Plastics additives in the indoor environment--flame retardants and plasticizers

Phthalic acid esters and phosphororganic compounds (POC) are generally known as semivolatile organic compounds (SVOCs) and are frequently utilized as plasticizers and flame retardants in commercial products. In the indoor environment, both compound groups are released from a number of sources under normal living conditions and accumulate in air and dust. Therefore, inhalation of air and ingestion of house dust have to be considered as important pathways for the assessment of exposure in living habitats. Especially in the case of very young children, the oral and dermal uptake from house dust might be of relevance for risk assessment. A critical evaluation of indoor exposure to phthalates and POC requires the determination of the target compounds in indoor air and house dust as well as emission studies. The latter are usually carried out under controlled conditions in emission test chambers or cells. Furthermore, chamber testing enables the determination of condensable compounds by fogging sampling. In the case of automobiles, specific scenarios have been developed to study material emissions on a test stand or to evaluate the exposure of users while the vehicle is driving. In this review, results from several studies are summarized and compared for seven phthalic esters and eight POC. The available data for room air and dust differ widely depending on investigated compound and compartment. Room air studies mostly include only a limited number of measurements, which makes a statistical evaluation difficult. The situation is much better for house dust measurements. However, the composition of house dust is very inhomogeneous and the result is strongly dependent on the particle size distribution used for analysis. Results of emission studies are presented for building products, electronic equipment, and automobiles. Daily rates for inhalation and dust ingestion of phthalic esters and POC were calculated from 95-percentiles or maximum values. A comparison of the data with results from human biomonitoring studies reveals that only a small portion of intake takes place via the air and dust paths.