Consumer products are important reservoirs and sources of organophosphate tri-esters and di-esters: Characteristics, mass inventory, and implication for waste management

Numerous studies documented the occurrence of organophosphate tri-esters (tri-OPEs) and di-esters (di-OPEs) in the environment. Little information is available on their occurrence in waste consumer products, reservoirs and sources of these chemicals. This study collected and analyzed 92 waste consumer products manufactured from diverse polymers, including polyurethane foam (PUF), polystyrene (PS), acrylonitrile butadiene styrene (ABS), polypropylene (PP), and polyethylene (PE) to obtain information on the occurrence and profiles of 16 tri-OPEs and 10 di-OPEs. Total concentrations of di-OPEs (18-370,000 ng/ g, median 1,700 ng/g) were one order of magnitude lower than those of tri-OPEs (94-4,500,000 ng/g, median 5,400 ng/g). The concentrations of both tri- and di-OPEs in products made of PUF, PS, and ABS were orders of magnitude higher than those made of PP and PE. The compositional patterns of OPEs varied among different polymer types but were generally dominated by bisphenol A bis(diphenyl phosphate), triphenyl phosphate, tris(1-chloro-2-propyl) phosphate, di-phenyl phosphate (DPHP), and bis (2-ethylhexyl) phosphate. Two industrially applied di-OPEs (di-n-butyl phosphate and DPHP) exhibited higher levels than their respective tri-OPEs, contrary to their production volumes. Some non-industrially applied chlorinated di-OPEs were also detected, with concentrations up to 97,000 ng/g. These findings suggest that degradation of tri-OPEs during the manufacturing and use of products is an important source of di-OPEs. The mass inventories of tri-OPEs and di-OPEs in consumer products were estimated at 3,100 and 750 tons/year, respectively. This study highlights the importance of consumer products as emission sources of a broad suite of OPEs.