Difference between revisions of "Urea peroxide"

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*Oxidizing organic compounds
*Oxidizing organic compounds
*Separating the adduct into its constituent substances without losing either

Revision as of 18:42, 23 February 2016

urea peroxide
Other names
Carbamide Peroxide
Molar mass 94.07 g·mol−1
Appearance White solid
Melting point 75 to 91.5 °C (167.0 to 196.7 °F; 348.1 to 364.6 K) (decomposes)
500 g/l
Vapor pressure 23.3 mm Hg ( 30 °C)
Safety data sheet ReagentWorld
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references

Urea peroxide is a crystalline adduct composed of equal amounts of hydrogen peroxide and urea. It is used in commercial tooth-whiteners, and to loosen impacted earwax. It is also used to make plastics.



Urea peroxide is a convenient replacement for 90% hydrogen peroxide in oxidation reactions.

In aqueous solution it behaves identically to a solution of urea and hydrogen peroxide added separately to water. Urea can be separated from this adduct by dissolving it in water and adding manganese dioxide which catalyses the decomposition of hydrogen peroxide; this way you can obtain high grade urea, but the peroxide is lost. Separating the two compounds without losing either is more tricky; one method involves using calcium or barium hydroxides to precipitate peroxide, leaving urea dissolved, and, after filtering out the alkaline earth metal peroxide, recovering hydrogen peroxide from it with sulfuric acid. This, however, requires a very concentrated solution of the adduct, decanted or vacuum-filtered from a sludge of wet powdered percarbamide.


Urea peroxide is a free flowing white powder.


97% urea peroxide is available from Sigma Aldrich. In various countries it is also available in drugstores, under the names "Percarbamide" or "Hydroperite".


Urea peroxide is prepared by combining 3:2 molar quantities of hydrogen peroxide and urea.


  • Oxidizing organic compounds
  • Separating the adduct into its constituent substances without losing either



Inhalation of dust causes irritation of nose from hydrogen peroxide formed when heated. Contact with eyes causes severe damage. Contact with moist skin causes temporary itching or burning sensation. Ingestion causes irritation of mouth and stomach.

Forms dangerous peroxides with ethers and ketones.

Can be made to explode.


Urea hydrogen peroxide is an oxidizing agent. Liable to spontaneous combustion when heated or in contact with organic materials. The contents of a screw-capped brown glass bottle spontaneously erupted after four years storage at ambient temperature. [MCA Case History No. 719]. Combustion may release Irritating ammonia gas.


Hydrolysis of urea peroxide gives urea and hydrogen peroxide.


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