Fatty acids, C8-18 (even numbered) and C18 unsatd., reaction products with triethanolamine, di-Me sulfate-quaternized

Endpoint summary

Description of key information

There were 4 negative Buehler studies and 2 negative Maximisation studies, with proper performed intradermal and dermal induction concentrations, adequate challenge concentration and clean negative controls. There was no evidence for a sensitisation potential from these studies, i.e. the sensitisation rates were 0%. In addition, there was no evidence for a skin sensitisation potential from two Human Repeated Insult Patch Tests involving a total of 208 volunteers.

Key value for chemical safety assessment

Skin sensitisation

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not sensitising)

Additional information:

In two dermal sensitization studies with the target TEA-Esterquat (CAS 91032-11-0; Clariant 2002 and Kao 1990) guinea pigs were tested using the method of Buehler according to OECD guideline 406. Dermal induction was performed with undiluted test substance. None of the animals of the test or control group showed any positive skin reactions after challenge treatment with the undiluted test substance. The sensitisation rate at 24 h and at 48 h was 0 %. In addition, there were 2 negative Buehler studies (Evonik, 1993 and Clariant 2004) and 2 negative Maximisation studies (Kao 1997 and and Evonik 1992) performed with TEA-Esterquats, with proper performed intradermal and dermal induction concentrations, adequate challenge concentration and clean negative controls. There was no evidence for a sensitisation potential from these studies, i.e. the sensitisation rates were 0%. One Buehler study (Cognis, 1994b) revealed positive reactions in > 15 % out of 20 animals with a challenge concentration of 10 % test substance. Grades were at the lower end of the scale i.e. grades ≤ 1. A re-challenge with 3 % test substance revealed slight reactions (≤ grade 1) in only three animals on only one side of their flanks. The negative control groups showed each time no reactions. Since a reaction is only regarded as positive, if they appear on both flanks and since the grade has not increased in severity, this reaction may reflect irritation rather than sensitisation. This also correlates with the reduced challenge concentration. However, taking the number of animals having reacted positively at 10% challenge into consideration, the classification & labeling cut off level of 15 % was met. Due to the grades being on the lower end of the scale the findings in this study reflect a weak sensitisation. The result of another Buehler study (Cognis, 1994a) was considered ambiguous for the following reasons: A challenge concentration of 3 % resulted in reactions in the test and negative control group on both flanks. This observation was confirmed at re-challenge with the same concentration. A re-challenge with 1 % test substance was evaluated negative, as no effects were observed on the right flank (which one is recommended for treatment by the OECD guideline 406). However, reduced reactions only at one time point and with grade 1 in 3/20 animals were observable only on the left flank. Also, inconsistent pattern and in most cases rapid fading of responses were observed at challenge and re-challenge in test and control animals. These findings may reflect irritation rather than sensitization. One study is a modified Buehler study (Stepan, 1983), which did not include a negative control. Therefore, the results could not be interpreted sufficiently and the study was rated as ‘not reliable’ (Klimisch 3) i.e. excluded from evaluation. Three out of the 9 remaining Buehler tests were rated as ‘not reliable’ (Klimisch 3). While compliant with the testing guidelines, a high level of irritation was observed (Kao (1989b), Cognis (1991) and Cognis (1995a)) in test and control animals. Since no re-challenge was conducted in these studies, no clear conclusion can be drawn and therefore a Klimisch code of 3 was assigned. One out of the three Maximisation studies is also rated as ‘not reliable’ (Klimisch 3) because all control animals showed irritating reactions which were even more severe than those seen in the test animals. Again, due to the potential masking effect of irritation, no clear assessment of the skin sensitising potential can be made from this study (Cognis, 1990a).   

Reliable studies, evaluated according to the requirements for classification & labeling are summarized in table 1.

There was no evidence for a skin sensitisation potential from the two Human Repeated Insult Patch Tests involving a total of 208 volunteers.

Table 1: Reliable sensitisation studies with different methods

Method	fully saturated TEA-EQ	partially unsaturated TEA-EQ	oleic acid-based TEA-EQ
Buehler	2 negative	2 negative 1 ambiguous 1 weak sensitizer
Maximisation (Magnussen and Kligman)		1 negative	1 negative
Human HRIPT	2 negative studies with a total of 208 volunteers

None of the 2 studies involving exposures of a total of 208 human volunteers to TEA-Esterquats was considered to induce a skin sensitisation response in humans (see section 7.10.4). The ability of chemicals to penetrate the human skin is a pre-requisite to cause a skin sensitisation response. Due to the relatively high molecular weight and physico-chemical properties the dermal penetration of TEA-Esterquats can be considered to be very low as outlined in chapter 7.1 toxicokinetics.

In conclusion, there was no evidence that the investigated TEA-Esterquats induced and/or elicited skin sensitisation responses in humans or the more accurate predicting adjuvant-type method in animals. A comparable conclusion is also drawn in the HERA Risk Assessment Report (RAR), where the TEA-Esterquats as well as two other substance classes of the Esterquat family (HEQ and MDEA-Esterquat) have been evaluated. The whole Esterquat family was judged to be non-sensitizing in the HERA RAR.

Respiratory sensitisation

Endpoint conclusion

Endpoint conclusion:

no study available

Justification for classification or non-classification

Classification, Labelling, and Packaging Regulation (EC) No 1272/2008 

The available experimental test data are reliable and suitable for classification purposes under Regulation (EC) No 1272/2008. The substance is not considered to be classified for skin sensitisation under Regulation (EC) No 1272/2008, as amended for the tenth time in Regulation (EU) No 2017/ 776.