| Hexabromocyclododecane | |
|---|---|
 |
|
| IUPAC name |
|
| Other names | Hexabromocyclododecane |
| Identifiers | |
| Abbreviations | HBCDD HBCD |
| CAS number | [] |
| SMILES |
|
| Properties | |
| Molecular formula | C12H18Br6 |
| Molar mass | 641.7 |
| Melting point |
186 °C (175–195 °C, depending upon isomer) |
| Solubility in water | 3.4 µg/L in water |
| Hazards | |
| EU classification | SVHC |
| R-phrases | R43 |
| S-phrases | S24 |
| NFPA 704 |
 1
2
0
|
| Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) | |
| Infobox references | |
Hexabromocyclododecane (HBCD or HBCDD) is a brominated flame retardant. It consists of twelve carbon, eighteen hydrogen, and six bromine atoms tied to the ring. Its primary application is in extruded (XPS) and expanded (EPS) polystyrene foam that is used as thermal insulation in the building industry. HBCD is highly efficient in this application so that very low levels are required to reach the desired flame retardancy. Typical HBCD levels in EPS are 0.7% and in XPS 2.5%. At present, according to BSEF, the brominated flame retardant industry panel, HBCD is the only suitable flame retardant for these applications. Any other flame retardant would likely need higher load levels in the polystyrene foam. Other uses are upholstered furniture, automobile interior textiles, car cushions and insulation blocks in trucks, packaging material, video cassette recorder housing and electric and electronic equipment. The industrial demand in Europe is estimated as 9500 tons per year.[1]
HBCD's toxicity and its harm to the environment are currently discussed. HBCD can be found in environmental samples such as birds, mammals, fish and other aquatic organisms as well as soil and sediment.[2] On this basis, on 28 October 2008 the European Chemicals Agency decided to include HBCD in the SVHC list[3], Substances of Very High Concern, within the REACH framework. HBCD has been found widely present in biological samples from remote areas and supporting evidences for its classification as Persistent, Bioaccumulative and Toxic (PBT) and undergoes long-range environmental transportation.[4]
Because HBCD has 16 possible stereo-isomers with different biological activities, the substance poses a difficult problem for manufacture and regulation. An article by Robin Law of the Centre for Environment, UK discusses this issue in depth.[5]
Due to its persistence, toxicity, and ecotoxicity, a global ban on HBCD is currently being considered under the framework of the Stockholm Convention on Persistent Organic Pollutants.[6] HBCD is also included on the list of substances added to a proposal to revise the RoHS (Restriction of Hazardous Substances) directive.[7] There is a large and increasing stock of HBCD in the anthroposphere, mainly in EPS and XPS insulation boards.[8]
References
- ^ BSEF 2001 Report
- ^ Covaci A, Gerecke AC et al. Hexabromocyclododecanes (HBCDs) in the environment and humans: a review, Environ. Sci. Technol. 2006 Jun 15;40(12):3679–88. PMID 16830527
- ^ ECHA SVHC Official List
- ^ ECHA HBCD SVHC Supporting Documentation
- ^ Hexabromocyclododecane Challenges Scientists and Regulators
- ^ "Stockholm Convention: Newly Proposed Chemicals". http://chm.pops.int/Convention/POPsReviewCommittee/Chemicalsunderreview/NewProposals/tabid/245/language/en-US/Default.aspx. Retrieved 2008-12-05.
- ^ RoHS Directive, proposed changes, December 2008
- ^ Dynamic Substance Flow Analysis Model for Selected Brominated Flame Retardants as a Base for Decision Making on Risk Reduction Measures, study for the Swiss National Science Foundation, 2007
External links
- An Overview of Alternatives to Tetrabromobisphenol A (TBBPA) and Hexabromocyclododecane (HBCD), University of Massachusetts Lowell, March 2006
- ECHA: MEMBER STATE COMMITTEE SUPPORT DOCUMENT FOR IDENTIFICATION OF HEXABROMOCYCLODODECANE AND ALL MAJOR DIASTEREOISOMERS IDENTIFIED AS A SUBSTANCE OF VERY HIGH CONCERN, 8 October 2008
- Factsheet BSEF - propaganda of producers of bromine chemicals
- Factsheet CEFIC-EFRA - propaganda of european chemical industry
- Greenwashing of bromine industry
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