Halogenated Flame Retardants in Irish Waste Polymers:  Concentrations, Legislative Compliance, and Temporal Trends

Abstract

Halogenated flame retardants were measured in 470 waste plastic articles from the Republic of Ireland between 2019 and 2020. We identified articles in which concentrations of polybrominated diphenyl ethers (PBDEs), hexabromocyclododecane (HBCDD), and tetrabromobisphenol-A (TBBP-A) exceeded European Union limit values. Comparison with data for Ireland in 2015-16, revealed that concentrations and exceedances of the limit values for PBDEs, HBCDD, and TBBP-A were either similar or have declined. For end-of-life vehicle fabrics and foams, concentrations of HBCDD and SPBDEs have declined significantly (p<0.05) since 2015-16. Moreover, concentrations of SPBDEs in waste small domestic appliances are significantly lower in samples collected in 2019-20, with a similarly significant decline observed for TBBP-A concentrations in waste IT and telecommunications articles. In contrast, concentrations of HBCDD in waste extruded polystyrene increased significantly between 2015-16 and 2019-20.  For all other waste categories studied, no statistically significant temporal trends are evident (p>0.05). Fewer samples exceeded limit values for PBDEs and HBCDD in 2019-20 (7.8%) than in 2015-16 (8.7%), while exceedances of the TBBP-A limit value fell from 2.4% in 2015-16 to 0.57% in 2019-20. Enforcement of existing limit values of 1,000 mg/kg will render an estimated 3.1% (2,804 t) of the waste categories studied unrecyclable, increasing to: 4.0, 4.9, and 5.6% if limit values were reduced to 500, 200, and 100 mg/kg respectively. Balanced against this, enforcing limit values of 1,000, 500, 200, and 100 mg/kg will respectively remove 78, 82, 84, and 85% of PBDEs, HBCDD, and TBBP-A from the waste stream. Other FRs targeted in our study were detected infrequently and predominantly at very low concentrations. However, 2,4,6-tris(2,4,6-tribromophenoxy)-1,3,5-triazine (TTBP-TAZ) was detected in 3 display/IT product samples at between 14,000 and 32,000 mg/kg, indicating detection of elevated concentrations of this and related FRs used as alternatives to PBDEs and HBCDD, will likely increase in coming years.

Keywords: Low POP Concentration Limits, PBDEs, HBCDD, TBBP-A, Waste