Investigating PBDEs in electrical and vehicle waste to inform POPs regulations

The Challenge

Polybrominated diphenyl ethers (PBDEs) have been used as flame retardants in plastic and foam components in electrical and electronic equipment and motor vehicles since the 1970s. Specific PBDEs were added to the list of banned persistent organic pollutants (POPs) in 2009. However, the legacy of pre-2009 products becomes an issue for waste electronic and electrical equipment (WEEE) and end-of-life vehicles (ELVs) streams for many years.

Ahead of discussions regarding the setting of limits under the Persistent Organic Pollutants (POPs) regulations, DEFRA commissioned WRc to quantify the concentrations of the flame retardants present as individual congeners.

The Solution

A statistically based sampling programme was carried out at several metal shredder sites. A hand held X-Ray fluorescence instrument was used as a crude screening tool to identify WEEE plastics with elevated total bromine levels as a screen for elevated concentrations of brominated flame retardants. Analytical method development was required to quantify the low concentrations of individual PDBE congeners. The concentrations of listed PBDEs varied from <1 to 365000 mg/kg but were generally below 5000 mg/kg across key WEEE categories: TVs, industrial IT equipment, printed circuit boards, digiboxes, large household appliances, small household appliances, fridges and PC monitors.

The study considerably increased the body of evidence available to support POPs regulation discussions with the European Commission and provided a series of recommendations to refine it further, including expansion of the dataset to include ELVs. The identified levels indicated that as PDBE-containing goods would be discarded for many years, interventions would be required to prevent PDBE-contaminated plastics entering the plastic recyclate streams and importantly re-entering new product streams.