Tetrabromobisphenol A
Encyclopedia
Tetrabromobisphenol A is a brominated flame retardant.
of bisphenol A
and is synthesized from this substance. Most commercial TBBPA products are of a relatively low purity, in fact containing a mixture of products brominated to varying extents. This is not generally considered to be a drawback, since in most applications of this substance (i.e. flame-retarding) it is the average %Br that is of importance. The mixture resulting from the bromination of bisphenol A is therefore not purified, allowing a more efficient, lower cost product.
. In the reactive application, TBBPA is bound chemically to the polymer
s. The main use are epoxy resins of printed circuit board
s. As an additive flame retardant it is used in acrylonitrile butadiene styrene
, which are used e.g. in TVs. The annual consumption worldwide has been estimated as 119,600 tons in 2001, of which 11,600 tons were used by the European industry.
, hydrosphere
, soil
, and sediment
s. It also occurs in sewage sludge and house dust. TBBPA has been the subject of an eight year evaluation under the EU Risk Assessment procedure which reviewed over 460 studies. The Risk Assessment was published on the EU Official Journal in June 2008. TBBPA will now go through REACH registration.
Synthesis
TBBPA is a derivativeDerivative (chemistry)
In chemistry, a derivative is a compound that is derived from a similar compound by some chemical or physical process. In the past it was also used to mean a compound that can be imagined to arise from another compound, if one atom is replaced with another atom or group of atoms, but modern...
of bisphenol A
Bisphenol A
Bisphenol A is an organic compound with two phenol functional groups. It is used to make polycarbonate plastic and epoxy resins, along with other applications....
and is synthesized from this substance. Most commercial TBBPA products are of a relatively low purity, in fact containing a mixture of products brominated to varying extents. This is not generally considered to be a drawback, since in most applications of this substance (i.e. flame-retarding) it is the average %Br that is of importance. The mixture resulting from the bromination of bisphenol A is therefore not purified, allowing a more efficient, lower cost product.
Uses
TBBPA can be used as reactive and additive flame retardantFlame retardant
Flame retardants are chemicals used in thermoplastics, thermosets, textiles and coatings that inhibit or resist the spread of fire. These can be separated into several different classes of chemicals:...
. In the reactive application, TBBPA is bound chemically to the polymer
Polymer
A polymer is a large molecule composed of repeating structural units. These subunits are typically connected by covalent chemical bonds...
s. The main use are epoxy resins of printed circuit board
Printed circuit board
A printed circuit board, or PCB, is used to mechanically support and electrically connect electronic components using conductive pathways, tracks or signal traces etched from copper sheets laminated onto a non-conductive substrate. It is also referred to as printed wiring board or etched wiring...
s. As an additive flame retardant it is used in acrylonitrile butadiene styrene
Acrylonitrile butadiene styrene
Acrylonitrile butadiene styrene is a common thermoplastic. Its melting point is approximately 105 °C ....
, which are used e.g. in TVs. The annual consumption worldwide has been estimated as 119,600 tons in 2001, of which 11,600 tons were used by the European industry.
Relevance
TBBPA emits from different processes to the environment and can be found in trace concentration in the atmosphereAtmosphere
An atmosphere is a layer of gases that may surround a material body of sufficient mass, and that is held in place by the gravity of the body. An atmosphere may be retained for a longer duration, if the gravity is high and the atmosphere's temperature is low...
, hydrosphere
Hydrosphere
A hydrosphere in physical geography describes the combined mass of water found on, under, and over the surface of a planet....
, soil
Soil
Soil is a natural body consisting of layers of mineral constituents of variable thicknesses, which differ from the parent materials in their morphological, physical, chemical, and mineralogical characteristics...
, and sediment
Sediment
Sediment is naturally occurring material that is broken down by processes of weathering and erosion, and is subsequently transported by the action of fluids such as wind, water, or ice, and/or by the force of gravity acting on the particle itself....
s. It also occurs in sewage sludge and house dust. TBBPA has been the subject of an eight year evaluation under the EU Risk Assessment procedure which reviewed over 460 studies. The Risk Assessment was published on the EU Official Journal in June 2008. TBBPA will now go through REACH registration.