The following abstract presents results of a study conducted by a contract laboratory for the National Toxicology Program (NTP). The findings have not been peer reviewed and were not evaluated in accordance with the levels of evidence criteria established by the NTP on March 2009 (see http://ntp.niehs.nih.gov/ntp/htdocs/levels/09-3566%20NTP-ITOX-R1.pdf). The findings and conclusions for this study should not be construed to represent the views of the NTP or the US Government.
The Immunotoxicity of Triethanolamine
Contact Hypersensitivity Studies in Female B6C3F1 Mice
NTP Report Number: IMM90005
Triethanolamine, produced along with mono- and diethanolamine by ammonolysis of ethylene oxide, is used in many cosmetics, fatty acid soaps, household detergents and emulsions, wood scouring, and as a water repellent in textiles. U. S. production and sales for 1989 was estimated to be 72 x 108 lb. Although triethanolamine is a skin, eye, and mucous membrane irritant, no information could be found on its sensitizing potential.
Triethanolamine was obtained from the Texaco Chemical Co. (White Plains, N.Y.; Lot # 7G-60) and was determined to be > 99% pure by HPLC. The material was prepared in an acetone:olive oil mixture (4:1) which also served as the vehicle. Primary irritancy studies indicated that all concentrations of triethanolamine tested (up to 30%) were non-irritating. Female B6C3F1 mice were sensitized dermally to either 3%, 10%, or 30% solutions of triethanolamine daily for 5 consecutive days and challenged 7 days later with a 30% solution. A 0.5% solution of 1-fluoro-2,4-dinitrobenzene (DNFB, Sigma Chemical Corp., Lot #87F-3777, > 99% pure by HPLC) was used as a positive control. Site preparation included dermabrasion as well as intradermal injections of Freund's complete adjuvant into some mice. The animals were divided into 10 treatment groups of 8 mice per group as shown in Table 1. The irritancy response was determined by monitoring extravasation of 125I-bovine serum albumin into the treated area. The contact hypersensitivity response was assessed by monitoring the infiltration of 125I-iododeoxyuridine labeled cells into the challenge site and the mouse ear swelling test.
Table 1. Study Design: Contact Hypersensitivity Study with Triethanolamine
|2 (8)||Baseline Control||+||Vehicle||30% TEO|
|3 (8)||Experimental||+||3% TEO||30% TEO|
|4 (8)||Experimental||+||10% TEO||30% TEO|
|5 (8)||Experimental||+||30% TEO||30% TEO|
|6 (8)||DNFB Positive Control||-||0.5% DNFB||0.5% DNFB|
|7 (8)||DNFB Negative Control||-||Vehicle||0.5% DNFB|
|8 (8)||Baseline Control||-||Vehicle||30% TEO|
|9 (8)||Experimental||-||10% TEO||30% TEO|
|10 (8)||Experimental||-||30% TEO||30% TEO|
note: TEO = triethanolamine; FCA = Freund's complete adjuvant; DNFB = 1-fluoro-2,4-dinitrobenzene
There were no treatment-related effects on survival or body weights. There were no statistically significant or dose-related hypersensitivity responses to triethanolamine observed by either the radioisotopic method or the ear swelling test, with or without Freund's complete adjuvant. The positive response with 0.5% DNFB is shown for comparison (Group 6).
Under these experimental conditions, no statistically significant group or dose-dependent contact hypersensitivity responses to triethanolamine were observed in mice by dermal exposure.