VOL.: 77 (2000) (p. 381)
CAS No.:
5. Summary of Data Reported and Evaluation
5.1 Exposure data
Triethanolamine is a viscous liquid widely used as a corrosion inhibitor, a surface-active agent and an intermediate in various products including metalworking fluids, oils, fuels, paints, inks, cement, cosmetic and personal products, as well as herbicide and algicide formulations. Occupational exposure may occur by inhalation and dermal contact, particularly in metal-machining occupations. No data were available on environmental exposure to this substance. The general population may be exposed through contact with a variety of personal care products.
5.2 Human carcinogenicity data
Two cohort studies, two proportionate mortality studies and two nested case–control studies looked at cancer mortality or incidence among workers using metalworking fluids with ethanolamines as additives, with or without sodium nitrite. Small excesses were observed for cancers at various sites, in particular, stomach, oesophagus and larynx. In most of these studies, only associations with use of soluble oils or synthetic fluids were presented and no results were given specifically in relation to triethanolamine exposure. It is difficult to draw conclusions regarding triethanolamine using data from studies of exposures to these complex mixtures.
5.3 Animal carcinogenicity data
Triethanolamine was adequately tested for carcinogenicity in one study in mice and in one study in rats by oral administration in the drinking-water. No increase in the incidence of tumours was observed. It was also tested by dermal application in one study in rats and no increase in the incidence of tumours was found.
In a Tg.AC transgenic mouse model, dermal application of triethanolamine produced no increase in tumours.
5.4 Other relevant data
Triethanolamine is rapidly absorbed and excreted in rodent urine (about 60%) and faeces (about 20%), mainly in the unchanged form. Biodegradation of triethanolamine to monoethanolamine or diethanolamine or to any other putative metabolite has not been shown in rodents, nor has its incorporation into endogenous macromolecules. There is no evidence for formation of N-nitrosodiethanolamine from triethanolamine under physiological conditions.
In humans, triethanolamine is reported to be a skin sensitizer. Repeated dermal application of high concentrations of triethanolamine to rats led to a necrotizing inflammatory process in the skin.
Data on reproductive and developmental effects in humans were not available. No reproductive or developmental effects were produced when rats and mice were exposed by topical administration. Other routes of exposure have not been studied.
No data on the genetic and related effects of triethanolamine in humans were available to the Working Group.
Triethanolamine did not induce mutations in bacteria, unless nitrite was also present. It did not influence the frequency of micronuclei in mouse peripheral blood in vivo after dermal application. Triethanolamine did not induce unscheduled DNA synthesis, sister chromatid exchange, chromosomal aberrations or cell transformation in rodent cells in vitro. Triethanolamine had no effect on sex-linked recessive lethal mutations in Drosophila melanogaster or on gene conversion in Saccharomyces cerevisiae.
5.5 Evaluation
There is inadequate evidence in humans for the carcinogenicity of triethanolamine.
There is inadequate evidence in experimental animals for the carcinogenicity of triethanolamine.
Overall evaluation
Triethanolamine is not classifiable as to its carcinogenicity to humans (Group 3).
For definition of the italicized terms, see Preamble Evaluation.
Synonyms
See Also:
Toxicological Abbreviations
Triethanolamine (ICSC)