Polyurethane heat preservation materials: The significant sources of organophosphorus flame retardants

The concentrations and compositions of organophosphorus flame retardants (OPFRs) in various heat preservation materials from different brands and types in China were investigated, as well as their OPFR burdens and emission amounts. The average concentrations of ΣOPFRs were 41.4 ± 10.2, (7.1 ± 4.0) × 10⁴, and 56.3 ± 19.3 μg/g in phenolic foams (PF), polyurethane foams (PUR), and extruded polystyrene boards (XPS), respectively. OPFRs in the PUR materials were ∼3 orders of magnitude higher than those in the other two materials, suggesting that organophosphate esters were added as flame retardants (FRs) in the PUR materials. Obvious variations in the concentrations and compositions of OPFRs were discovered in those heat preservation materials due to their material types, brands, and fire-ratings, as well as contaminations. TCIPP was the most dominant OPFR with a range from 22.3 (in PF) to 6.73 × 10⁴ (in PUR) μg/g, which emphasized that TCIPP was the most commonly used flame retardant additives in China. Based on the OPFR concentrations, OPFR emission rates, and application amounts of heat preservation materials, we calculated the total burdens of OPFRs in those materials and their emission amounts in China. The potential total burden of OPFRs in the completed new buildings of China in 2017 was estimated to be ∼(2.37 ± 1.11) × 10⁴ t, while the total emission of OPFRs from those new materials was ∼3.19 ± 1.65 t/y. As significant sources of OPFRs, the heat preservation materials used in exterior or interior walls may pose potential health risks to humans.