2-Propenoic acid, 4-[[(4-benzoylphenoxy)carbonyl]oxy]butyl ester

Short-term toxicity to fish

Description of key information

The LC50 was after 48 h 2.10 mg/L, after 72 h 1.45 mg/L and after 96 h 1.05 mg/L.

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Effect concentration:

1.05 mg/L

Additional information

Key Study

The acute toxicity of the test item to fish (zebrafish), was determined according to OECD-Guideline for Testing of Chemicals No 203 (1992) and EU Council Regulation No. 440/2008/ C.1 (2008). A semi-static test with daily renewal of the test media was conducted with the nominal test item concentrations of 0.625 - 1.25 - 2.50 - 5.00 - 10.0 mg/L (factor 2), corresponding to mean measured concentrations of 0.251 - 0.621 - 1.03- 2.05 - 5.19 mg/L. Duration of the test was 96 hours. 7 test organisms were exposed to each test concentrations and control. Water quality parameters temperature, pH-value and O2 -saturation measured at 0, 24, 48, 72 and 96 hours were within the acceptable Iimits. The determination of the concentrations of the test item was carried out via HPLC-DAD from freshly prepared media after 0 and 72 h, and from the corresponding 24 h old test media after 24 and 96 h. The measured concentrations in freshly prepared media were in the range of 43 - 76 % of the nominal values and 8 - 46 % in 24 h aged test media. The LC50 was 2.10 mg/L after 48h, 1.45 mg/L after 72h and 1.05 mg/L after 96h (Basedon mean measured test item concentrations). Additionally to the test item another compound with a relative retention time of approx. 0.34 (absorption maximum 291 nm) was detected in all exposure concentrations at test end.

Supporting Study

The purpose of this study was to determine the acute toxicity of the test item on the Zebrafish (Brachydanio rerio). The study procedure was based an the EEC guideline using a semistatic procedure and 100 mg/L Tween 80 as auxiliary compound. To reduce the speed of hydrolysis all test solutions were adjusted to about pH 7 using hydrochlorid acid. Zebrafish were exposed over a 96 -hour period to a range of 7 concentrations spaced by a factor of about 2.2: 0.0464. 0.1, 0.215, 0.464, 1.0, 2.15 and 4.64 mg/L and controls. Since the analytical determinations indicated a loss of the test compound of more than 20% after 48 hours the results were calculated also related to the anaIytically determined values. To study a possible fortification of the acute toxicity by using the auxiliary compound Tween 80, the concentrations 1.0 and 4.64 mg/L were run in parallel without the addition of Tween 80: Tween 80 did not increase the acute toxicity of the test compound in this study.

Results (on the basis of the nominal concentrations):

LC 50 after 96 hours

Greater 1.00 mg/L ( 5% Significance Level)

Smaller: 2.2 mg/L ( 1% Significance Level)

Analytically determined:

LC 50 (96 h)

Greater 0.49 mg/L (5 % Significance Level)

Smaller 1.1 mg/L (1% Significance Level)