Occupational exposure to isothiazolinones. A study based on a product register.

A national data base on chemical products (the Danish Product Register (PROBAS)) was searched in order to survey occupational exposure to isothiazolinones. 5-chloro-2-methyl-4-isothiazolin-3-one/2-methyl-4-isothiazolin+ ++-3-one(MCI/MI) was registered in 550 products, 1,2-benzisothiazolin-3-one(BIT) in 156 products and 2-n-octyl-4-isothiazolin-3-one in 16 products. For the MCI/MI-containing products, of which 343 had information on concentration, 64% of the products contained above or equal to 0.001% (10 ppm) MCI/MI. Main product categories were paints, hair shampoos, skin care products, and cleaning agents. For BIT-containing products, of which 139 had information on concentration, 54% of the products contained above or equal to 0.01% (100 ppm) BIT. Main product categories were cleaning agents, polishes, and paints. Only a few products were registered with content of 2-n-octyl-4-isothiazolin-3-one and these were not studied further. The dermatological literature has often focused on isothiazolinones in cosmetics as the source of allergy. The present study showed that attention should also be paid to occupational exposure, as isothiazolinones occur in many industrial product categories.