Sulfuric acid, mono-C12-14 (even numbered)-alkyl esters, compds. with ethanolamine

Carcinogenicity

Description of key information

OECD 453, rat, combined chronic toxicity/carcinogenicity, oral: not carcinogenic
NOAEL = 1125 mg/kg bw/day; LOAEL > 1125 mg/kg bw/day

Key value for chemical safety assessment

Carcinogenicity: via oral route

Link to relevant study records

Reference

Endpoint:

carcinogenicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Comparable to Guideline study with acceptable restrictions.

Reason / purpose for cross-reference:

reference to same study

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 453 (Combined Chronic Toxicity / Carcinogenicity Studies)

Deviations:

yes

Remarks:

Some examinations like urinalysis are missing.

GLP compliance:

no

Remarks:

Tests were conducted prior to the implementation of GLP (1976-1978).

Species:

rat

Strain:

Wistar

Sex:

male/female

Details on test animals or test system and environmental conditions:

Diets were prepared by thoroughly mixing the appropriate quantity of Dobanol-25-sulphate HCB with a purified diet to provide feed containing the required amount of active ingredient, ie. the surfactant was not added to the diet as a part replacement for any ingredient, but was added “on top of the diet”.
Rats were individually housed and provided with diet and water ad libitum. The animals were inspected daily for signs of ill-health while body weights, and food and water intakes, were measured weekly for the first 13 weeks, again at week 16, and thereafter at intervals of 4 weeks until the end of the study.

Route of administration:

oral: feed

Vehicle:

other: plain diet

Analytical verification of doses or concentrations:

not specified

Duration of treatment / exposure:

2 years

Frequency of treatment:

Daily

Post exposure period:

none

Remarks:

Doses / Concentrations:
0, 0.015, 0.15, 1.5%
Basis:
nominal in diet

Remarks:

Doses / Concentrations:
0, 11, 113, 1125 mg/kg bw
Basis:
actual ingested

No. of animals per sex per dose:

45

Control animals:

yes, plain diet

Other examinations:

Animals dying or killed during the test received a full post-mortem examination at which tissues were taken for histological examination. Animals surviving to the end of the test were starved overnight and blood was taken under anaesthesia for haematology and biochemical measurements after which the animals were killed and a number of organs (heart, liver, spleen kidneys, testes, adrenals and brain) were removed and weighed. These organs and a range of other tissues from each rat were preserved for histological examination. Histological examination was undertaken on stained tissue sections from all animals fed the control diet and each dietary level of the test substances.

Clinical signs:

no effects observed

Mortality:

no mortality observed

Body weight and weight changes:

effects observed, treatment-related

Food consumption and compound intake (if feeding study):

effects observed, treatment-related

Food efficiency:

no effects observed

Water consumption and compound intake (if drinking water study):

effects observed, treatment-related

Ophthalmological findings:

not examined

Haematological findings:

no effects observed

Clinical biochemistry findings:

no effects observed

Urinalysis findings:

not examined

Behaviour (functional findings):

not examined

Organ weight findings including organ / body weight ratios:

effects observed, treatment-related

Gross pathological findings:

effects observed, treatment-related

Histopathological findings: non-neoplastic:

effects observed, treatment-related

Histopathological findings: neoplastic:

no effects observed

Details on results:

The test materials used in the individual studies were prepared by two different production methods (high conversion bleached or HCB; and low conversion, unbleached or LCU). They differed slightly in chain length distribution, the latter having a slightly higher proportion of the C15 AS. In both studies, the test material was dosed at 0, 0.015, 0.15 and 1.5% in the diet. There was no increase in tumor incidence, nor any impact on tumor type in either study. For both studies, approximately 70% of animals survived to study termination. Mortality was similar across dosage groups and controls.Animals in the 1.5% dose groups in both studies exhibited reduced food and water consumption, and slower growth rates. Within these high dose groups, there was a decreased number of total tumors and tumor-bearing animals. Elevated serum GPT, LDH and AP were observed in high dose males.
Increased absolute liver weights and liver to body weight ratios, hypertrophy of the hepatic parenchyma, increased relative testicular weights, reduced incidence and severity of chronic nephropathy and nephrocalcinosis, and reduced arterial medial hypertrophy were among the findings at the higher dose levels.

Relevance of carcinogenic effects / potential:

The material was not tumorigenic at the any dose level, including the highest dose of 1.5%.

Dose descriptor:

NOEL

Effect level:

> 1 125 mg/kg bw/day (actual dose received)

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: No neoplasm observed.

Remarks on result:

other: Effect type: carcinogenicity

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

NOAEL

1 125 mg/kg bw/day

Study duration:

chronic

Species:

rat

Carcinogenicity: via inhalation route

Endpoint conclusion

Endpoint conclusion:

no study available

Carcinogenicity: via dermal route

Endpoint conclusion

Endpoint conclusion:

no study available

Justification for classification or non-classification

The available data on carcinogenicity do not meet the criteria for classification according to Regulation (EC) 1272/2008 or Directive 67/548/EEC, and are therefore conclusive but not sufficient for classification.

Additional information

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 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.

There is a substantial data base on the counter ion monoethanolamine (MEA) online available. MEA is listed in Annex VI of Regulation 1272/2008. It is classified Acute Tox. 4; H302, H312 and H332 as well as Skin Corr. 1B; H314. Additionally a specific concentration limit is established for STOT SE3, H335 at concentrations ≥ 5% in Annex VI of Regulation 1272/2008. The effects of MEA on human health were assessed by the OECD in the SIDS initial assessment Report [3]. No long-term toxicity study with MEA is available. However in several in vitro and in vivo studies MEA did not show genotoxic potential. Therefore it is unlikely that MEA will possess carcinogenic effects. Thus, read across to alkyl sulfates with other counter ions is considered to be valid and reliable. This approach was also followed by the OECD in the SIDS initial assessment profile [1] and by the voluntary industry programme carrying out Human and Environmental Risk Assessments (HERA [2]).

 

A reliable combined chronic toxicity/carcinogenicity study was conducted with C12 -15AS Na (CAS 68890-70-0). For two combined chronic toxicity/carcinogenicity studies similar to OECD Guideline 453 C12-15AS Na (CAS 68890-70-0) was prepared by two different production methods (high conversion bleached or HCB; and low conversion, unbleached or LCU). The substances of these different production methods differed slightly in chain length distribution, the latter having a slightly higher proportion of the C15AS Na. In both studies, the test material was dosed at 0, 0.015, 0.15 and 1.5% in the diet. There was no increase in tumour incidence, nor any impact on tumour type in either study. For both studies, approximately 70% of animals survived to study termination. Mortality was similar across dosage groups and controls. Animals in the 1.5% dose groups in both studies exhibited reduced food and water consumption, and slower growth rates. Within these high dose groups, there were a decreased number of total tumours and tumour-bearing animals.

Other pathological findings are summarized in the Section Repeated dose toxicity. Increased absolute liver weights and liver to body weight ratios, hypertrophy of the hepatic parenchyma, increased relative testicular weights, reduced incidence and severity of chronic nephropathy and nephrocalcinosis, and reduced arterial medial hypertrophy were among the findings at the higher dose levels.

Alkyl sulfates (AS) show a consistent absence of mutagenic activity when tested in in-vitro and in-vivo tests. Neither AS nor its metabolites possess electrophilic functional groups or functional groups associated with mutagenic activity. Taken together with the results of the carcinogenicity studies, AS are considered as non-carcinogenic.

REFERENCES

[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] SIDS initial assessment report, (2013);

http://webnet.oecd.org/HPV/UI/SIDS_Details.aspx?key=8aefe41b-8499-4052-943f-f6dd6f8c5997&idx=0