Azodicarbonamide

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Azodicarbonamide
Azodicarbonamide.png
Identifiers
CAS number123-77-3 YesY
PubChem31269
ChemSpider4575589 YesY
UNII56Z28B9C8O YesY
EC-number204-650-8
ChEMBLCHEMBL28517 YesY
Jmol-3D imagesImage 1
Properties
Molecular formulaC2H4N4O2
Molar mass116.08 g mol−1
AppearanceYellow to orange/red crystalline powder
Melting point225 °C (437 °F; 498 K) (decomposes)
Hazards
MSDS[1]
EU classificationHarmful (XN)
R-phrasesR42 R44
S-phrasesS22 S24 S37
NFPA 704
Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
 YesY (verify) (what is: YesY/N?)
Infobox references
 
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Azodicarbonamide
Azodicarbonamide.png
Identifiers
CAS number123-77-3 YesY
PubChem31269
ChemSpider4575589 YesY
UNII56Z28B9C8O YesY
EC-number204-650-8
ChEMBLCHEMBL28517 YesY
Jmol-3D imagesImage 1
Properties
Molecular formulaC2H4N4O2
Molar mass116.08 g mol−1
AppearanceYellow to orange/red crystalline powder
Melting point225 °C (437 °F; 498 K) (decomposes)
Hazards
MSDS[1]
EU classificationHarmful (XN)
R-phrasesR42 R44
S-phrasesS22 S24 S37
NFPA 704
Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
 YesY (verify) (what is: YesY/N?)
Infobox references

Azodicarbonamide, or azo(bis)formamide, is a chemical compound 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.

Uses[edit]

As a food additive[edit]

As a food additive, azodicarbonamide is used as a flour bleaching agent and a dough conditioner.[2] It reacts with moist flour as an oxidizing agent.[3] The main reaction product is biurea, a derivative of urea, which is stable during baking.[3] Secondary reaction products include semicarbazide and ethyl carbamate.[2]

Safety and regulation[edit]

As a food additive, azodicarbonamide is not authorised for use in Australia and the European Union.[4]:548[5] In the United States, azodicarbonamide has generally recognized as safe (GRAS) status and is allowed to be added to flour at levels up to 45 ppm.[6][4]:548

Other uses[edit]

The principal use of azodicarbonamide is in the production of foamed plastics as a blowing agent. 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.

Azodicarbonamide is used in plastics, synthetic leather, and other industries and can be pure or modified. Modification affects the reaction temperatures. Pure azodicarbonamide generally reacts around 200 °C. In the plastic, leather, and other industries, modified azodicarbonamide (average decomposition temperature 170 °C) contains additives that accelerate the reaction or react at lower temperatures.

Safety and regulation[edit]

Azodicarbonamide as a blowing agent in plastics has been banned in the European Union since August 2005 for the manufacture of plastic articles that are intended to come into direct contact with food.[7]

In the UK, the Health and Safety Executive has identified azodicarbonamide as a respiratory sensitizer (a possible cause of asthma) in workplace settings and determined that containers of it should be labeled with "May cause sensitisation by inhalation."[8] The World Health Organization has linked azodicarbonamide to "respiratory issues, allergies and asthma" for individuals at workplaces where azodicarbonamide is manufactured or handled in raw form. The available data are restricted to these occupational environments. Exposure of the general public to azodicarbonamide could not be evaluated because of the lack of available data.[9]

References[edit]

  1. ^ "Azodicarbonamide (CICADS)". Inchem. International Programme on Chemical Safety. Archived from the original on 24 August 2010. Retrieved 2010-08-14.  Also published by World Health Organization, Geneva, 1999.
  2. ^ a b FDA Frequently Asked Questions on Azodicarbonamide (ADA) Page Last Updated: 20 June, 2014
  3. ^ a b WHO FAO 1965. Toxicological Evaluation of Some Antimicrobials, Antioxidants, Emulsifiers, Stabilizers, Flour-Treatment Agents, Acids and Bases: Azodicarbonamide FAO Nutrition Meetings Report Series No. 40A,B,C. WHO/Food Add./67.29
  4. ^ a b Smith, Jim; Hong-Shum, Lily (2011). Food additives data book (2nd ed.). Chichester, West Sussex: Wiley-Blackwell. ISBN 978-1405195430. 
  5. ^ European Commission. "European Union: Authorisation of Additives". Retrieved 2014-12-31. 
  6. ^ "21CFR172.806". Code of Federal Regulations. April 1, 2012. 
  7. ^ "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. Retrieved 2011-03-10. 
  8. ^ "Substances causing/worsening asthma". UK Occupational Health and Safety. WorkSafe Victoria. Retrieved 2010-08-14. 
  9. ^ "Concise International Chemical Assessment Document 16: Azodicarbonamide". World Health Organization. Retrieved 2014-02-05. 

External links[edit]