Anthraquinone dyes in a variety of functions from drug formulations fabric colorative to area markings as might be used of the military. The effects of a prototype violet dye mixture (VDM) consisting of: Disperse Red 11 (DR11) 1,4-diamino-2-methoxy-anthraquinone and Disperse Blue 3 (DB3) 1-methylamino-4-hydroxyethylamino-anthraquinone on F344 male and females rats have been investigated. Acute inhalation exposures (6 hr) to VDM ranged from 1000 mg/cu m, with an additional exposure to 40 mg/cu m 6 hr/day for 5 days (MMAD's ranged from 3.37 to 4.95 micrometers). Histopathology and/or liver function was evaluated at 0, 3 and 7 days post. Unexpected lethality due to severe liver damage was observed with acute exposures of > or = to 300 mg/cu m and in the 5 day 40 mg/cu m exposure. In addition, nasal olfactory epithelium exhibited degeneration and necrosis with acute exposures > or - 10 mg/cu m. Lung instillations were performed using 250, 500, and 1000 micrograms of the VDM. No lung or liver toxicity was observed. These data led us to suspect oral exposure via preening to be the critical process. Gavage studies confirmed this. The enzymatic homology between the liver and olfactory epithelium for these compounds is not fully understood, but the potentiated impact of the individual dyes emphasizes the need to utilize mixtures in assessing real-world toxic risks.