Biological monitoring for exposure to volatile organic compounds (VOCs) (IUPAC Recommendations 2000)

This paper deals with the appropriate application of biological monitoring (BM) for exposure to volatile organic compounds (VOCs). Sampling guidelines, approved analytical procedures, quality control systems, detailed aspects for the interpretation of biomonitoring data, a compilation of international biological action values for VOC exposure at the workplace (e.g., BAT, BEI®), and state of the art reference values are outlined or referred to in this review for recommendation as guidelines for health professionals in occupational and environmental settings.VOCs are frequently encountered at the workplace, in daily routines and widely used consumer products. They cover a broad spectrum of chemical classes with different physicochemical and biological properties. Inhalation is a prominent route of exposure due to their volatility but many VOCs can quite readily be absorbed through the skin. BM allows assessment of the integrated exposure by different routes including inhalation and concomitant dermal and oral uptake—a helpful tool for relating exposure to body burden and possible health effects. Because of the different toxicological profiles of VOCs, no uniform approach for BM can be recommended. VOCs in blood and urinary VOC metabolites are most often applied for BM. Limit values for workplace exposure have been established for many VOCs. In this field, profound analytical methodology and extensive experience exist in numerous international scientific laboratories for reliable routine application. Contamination and loss of VOCs during specimen collection, storage and sample treatment, and applied calibration procedure are the most important uncertainties for analytical quantification of VOCs in blood. For interpretation of the analytical results appropriate time of sampling, according to toxicokinetics of the compound, is crucial due to VOC elimination with short but differing biological half-lives. Lifestyle factors (such as smoking habits, alcohol consumption, and dietary habits), workload, personal working habits, exposure to VOC mixtures and endogeous factors (as genetic polymorphism for VOC metabolizing enzymes, body mass) contribute to BM results and have to be considered in detail. Future analytical work should focus on the improvement of analytical methodology of VOC determination in body fluids at low-level environmental exposure and evaluation of corresponding reference intervals.