The risk factors for occupational contact dermatitis among workers in a medium density fiberboard furniture factory in Eastern Thailand.

The aim of this study was to determine the occupational exposure to formaldehyde on the medium-density fiberboard (MDF) dust and allergic contact dermatitis among the workers at a furniture factory. Data were collected from 439 subjects using questionnaires and patch testing to evaluate allergic contact dermatitis resulting from formaldehyde on wood dust exposure in the workplace. The geometric mean concentration of formaldehyde on MDF dust that the workers in the production department were exposed to was 2.07 ppm (GSD 4.54). Patch test results revealed that some subjects developed allergy to various substances, including epoxy resin (16.7%) and formaldehyde (5.6%). The odds ratios (95% CI) for contact dermatitis were 3.6 (1.7-7.3) among those with a history of metal allergy, 1.8 (0.6-5.2) whose family members having a history of allergic contact dermatitis. Exposure to MDF dust in the workplace should be reduced, as the current levels of exposure exceed the permissible OSHA standard.