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Skeletal formula of BCDMH
Ball-and-stick model of BCDMH
Laboratory sample of BCDMH
IUPAC name
Other names
bromochloro-5,5-dimethylhydantoin, BCDMH, agribrom, aquabrom, aquabrome, bromicide, di-halo, halogene T30, nylate, photobrome, slimicide 78P
3D model (JSmol)
ECHA InfoCard 100.036.557
Molar mass 241.47 g/mol
Appearance White solid
Density 1.9 g/cm3
Melting point 159 to 163 °C (318 to 325 °F; 432 to 436 K)
0.15 g/100 ml (25 °C)
Main hazards Flamability, Inhalation
Safety data sheet External MSDS
R/S statement (outdated) S8, S17, S26, S36, S37, S39, S41, S45
NFPA 704
Flammability code 1: Must be pre-heated before ignition can occur. Flash point over 93 °C (200 °F). E.g., canola oil Health code 3: Short exposure could cause serious temporary or residual injury. E.g., chlorine gas Reactivity code 1: Normally stable, but can become unstable at elevated temperatures and pressures. E.g., calcium Special hazards (white): no codeNFPA 704 four-colored diamond
Flash point Decomposes at 160°C
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Infobox references

1-Bromo-3-chloro-5,5-dimethylhydantoin (BCDMH) is a chemical structurally related to hydantoin. It is a white crystalline compound with a slight bromine and acetone odor and is insoluble in water, but soluble in acetone.

BCDMH is an excellent source of both chlorine and bromine as it reacts slowly with water releasing hypochlorous acid and hypobromous acid. It used as a chemical disinfectant used for recreational water and drinking water purification. BCDMH works in the following manner:[1]

The initial BCDMH reacts with water (R = Dimethylhydantoin):

BrClR + 2 H2O → HOBr + HOCl + RH2

Hypobromous acid partially dissociates in water:

HOBr → H+ + OBr

Hypobromous acid oxidizes the substrate, itself being reduced to bromide:

HOBr + Live pathogens → Br + Dead pathogens

The bromide ions are oxidized with the hypochlorous acid that was formed from the initial BCDMH:

Br + HOCl → HOBr + Cl

This produces more hypobromous acid. However, the hypochlorous acid itself does act directly as a disinfectant in the process.


This compound is prepared by first brominating, then chlorinating 5,5-dimethylhydantoin:[2]

Preparation of BCDMH.png


  1. ^ South Australian Health Commission, "Standard for the Operation of Swimming Pools and Spa Pools in South Australia", Supplement C: Bromine Disinfection, page 8. Retrieved on 2009-05-12.
  2. ^ Yasukazu Ura, Gozyo Sakata (2005), "Chloroamines", Ullmann's Encyclopedia of Industrial Chemistry, Weinheim: Wiley-VCH, doi:10.1002/14356007.a06_553 

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