Butanedioic acid, 1-[2-[(1-oxo-2-propen-1-yl)oxy]ethyl] ester

Endpoint summary

Additional information

Short-term toxicity to fish:

A study was performed to assess the acute toxicity of the test material to rainbow trout (Oncorhynchus mykiss). The method followed that described in the OECD Guidelines for Testing of Chemicals (1992) No 203, "Fish, Acute Toxicity Test" referenced as Method C.1 of Commission Directive 92/69/EEC (which constitutes Annex V of Council Directive 67/548/EEC).

The 96-Hour LC50 based on nominal test concentrations was 24 mg/l with 95% confidence limits of 18 - 32 mg/l. The No Observed Effect Concentration was 10 mg/l.

It was considered unnecessary and unrealistic to test at concentrations in excess of 100 mg/l.

Short-term toxicity to aquatic invertebrates (Daphnia Magna):

A study was performed to assess the acute toxicity of the test material to Daphnia magna. The method followed that described in the OECD Guidelines for Testing of Chemicals (April 2004) No 202, "Daphnia sp, Acute Immobilisation Test" referenced as Method C.2 of Commission Directive 92/69/EEC (which constitutes Annex V of Council Directive 67/548/EEC).

The 48-Hour EC50 for the test material to Daphnia magna based on nominal test concentrations was 75 mg/l with 95% confidence limits of 56 - 100 mg/l. The No Observed Effect Concentration was 56 mg/l.

Toxicity to aquatic algae and cyanobacteria:

A study was performed to assess the effect of the test material on the growth of the green algaScenedesmus subspicatus. The method followed that described in the OECD Guidelines for Testing of Chemicals (1984) No 201, "Alga, Growth Inhibition Test" referenced as Method C.3 of Commission Directive 92/69/EEC (which constitutes Annex V of Council Directive 67/548/EEC).

Following a preliminary range-finding test,Scenedesmus subspicatuswas exposed to an aqueous solution of the test material at concentrations of 1.0, 3.2, 10, 32 and 100 mg/l (three replicate flasks per concentration) for 72 hours, under constant illumination and shaking at a temperature of 24 ± 1°C. Samples of the algal populations were removed daily and cell concentrations detennined for each control and treatment group, using a Coulter Multisizer Particle Counter.

Exposure ofScenedesmus subspicatusto the test material gave an ErC50 (0 - 72 h) value of 38 mg/l with 95% confidence limits 31 - 46 mg/l and an ErC10 of 2.1 mg/l. The No Observed Effect Concentration at 72 hours was 1.0 mg/l.

Analysis of the test preparations at 0 hours showed measured test concentrations to range from 81% to 101% of nominal. Given that the preliminary recovery analyses conducted in the presence of algal cells indicated that they had a significant effect on the recovery of the test material at the lowest test concentration employed, additional test samples were prepared at 0 hours in culture medium alone (no algal cells). Analysis of these test samples showed measured test concentrations to range from 79% to 101% of nominal. Analysis of the test preparations at 72 hours (with algal cells) showed a concentration dependent decline in measured test concentrations in the range 35% to 104% of nominal. This decline was in-line with the preliminary stability analyses that indicated that the test material was unstable in culture medium at the lower test concentrations.

Given this decline in measured test concentrations it was considered justifiable to base the results on the geometric mean measured test concentrations in order to give a "worst case" analysis of the data. Based on the geometric mean measured test concentrations, the ErC50 (0 - 72 h) value was 38 mg/l with 95% confidence limits of 31 - 47 mg/l, the ErC10 was estimated at 1.3 mg/l and the No Observed Effect Concentration at 72 hours was 0.53 mg/l.

Toxicity to microorganisms:

A study was performed to assess the effect of the test material on the respiration of activated sewage sludge. The method followed that described in the OECD Guidelines for Testing of Chemicals (1984) No 209 "Activated Sludge, Respiration Inhibition Test", EEC Commission Directive 87/302/EEC and US EPA Draft Ecological Effects Test Guidelines OPPTS 850.6800.

Following a preliminary range-finding test, activated sewage sludge was exposed to an aqueous solution of the test material at concentrations of 100, 180, 320, 560 and 1000 mg/l for a period of 3 hours at a temperature of 21°C with the addition of a synthetic sewage as a respiratory substrate. The rate of respiration was determined after 30 minutes and 3 hours contact time and compared to data for the control and a reference material, 3,5-dichlorophenol.

The effect of the test material on the respiration of activated sewage sludge gave a 3-Hour EC50 of 510 mg/I. The No Observed Effect Concentration (NOEC) after 3 hours exposure was 180 mg/l. It was considered unnecessary and unrealistic to test at concentrations in excess of 1000 mg/l.