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1,3-Dichloro-5,5-dimethylhydantoin

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Synonyms & Trade Names
Dactin, DDH, Halane
CAS No.
118-52-5
RTECS No.
MU0700000
DOT ID & Guide
Formula
C₅H₆Cl₂N₂O₂
Conversion
IDLH
5 mg/m3
See: 118525
Exposure Limits
NIOSH REL
TWA 0.2 mg/m3 ST 0.4 mg/m3
OSHA PEL
TWA 0.2 mg/m3 See Appendix G
Measurement Methods
None available
See: NMAM or OSHA Methods
Physical Description
White powder with a chlorine-like odor.
Molecular Weight
197.0
Boiling Point
?
Melting Point
270°F
Solubility
0.2%
Vapor Pressure
?
Ionization Potential
?
Specific Gravity
1.5
Flash Point
346°F
Upper Explosive Limit
?
Lower Explosive Limit
?
Combustible Solid
Incompatibilities & Reactivities
Water, strong acids, easily oxidized materials such as ammonia salts & sulfides
Exposure Routes
inhalation, ingestion, skin and/or eye contact
Symptoms
irritation eyes, mucous membrane, respiratory system
Target Organs
Eyes, respiratory system
Personal Protection/Sanitation
(See protection codes)
Skin:Prevent skin contact
Eyes:Prevent eye contact
Wash skin:When contaminated
Remove:When wet or contaminated
Change:Daily
Provide:Eyewash
First Aid
(See procedures)
Eye:Irrigate immediately
Skin:Soap wash promptly
Breathing:Respiratory support
Swallow:Medical attention immediately
Respirator Recommendations

NIOSH/OSHA

Up to 2 mg/m3:
(APF = 10) Any supplied-air respirator

Up to 5 mg/m3:
(APF = 25) Any supplied-air respirator operated in a continuous-flow mode
(APF = 50) Any self-contained breathing apparatus with a full facepiece
(APF = 50) Any supplied-air respirator with a full facepiece

Emergency or planned entry into unknown concentrations or IDLH conditions:
(APF = 10,000) Any self-contained breathing apparatus that has a full facepiece and is operated in a pressure-demand or other positive-pressure mode
(APF = 10,000) Any supplied-air respirator that has a full facepiece and is operated in a pressure-demand or other positive-pressure mode in combination with an auxiliary self-contained positive-pressure breathing apparatus

Escape:
(APF = 50) Any air-purifying, full-facepiece respirator (gas mask) with a chin-style, front- or back-mounted canister providing protection against the compound of concern and having an N100, R100, or P100 filter.
Click here for information on selection of N, R, or P filters.
Any appropriate escape-type, self-contained breathing apparatus

Important additional information about respirator selection

See also
INTRODUCTION
Page last reviewed: October 30, 2019
Content source: National Institute for Occupational Safety and Health