Sodium 2-sulphonatoethyl laurate

Endpoint summary

Additional information

There are no mutagenicity or gentoxicity assay results available for lauric acid 2-sulfoethyl ester, sodium salt (sodium lauroyl isethionate) CAS No 7381-01-3.  There are however studies on the source chemical Coco fatty acids 2 -sulfoethyl ester, sodium salt CAS no 61789 -32 -0, which are described below.

There is one Ames bacterial reverse mutation assay available for Coco fatty acids 2-sulfoethyl ester, sodium salt CAS No 61789 -32 -0; Unilever Ames LB-7819 which is a Klimisch 2 study carried out to GLP and OECD guideline 471, this study included five strains of S. typhimurium (TA1538, TA1535, TA1537, TA98 and TA100). The study was negative with and without metabolic activation.  

In the Klimisch 2, mammalian cell gene mutation assay, a Mouse lymphoma L5178Y (TK+/-) assay carried out to OECD guideline 476 under GLP, it was found that Coco fatty acids 2-sulfoethyl ester, sodium salt CAS No 61789 -32 -0 did not induce mutation at the tk locus of the L5178Y mouse lymphoma cells. The conditions for the study included treatments up to toxic concentrations in two independent experiments in the absence and presence of the rat liver metabolic activation system (S9 mix).

There are two studies available investigating the in-vitro potential to cause adverse effects on the chromosomes (clastogenicity). The first study is an in-vitro cytogentics study which is Klimisch 2 to OECD guideline 487 (a draft at the time of testing in 2007) Unilever in vitro micronucleus assay KIM070199. This study in human lymphocytes concluded that the sodium cocoyl isethionate (Coco fatty acids 2-sulfoethyl ester, sodium salt CAS No 61789 -32 -0) did not induce micronuclei in the culture human peripheral blood lymphocytes when tested under two different experimental conditions at concentrations up to either its limit of cytotoxicity or the maximum practicable concentration, in both the absence and present of S-9.

There is also a chromosomal aberration study in Chinese hamster ovary cells, Unilever Chromosomal Aberration LB-7818. This study was Klimisch 2 as it was carried out according to OECD guideline 473 in full GLP compliance. The Coco fatty acids 2-sulfoethyl ester, sodium salt CAS No 61789 -32 -0 was tested up to concentration that produced 57% and 71% reductions in the mitotic index at the 10 and 16 hour harvests at the highest concentration of 150µg/ml. Reduction was 94% and 74% at the 10 and 19 hour harvest for the S-9 activated study. This confirmed that sufficiently high concentrations were tested. No statistically significant increase in chromosome aberrations was observed in either the non-activated or S-9 activated test systems, the test substance Sodium Cocoyl Isethionates Coco fatty acids 2-sulfoethyl ester, sodium salt CAS No 61789 -32 -0 was concluded to be negative.

Read-across from the source chemical,Coco fatty acids 2 -sulfoethyl ester, sodium salt CAS no 61789 -32 -0 to the target chemical is considered to be justified based upon a commonality of functional groups, constituents, breakdown products and metabolic pathways.Therefore we consider these study endpoint results as sufficiently conservative to be taken account of in the risk assessment of lauric acid 2-sulfoethyl ester, sodium salt (sodium lauroyl isethionate) CAS No 7381-01-3.

Justification for selection of genetic toxicity endpoint

For the genetic toxicology end point it is not possible to select a single key study as the assessment of genotoxic effects is based upon a weight of evidence approach.  An Ames bacterial reverse mutation assay, which investigates the potential for mutations to DNA in bacteria, is available. There is also an in-vitro mammalian cell gene mutation assay, the (L5178 TK+/-) mouse lymphoma assay. In addition there are two clastogenicity assays looking for damage to the chromosomes, an in-vitro micronucleus study and a chromosomal aberration assay in Chinese hamster ovary cells. All studies have been considered for classification purposes using a weight of evidence approach.

Short description of key information:

In vitro genotoxicity and mutagenicity studies are available for Coco fatty acids 2-sulfoethyl ester, sodium salt CAS No 61789-32-0 and read-across has been conducted to the target substance. There is one Ames bacterial reverse mutation assay available, and in addition there is an in-vitro mammalian cell gene mutation assay, the (L5178 TK+/-) mouse lymphoma assay, an in-vitro micronucleus study and a chromosomal aberration assay in Chinese hamster ovary cells.  All are negative.

Endpoint Conclusion: No adverse effect observed (negative)

Justification for classification or non-classification

Classification is based upon read-across from the source chemical Coco fatty acids 2-sulfoethyl ester, sodium salt CAS No 61789-32-0 to the target substance.There is one Ames bacterial reverse mutation study, a Mouse lymphoma L5178Y (TK+/-) mammalian cell mutation assay and two assays for clastogenicity, the in-vitro micronucleus assay and the Chromosomal Aberration assay in Chinese hamster ovary. All studies are of high quality all being Klimisch 2. The studies are all consistently negative, so there is a significant weight of evidence that Coco fatty acids 2-sulfoethyl ester, sodium salt CAS No 61789-32-0 is not mutagenic or clastogenic. There are no data to indicate any requirement to classify Coco fatty acids 2-sulfoethyl ester, sodium salt CAS No 61789-32-0 and consequently lauric acid 2-sulfoethyl ester, sodium salt (sodium lauroyl isethionate) CAS No 7381-01-3for genetic toxicity.