In vitro assays as a tool for determination of VOCs toxic effect on respiratory system: A critical review

•Advantages and drawbacks of in vitro tests to measure VOCs toxicity are presented.•In this paper are discussed three important steps of such studies for indoor air.•A crucial step of toxicity testing is proper exposure of selected cells to the VOCs.•The best available solution in the VOCs toxicity testing seems to be the ALI system.•The choice of the biological test should depend on the toxic activity of VOCs.

This review provides a critical summary of the research on the toxic effects of volatile organic compounds (VOCs) on human health using in vitro assays performed over the last years.The quality of such studies depends on the appropriate generation of the standard gaseous mixture, the exposure of the cells to VOCs and selection of sensitivity/ selectivity of cellular activity assays. Each of these steps requires the use of special analytical equipment.Generating the standard gas mixture, in which the type of components and their concentration levels are stable and known (with given uncertainty of value), is a crucial factor in cell culture-based studies on air quality.The literature shows a clear role for VOCs in adverse respiratory system effects at high concentrations. The effects at environmentally relevant levels are still unknown. Future research should be carried out with more consistency in study design and focusing on the VOCs toxicity effect.