Evaluation of an Azo and Two Anthraquinone Dyes for Allergic Potential

Two dye mixtures and the individual component dyes were evaluatedfor the potential to induce contact or pulmonary hypersensitivity.These dye mixtures were suspect because of anecdotal reportsof both pulmonary and contact hypersensitivity in assembly workers,and because the component dyes were structurally related todyes known to be contact sensitizers. One mixture consistedof disperse blue 3 (DB3) and disperse red 11 (DR11), which areanthraquinones, and the other mixture contained DR11 and solventred 1 (SR1), an azo dye. Contact hypersensitivity was examinedusing the local lymph node assay (LLNA) and a modified mouseear swelling test (MEST). Both the MEST and the LLNA indicatedthat SR1 has weak contact-sensitizing potential. None of theother individual dye compounds or the two mixtures were identifiedas contact sensitizers by either method. To evaluate the mixturesas potential pulmonary allergens, guinea pigs were repeatedlyexposed by inhalation (300 mg/m³ 6 hr/day) 5 days/week, for1 week. Weekly exposures were repeated three times with 2 weeksof nonexposure time in between. Guinea pigs were then challengedthrough the jugular vein using a dye-dimethylsulfoxide mixture.During the challenge, breathing mechanics (dynamic complianceand resistance) were measured in mechanically ventilated animals.Changes in these measurements, indicative of bronchoconstriction,were not observed in animals exposed to either dye mixture,nor were antibodies detected in the sera of exposed animalsusing individual dye-specific enzyme-linked immunosorbent assays.In conclusion, two methods indicate that SR1 may have contact-sensitizingpotential. There was no indication of contact-sensitizing potentialfor either DB3 or DR11 and no evidence that any of the dyescaused pulmonary hypersensitivity.