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 The findings have not been peer reviewed and were not evaluated in accordance with the levels of evidence criteria established by NTP in March 2009.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.
2,4,7-Trinitrofluoren-9-one was selected for evaluation as a sensitizing agent for contact hypersensitivity in mice. TNIF is used in photocopiers. It forms charge-transfer complexes with aromatic hydrocarbons and amines.
The objective of this study was to determine the sensitizing potential of 2,4,7-trinitrofluoren-9-one when applied dermally to female B6C3F1 mice.
2,4,7-Trinitrofluoren-9-one was tested on female B6C3F1 mice. The doses of 2,4,7-trinitrofluoren-9-one ranged from 1.0% to 5.0% in acetone/olive oil for sensitization and 5.0% for challenge. Mice received 20 µl by direct dermal application for 5 consecutive days to a prepared site. Site preparation included intradermal injection of Freund's complete adjuvant in some mice. 1-fluoro-2,4-dinitrobenzene, 99.3%, Sigma Chemical Co.) was used as a positive control at a concentration of 0.25% for sensitization and 0.5% for challenge. Measurement of the contact hypersensitivity was accomplished by the radioisotopic assay and the Mouse Ear Swelling Test.
A statistically significant (p<0.05) and dose-dependent (p<0.05) contact hypersensitivity response to 2,4,7-trinitrofluoren-9-one was demonstrated. This response is not, however, considered biologically significant since it was observed only by MEST of adjuvant pretreated animals on day +1, it was not observed on day +2 or by the radioisotopic assay and was not observed following a second round of sensitization and challenge in another group of animals.
The studies were conducted at the Medical College of Virginia Immunotoxicology Laboratory.