Azodicarbonamide
Encyclopedia
Azodicarbonamide, or azobisformamide, is a synthetic chemical with the molecular formula C2H4O2N4. It is a yellow to orange red, odorless, crystalline powder. As a food additive
, it is known by the E number
E927.
, a flour bleaching agent
and improving agent. It reacts with moist flour as an oxidizing agent. The main reaction product is biurea (not urea
), which is stable during baking.
Secondary reaction products include semicarbazide
and ethyl carbamate
.
The United States allows azodicarbonamide to be added to flour at levels up to 45 ppm.
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.
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."
Azodicarbonamide may cause an allergic reaction in those sensitive to other azo compound
s, 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.
Food additive
Food additives are substances added to food to preserve flavor or enhance its taste and appearance.Some additives have been used for centuries; for example, preserving food by pickling , salting, as with bacon, preserving sweets or using sulfur dioxide as in some wines...
, it is known by the E number
E number
E numbers are number codes for food additives that have been assessed for use within the European Union . They are commonly found on food labels throughout the European Union. Safety assessment and approval are the responsibility of the European Food Safety Authority...
E927.
Use as a food additive
Azodicarbonamide is used in food industry as a food additiveFood additive
Food additives are substances added to food to preserve flavor or enhance its taste and appearance.Some additives have been used for centuries; for example, preserving food by pickling , salting, as with bacon, preserving sweets or using sulfur dioxide as in some wines...
, a flour bleaching agent
Flour bleaching agent
Flour bleaching agent is a food additive added to flour in order to make it appear whiter and to oxidize the surfaces of the flour grains and help with developing of gluten.Usual bleaching agents are:...
and improving agent. It reacts with moist flour as an oxidizing agent. The main reaction product is biurea (not urea
Urea
Urea or carbamide is an organic compound with the chemical formula CO2. The molecule has two —NH2 groups joined by a carbonyl functional group....
), which is stable during baking.
Secondary reaction products include semicarbazide
Semicarbazide
In organic chemistry, semicarbazide is a derivative of urea, where NH2 on one side has been replaced with H2NNH2 hydrazine, yielding H2NNHCNH2.Semicarbazide is used as a detection reagent on thin layer chromatography...
and ethyl carbamate
Ethyl carbamate
Ethyl carbamate is a chemical compound with the molecular formula C3H7NO2 first prepared in the nineteenth century. Structurally, it is an ester of carbamic acid...
.
The United States allows azodicarbonamide to be added to flour at levels up to 45 ppm.
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.
Safety
In the UK, the Health and Safety ExecutiveHealth and Safety Executive
The Health and Safety Executive is a non-departmental public body in the United Kingdom. It is the body responsible for the encouragement, regulation and enforcement of workplace health, safety and welfare, and for research into occupational risks in England and Wales and Scotland...
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."
Azodicarbonamide may cause an allergic reaction in those sensitive to other azo compound
Azo compound
Azo compounds are compounds bearing the functional group R-N=N-R', in which R and R' can be either aryl or alkyl. IUPAC defines azo compounds as: "Derivatives of diazene , HN=NH, wherein both hydrogens are substituted by hydrocarbyl groups, e.g. PhN=NPh azobenzene or diphenyldiazene." The more...
s, 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.