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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.

The new ECHA CHEM database has been released by ECHA, and it now contains all REACH registration data. There are more details on the transition of ECHA's published data to ECHA CHEM here.

Diss Factsheets

Ecotoxicological information

Endpoint summary

Administrative data

Description of key information

Additional information

For the aquatic ecotoxicity endpoints a number of results have been read-across from Fatty acids, C12-18 and C18-unsatd., 2-sulfoethyl esters, sodium salts and coco fatty acids 2 -sulfoethyl sodium salt to lauric acid, 2 -sulphethyl, sodium salt.. Read-across from the source chemical Fatty acids, C12-18 and C18-unsatd., 2-sulfoethyl esters, sodium salts (CAS no 85408-62-4) and coco fatty acids 2-sulfoethyl sodium salt to the target chemical is considered to

be justified as the substances are very similar and the source chemicals contains a higher content of longer alkyl chain products which are known to be more toxic than the shorter alkyl chain products. The conclusion that the source chemical is more toxic than the target chemical is considered sufficient to select the more toxic derivative as the worst-case representative in the hazard assessment of both substances. For this reason read-across of ecotoxicity results of the source chemicals (C12-18 and C18-unsatd and coco) to the target chemical (lauryl) is considered to be justified without the introduction of an additional safety factor.

An overview of the most relevant results is provided in the table.



Results, converted to active ingredient








Acute fish 96h

OECD 203

LC50 > 25 mg/L

LC50 > 9.9 mg/L (geomean)

Reliability 2

Unilever, 1982

Acute Daphnia 48h

OECD 202

EC50 > 50 mg/L

EC50 ca 229.7 mg/L

Reliability 2


Roberts, J 2008

Algae 72h

OECD 201

ErC50 > 4.8 mg/L

ErC50 > 4.8 mg/L

Reliability 1


Roberts, J 2008

Activated sludge

OECD 209

EC50 = 1000 mg/L

EC50 = 687 mg/L

Reliability 2

Reinhardt, J







Algae 72h

OECD 201

ErC10 = 0.31 mg/L

ErC10 = 0.3 mg/L

Reliability 1


Roberts, J 2008

 Chronic Fish (FELS)OECD 210  NOEC= 0.045 mg/L  NOEC= 0.4 mg/L Reliability 2  Calculation  Hurd, 2009
 Chronic Daphnia OECD 211  NOEC= 0.154 mg/L  NOEC= 1.1 mg/L   Reliability 2  Calculation  Roberts, J 2010




Acute toxicity results are available for three taxonomic groups (fish, invertebrates and algae). Solubility of fatty acid 2-sulfoethyl esters differs strongly with the alkyl chain length. The test substance has as for many other surfactants a specific Krafft point/cmc relation which means that at certain temperatures and concentrations cristallinic gels can be formed. 

Great effort has therefore being paid in preparing the test solutions and in quantifying the dissolved fraction of the different alkyl chain 2-sulfoethyl esters during the aquatic ecotoxicity tests. Most of the Key datapoint for the PNEC derivation is the algae study which is read-across from Fatty acids, C12-18 and C18-unsatd., 2-sulfoethyl esters, sodium salts to lauric acid 2 -sulfoethyl sodium salt. The lauric acid 2-sulfoethyl sodium salt contains a lower content of the more toxic but also less soluble longer alkyl chain 2-sulfoethylesters. Due to this lower solubility of the longer alkyl chain 2-sulfoethyl esters and evaluating the solubility data for each alkyl chain 2-sulfoethyl ester it is very likely that the fraction of the toxicity determining longer alkyl chains is almost equal for both substances when dissolved under the same conditions.

Further to the above, chronic toxicity values for lauric acid 2 -sulfoethyl sodium salt have been calculated for both Fish Early Life Stage and Daphnia using a toxic unit approach. The predicted toxicity of each chain length was calculated using a polar narcotic QSAR relevent for the respective species and the relative toxicities of thedifferent molecular species expressed as a ratio of the molar dissolved fraction to thepredicted toxicity. The results show that the lauroyl species contributes to 4% and 5.3% of the overall toxicity of the tested substances in the FELS and daphnia studies respectively.