Legacy Flame Retardants, Emerging Flame Retardants and Dioxins: Links and Tools for Risk Assessment

Some classes of brominated flame retardant (BFR) such as PBDEs and HBCDD are now well established as legacy contaminants. More evidence and association between these classes of chemicals and negative impacts on the environment and health are being reported, and as a result restrictions on their use are being imposed. As a result of these restrictions, new flame retardants are being placed on the market. These are usually chemicals with similar properties and which are documented regarding production and use as FRs where they have been shown to occur/ distribute to the environment and/or wildlife, humans or other biological matrices, are classed as ‘emerging’ contaminants.

Chemicals that are documented as potential FRs and have been shown to be present in materials or products are termed ‘novel’ flame retardants, and the term ‘potential’ FRs has been used for chemicals reported to have applications as FRs (e.g. in patents). Many of these organo-bromine compounds have the potential when they break down to form brominated dioxins and related compounds. These are potentially more toxic than the parent compounds but are rarely considered in risk assessments for BFRs. There is also a potential for mixed chloro- bromo- dioxins to be produced where there is also a source of chlorine present. Analysis for dioxins is complex, and whilst more widely available now that a few years ago, is still usually confined to chlorinated congeners. Exposure estimates and risk assessments for dioxins do not usually consider brominated and mixed halogenated congeners. Work done to estimate relative potencies for brominated and bromo- chloro-dioxins and furans will be described and the importance of holistic risk assessments that covers both FRs and dioxins will be discussed.

Watch the presentation here.