Alcohols, C9-11, branched and linear, ethoxylated, sulfates, ammonium salts

Endpoint summary

Description of key information

skin irritation (OECD 404): irritating
eye irritation (OECD 405): highly irritating/corrosive
SCLs according to GHS:
>=5% - <10% Eye Irrit. Cat.2
< 5% No Classification

Key value for chemical safety assessment

Skin irritation / corrosion

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (irritating)

Eye irritation

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (irritating)

Respiratory irritation

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

No data regarding the skin and eye irritating properties of AES (C9 -11) NH4 (CAS 160901-27-9) is available. Therefore the endpoint skin irritation is covered by read-across to structurally related AES, i.e. AES (C8-10) Na and AES (C9-11) Na (CAS 160901-28-0). With regard to eye irritation AES (C9-11) NH4 (CAS 160901-27-9) is classified as worst case scenario according to the classification criteria of Directive 67/548/EEC and Regulation (EC) No 1272/2008 as Xi, R41 and Eye Dam.1, H318, respectively. However, to assess specific concentration limits (SCL) for eye irritation a read-across to structurally related AES, i.e. AES (C12-14, 1-2.5) Na (CAS 68891-38-3) and AES (C10-16, 1-2.5) Na (CAS 68585-34-2) was performed. The AES reported within the AES category show similar structural, physico-chemical, environmental and toxicological properties. The approach of grouping different AES for the evaluation of their effects on human health and the environment was also made by the Danish EPA (2001) and HERA (2003), supporting the read-across approach between structurally related AES. Within the Danish EPA report (2001) it was concluded that “The skin irritating properties of AES normally decrease with increasing level of ethoxylation.” Therefore read-across was performed to AES with an ethoxylation grade of 1 - 2.5 reflecting the ethoxylation grade of AES (C9-11) NH4 (CAS 160901-27-9).

There is one study with AES (C9-11) Na (CAS 160901-28-0, analytical purity 30%) and two studies for the read-across substance AES (C8-10) Na addressing skin irritation.

One in vitro study was performed according to OECD Guideline 431 to assess the skin corrosive potential of AES (C8-10, 2 EO) Na. 25 mg of the test substance was applied atop an EpiDerm ™ tissue, comprising of a reconstructed epidermis with a functional stratum corneum, for 3 and 60 minutes (Lehmeier, 2012a). The viability of the treated tissue, as assessed via the MTT assay, was 84% of control after 3 min exposure and 48% of control after 60 min exposure period. Thus, AES (C8-10, 2 EO) Na (CAS not yet assigned) was not corrosive.

The second study with AES (C8-10, 2 EO) Na was performed according to OECD Guideline 439. 25 mg of the test substance was applied atop an EpiDerm ™ tissue, comprising of a reconstructed epidermis with a functional stratum corneum, for 60 minutes (Lehmeier, 2012b). The viability of the treated tissue, as assessed via the MTT assay, was 7% of control after 60 min exposure. Thus, AES (C8-10, 2 EO) Na was irritating.

In an in vivo study with AES (C9-11) Na (CAS 160901-28-0, analytical purity 30%) similar to OECD Guideline 404 six New Zealand White rabbits were treated with 0.5 mL for 24 h under occlusive conditions (Nicholson 1977). As the 48 h reading was missing this was extrapolated from the 24 and 72 h readings. Only the intact skin values were used for grading the skin lessions. The mean erythema and mean edema scores (24, 48 and 72 h) were 1.6 and 1.1, respectively. No information on reversibility of the effects is available as the observation period was only 72 h.

Data on eye irritation:

As worst case scenario AES (C9-11) NH4 (CAS 160901-27-9) is classified according to the classification criteria of Directive 67/548/EEC and Regulation (EC) No 1272/2008 as Xi, R41 and Eye Dam.1, H318, respectively.

However, as corrosion and irritation depends on the concentration of the substance in a solvent, further studies with lower concentrations of the test substance were also considered to assess whether specific concentration limits can be set. For this purpose, two studies with AES (C12-14, 4 EO) Na (CAS 68891-38-3) and two studies with AES (C10-16, 2 EO) Na (CAS68585-34-2) with a concentration range of 1 to 10% were evaluated.

 

One study was performed with 0.1 mL AES (C12-14, 4 EO) Na (CAS 68891-38-3, analytical purity 10%) similar to OECD Guideline 405 (Kukulinski, 1980a) on three New Zealand White rabbits with an observation period of 7 days. The mean (24, 48 and 72 h reading) cornea, iris, conjunctivae and chemosis scores over all animals were 1.6, 0.6, 2 and 1.6 representing an eye irritating effect of the test substance at a concentration of 10%. The effects were not fully reversed within the 7 days observation period. Therefore the test substance showed eye irritating potential.

The second study was performed with 0.1 mL AES (C12-14, 4 EO) Na (CAS 68891-38-3) similar to OECD Guideline 405 (Kukulinski, 1980b) on three New Zealand White rabbits with an observation period of 7 days, however at a concentration of 5%. The mean (24, 48 and 72 h reading) cornea, iris, conjunctivae and chemosis scores over all animals were 0.4, 0, 1 and 0.3. All effects reversed within the 7 days observation period. Thus, the test substance was not irritating to the eye at a concentration of 5%.

In a further supporting study with AES (C12-14, 2 EO) Na (CAS 68893-38-3, analytical purity 27%) according to OECD guideline 405, 0.1 mL of the test substance was applied to the rabbits eye at a concentration of 20% resulting in an actual concentration of 5.4% (Biffi, 1997). The mean (24, 48 and 72 h reading) cornea, iris, conjunctivae and chemosis scores over all animals were 0, 0, 1.2 and 0. The conjunctival redness reversed within the 7 days observation period. Thus the test substance was not irritating to eyes at a concentration of 5.4 %.

The supporting study with AES (C10-16) Na (CAS 68585-34-2, no data on grade of ethoxylation, analytical purity 58%) was performed similar to OECD Guideline 405 (York, 1980). The mean (24, 48 and 72 h reading) cornea, iris, conjunctivae and chemosis scores over all animals were 0.7, 1, 3 and 3.3. All findings were fully reversible within the observation period. Thus, the test substance showed eye irritating properties at a concentration of 5%.

Based on the above results with different concentrations of structurally related alkyl ether sulfates a cut of value for classification as severe irritating to eyes is set at a concentration of 10% and for classification as irritating at a concentration of 5% for the AES of the category.

References:

Danish EPA - Environmental and Health Assessment of Substances in Household Detergents and Cosmetic Detergent Products (2001). Environmental Project No. 615, pp. 24-28

HERA (2003). Human & Environmental Risk Assessment on ingredients of European household cleaning products Alcohol Ethoxysulphates, Human Health Risk Assessment Draft, 2003. http: //www. heraproject. com.

Justification for selection of skin irritation / corrosion endpoint:
Reliable OECD guideline study.

Justification for selection of eye irritation endpoint:
Worst case assumed

Effects on skin irritation/corrosion: irritating

Effects on eye irritation: corrosive

Justification for classification or non-classification

According to the classification criteria of Directive 67/548/EEC and Regulation (EC) No 1272/2008 the test substance needs to be classified with Xi, R38/R41 and Skin Irrit. 2, H315 and Eye Dam.1, H318.

It could be shown with experimental data on eye irritation that below 10% active substance only the classification Eye Irrit. Cat.2 remains and below 5% active substance no classification at all is necessary. Hence, the Generic Concentration Limits (GCLs) can be substituted by the mentioned specific ones (SCLs).

Due to the fact, that these SCLs comply with the generic ones set in Directive 1999/45/EC (DPD), SCLs will only be applied according to Regulation (EC) 1272/2008 (CLP).