Azodicarbonamide
| Azodicarbonamide | |
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Carbamoyliminourea |
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Other names
Azodicarboxamide; Azobisformamide; C,C'-Azodi(formamide); Diazenedicarboxamide |
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| Identifiers | |
| CAS number | 123-77-3  |
| PubChem | 31269 |
| ChemSpider | 4575589 |
| UNII | 56Z28B9C8O |
| EC-number | 204-650-8 |
| ChEMBL | CHEMBL28517 |
| Jmol-3D images | Image 1 |
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| Properties | |
| Molecular formula | C2H4N4O2 |
| Molar mass | 116.08 g mol−1 |
| Appearance | Yellow to orange/red crystalline powder |
| Hazards | |
| MSDS | External MSDS |
| EU classification | Harmful (XN) |
| R-phrases | R42 R44 |
| S-phrases | S22 S24 S37 |
| NFPA 704 |
 1
2
2
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 (verify) (what is:  / ?)Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) |
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| Infobox references | |
Azodicarbonamide, or azobisformamide, is a synthetic chemical with the molecular formula C2H4O2N4.[1] It is a yellow to orange red, odorless, crystalline powder. As a food additive, it is known by the E number E927.
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[edit] Use as a food additive
Azodicarbonamide is used in food industry as a food additive, a flour bleaching agent and improving agent. It reacts with moist flour as an oxidizing agent.[2] The main reaction product is biurea[3] (not urea), which is stable during baking. Secondary reaction products include semicarbazide[4] and ethyl carbamate.[5]
The United States allows azodicarbonamide to be added to flour at levels up to 45 ppm.[6]
[edit] Other uses
The principal use of azodicarbonamide is in the production of foamed plastics as an additive. The thermal decomposition of azodicarbonamide results in the evolution of nitrogen, carbon monoxide, carbon dioxide, and ammonia gases, which are trapped in the polymer as bubbles to form a foamed article. Common examples of this application are window and door gaskets, padded floor mats, gym/exercise mats, shoe soles, etc.
Azodicarbonamide as used in plastics, synthetic leather and other uses can be pure or modified. This is important because modification affects the reaction temperatures. Pure azodicarbonamide generally reacts around 200 °C, but there are some products that the reaction temperature must be lower, depending on the application. In the plastic, leather and other industries, modified azodiarbonamide (average decomposition temperature 170 °C) contains additives that accelerate the reaction or react at lower temperatures.
Use of azodicarbonamide as a blowing agent in plastics is banned in Europe[7].
[edit] Safety
In the UK, the Health and Safety Executive has identified azodicarbonamide as a respiratory sensitizer (a possible cause of asthma) and determined that products should be labeled with "May cause sensitisation by inhalation."[8]
Azodicarbonamide may cause an allergic reaction in those sensitive to other azo compounds, such as food dyes. The consumption of azodicarbonamide may also heighten an allergic reaction to other ingredients in a food.
Toxicological studies of the reactions of azodicarbonamide show that it is rapidly converted to biurea in dough, which is a stable compound not decomposed upon cooking.[9]
[edit] See also
[edit] References
- ^ "Azodicarbonamide (CICADS)". Inchem. International Programme on Chemical Safety. http://www.inchem.org/documents/cicads/cicads/cicad16.htm#PartNumber:2. Retrieved 2010-08-14.
- ^ "Azodicarbonamide FCC Grade (98%)". Garuda International, Inc.. 2009-02-13. http://www.garudaint.com/product.php?id=86. Retrieved 2010-08-14.
- ^ Joiner, Robert (September 1963). "A New Powdered Agent for Flour Maturing". Cereal Chemistry 40: 539–553. http://www.aaccnet.org/cerealchemistry/backissues/1963/Chem40_539.pdf.
- ^ Becalski A, Lau BP, Lewis D, Seaman SW (2004-09-10). "Semicarbazide formation in azodicarbonamide-treated flour: a model study". Journal of agricultural and food chemistry (Journal of Agricultural and Food Chemistry) 52 (18): 5730–4. doi:10.1021/jf0495385. PMID 15373416.
- ^ Cañas, BJ; Diachenko, GW; Nyman, PJ (January 1997). "Ethyl carbamate levels resulting from azodicarbonamide use in bread". Food Additives & Contaminants 14 (1): 89–94. doi:10.1080/02652039709374501. PMID 9059587.
- ^ "CFR - Code of Federal Regulations Title 21". United States Department of Health and Human Services. 2009-04-01. http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfcfr/CFRSearch.cfm?CFRPart=172&showFR=1&subpartNode=21:3.0.1.1.3.9. Retrieved 2010-08-14.
- ^ "COMMISSION DIRECTIVE 2004/1/EC of 6 January 2004 amending Directive 2002/72/EC as regards the suspension of the use of azodicarbonamide as blowing agent". Official Journal of the European Union. 2004-01-13. http://eur-lex.europa.eu/LexUriServ/LexUriServ.do?uri=OJ:L:2004:007:0045:0046:EN:PDF. Retrieved 2011-03-10.
- ^ "Substances causing/worsening asthma". UK Occupational Health and Safety. WorkSafe Victoria. http://www.ohsrep.org.au/index.cfm?section=10&Category=69&viewmode=content&contentid=62. Retrieved 2010-08-14.
- ^ "054. Azodicarbonamide (FAO Nutrition Meetings Report Series 40abc)". FAO/WHO. 1966-10-18. http://www.inchem.org/documents/jecfa/jecmono/40abcj28.htm. Retrieved 2010-08-14.
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