You are here:
Migration of Organophosphorus Flame Retardants from Sources to Settled Dust
Citation:
Liu, X. Migration of Organophosphorus Flame Retardants from Sources to Settled Dust. 16th Conference of the International Society of Indoor Air Quality and Climate (ISIAQ) (Indoor Air 2020, virtual), Durham, North Carolina, November 01 - 05, 2020.
Impact/Purpose:
Because of their extensive use in industrial and consumer products and their low vapor pressure, Organophosphorus flame retardants (OPFRs), such as tris(2-chloroethyl) phosphate (TCEP), tris(1-chloro-2-propyl) phosphate (TCPP), and tris(1,3-dichloro-2-propyl) phosphate (TDCPP) are ubiquitous and important contaminants of indoor dust. Acute and chronic adverse health effects, including carcinogenicity, immune and endocrine disruption, and adverse reproductive and neurodevelopmental effects related to animals and humans have been reported for OPFRs. This research investigated the migration of OPFRs from the surfaces of contaminated sources to settled dust under different conditions in small chamber tests. This study shed light on the relationship between OPFR concentrations in settled dust and air and the partitioning of OPFRs between the gas phase and settled dust indoors. The results help to fill the data gaps required for estimating indoor exposures and developing strategies that enlighten risk assessments and policy decisions to minimize exposures and protect human health. It supports EPA Office of Pollution Prevention and Toxics (OPPT) action plan chemicals for chemical assessments under the Toxic Substances Control Act.
Description:
Organophosphorus flame retardants (OPFRs) are used in high amounts as additives in industrial and consumer products, such as electrical and electronic products, furniture, plastics, textile, and building construction materials. Due to their relatively low volatility, OPFRs have slow emissions but long-term effects in the indoor environment. They can leach or diffuse out of the products and are released to the surrounding air and accumulate in indoor dust, leading to human exposure with acute and chronic adverse health effects. Limited information is available on the mechanisms through which OPFRs migrate from contaminated sources into dust on the surface of the sources. This research studied the transfer of OPFRs, tris(2-chloroethyl) phosphate (TCEP, CAS# 115-96-8), tris(1-chloro-2-propyl) phosphate (TCIPP, CAS# 13674-84-5), and tris(1,3-dichloro-2-propyl) phosphate (TDCIPP, CAS# 13674- 87-8), from different sources to settled dust on the source surfaces through direct contact. Six tests were conducted in the 53L stainless steel small chambers at 23°C, 50% relative humidity and different air change rates (0.25, 0.5, and 1 h-1). The OPFR sources were polyisocyanurate rigid polyurethane foam and alkyl paint. The settled dusts include house dust and Arizona Test Dust. The OPFR migration rates and partition coefficients were determined. The impacts of ventilation and dust loading on the OPFR migration from source surface to dust were also investigated. This study sheds light on the correlation of OPFR concentrations in settled dust and the surface materials. The results could help to fill the data gaps required for interpreting the exposure data and for risk assessment.