Volatile organic compounds (VOCs) have been implicated as causative agents in asthma and building-related illness. To determine whether a mixture of VOCs could impair lung function or cause airway inflammation among subjects without bronchial hyperresponsiveness, the authors conducted a randomized, crossover-design trial of controlled human exposures to filtered air for four hours, VOCs at 25 mg/m(3) for four hours, and VOCs at 50 mg/m(3) for four hours, using a VOC mixture based on sampling of indoor environments. VOC exposures caused dose-related increases in lower respiratory, upper respiratory, and non-respiratory symptoms, with no significant change in lung function (FEV(1);, FVC, or FEF(25-75), nasal lavage cellularity or differential cell counts, induced sputum cellularity or differential cell counts, or biomarkers of airway inflammation, including IL-8, LTB(4), or albumin in nasal lavage or induced sputum samples. Atopic individuals had significantly reduced FEE(25-75 following exposure to VOCs at 50 mg/m(3), suggesting that these individuals may be more sensitive to the health effects of VOCs. The authors conclude that reductions in levels of VOCs to substantially less than 25 mg/m(3) are required if a "non-irritating" work environment is desired.