Indoor air quality investigators often sample many volatile organic chemicals but with insufficient knowledge of their potential impacts on occupants. Studies performed in North American offices and residences since 1990 were reviewed and central tendency and maximum VOC concentrations were summarized by building type. These concentrations http://terra.site11.com were assessed relative to various guideline values for odor, sensory irritancy and noncancer chronic toxicity to identify compounds that may reach levels of concern. These comparisons revealed that less than one-fifth of the 106 VOCs studied reached levels that were ?10% of guideline values. Guidelines are needed for other VOCs and other health endpoints.