Workers in four laboratories located in the basement of an office building developed pruritic skin lesions. Of the ten workers in these laboratories, eight began to complain of pruritus in the first week of May of 1993. The most consistent symptom was a prickling sensation on exposed skin, face and backs of hands and areas which would be rubbed by clothing. Small, red, papular lesions developed on the forearms and back of the hands of four workers. Two also reported hives. Symptoms usually resolved on weekends. A NIOSH health hazard evaluation was conducted at the site. Installation of fibrous glass insulation in the basement mechanical rooms began in early April of 1993, but was stopped when workers complained of an unpleasant smell from a xylene (1330207) based adhesive. A water based adhesive was substituted and work resumed on weekends starting in May. By the third week of May installation of the insulation was again progressing during the week as well. The fibrous glass insulation was often cut in the corridor adjacent to the laboratories. Rubbish bins containing discarded pieces of cut fibrous glass were often left in the hallways. Several deficiencies in the cleaning and circulation of air to the four laboratories were noted. The authors conclude that the most likely cause of the problem was exposure to glass fibers.