Occupational psoriasis after exposure to rockwool

Rockwool belongs to the class of manmade vitreous fibers (MMVFs) or synthetic vitreous fibers (SVF), that are made primarily of glass, rock, slag, or clay and are classified in four general groups: glass filaments, mineral wool, refractory ceramic fibers, and fibers for special purposes. Mineral wool, including rockwool, glass wool, and slag wool, contains masses of entangled vitreous fibers with no visible three-dimensional order, of diameters ranging from 0.2 to about 10 μm. In some situations, SVF materials can release airborne fibers, some of which are small enough to be respirable. Thus, workers may be exposed to SVFs by skin contact and/or by inhalation. Rockwool fibers, like the other SVFs, are used widely as insulating materials in residential and industrial settings. They may irritate the skin of workers engaged in manufacturing, fabricating, or installing SVF products through direct handling and contact with contaminated clothes and personal protective equipment. This irritation is a mechanical reaction to sharp, broken ends of fibers that rub against, or become embedded in, the outer layer of the skin. Typically, the irritation can be relieved by washing exposed skin gently with warm water and mild soap, and disappears in a few days. In 2009, the EU changed the classification of MMVF products, and removed the old risk definition for chemical substances R38 (irritating to the skin) and the new hazard statements H315 (causes skin irritation), without considering the mechanical hazard linked to the exposure to these fibers. To our knowledge, we describe the first case of occupational psoriasis induced by rockwool.