwater fish.

This is supported by data from the structurally related methyl acrylate, isobutyl acrylate, n-butyl acrylate, ethyl acrylate and 2-ethylhexyl acrylate. Based on data from n-butyl acrylate, ethyl acrylate and methyl acrylate, tert-butyl acrylate is estimated to be also acutely toxic to saltwater fish.

LC50 (96h, static) = 2.37 mg/L (estimated) (Leuciscus idus, DIN 38412, part 15);

LC50 (96 h, flow through) = 2.1 mg/L (measured) (Pimephalis promelas, ASTM 1980) (isobutyl acrylate)

LC50 (96 h, flow through) = 5.2 mg/L (measured) (Salmo gairdneri, OECD 203) (n-butyl acrylate)

LC50 (96 h, flow through) = 2.1 mg/L (measured) (Cyprinodon variegatus, OECD 203) (n-butyl acrylate)

LC50 (96 h, flow-through) = 2 mg/L (measured) (Cyprinodon variegatus, EPA OTS 797.1400 (ethyl acrylate)

LC50 (96 h, flow through) = 3.4 mg/L (measured) (Oncorhynchus mykiss, OECD 203) (methyl acrylate)

LC50 (96 h, flow through) = 1.1 mg/L (measured) (Cyprinodon variegatus, OECD 203) (methyl acrylate)

LC50 (96 h, semi-static) = 1.81 mg/L (measured) (Oncorhynchus mykiss, OECD 203) (2-ethylhexyl acrylate)

LC50 (96 h, flow-through) = 4.6 mg/L (measured) (Oncorhynchus mykiss, EPA OTS 797.1400) (ethyl acrylate)

Additional information

Tert-butyl acrylate was tested in an acute toxicity study with Leuciscus idus under static test conditions without analytical monitoring (BASFSE, 1978). The test procedure followed the national guideline DIN 38412, part 15. Based on nominal test concentrations the 96-hour LC50 was determined to be 56.2 mg/L. At lethal concentrations gasping, staggering and at > 147 mg/L narcotic like effects were observed. Since tert-butyl acrylate is of considerable volatility, results from tests in open system and without analytical monitoring are only valid with restrictions. Therefore, test concentrations were recalculated based on the nominal test concentrations at test start and the assumption that at test termination all concentrations were below the limit of detection (0.1 mg/L) as worst case. Recalculated test concentrations (geometric means) were: 1.78, 2.15, 2.61, 3.16, 3.83, and 4.64 mg/L. The 96-hour LC50 was recalculated to be 2.37 mg/L which puts the effect value for fish in the same range as the other two trophic levels (daphnia and algae) supporting the validity of the recalculation.

In addition, valid experimental data from the structurally related methyl acrylate, 2-ethylhexyl acrylate, ethyl acrylate, n-butyl acrylate and methyl acrylate are available.

Isobutyl acrylate was tested in an acute toxicity test with Pimephalis promelas under flow-through conditions. Biological and chemical procedures followed the American Society for Testing and Materials recommendations (ASTM, 1980). The test was repeated once. Based on mean measured concentrations, the 96-hour LC50 was determined to be 2.09 and 2.11 mg/L, respectively. Reported behavioural effects were: hyperactive locomotor activity, overreactivity to outside stimuli, tetany, with no signs of permanent deformities (lordosis/scoliosis) (Russom et al. 1988).

The 96-hour LC50 for n-butyl acrylate in rainbow trout was determined to be 5.2 mg/L based on the mean measured concentrations (BAMM, 1990). This study followed OECD Guideline 203 using a flow-through design. Nominal exposure concentrations ranged from 0.438 to 14 mg/L and mean measured concentrations (0 and 96 hrs) ranged from 0.49 to 7.2 mg/L. Behavioural/sublethal effects noted during the study included surfacing, labored respiration, quiescence, on-bottom orientation and loss of equilibrium. A no-effect concentration (NOEC) of n-Butyl Acrylate toxicity to rainbow trout was determined to be 3.8 mg/L, based upon behavioural and sublethal effects at 14 and 7.2 mg/L. The lack of mortality or behavioral/sublethal effects at the test concentrations of 3.8, 1.9, 0.93 and 0.49 mg/L supported this conclusion.

In a saltwater study conducted in the sheepshead minnow (BAMM, 1996), the 96-hour LC50 for n-butyl acrylate was estimated to be 2.1 mg/L. This study was conducted according to OECD Guideline 203 using a flow-through design. The LC50 value was based on analytically determined concentrations. After 96 hours of exposure, mortality was 0, 100 and 100 % in the 1.3, 3.5 and 5.1 mg butyl acrylate/L treatment groups, respectively. Although no mortality was observed in the 1.3 mg butyl acrylate/L treatment group, the majority of the fish were exhibiting clinical signs of toxicity at test termination (e.g., lethargy, erratic swimming and surfacing). Due to the clinical signs of toxicity observed in the 1.3 mg butyl acrylate/L treatment group, the NOEC was considered to be 1.3 mg butyl acrylate/L.

Ethyl acrylate was tested in acute toxicity tests with saltwater species Cyprinodon variegatus and freshwater species Oncorhynchus mykiss (BAMM, 1995; BAMM 1990), where fish (20 per concentration) were exposed up to test concentrations of 10 and 14 mg/L for 96 hours in a flow-through system according to EPA OTS 797.1400. Test concentrations were analytically verified. Effect concentrations were calculated based on the arithmetic mean, since concentrations of ethyl acrylate did not remain between 80 - 120% of the nominal test concentrations. Effects in saltwater fish included lethargy, loss of equilibrium, discoloration and erratic swimming at 1.6 mg/L, and lethargy and discoloration were observed at 0.86 mg/L, whereas mortality (after 96) hours was observed from 3.2 mg/L. Behavioural/sublethal effects noted in freshwater fish during the study included on-bottom orientation, surfacing, dark discoloratin, quiescence and loss of equilibrium from 1.7 mg/L and mortality was observed from 6.5 mg/L. The 96h-LC50 values for salt- and freshwater fish was determined to be 2 and 4.6 mg/L, respectively.

Additionally, methyl acrylate was assessed in acute toxicity tests with saltwater species Cyprinodon variegatus and freshwater species Oncorhynchus mykiss (BAMM, 1995; BAMM 1995), where fish species were exposed to test concentrations up to 10 mg/L for 96 hours in a flow-through system according to OECD 203 and under GLP conditions. Test concentrations were analytically verified. Effect concentrations were calculated based on the arithmetic mean, since concentrations of methyl acrylate did not remain between 80 - 120% of the nominal test concentrations. Effects in saltwater fish included lethargy, loss of equilibrium, discoloration and erratic swimming; symptoms already showed at the lowest tested concentrations. Mortality (after 96 hours) was observed from 2.2 mg/L. Behavioural/sublethal effects noted in freshwater fish started after 72 hours and included surfacing, lethargy and loss of equilibrium from 4.1 mg/L. Mortality was observed in the highest concentration after 72 and two highest concentrations after 96 hours exposure. The 96 -hLC50 values for salt- and freshwater fish was determined to be 1.1 and 3.4 mg/L, respectively.

Furthermore, the acute toxicity of 2-ethylhexyl acrylate to fish was assessed in an OECD203 study performed in accordance with GLP. In this study, rainbow trout were exposed for 96 hours in a semi-static test to nominal concentrations of 0.0 (control), 0.681, 1.0, 1.47, 2.15, 3.16, and 4.64 mg/L. Test concentrations were analytically verified, but did not remain 80 – 120% of the nominal concentrations. Therefore, the effect value is based on the geometric means of the measured concentrations. Substance-related effect(s) included accelerated respiration, convulsions, narcotic-like state, tumbling, swimming near water surface, swimming near the bottom and a vertical position. Mortality was observed after 48 hours at the highest concentration, and at the two highest concentrations after 72 and 96 hours. Cumulative mortality increased with time. Based on these results, the 96-h EC50 value was determined to be 1.81 mg/L.