Leaching of halogen free and brominated flame retardants from plastics

This study will be presented in ” Sixth International Symposium On Flame Retardants” April 7-10, 2013, San Francisco, California.
Information about the production, distribution and consumption of flame retardants in electric and electronic (E&E) equipment (plastics) is well described. However, there is a knowledge gap in the amount of flame retardants leaching from plastics of electric and electronic (E&E) equipment to the environment. In the EU funded project ENFIRO, halogen free flame retardants (HFFR) are studied that are viable alternatives to specific commercial brominated flame retardants (BFR). Leaching studies of BFRs from different types of plastics have been described in literature, however, limited information on leaching of HFFRs is available
 ENFIRO studied15 HFFRs of which 6 are metal-based. Metal-based flame retardants are stable in plastic (polymer) products, but can leach, dissociate and enter the environment. Monitoring of the fate of metal-based HFFRs in the environment is difficult as metals can have various sources of emission. Leaching tests of HFFRs from plastics is an alternative method that may contribute to the exposure and risks assessment and understanding of the fate of HFFRs in the environment. The current study shows leaching properties of different HFFRs from polymers incomparison with BFRs. Thereby, the influences of pellets vs. moulded plates and pH on the leaching properties are studied. Two types of leaching protocols were tested. The TLCP protocol, from the US EPA, using worse-case leaching conditions (low pH) to simulate a municipal waste landfill, and studied if waste has toxic characteristics and is hazardous.
The second protocol (DIN 38414-S4) determines leaching by water (neutral pH), and has been widely used for regulatory purposes in Europe. We show that no differences in leaching properties between the DIN and TCLP methods for two metal-based PBT pellets were found. However, higherleaching rate coefficients of HFFRs from PBT pellets than PBT moulded plates were found, which is probably a
result of the differences in surface: volume ratio and the porosity of the materials. Also the influences ofnanoclay on the leaching behavior of the HFFRs have been studied.
More information : pdf format
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