Occupational vitiligo due to unsuspected presence of phenolic antioxidant byproducts in commercial bulk rubber.
O'Malley-MA; Mathias-CG; Priddy-M; Molina-D; Grote-AA; Halperin-WE
J Occup Med 1988 Jun; 30(6):512-516
A study of occupational vitiligo (skin depigmentation) in industrial workers was conducted. The study was initiated because of the occurrence of vitiligo in employees in the rubber injection molding department of a company manufacturing specialized cylindrical hydraulic pumps. The vitiligo was suspected to be chemically induced. A total of 200 workers, 159 males, 120 whites, currently employed in the rubber department and general production areas were given dermatological examinations. They also completed a questionnaire asking if they had any white spots on their skin. All rubber stock formulations and spray adhesives used in the injection molding process were reviewed to determine if they contained phenolic compounds known to cause chemical depigmentation. Samples of unprocessed solid bulk rubber and cured and uncured custom formulated rubber were heated to 150 degrees-C and the gaseous effluents were analyzed by gas chromatography/mass spectrometry (GC/MS). Samples of two antioxidants added to unprocessed solid bulk rubber were also analyzed. Fifteen subjects reported white spots on their skin. Five of these had clinically confirmed vitiligo. These subjects frequently handled rubber used in the injection molding process. None of the additives specified in the rubber formulations was a phenol or catechol. GC/MS showed the presence of 2,4-di-tert-butylphenol (96764) (DTBP) at concentrations of 0 to 0.05 percent in cured and uncured rubber samples. p-tert- Butylphenol (98544) (PTBP) was detected in unprocessed bulk rubber. The antioxidant samples contained 7.4 and 0.88 percent DTBP and 1 percent PTBP. Wipe sampling showed that skin exposure to DTBP could occur simply by handling the rubber. The authors conclude that the unsuspected presence of PTBP, a known depigmenting agent, in the rubber could have contributed to the outbreak. DTBP and PTBP were byproducts formed when the antioxidant agents were synthesized.
NIOSH-Author; Phenols; Chemical-analysis; Rubber-workers; Skin-disorders; Humans; Industrial-factory-workers; Antioxidants; Pigmentation-disorders
Journal of Occupational Medicine