The following abstract presents results of a study conducted by a contract laboratory for the National Toxicology Program. The findings have not been peer reviewed and were not evaluated in accordance with the levels of evidence criteria established by NTP in March 2009. The findings and conclusions for this study should not be construed to represent the views of the NTP or the U.S. Government.
Glutaraldehyde (1,5-pentanediol) was the first compound selected for evaluation as a sensitizing agent for contact hypersensitivity in animals. Glu has many uses, including cold chemical sterilization, as a fixative, in tanning leather, as a preservative in cosmetics, as a treatment of certain dermatological disorders, and in endontic therapy. This wide variety of uses leads to relatively frequent dermal contacts with the agent. However, the low number of reports of hypersensitive reactions to Glu indicates a low incidence of sensitization. As a weak sensitizer of contact hypersensitivity in humans, Glu represents a stringent test for any animal model for the evaluation of potential sensitizing agents.
Glutaraldehyde was tested on female albino Hartley strain guinea pigs and female B6C3F1 mice. The doses of Glu were 0.3, 1.0, and 3.0% for sensitization and 10% for challenge. Guinea pigs received 100 µl by direct dermal application, for 14 consecutive days, to a site prepared by shaving and dermabrading. Mice received 20 µl by direct dermal application, for 5 consecutive days, to a prepared site. DNFB (1-fluoro-2,4- dinitrobenzene, 98%) was used as a positive control at a concentration of 1%. Guinea pigs and mice exposed to Glu showed no effects on body weight or body weight gain. Measurement of the contact hypersensitivity response was done by both visual evaluation (scoring) and radioisotopic assay.
Guinea pigs sensitized with concentrations of 1 and 3% Glu developed contact hypersensitivity reactions. No hypersensitivity reactions could be detected in mice following sensitization at any concentration tested. DNFB sensitization resulted in contact hypersensitivity reactions in both mice and guinea pigs.