Unfortunately the XRF analyser does not identify the type of bromine present within the compound nor the compound itself. So while it serves as a useful tool for the presence of bromine it does not indicate whether the bromine is due to a brominated flame retardant (BFR) or some other bromine compound. Furthermore, the fact that this study is limited to polybrominated diphenyl ethers (PBDE) means that even if we assume that the XRF reading is in fact due to a brominated flame retardant (an acceptable assumption) it does not mean it is a BDE. The bromine reading can be caused by other polybrominated flame retardants such as hexabromocyclododecane (HBCDD or HBCD) or Tetrabromobisphenol A (TBBPA) or any of the other 75 lesser used brominated flame retardants.
However by using the concentration of individual BDEs obtained from laboratory analysis the XRF analysis results can be used to estimate a rough quantity of potential BDEs within the consumer product. The chemical analysis undertaken by the Institute for Environmental Studies of the Free University in Amsterdam, Holland, was used to identify the type and quantity of different congeners of the various brominated diphenyl ethers.
A review of literature of the type of products that contain BDEs identified a number of categories that needed to be investigated. BDE’s are prevalent in electrical and electronic equipment (TV, stereos, computers, printers, faxes, switches, plugs), household appliances (electrical heaters, hairdryers, hair tongs, dishwashers, fridges, kettles, toasters), furniture and upholstery (curtains, drapes, car interiors) and flooring materials (carpet, underlay). The testing was not solely limited to these products but a limitation of this study meant that due to time constraints the focus had to remain on these items. Seven major retail firms and a large car recycling company kindly agreed to the testing of these articles.
In Table E.1 the consumer product that contained the greatest percentage of bromine are listed for reference. Obviously the highest percentage of bromine present does not necessarily mean that it contains the largest total amount of bromine. The total bromine is dependent on the type of BDE and the total weight of the plastic component containing the BDE.
|Consumer Product||Part containing Br||
XRF – reading
|Approx % bromine content by Mass Footnote 23|
|Stereo CD player||Body||182548||18.3|
|Widescreen TV (retest value)||Back cover||172866||17.3|
|Multi-plug / power board||Body||152957||15.3|
|Fax machine||Thermal cover||99697||10.0|
|Oil heater||Plastic stand and controls||92961||9.3|
|Computer||Printed circuit board||89901||9.0|
|Iron||Handle and body||86332||8.6|
|Energy saving light||Plastic holder||56011||5.6|
As can be seen from the table the greatest values that were recorded by the XRF analyser were not on plastics that are in direct or close contact or to sources of significant heat. Interestingly, the levels of BFRs found in all types of power tools were much lower than expected. The tools tested ranged from hammer drills, circular saws, angle grinders and even heat guns for paint stripping, yet little or no BFRs were found.
Historically BFRs have been more prevalent when flame retardants were mandatory particularly in flooring, upholstery and curtains, in certain countries such as the UK (The Furniture and Furnishings (Fire) (Safety) Regulations 1988). Consequently 3 households were targeted that contained a variety of these products and importantly where the date of origin was known to be from different periods over the last 20 years. Surprisingly no brominated flame retardants appeared to be present in any of these items.
Similarly the amount of BFRs present in upholstery was much less than expected. None was found in furniture manufactured from Europe, only a very small amount from NZ made furniture mainly from the fabric (manufactured overseas) rather than the foam. Slightly larger amounts were found on occasions from imported furniture from Asia but still less than 0.1%, the current legal limit for goods produced in the EU.
At the car recyclers a variety of cars were tested that varied from the early 80’s to the mid 90’s. Manufacturers included Japanese (Toyota Corolla/Camry/Subaru Legacy), European (BMW), and Australian (GM Holden). On only a few occasions were BFRs found and this was limited to the interior hood lining of a Toyota Corolla late 80’s, interior side panel of a Mazda Astina 1992 and a seat of a Toyota Camry 1996. No bromine was detected in any other parts made from polymers.
As mentioned above BFRs were not found in any of the retail flooring outlets including; carpets, rugs or foam underlay. Most of the foam carpet underlay is manufactured by Dunlop® in New Zealand. Since they do not use BFRs for this product (personal communication) these findings confirm this.
A number of children’s clothes, footwear and toys particularly for the 0-5 year age group were tested. There was very limited presence of BFR with a maximum of 0.04% bromine being recorded. The only exception to this was children’s boaster car seats (0.27% Bromine) and bean bag refills (0.32% Bromine). Both of these are made from expanded polystyrene (EPS) like the under floor insulation material Expol® (0.39% Bromine). The brominated flame retardant used in modern EPS is not a polyBDE but is in fact hexabromocyclododecane (personal communication with the technical director of Expol). This is confirmed by the laboratory analysis that shows the absence of BDEs and presence of HBCD.
On several occasions plastics used in the manufacture, processing and packaging of food were tested and as to be expected no BFRs were present.
The limit of detection of the XRF analyser used is 10 ppm for bromine. This is well below the normal application rate of BFR’s. Calibrating the XRF for bromine is carried out prior to each test series, immediately after start-up, on two European Reference Materials (ERM).
Back to footnote reference 23 Note that the bromine content can relate to a variety of bromine compounds, not all flame retardants but most would fall in this group. Within the group of flame retardant many would contain more modern flame retardants, TBBP-A or non halogenated flame retardants (likely more the imports from the EU).