Need for Additional Study of the Causes of Worker Symptoms in Office Buildings
The results of the analyses of the CHBS and the early BASE study data sets have indicated that emissions of VOCs from building materials, office machines, cleaning products and water-based paints may in some way account for SBS type symptoms commonly experienced by office workers. It is cautioned, however, that these results are only from two studies of relatively small numbers of buildings and that neither study attempted to incorporate concentrations of ozone, formaldehyde or other highly irritating pollutants. Some of these potent pollutants are expected not to be measured by standard sampling and analytical techniques. Furthermore, the concentrations of VOCs measured in office buildings are generally well below levels that are believed to elicit irritant symptoms when humans are exposed to the compounds individually or in simple mixtures. Thus, the causal mechanisms for irritant symptoms among office workers remain to be discovered.

Potential for Oxidation Reactions in Indoor Air to Cause Worker Symptoms
Recent studies of indoor air chemistry and the reaction of ozone with terpene hydrocarbons such as limonene, suggest that such oxidation reactions may produce strong airway irritants. In laboratory studies in which mice were exposed to the reaction products of terpene ozone mixtures, the identifiable products and residual reactants could not account for the observed reduction in respiratory rate (Wolkoff et al, 2000). The unexplained reduction in respiratory rate may be due to the formation of oxygenated species that are not captured by standard sampling and analytical techniques or chemically unstable intermediate compounds. Exposure of the eyes of human subjects to an aged mixture of ozone and limonene at low concentration (31 and 75 ppb, respectively) in single-blind experiments produced a significant increase in blink frequency relative to ozone and limonene tested individually (Kleno and Wolkoff, 2002). This experiment supports the hypothesis that products of reactive indoor air chemistry are strong irritants.