Hexabromocyclododecane

Fixed

2.24 to 2.38 g · cm -3

  • 3.0 x 10-5 Pa ( technical mixture, 25 ° C)
  • 3.0 x 10-4 Pa ( α - HBCD, 25 ° C)
  • 4.3 x 10-5 Pa ( β - HBCD, 25 ° C)
  • 2.4 x 10-5 Pa ( γ - HBCD, 25 ° C)

Practically insoluble in water:

  • 2.3 mol · l -7 ( technical mixture, 25 ° C)
  • 2.8 mol · l -6 ( α - HBCD, 25 ° C)
  • 9.9 mol · l -7 ( β - HBCD, 25 ° C)
  • 1.7 mol · l -7 ( γ - HBCD, 25 ° C)

Attention

> 10 g · kg -1 ( LD50, rat, oral)

Template: Infobox chemical / molecular formula search available

Hexabromocyclododecane (HBCD or HBCDD ) is an additive flame retardant, which is used mainly in polystyrene foam in high impact polystyrene and upholstered furniture. This is achieved in particular that develop local fires slower. In the polymer matrix, it is not chemically bound, but as a homogeneous dispersion.

Properties

Chemical Properties

HBCD 16 exist isomers which differ in the spatial arrangement of six covalently bound bromine substituents. In industrial products, the α -, β - and γ the isomer occur.

Use

The main application areas of HBCD are the insulation foams EPS (expanded polystyrene foam ) and XPS ( extruded polystyrene rigid foam). By equipping with HBCD is achieved that polystyrene is classified as "flame resistant ". In addition, HBCD was up in 2013 as a flame retardant in HIPS housings, textiles and upholstery use. Typical use concentrations of HBCD were around 0.7 % in EPS, XPS and 2.5% in 6-15 % in textiles. The industrial consumption in Europe was estimated in 2001 to around 9500 tonnes per year. The global annual consumption was 16,700 tons.

Analysis

To analyze the isomer usually chromatographically separated (eg by HPLC ) at selected cyclodextrin. The detection by mass spectrometry usually with the HPLC/MS- or GC / MS coupling. In biological matrices, is a more complex sample preparation, usually with a primary extraction of the total lipid extract, and subsequent purification by silica gel columns and / or lipophilic gel chromatography is required.

Environmental relevance

HBCD can pass through various processes in the environment and comes in trace concentrations in all environmental compartments such as air, water and soil. In sediments in sludge and fish in high concentrations of the α - isomer were detected. In a survey conducted by WWF study HBCD was also found in the blood of European parliamentarians.

In 2008, HBCD was added as a PBT substance in the list of SVHC. In the latest draft of the Directive 2002/95/EC RoHS HBCD is added to the banned substances. The material was recorded in May 2013 in the Stockholm Convention on Persistent Organic Pollutants. For use as a flame retardant is considered a world-wide production and application prohibition. For the main application area as additional insulation panels in a one-year exemption rule applies.

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