Butyl acrylate

Short-term toxicity to fish

Description of key information

n-Butyl acrylate is acutely toxic to freshwater and marine fish.
LC50 (96 h, flow through) = 5.2 mg/L (measured) (Salmo gairdneri, OECD 203)
LC50 (96 h, flow through) = 2.1 mg/L (measured) (Cyprinodon variegatus, OECD 203)

Additional information

In the key study for acute toxicity to fish (BAMM, 1990), the 96-hour LC50 for rainbow trout was 5.2 mg/L based on the mean measured concentrations. 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. Behavioral/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 behavioral 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 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.

Three other studies were available reporting a 48h-LC50 value of 23 mg/L in Juncke et al., 1978 and Hommel 1987, and a 72h-LC50 value of 4.41 mg/L in Reinert 1987, but these studies had all a reliability of 4 due to insufficient information.

In addition, a robust data set of acute studies is available from the other members of the acrylic ester category (methyl, 2-ethylhexyl, ethyl, isobutyl, and tert-butyl acrylate).