EVALUATION OF AN AZO AND 2 ANTHRAQUINONE DYES FOR ALLERGIC POTENTIAL

Two dye mixtures and the individual component dyes were evaluated for the potential to induce contact or pulmonary hypersensitivity. These d ye mixtures were suspect because of anecdotal reports of both pulmonar y and contact hypersensitivity in assembly workers, and because the co mponent dyes were structurally related to dyes known to be contact sen sitizers. One mixture consisted of disperse blue 3 (DB3) and disperse red 11 (DR11), which are anthraquinones, and the other mixture contain ed DR11 and solvent red 1 (SR1), an azo dye. Contact hypersensitivity was examined using the local lymph node assay (LLNA) and a modified mo use ear swelling test (MEST). Both the MEST and the LLNA indicated tha t SR1 has weak contact sensitizing potential. None of the other indivi dual dye compounds or the two mixtures were identified as contact sens itizers by either method. To evaluate the mixtures as potential pulmon ary allergens, guinea pigs were repeatedly exposed by inhalation (300 mg/m(3), 6 hr/day) 5 days/week, for 1 week. Weekly exposures were repe ated three times with 2 weeks of nonexposure time in between. Guinea p igs were then challenged through the jugular vein using a dye-dimethyl sulfoxide mixture. During the challenge, breathing mechanics (dynamic compliance and resistance) were measured in mechanically ventilated an imals. Changes in these measurements, indicative of bronchoconstrictio n, were not observed in animals exposed to either dye mixture, nor wer e antibodies detected in the sera of exposed animals using individual dye-specific enzyme-linked immunosorbent assays. In conclusion, two me thods indicate that SR1 may have contact-sensitizing potential. There was no indication of contact-sensitizing potential for either DB3 or D R11 and no evidence that any of the dyes caused pulmonary hypersensiti vity. (C) 1994 Society of Toxicology.