Sulfonic acids, C14-16 (even numbered)-alkane hydroxy and C14-16 (even numbered)-alkene, sodium salts

Endpoint summary

Description of key information

oral: OECD 401: LD50 rat = 2079 mg/kg bw

dermal: comparable to OECD 402: LD50 rabbit = 6300 mg/kg bw

inhalative: comparable to OECD403: LC50 rat (4h) > 52 mg/L

Key value for chemical safety assessment

Acute toxicity: via oral route

Endpoint conclusion

Endpoint conclusion:

adverse effect observed

Dose descriptor:

LD50

Value:

2 079 mg/kg bw

Quality of whole database:

The available information comprises an adequate and reliable study (reliability 1) and supporting data with slight qualitative deficiencies. Taken together, the information from these independent sources is consistent and provides sufficient quality for hazard assessment. Therefore, the available information as a whole is sufficient to fulfil the standard information requirements set out in Annex VII, section 8.5 of Regulation (EC) No 1907/2006.

Acute toxicity: via inhalation route

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

discriminating conc.

Value:

0.052 mg/m³ air

Quality of whole database:

The available information comprises an adequate and reliable study (reliability 2) with slight qualitative deficiencies. The information from this key study is of sufficient quality for the hazard assessment. Therefore, the available information is sufficient to fulfil the standard information requirements set out in Annex VIII, section 8.5 of Regulation (EC) No 1907/2006.

Acute toxicity: via dermal route

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

LD50

Value:

6 300 mg/kg bw

Quality of whole database:

The available information comprises an adequate and reliable study (reliability 2) with slight qualitative deficiencies. Further data available are of insufficient quality and therefore not suitable for hazard assessment. The information from the key study is of sufficient quality for the hazard assessment. Therefore, the available information as a whole is sufficient to fulfil the standard information requirements set out in Annex VIII, section 8.5 of Regulation (EC) No 1907/2006.

Additional information

Sulfonic acids, C14-16 (even numbered)-alkane hydroxy and C14-16 (even numbered)-alkene, sodium salts was tested via the oral, dermal and inhalative route. There are 3 studies and a literature review on Sulfonic acids, C14-16 (even numbered)-alkane hydroxy and C14-16 (even numbered)-alkene, sodium salts available as data sources for the oral route. The key study demonstrated an LD50 of 2079 mg/kg bw in the rat, recalculated to neat test substance (Markert & Weigand, 1984a). In this study the test substance contained 90% active ingredient and was well characterized, impurities were reported, and the experimental groups included an appropriate amount of male and female animals. In the available review (Ter Haar, 1983a) the testing of 6 different samples of 36.9% Sulfonic acids, C14-16 (even numbered)-alkane hydroxy and C14-16 (even numbered)-alkene, sodium salts in male rats is described, and although documentation is limited, acceptable LD50 values, ranging from 3800 to 4500 mg/kg bw and referring to active ingredient, are reported, which are acceptable for assessment. Another study report is available, conducted with a test substance containing 35% active ingredient (Weigand, 1972). This study demonstrates an LD50 of 2210 mg/kg bw in female rats, recalculated to active ingredient, which is comparable to that provided by the key study. These values for acute toxicity are also in accordance with those for alkyl sulphates of comparable chain lengths, which are similar in structure and comparable in their toxicological behaviour, and demonstrate acute oral LD50 values of 3000 and > 8000 mg/kg bw for C14 alkyl sulphate, sodium salt and C16 alkyl sulphate, sodium salt, respectively, in the mouse and > 4010 mg/kg bw for C14-18 alkyl sulphates, sodium salt in rats. In the last study on acute oral toxicity (Sterner, 1973) the test substance was not characterised, doses were referred to as volume per body weight and had to be recalculated to weight per body weight on the basis of the expected density and the given purity of 34.1%. Therefore, although representing the most sensitive result with an LD50 of 1379 mg/kg bw, the last available study was not chosen for assessment because the documentation is too limited and this result is in contradiction to the rest of the available data for Sulfonic acids, C14-16 (even numbered)-alkane hydroxy and C14-16 (even numbered)-alkene, sodium salts and for alkyl sulphates, which are comparable in structure and overall characteristics.

Two data sources are available providing information concerning dermal toxicity of Sulfonic acids, C14-16 (even numbered)-alkane hydroxy and C14-16 (even numbered)-alkene, sodium salts. The first one, which is the key study, is the aforementioned review on alpha olefin sulfonates (AOS), in which 6 different samples with 36.9% C14-16 AOS were tested (Ter Haar, 1983a). For dermal toxicity LD50 values ranging from 6300 to >16000 mg/kg bw were determined, referring to active ingredient. The conclusion of the author was that the dermal LD50 for C14-16 AOS is > 6000 mg/kg bw. A second review by Arthur D. Little, Inc. on the 'Environmental and Human Safety of Major Surfactants, Volume 1. Anionic Surfactants, Part 4. Alpha Olefin Sulfonates', reported to 'The Soap and Detergent Association', further mentions 2 unpublished industry studies claiming dermal LD50 values ranging from 578 to 2150 mg/kg bw. No further details were mentioned, study references were not reported. The reported dermal LD50 values reported by those studies are even lower than those derived for acute oral toxicity by the majority of the available data sources. This assumption is not plausible as toxicokinetic data demonstrate that absorption via the intact skin is negligible. Therefore, and according to the limited documentation and the missing study references, these data sources were not considered acceptable for assessment.

The only source of data on inhalative toxicity available for Sulfonic acids, C14-16 (even numbered)-alkane hydroxy and C14-16 (even numbered)-alkene, sodium salts (C14 -16 AOS) is the aforementioned review by Arthur D. Little, Inc. (1993a), reported to 'The Soap and Detergent Association'. Information on the preparation of the test material, the purity and the exposure of the animals is provided in that review. An LC50 of 229 mg/L air for a 1-hour exposure to C14-16 AOS with 90% active ingredient is reported, which was converted to an LC50 of 52 mg/L air for a 4-hour exposure to neat test substance, based on Haber's law and in accordance to the Guidance to Regulation (EC) No 1272/2008 on classification, labelling and packaging (CLP) of substances and mixtures. According to this document it is accepted practice to adjust LC50 values obtained from studies with exposure durations differing from the standard 4-hour exposure length using Haber’s law (c* t = K). Based on this equation the effect K is directly proportional to concentration c and exposure time t, therefore, an effect observed after 1-hour exposure at a certain concentration c should be equivalent to an effect observed after 4 hours at a fourth of the original concentration: K = c/4 * 4t. This division factor of 4 is further recommended by the aforementioned Guidance document for the conversion of exposure times to dusts and mists (aerosols) as described in the data source. Therefore, this information is acceptable and sufficient for regulatory purposes. Besides, inhalation is not the most relevant route of exposure, as Sulfonic acids, C14-16 (even numbered)-alkane hydroxy and C14-16 (even numbered)-alkene, sodium salts is manufactured and marketed as aqueous solution to a great extent, and data on the other 2 exposure routes is available, as well.

Justification for selection of acute toxicity – oral endpoint

The most reliable study (guideline study in compliance with GLP, reliability 1) was selected as key study and therefore chosen for the hazard assessment.

Justification for selection of acute toxicity – inhalation endpoint

The only availalable study comprised adequate quality (reliability 2) and was therefore selected as key study for the hazard assessment.

Justification for selection of acute toxicity – dermal endpoint

The most reliable study (reliability 2) was selected as key study and therefore chosen for the hazard assessment.

Justification for classification or non-classification

Based on the available data Sulfonic acids, C14-16 (even numbered)-alkane hydroxy and C14-16 (even numbered)-alkene, sodium salts does not meet the criteria to be classified for acute toxicity according to EU Directive 67/548/EEC and Regulation (EC) No 1272/2008.