Registration Dossier

Administrative data

Description of key information

skin irritation (OECD 404): irritating
eye irritation (worst case assumption): highly irritating/corrosive
SCLs according to GHS:
>=10% - <20% Eye Irrit. Cat.2, R36
<10% 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

There is no study regarding skin and eye irritation/corrosion available for C9-11 AS Na (CAS 84501-49-5). Therefore this endpoint is covered by read across to structurally related alkyl sulfates (AS), i.e.C8 AS Na (CAS 142-31-4) and C12 AS Na (CAS 151-21-3) for skin irritation and C10-16 AS Na (CAS 68585-47-7) and C12-13 AS K (CAS 91783-22-1) for eye irritation.The possibility of a read-across to other alkyl sulfates in accordance with Regulation (EC) No 1907/2006 Annex XI 1.5 “Grouping of substances and read-across approach” was assessed. In Annex XI 1.5 it is given that a read-across approach is possible for substances whose physicochemical, toxicological and ecotoxicological properties are likely to be similar or follow a regular pattern as a result of structural similarity. The AS reported within the AS category show structural similarity. The most important common structural feature of the category members is the presence of a predominantly linear aliphatic hydrocarbon chain with a polar sulfate group, neutralized with a counter ion. This structural feature confers the surfactant properties of the alkyl sulfates. The surfactant property of the members of the AS category in turn represent the predominant attribute in mediating effects on mammalian health. Therefore, the AS of the AS category have similar physicochemical, environmental and toxicological properties, validating the read across approach within the category. The approach of grouping different AS for the evaluation of their effects on human health and the environment was also made by the OECD in the SIDS initial assessment profile [1] and by a voluntary industry programme carrying out Human and Environmental Risk Assessments (HERA [2]), further supporting the read across approach between structurally related AS.

Skin irritation

Regarding skin irritation one relevant study is available for the read-across substances C8 AS Na (CAS 142-31-4) and C12 AS Na (CAS 151-21-3).

In an OECD guideline 404 study, C8 AS Na (CAS 142-31-4, analytical purity 92.5%) was applied to 3 New Zealand rabbits under semi-occlusive conditions for 4 h (BASF, 2012c). Skin reactions were scored 1, 24, 48 and 72 h. The observation period was 14 d. Clinical observations comprised of scaling to severe scaling, incrustations, eczema like lesions, bloody, yellowish incrustations, yellowish discoloration of application site and plaque like incrustations. The mean erythema score after 24, 48 and 72 h was 3 for each rabbit. The mean edema scores after 24, 48 and 72 h were 2, 3.3 and 3 for animals 1, 2 and 3, respectively. Erythema and edema were not fully reversible within 14 d. Thus the test substance was classified as skin irritating Category 2 according to Regulation 1272/2008/EC.

The study conducted with C12 AS Na (CAS 151-21-3, analytical purity 100%) was performed similar to OECD Guideline 404 under occlusive conditions (Esposito, 1976). Each of six New Zealand White rabbits was exposed for 24 h to 0.5 mL of the unchanged test item and was observed for a period of 72 h for erythema and edema. The 48 h reading time point was missing. The mean erythema and edema score after 24 and 72 h were 2.2 and 1.7. Both were not reversible within 72 h. When using the higher value of the 24 and 72 h reading time point as value for the 48 h value (per animal) the mean erythema and edema score of all animals were 2.4 and 2.2, respectively. Thus the test substance was classified as skin irritating Category 2 according to Regulation 1272/2008/EC.

Conclusion on the skin irritating properties of C9-11 AS Na (CAS 84501-49-5)

Based on the results mentioned above the data on the read across substances justify a classification of C9-11 AS Na (CAS 84501-49-5) for skin irritation. According to CLP ≥ 10% C9-11 AS Na (CAS 84501-49-5) needs to be classified as H315, Skin Irrit. 2. No classification is required below 10% C9-11 AS Na (CAS 84501-49-5).

Eye irritation

No data are available for the neat substance allowing a definitive classification of C9-11 AS Na (CAS 84501-49-5). However, there are several studies investigating the eye irritating potential of alkyl sulfates (AS) which have shown that AS concentrations of 10% and higher are moderately to strongly irritating to rabbit eyes and that formulations containing more than 20% AS can cause serious eye damage. Unless data are available that show absence of the irritating potential as defined by the EC criteria the classification Eye Dam. 1, H318 according to Regulation (EC) 1272/2008 will be applied for the neat substance.

Setting of SCLs for eye irritation

As corrosion and irritation depends on the concentration of the substance in a solvent, further studies with lower concentrations of the read across substances were also considered to assess whether specific concentration limits can be set.

For this purpose a read across to structurally related AS, i.e C12-13 AS K (CAS 91783-22-1) and C10-16 AS Na (CAS 68585-47-7) with a concentration range of 10 to 22% was performed

In the study with C12-13 AS K (CAS 91783-22-1, analytical purity 44%) 0.1 mL of the diluted test item (1:1 mixture with water) was applied to one eye of each of three New Zealand White rabbits according to OECD guideline 405 without rinsing (Braun, 1978). In a second experiment with additional 3 rabbits the procedure was repeated but the treated eye was rinsed with 20 mL of lukewarm tap water 4 seconds after application of the test item. The eye reactions were recorded 1, 24, 48, 72 h and 4, 7, 14, 21 and 28 days in both experiments. The mean (24, 48 and 72 h reading) cornea, iris, conjunctivae and chemosis scores of experiment 1 were 2, 0.8, 2.1 and 1.7. The findings reversed in 2/3 animals within 14 days while 1/3 animals showed signs of irritation after 21 days. However, the signs of irritation show a clear tendency to decrease with time. No reading on day 28 was possible. Findings in the experiment with rinsing of the eye were less pronounced but irritating properties were also observed. As the ocular findings clearly reversed within 21 days the result of the study indicate the concentration of 22% to be the turning point between classification as severe damage to the eye and reversible eye damaging.

The first study with 0.1 mL undiluted C10-16 AS Na (CAS 68585-47-7, analytical purity 10%) was performed similar to OECD guideline 405 on three New Zealand White rabbits with an observation period of 7 days (Kukulinski, 1980). The mean (24, 48 and 72 h reading) cornea, iris, conjunctivae and chemosis scores over all animals were 1.4, 0.7, 2 and 1.6. Corneal opacity was still observed in 1/3 animals (scored 1) and conjunctival redness was still present in 2/3 animals (both scored 1) upon reading at day 7. Depending on the classification requirements the test substance is not or only moderate irritating to the eye at a concentration of 10%.

The second study with C10-16 AS Na (CAS 68585-47-7, analytical purity 10%) was performed similar to OECD guideline 405 (Kukulinski, 1980). 0.1 mL of the undiluted test item was instilled into one eye of each of three New Zealand White rabbits. Eye reactions were scored at least 24, 48 and 72 h and 14 days after application of the test item. The mean (24, 48 and 72 h reading) cornea, iris, conjunctivae and chemosis scores were 0.9, 0.7, 1.9 and 1.6. All findings were fully reversible within the observation period. Thus, the test substance showed no eye irritating properties at a concentration of 10%.

Conclusion on the eye irritating properties of C9-11 AS Na (CAS 84501-49-5)

Based on the above mentioned results with different concentrations of structurally related alkyl sulfates a cut of value for classification as severe irritating to eyes is set at a concentration of 20% and for classification as irritating at a concentration of 10%. Since the available data of the read-across substance C10-16 AS Na (CAS 68585-47-7) indicates no eye irritation potential at a concentration of 10%, no classification is required below 10% C9-11 AS Na (CAS 84501-49-5).

According to CLP ≥ 20% C9-11 AS Na (CAS 84501-49-5) needs to be classified as H318, Eye Dam. 1. Based on a weight of evidence approach ≥ 10 % - < 20% C9-11 AS Na (CAS 84501-49-5) needs to be classified as H319, Eye Irrit. 2 according to CLP. Below 10% no classification at all is required.

 

No data on respiratory irritation are available. AS is mainly used in liquid media and due to its very low vapour pressure [2] inhalation is not viewed as a significant route of exposure. Inhalation of AS may occur by inhalation of aerosols generated by spray cleaners or by inhalation of detergent dusts (e.g. washing powder). In both cases the substance will be used in low concentrations. However in case the substance is available as neat powder the substance will also be classified as STOT Single exp. Cat 3 according to CLP at concentrations exceeding 20%

 

[1] SIDS initial assessment profile, (2007); http://www.aciscience.org/docs/Alkyl_Sulfates_Final_SIAP.pdf

[2] (HERA Draft report, 2002); http://www.heraproject.com/files/3-HH-04-%20HERA%20AS%20HH%20web%20wd.pdf


Justification for selection of skin irritation / corrosion endpoint:
No study chosen as weight of evidence approach was followed.

Justification for selection of eye irritation endpoint:
No study chosen as weight of evidence approach was followed.

Effects on skin irritation/corrosion: irritating

Effects on eye irritation: corrosive

Justification for classification or non-classification

According to the classification criteria of Regulation (EC) No 1272/2008 the test substance needs to be classified with Skin Irritation Category 2, H315 and Eye Dam.1, H318, respectively. As the neat substance has to be classified as skin irritating, the substance will also be classified as “may cause respiratory irritation” (STOT SE3, H335) in case the substance is available as neat powder.

It could be shown with experimental data on eye irritation that at 10 to 20% active substance only the classification Eye Irritating Category 2 according to Regulation (EC) No 1272/2008 remains. Below 10% active substance no classification at all is necessary. Hence, the Generic Concentration Limits (GCLs) can be substituted by the mentioned specific ones (SCLs).