Sulfuric acid, mono-C12-14(even numbered)-alkyl esters, ammonium salts

Endpoint summary

Description of key information

No data are available for the target substance sulfuric acid, mono-C12-14 (even numbered)-alkyl esters, ammonium salts (CAS 90583-11-2). Therefore, read-across from structural analogue substances has been applied.

skin irritation (equivalent or similar to OECD 404): irritating

Read-across from structural analogue source substance sodium dodecyl sulfate (CAS 151-21-3), supported by an additional study with a structural analogue substance.

eye irritation (OECD 405): serious eye damage

Read-across from structural analogue source substance sulfuric acid, mono-C12-16-alkyl esters, potassium salts (CAS 90583-12-3), supported by additional studies with structural analogue substances.

SCLs for eye irritation / severe eye damage according to Regulation (EC) No. 1272/2008 (CLP):

>= 10% < 20% Eye Irrit. Cat. 2, H319

< 10% no classification for eye irritation / serious eye damage

Key value for chemical safety assessment

Skin irritation / corrosion

Link to relevant study records

Reference

Endpoint:

skin irritation: in vivo

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Remarks:

Summary of available data used for the endpoint assessment of the target substance.

Adequacy of study:

key study

Justification for type of information:

Refer to the Category Approach Justification document provided in IUCLID6 Section 13

Reason / purpose for cross-reference:

read-across source

Reason / purpose for cross-reference:

read-across source

Irritation parameter:

erythema score

Basis:

mean

Time point:

24/48/72 h

Score:

2.2

Max. score:

4

Reversibility:

not fully reversible within: 72 h

Remarks on result:

other: Source, key, 151-21-3, 1976

Irritation parameter:

edema score

Basis:

mean

Time point:

24/48/72 h

Score:

1.7

Max. score:

4

Reversibility:

not fully reversible within: 72 h

Remarks on result:

other: Source, key, 151-21-3, 1976

Irritation parameter:

erythema score

Basis:

mean

Time point:

48 h

Remarks on result:

not measured/tested

Irritation parameter:

edema score

Basis:

mean

Time point:

48 h

Remarks on result:

not measured/tested

Irritant / corrosive response data:

No information regarding time point 48 h are given in the study report.

Interpretation of results:

other: Skin irrit. 2, H315. Classification according to Regulation (EC) No. 1272/2008 (CLP/EU GHS).

Conclusions:

Exposure of shaved skin for 24 h to the neat test substances under occlusive conditions yielded distinct erythema and edema formation.

Executive summary:

The skin irrtation / corrosion potential of the target substance is estimated based on an adequate and reliable in vivo key study of a structural analogue source substances. Exposure of shaved skin for 24 h to the neat test substances under occlusive conditions yielded distinct erythema and edema formation. Effects were not fully reversible within the 72 h observation period of the study. The skin reactions observed fulfil the classification criteria for skin irritation, category 2, as defined in Regulation (EC) No. 1272/2008. Therefore, a skin irritation potential is also identified for the target substance. As explained in the category justification, the differences in molecular structure between the target and the source substances are unlikely to lead to differences in the skin irritation / corrosion potential.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (irritating)

Eye irritation

Link to relevant study records

Reference

Endpoint:

eye irritation: in vivo

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Remarks:

Summary of available data used for the endpoint assessment of the target substance.

Adequacy of study:

key study

Justification for type of information:

Refer to the Category Approach Justification document provided in IUCLID6 Section 13

Reason / purpose for cross-reference:

read-across source

Reason / purpose for cross-reference:

read-across source

Reason / purpose for cross-reference:

read-across source

Reason / purpose for cross-reference:

read-across source

Irritation parameter:

cornea opacity score

Basis:

animal #1

Time point:

24/48/72 h

Score:

1

Max. score:

4

Reversibility:

not reversible

Remarks on result:

other: Source, key, 90583-12-3, 1988

Irritation parameter:

iris score

Basis:

animal #1

Time point:

24/48/72 h

Score:

0

Max. score:

2

Remarks on result:

other: Source, key, 90583-12-3, 1988

Irritation parameter:

conjunctivae score

Basis:

animal #1

Time point:

24/48/72 h

Score:

2

Max. score:

3

Reversibility:

not reversible

Remarks on result:

other: Source, key, 90583-12-3, 1988

Irritation parameter:

chemosis score

Basis:

animal #1

Time point:

24/48/72 h

Score:

1

Max. score:

4

Reversibility:

not reversible

Remarks on result:

other: Source, key, 90583-12-3, 1988

Interpretation of results:

other: Eye damage 1, H318. Classification according to Regulation (EC) No 1272/2008 (CLP/EU GHS)

Conclusions:

Application of a 30% aqueous solution of the test substance to the eyes of a rabbit resulted in severe effects regarding corneal opacity, conjunctival and chemosis responses. Effects were not fully reversible within the 21 days period of the test.

Executive summary:

The eye irritation potential of the target substance is estimated based on an adequate and reliable in vivo study of a structural analogue source substance. Application of a 30% aqueous solution of the test substance to the eyes of a rabbit resulted in severe effects regarding corneal opacity, conjunctival and chemosis responses. Effects were not fully reversible within the 21 days period of the test. No reaction with respect to iridial effects were observed at any time during the study period. The eye reactions observed fulfil the classification criteria for eye damage, category 1, as defined in Regulation (EC) No. 1272/2008. As explained in the category justification, the differences in molecular structure between the target and the source substances are unlikely to lead to differences in the eye irritation potential.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (irreversible damage)

Respiratory irritation

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

There are no data on skin and eye irritation / corrosion available for the target substance sulfuric acid, mono-C12-14 (even numbered)-alkyl esters, ammonium salts (CAS 90583-11-2). Therefore, these endpoints are covered by read-across from structurally related alkyl sulfates (AS). The possibility of a read-across from 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 physico-chemical, 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, neutralised 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 represents the predominant attribute in mediating effects on mammalian health. Therefore, the members of the AS category have similar physico-chemical, 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.

Ammonium sulfate is used to produce AS NH4 within the current AS category. There is a substantial data base on ammonium sulfate online available. Ammonium sulfate is not listed in Annex VI of Regulation (EC) No. 1272/2008 (CLP). In addition, the effects of ammonium sulfate on human health were assessed by the OECD in the SIDS initial assessment report [3]. Ammonium sulfate gives no rise to concern of adverse effects on human health. Therefore, a contribution of ammonium sulfate to the effects on human health is considered to be negligible when assessing human health effects of the target substance sulfuric acid, mono-C12-14 (even numbered)-alkyl esters, ammonium salts (CAS 90583-11-2).

Skin irritation

Since no data for the target substance are available, a key study performed with the analogue substance sodium dodecyl sulfate (CAS 151-21-3) is used to evaluate this endpoint. The result of the key study is further supported by another study with the analogue substance sulfuric acid, mono-C12-16-alkyl esters, ammonium salts (CAS 90583-12-3).

The key study conducted with sodium dodecyl sulfate (CAS 151-21-3, analytical purity 100%) was performed similar to OECD Guideline 404 under occlusive conditions (BASF, 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. No scoring was done 48 h after application. 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.

A supporting study conducted with sulfuric acid, mono-C12-16-alkyl esters, ammonium salts (CAS 90583-12-3, analytical purity 30%) was performed according to OECD Guideline 404 under semiocclusive conditions (BASF, 1987a). Each of five Kleinrusse white rabbits was exposed for 4 h to 0.5 mL of the unchanged test item and was observed for a period of 21 days for erythema and edema. Skin reactions were scored 24, 48 and 72 h after termination of treatment. The mean erythema and edema score after 24, 48 and 72 h were 3.9 and 3.5. The skin reactions were fully reversible within the 21 day observation period. In consequence, the test substance was classified as skin irritating category 2 according to Regulation (EC) No. 1272/2008 (CLP).

Eye irritation

Data regarding eye irritation are read-across from the structural analogue substance sulfuric acid, mono-C12-16-alkyl esters, ammonium salts (CAS 90583-12-3) as no data for the target substance are available.

In an OECD guideline 405 key study (BASF, 1988a) 0.1 g of sulfuric acid, mono-C12-16-alkyl esters, ammonium salts (CAS 90583-12-3, analytical purity 30%) was applied to the eye of one rabbit (strain: Kleinrusse). The observation period was 21 days. Eye reactions were scored 24, 48 and 72 h after application. The mean (24, 48 and 72 h reading) cornea, iris, conjunctivae and chemosis scores were 1, 0, 2 and 1. The corneal and the conjunctival findings as well the chemosis did not revers fully until days 21. Thus, the test item produced irreversible effects on the eye at a concentration of 30 %.

Definition of specific concentration limits (SCL)

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, one study with sulfuric acid, mono-C12-13-alkyl esters, potassium salts (CAS 91783-22-1) and two studies with sulfuric acid, mono-C10-16-alkyl esters, sodium salts (CAS 68585-47-7) with a concentration range of 10 to 22% were evaluated.

In the study with sulfuric acid, mono-C12-13-alkyl esters, potassium salts (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 (P&G, 1978b) without rinsing. 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 eye damaging.

The first study with 0.1 mL undiluted sulfuric acid, mono-C10-16-alkyl esters, sodium salts (CAS 68585-47-7, analytical purity 10%) was performed similar to OECD guideline 405 (Stepan, 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 1.4, 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 sulfuric acid, mono-C10-16-alkyl esters, sodium salts (CAS 68585-47-7, analytical purity 10%) was performed similar to OECD guideline 405 (Stepan, 1980b). 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%.

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%.

Respiratory inhalation

No data on respiratory irritation are available for the target substance sulfuric acid, mono-C12-14 (even numbered)-alkyl esters, ammonium salts (CAS 90583-11-2). Alkyl sulfates are mainly used in liquid media and due to their very low vapour pressure [2] inhalation is not considered 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.

 

[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

[3] http://webnet.oecd.org/HPV/UI/SIDS_Details.aspx?Key=2c80d506-86bf-4719-be9b-d922022506ec&idx=0

Justification for classification or non-classification

According to the classification criteria of the CLP Regulation (EC) No. 1272/2008, structural analogue substances need to be classified as Skin Irrit. 2, H315, and Eye Damage 1, H318. Based on read-across the target substance sulfuric acid, mono-C12-14 (even numbered)-alkyl esters, ammonium salts (CAS 90583-11-2) is, therefore, also classified accordingly.

It could be demonstrated with experimental data on eye irritation that at 10 to 20% active substance only the classification as Eye Irrit. 2, H319, according to the CLP Regulation (EC) No. 1272/2008 is warranted. Below 10% active substance, no classification at all is necessary. Hence, the generic concentration limits (GCLs) can be replaced by the specific concentration limits (SCLs).