Ethylene bis[3,3-bis(3-tert-butyl-4-hydroxyphenyl)butyrate]

Endpoint summary

Additional information

Alga

The toxicity of Hostanox O 3 to the unicellular freshwater green alga Desmodesmus subspicatus was determined according to the principles of OECD 201. The aim of the study was to assess the effects on growth rate and yield over a period of 72 hours in a limit test.

The study was conducted under static conditions with an initial cell density of 4910 cells/mL. Based on the results of a preliminary range finding test the saturated solution*was tested.Six replicates each were tested for the saturated solution and the control. Environmental conditions were determined to be within the acceptable limits.

The saturated solution and the control were analysed by LC-MS/MS after 0 hours (fresh media) and 72 hours (old media). The measured concentration of Hostanox O 3 was 2.33 mg/L at test start. At the end of the test HostanoxO 3 gave recovery of 108 % of the initial measured value. All effect values are given based on the geometric mean measured concentration of the test item.

 

In this study the test item Hostanox O 3 Pills caused no inhibition on growth of the freshwater green alga Desmodesmus subspicatus after 72 hours exposure when tested with the saturated solution. The geometric mean measured NOEC for inhibition of specific growth rate and yield after 72 hours was 2.18 mg/L.

Daphnia

In the acute immobilisation test with Daphnia magna (STRAUS) the effect of the saturated solution' (3.59 mg/L DOC / 3.44 mg/L TOC) as limit concentration of the test item Hostanox 0 3 , was determined according to OECD 202 (2004). The limit test was conducted under static conditions over 48 h. 20 test organisms were exposed to the limit concentration and control. The limit concentration and control after 0 h (new media) and after 48 h (old media) without daphnia were analytically verified via TOC/DOC analysis according to DIN EN 1484. Water quality parameters pH-value and dissolved oxygen concentration, measured at 0 and 48 h, were determined to be within the acceptable limits. The validity criteria of the test guideline were fulfilled.

At the saturated solution of the test item Hostanox 0 3 no biologically significant effect was determined.

Microrganisms

A Respiration Inhibition Test with activated sludge according to OECD Guideline No. 209 (2010) was carried out with the test item Hostanox O 3. Test system was activated sludge of a municipal treatment plant. The test was carried out under static conditions with the limit concentration of 1000 mg/L. The respiration rates of the control, reference and test item replicates were measured after a contact time of three hours, and the inhibitory effects of the test and reference item were determined in comparison to the control respiration rates. The inhibition of respiration for the test item replicates ranged from -10 to - 3 %.

The NOEC of the test item Hostanox O 3 is 1000 mg/L. Hostanox O 3 caused no inhibiting effects on activated sludge of a municipal sewage treatment plant at the limit concentration of 1000 mg/L.

Daphnia Reproduction

The Daphnia magna Reproduction Test (Semi-Static, 21 d) of Hostanox O 3 was conducted as a limit test with the saturated solution with 5.00 mg/L of Hostanox O 3 according to OECD .

The tested saturated solution* of the test item Hostanox O 3 and the control were analytically verified by LC-MS/MS of samples on days 0, 9, 14 (fresh media, 0 hours) and on days 1, 12, 16 (old media, 48 and 72 hours). The measured concentrations of the test item Hostanox O 3 were below the limit of quantification of the analytical method (LOQ_M) up to 0.441 mg/L in samples of the fresh (0 hours) and the old media (48 and 72 hours) of the saturated solution. The effects were calculated by nominal concentration due to fluctuating analytical results.

·  The averagevalues of juveniles per parental daphnidwere 86 for the control and 82 for the saturated solution* with 5.00 mg/L of Hostanox O 3 after 21 days. The reproductive output of the parental daphnids in the saturated solution*was comparable to the reproductive output of the parental daphnids in the control (t-test,p = 0.05).

·  The coefficient of variation of the number of living offspring produced per parent was 11 % for the control and 9 % for the saturated solution* with 5.00 mg/L of Hostanox O 3.

·  The intrinsic rates of natural increase (IR) of the surviving parent daphnids accounting for generation time and number of offspring were calculated as a measure for population growth and maintenance.
The IR of the saturated solution* with 5.00 mg/L of Hostanox O 3 was comparable to the control group (t-test,p = 0.05).

·  No biologically significant adult mortality or immobilization of parental daphnids was observed in the saturated solution with 5.00 mg/L of Hostanox O 3 and in the control. In the control, only one of ten parental daphnids did not survive until the end of the test, which is regarded to be not biologically significant.

·  No dead juveniles and aborted eggs were observed in control and thesaturated solution.

·  Four broods were observed during the test period for all surviving parental daphnids. The first brood was released from all parent daphnids in all treatments on days 8 and 9.

·  The mean dry body weight and total body lengths of all parental daphnids of the test and the control groups were determined at the end of the study.
The mean dry body weight of the parental daphnids was 1.10 mg per daphnid for the control and 0.93 mg per daphnid for the saturated solution with 5.00 mg/L of Hostanox O 3 Pills.
The mean body length of the parental daphnids was 5.25 mm per daphnid for the control and 5.08 mm per daphnid forthe saturated solution.

·  No males and ephippia (winter eggs) were observed in the respective control or test groups.

·  The water quality parameters (pH-value, dissolved oxygen, water hardness and temperature) were determined to be within the acceptable limits.

 

No biologically or statistically significant effect could be determined inthe saturated solution with 5.00 mg/L of Hostanox O 3 in comparison to the control.