Dioctadecyl disulphide

Endpoint summary

Additional information

 

The acute toxicity of the test item Hostanox SE 10 P to fish (zebrafish) was determined according to OECD-Guideline for Testing of Chemicals No. 203 (1992).

A semi-static limit test with daily renewal of the test media was conducted with the water accommodated fraction (WAF) of 100 mg/L.The water accommodated fraction was preparedwith a nominal loading of 100 mg/L test item Hostanox SE 10 P with dilution water after -48, -24, 0 and 24 h of exposure. The WAF was stirred for 48 hours with a magnetic stirrer at room temperature. After a separation phase of 1 hour the WAF was taken from the homogeneous liquid phase.Duration of the test was 96 h. 7 test organisms were exposed to the limit loading and the control. Water quality parameters pH-value, temperature and oxygen-saturation measured after 0, 24, 48, 72 and 96 h were determined to be within the acceptable limits.

No analytical evaluation of the limit loading level and the control was carried out since no suitable method for determination of the test item could be established.

In this study Hostanox SE 10 P did not cause any effects to zebrafish after 96 h when tested in a limit test with the water accommodated fraction of nominal 100 mg/L.

 

 

In the acute immobilization test with Daphnia magna (STRAUS) the effects of the saturated solution of the test item Hostanox SE 10 P with a nominal loading of 100 mg/L as limit concentration were determined according to OECD 202 (2004). The limit test was conducted under semi-static conditions over a period of 48 h. Twenty daphnids were exposed to the saturated solution and the control. No analytical evaluation of the saturated solution was carried out since no suitable method for determination of the test item could be established.All effect values given are based on the nominal loading of the test item Hostanox SE10 P. The water quality parameters (pH-value and dissolved oxygen concentration), measured at 0, 24 and 48 h, were determined to be within the acceptable limits. The validity criteria of the test guideline were fulfilled.

At the saturated solution with a nominal loading of 100 mg/L of the test itemHostanox SE 10 P,no effect was observed onDaphnia magna.

 

 

TheDaphnia magnaReproduction Test (Semi-Static, 21 days)of Hostanox SE 10 P was conducted as limit test with a nominal loading of 100 mg/L Hostanox SE 10 Paccording to OECD 211 (2008).

Ten daphnids individually held were used for the limit loading level of 100 mg/L and the control. At test start the daphnids were 2 to 24 h old. The test method was semi-static with a daily renewal of the test solutions. The aim of the Daphnia Reproduction Test over 21 days was to assess effects on the reproduction capacity and other test item-related effects, including occurrence of aborted eggs and stillborn juveniles, time of production of first brood, adult mortality, intrinsic rate of natural increase, dry body weight and length of the parent daphnids. No analytical evaluation of the limit loading level was carried out since no suitable method for determination of the test item could be established. The results given are based on the nominal loading level of 100 mg/L of the test item Hostanox SE 10 P.

 

The average values of juveniles per parental daphnid were 126 for the control and 120 for the limit loading level of 100 mgHostanox SE 10 P/L after 21 days. The reproductive output of daphnids in the loading level was comparable to the output of daphnids in the control(t-test,p = 0.05).

 

The coefficient of variation of the number of living offspring produced per parent was 8 % for the control and 7 % for the limit loading level of 100 mg/L.

 

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 limit loading level of 100 mg/L was comparabletothe control group (t-test,p = 0.05).

No adult mortality or immobilization of parental daphnids was observedin the control andthe limit loading level of 100 mg/L.

 

Related to the total number of produced juveniles (dead + alive) the percentage ofdead juveniles and aborted eggswas lower than 1 % in the limit loading level of 100 mg/L, which is seen to be not biologically significant. In the control no dead juveniles or aborted eggs were observed.

 

Five broods, respectively, were observed during the test period for all parental daphnids. The first brood was released from all parental daphnids inthelimit loading level of 100 mg/Land the control by day 9.

 

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

 

At the limit loading level with 100 mg Hostanox SE 10 P/L no biologically or statistically significant effects were determined. The No Observed Effect Level (NOEL) and the Lowest Observed Effect Level (LOEL) were as follows: NOEL: 100 mg/L, LOEL: > 100 mg/L.

The endpoints were assessed based on the nominal loading of the test item Hostanox SE 10 P.

 

 

The toxicity of Hostanox SE 10 P 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. Based on a preliminary range finding test, a limit test with a water accommodated fraction (WAF) was carried out.The water accommodated fraction was preparedwith a nominal loading of 100 mg/L test item Hostanox SE 10 P.Sixreplicates were tested for the limit concentration and the control.Environmental conditionswere determined to be within the acceptable limits.No analytical evaluation of the limit loading level and the control was carried out since no suitable method for determination of the test item could be established. All effect valuesofHostanox SE 10 P are given based on the nominal test item loading.

In this study no inhibition on growth of the freshwater green alga Desmodesmus subspicatus was found after 72 hours exposure to the test item Hostanox SE 10 P. The NOEL for inhibition of specific growth rate and yield after 72 hours was 100 mg/L.

 

 

A Respiration Inhibition Test with activated sludgeaccording to OECD Guideline No. 209 (2010) was carried out with the test item Hostanox SE 10 P.Test system was activated sludge of a municipal treatment plant. The test was carried out under static conditions with the limit concentration 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 -5 to 0 %.

Hostanox SE 10 P caused no inhibiting effects on activated sludge of a municipal sewage treatment plant at the limit concentration of 1000 mg/L. The NOEC of the test item Hostanox SE 10 P is1000mg/L.