View source for BCDMH

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| align="center" colspan="2" bgcolor="#ffffff" | [[Image:BCDMH.png|150px|BCDMH]]
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! {{chembox header}} | General
|-
| [[IUPAC nomenclature|Systematic name]]
| 1-Bromo-3-Chloro-5,5-Dimethylhydantoin
|-
| Other names
| bromochloro-5,5-dimethylhydantoin, BCDMH, agribrom, aquabrom, aquabrome, bromicide, di-halo, halogene T30, nylate, photobrome, slimicide 78P 
|-
| [[Chemical formula|Molecular formula]]
| C<sub>5</sub>H<sub>6</sub>BrClN<sub>2</sub>O<sub>2</sub> 
|-
| [[Molar mass]]
| 241.49 g/mol
|-
| Appearance
| White solid
|-
| [[CAS registry number|CAS number]]
| [126-06-7]
|-
! {{chembox header}} | Properties
|-
| [[Density]]
| 1.9 g/cm<sup>3</sup>
|-
| [[Soluble|Solubility]] in [[Water (molecule)|water]]
| 0.25 g/100 ml (25 °C)
|-
<!-- | Other solvents e.g. [[ethanol]], [[acetone]] -->
<!-- | solubility info on other solvents -->
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| [[Melting point]]
| 158 °C - 165 °C <!-- (mention any decomposition) -->
|-
| [[Boiling point]]
| n/a
|-
! {{chembox header}} | Hazards <!--  Summary only- MSDS entry provides more complete information -->
|-
| [[Material safety data sheet|MSDS]]
| [[{{PAGENAME}} (data page)#Material Safety Data Sheet|External MSDS]] <!-- please replace with proper link-->
|-
| Main [[Worker safety and health|hazard]]s
| Flamability, Inhalation
|-
| [[NFPA 704]]
| {{NFPA 704 | Health=3 | Flammability=1 | Reactivity=1 }}
|-
| [[Flash point]]
| Decomposes at 160°C
|-
| [[Risk and Safety Statements|R/S statement]]
| {{S8}}, {{S17}}, {{S26}}, {{S36}}, {{S37}}, {{S39}}, {{S41}}, {{S45}}
|-
|}
'''BCDMH''' is a chemical [[disinfectant]] used for recreational water and drinking [[water purification]]. 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]]. Chemically, BCDMH works in the following manner:

{|
|-----
The initial BCDMH reacts with water (R = Dimethylhydantoin):
|-----
<b>
| align="center" | BrClR
<td> <b>+
| align="center" |  <b>2 H<sub>2</sub>O
| align="center" | → || align="center" | <b>HOBr 
| align="center" | <b>+
| align="center" | <b>HOCl || align="center" | <b>+ 
| align="center" | <b>RH<sub>2</sub>
|-----
| align="center" | <i>BCDMH || align="center" |
| align="center" | <i>Water || align="center" |
| align="center" | <i>Hypobromous acid
| align="center" |
| align="center" | <i>Hypochlorous acid
| align="center" |
| align="center" | <i>Dimethylhydantoin
|}

{|
|-----
Hypobromous acid partially dissociates in water:
|-----
| align="center" | <b>HOBr || align="center" | →
| align="center" | <b>H<sup>+</sup>
| align="center" | <b>+ || align="center" | <b>OBr<sup>-</sup>
|-----
| align="center" | <i>Hypobromous acid
| align="center" | || align="center" | <i>Hydrogen ion
| align="center" | || align="center" | <i>Hypobromite ion
|}

{|
|-----
Hypobromous acid produces bromide ions when disinfecting:
|-----
| align="center" | <b>HOBr || align="center" | <b>+
| align="center" | <b>Live pathogens
| align="center" |  → || align="center" |  <b>Br<sup>-</sup>
| align="center" |  <b>+ || align="center" |  <b>Dead pathogens
|-----
| align="center" | <i>Hypobromous Acid
| align="center" | || align="center" | 
| align="center" |
| align="center" | <i>Bromide Ion || align="center" |
| align="center" |  || align="center" |
|}
{|
|-----
The bromide ions react with the hypochlorous acid that was formed from the initial BCDMH:
|-----
| align="center" | <b>Br<sup>-</sup> || align="center" |  <b>+
| align="center" | <b> HOCl
| align="center" | →  || align="center" | <b>HOBr
| align="center" | <b>+  || align="center" | <b>Cl<sup>-</sup>
|-----
| align="center" | <i>Bromide ion || align="center" |
| align="center" | <i>Hypochlorous acid
| align="center" |
| align="center" | <i>Hypobromous acid
| align="center" | || align="center" | <i>Chloride ion
|}
This produces more hypobromous acid. However, it should be noted that the hypochlorous acid itself does play in a direct role in the disinfectant process. 

== References ==
* [http://physchem.ox.ac.uk/MSDS/BR/1-bromo-3-chloro-5,5-dimethyl-2,4-imidazolidinedione.html ]
* [http://www.chemjiheng.com/bcdmh/bcdmh.htm ]
* [http://www.e1.greatlakes.com/common/msdspdf/00255.pdf ]
* [http://www.dh.sa.gov.au/pehs/publications/code-bromine.pdf ]

[[Category:Disinfectants]]
[[Category:Organobromides]]
[[Category:Organochlorides]]
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