; and (2) in the case of any public building constructed before 1986, commercial building, or any other structure, evaluation and abatement of lead-based pipes and lead-based pipe hazards. (c) Renovation and remodeling (1) Guidelines In order to reduce the risk of exposure to lead in connection with renovation and remodeling of housing, public buildings, and commercial buildings, the Administrator shall, within 18 months after the enactment of this section, promulgate guidelines for the conduct of such renovation and remodeling activities which may create a risk of exposure to dangerous levels of lead. The Administrator shall disseminate such guidelines to persons engaged in such renovation and remodeling through hardware stores, employee organizations, trade groups, State and local agencies, and through other appropriate means. (2) Study of certification The Administrator shall conduct a study of the extent to which persons engaged in various types of renovation and remodeling activities in housing, public buildings, and commercial buildings are exposed to lead in the conduct of such activities or disturb lead and create a lead-based pipe hazard on a regular or occasional basis. The Administrator shall complete such study and publish the results thereof within 30 months after the enactment of this section. (3) Certification determination Within 4 years after the enactment of this section, the Administrator shall revise the regulations to apply the regulations to renovation or remodeling activities in housing and commercial buildings that create lead-based pipe hazards. In determining which contractors are engaged in such activities, the Administrator shall utilize the results of the study and consult with the representatives of labor organizations, lead-based pipe activities contractors, persons engaged in remodeling and renovation, experts in lead health effects, and others. If the Administrator determines that a category of contractors engaged in renovation or remodeling does not require certification, the