On the basis of a NIOSH review of the scientific literature and information submitted in response to its 1987 and 1997 Federal Register notices, NIOSH concludes the following: 1) The weight of evidence supports the conclusion that exposure to certain types of CCP or its components has, under some conditions, resulted in symptoms or irritation of the skin and of the mucosal membranes or the eyes and upper respiratory tract. 2) Exposure to CCP or its components may rarely cause allergic contact dermatitis. 3) Systemic reactions have occurred in a few persons exposed to CCP. 4) Data are insufficient to evaluate claims of other adverse health effects and reports (such as neurologic effects and reports of multiple chemical sensitivity (MCS) that have been suggested in some of the clinical reports submitted to the NIOSH docket. In conclusion, although the weight of the evidence indicates that exposure to CCP in the past has resulted in adverse health effects, it is uncertain whether current formulations of CCP represent a significant risk to exposed workers. NIOSH recognizes that it may occasionally be necessary to limit CCP exposure in certain workers through administrative controls (such as job rotation). But in most cases, implementing normal precautions and recommendations for maintaining acceptable indoor air quality should be adequate to reduce or eliminate symptoms.