In response to requests for information made at the OSHA hearing on indoor environmental quality (IEQ), these posthearing comments were submitted. NIOSH has conducted at least 12 workplace evaluations where a previous IEQ investigation found environmental deficiencies. In one case the recommendations had not been implemented, and in three the follow up reports did not specify whether the recommendations had been followed. In the other eight cases some or all of the recommendations had been implemented. In five of these cases an improvement in environmental conditions was noted and in at least four of these, health complaints had decreased. There were 105 health hazard evaluation (HHE) reports of office buildings that NIOSH has analyzed as a group. Previous NIOSH HHE summaries provide no useful information on any associations between health problems and environmental tobacco smoke. In general, requests for evaluations of nonindustrial environments have generally involved health or comfort problems for which the causes were not understood. Even when workers complained of acute health effects of environmental tobacco smoke (ETS) during the course of a HHE, this information may or may not have been included in the study, and the summaries tallied only the primary problem in each building.