Reaction mass of dodecyl (S)-2-(((S)-2-hydroxypropanoyl)oxy)propanoate and dodecyl (S)-2-hydroxypropanoate

Endpoint summary

Description of key information

Aquatic invertebrates: The EC50 (48 h) value is considered to lie between 3.2 and 5.6 mg/L loading rate WAF (OECD 202 and EU Method C.2).

 

Algae: Based on growth rate, the EC50 (72 h) value is considered to lie between 32 and 100 mg/L loading rate WAF based on growth rate. Based on yield, the EC50 (72 h) value is considered to lie between 3.2 and 10 mg/L loading rate WAF based on yield. The NOEC for both growth rate and yield inhibition is expected to lie below a loading rate of 1.0 mg/L (OECD 201 and EU Method C.3).

Additional information

Daphnia magna

A study was performed to assess the acute toxicity of the test item to Daphnia magna.The method followed was designed to be compatible with the OECD Guidelines for Testing of Chemicals (April 2004) No 202,"Daphnia sp., Acute Immobilisation Test" referenced as Method C.2 of Commission Regulation (EC) No. 440/2008.

 

For the final test, Water Accommodated Fractions (WAFs) were individually prepared at loading rates of 1.0, 1.8, 3.2, 5.6 and 10 mg/L. One hour of gentle magnetic stirring was applied to accelerate dissolution of test item in test medium. The obtained mixtures were allowed to settle for a period of approximately two hours. Thereafter, the WAFs were collected by means of siphoning over glass wool and used as test concentrations. At the end of the preparation procedure, all test solutions were clear and colourless.

No biologically relevant immobility (i.e. >10%) was observed in the control and at the three lowest test concentrations throughout the test. At the end of the test, 85 and 100% immobility was observed at the WAFs prepared at loading rates of 5.6 and 10 mg/L, respectively. It should be noted that 10 % immobility is allowed in the control and therefore, effects ≤ 10 % are considered to be biologically not relevant.

 

The 48-hour EC50 value is expressed in terms of loading rate and is considered to lie between 3.2 and 5.6 mg/L loading rate WAF. 

Algae

A study was performed to assess the effect of the test item on the growth of the green alga Pseudokirchneriella subcapitata. The method followed was designed to be compatible with the OECD Guidelines for Testing of Chemicals (2006) No 201, "Freshwater Alga and Cyanobacteria, Growth Inhibition Test" referenced as Method C.3 of Commission Regulation (EC) 761/2009.

 

For the final test, Water Accommodated Fractions (WAFs) were individually prepared at loading rates of 1.0, 3.2, 10, 32 and 100 mg/L. One hour of gentle magnetic stirring was applied to accelerate dissolution of test item in test medium. The obtained mixtures were allowed to settle for a period of approximately three hours. Thereafter, the WAFs were collected by means of siphoning over glass wool and used as test concentrations. At the end of the preparation procedure, all test solutions were clear and colorless.

Biologically relevant growth rate and yield inhibition (i.e. > 10 %) was recorded at all test concentrations, except for the WAF prepared at a loading rate of 1.0 mg/L. A dose-related increase of growth rate and yield inhibition was measured at the loading rate of 3.2 and higher, reaching 85 % growth rate inhibition and 100 % yield inhibition at the WAF prepared at a loading rate of 100 mg/L. Based on these results, the NOEC for both growth rate and yield inhibition is expected to lie below a loading rate of 1.0 mg/L.

 

The 72-hour EC50 values are expressed in terms of loading rates. Based on growth rate, the EC50 (72 h) value is considered to lie between 32 and 100 mg/L loading rate WAF. Based on yield, the EC50 (72 h) value is considered to lie between 3.2 and 10 mg/L loading rate WAF. The NOEC for both growth rate and yield inhibition is predicted to be < 1.0 mg/L.