Chemical mass transfer of an organophosphate flame retardant between product source and dust in direct contact
(English)Manuscript (preprint) (Other academic)
Organophosphate flame retardants (OPFRs) are a group of semi-volatile organic compounds (SVOCs) which are ubiquitous and among the most abundant contaminants indoors. Despite the fact that their indoor presence has been shown to contribute significantly to human exposure and has been associated with potential health risks there is limited understanding as to how they are released from indoors sources. This study uses an emission micro-chamber to explore one of the currently understudied chemical migration pathways; direct transfer between a source material and settled dust in contact with the source. A tris(2-chloroisopropyl) phosphate (TCIPP)-treated insulation board is used as the source material. Rapid and substantial transfer was observed after only 8 h of source-dust contact, resulting in 80 times higher concentrations in dust compared to pre-experiment levels. Further time points at 24 h and 7 d showed similarly high average dust levels and the TCIPP in the dust and air in the chamber was calculated to be close to thermodynamic equilibrium during the experiment. It was concluded that TCIPP was effectively transferred from the insulation board to the dust on its surface and the surrounding air via gas-phase diffusion. As the TCIPP in the air and dust in the chamber appear close to equilibrium, there is no evidence from this experiment that TCIPP levels in dust in direct contact with product surfaces indoors would be enhanced compared to dust levels in the rest of the room. In a real room however where such well-mixed conditions as in the micro-chamber do not generally apply there might be a gradient of concentrations of TCIPP in air above the surface of a product. This could result in higher concentrations in dust sitting on the product than dust in the rest of the room.
Research subject Applied Environmental Science
IdentifiersURN: urn:nbn:se:su:diva-127261OAI: oai:DiVA.org:su-127261DiVA: diva2:907786