This testimony summarized information and comments from NIOSH regarding the public hearing on indoor air quality. NIOSH has conducted over 1,500 health hazard evaluations for indoor air quality in nonindustrial workplaces. The current OSHA proposal is limited to nonindustrial work environments. NIOSH suggests the standard be applied to all indoor work environments where the industrial process is such that there are no special requirements related to air quality. Definitions are suggested for air contaminants, building related illness, building owners or lessees, rest rooms, designated person, and material impairment. Suggestions are offered regarding the written compliance form, design and housekeeping of indoor surfaces, thermal comfort parameters, operator training materials, checklist for visual inspection, maintenance of indoor air quality equipment, ventilation system operation, control for specific contamination sources, air quality during renovation and remodeling, record keeping, carbon-dioxide (124389) monitoring, comments on risk assessment, validity of the California building study data for estimating occupational risk in air conditioned buildings due to poor indoor air quality, and responses to specific questions.