Enhancement of Phthalate Emissions from Vinyl Flooring due to Partitioning to Particles

Jennifer L. Benning (1), Andrea J. Tiwari (2), Zhe Liu (2), John C. Little (2), LINSEY C. MARR (2)

(1) South Dakota School of Mines and Technology, Rapid City, (2) Virginia Tech, Blacksburg

     Abstract Number: 452
     Last modified: May 12, 2010

Abstract
Semi-volatile organic compounds (SVOCs) are present in many building materials and household products. The presence of airborne particles can enhance the emission rate of SVOCs from materials by providing extra surface area for adsorption. Exposure to di-2-ethylhexyl phthalate (DEHP), an SVOC widely used as a plasticizer, is associated with developmental and reproductive effects and increased incidence of allergies and asthma. The objectives of this study are to measure partitioning of DEHP to different types of aerosols and to validate a mechanistic model of SVOC emissions from building materials. We have developed an experimental chamber to measure emissions of DEHP from vinyl flooring, and we introduce three different types of particles—inorganic, organic, and soot—into the chamber. Using a novel experimental approach, we collect gaseous and total (gaseous plus particulate) DEHP on a sorbent tube with an upstream filter and one without, respectively. When particles are introduced to the chamber at a concentration of 10 to 120 micrograms per cubic meter, total DEHP concentrations increase by a factor of 2 to 6 due to enhanced emissions from the vinyl flooring. Measured partitioning coefficients of 0.031 to 0.12 cubic meters per microgram agree with model predictions to within 20-50%. Partitioning coefficients across the three particles types are more similar when calculated on the basis of particle surface area rather than mass. The results provide an improved understanding of the effect of airborne particles on emissions and transport of SVOCs in the indoor environment, an essential step if remediation and mitigation strategies for improving indoor air quality are to be successful.