Agent Name

1,3-Dichloro-5,5-dimethylhydantoin

CAS Number

118-52-5

Formula

C5-H6-Cl2-N2-O2

Major Category

Nitrogen Compounds

Synonyms

1,3-Dichloro-5,5'-methylhydantoin; 1,3-Dichloro-5,5-dimethyl hydantoin; 1,3-Dichloro-5,5-dimethyl-2,4-imidazolidinedione; 1,3-Dichloro-5,5-dimethylhydantoin; 1,3-Dwuchloro-5,5-dwumetylohydantoina [Polish]; 2,4-Imidazolidinedione, 1,3-dichloro-5,5-dimethyl-; DDH; Dactin; Daktin; Dantoin; Dichlorantin; Dwuchlorantyny [Polish]; Halane; Hydan; Hydan (antiseptic); Hydantoin, dichlorodimethyl-; Omchlor; [ChemIDplus] UN8027

Category

Other Nitrogen Compounds

Description

White powder with a chlorine-like odor; [NIOSH]

Sources/Uses

Used as a chlorinating agent, for organic synthesis, and to stabilize vinyl chloride polymers; [ACGIH] Used as a disinfectant and industrial deodorant; used in water treatment and laundry bleaches; [HSDB]

Comments

Hypochlorous acid is released upon contact with water. A concentration of 10 ppm is the maximum level recommended to prevent respiratory irritation when used to sanitize swimming pools. A worker exposed to a concentration exceeding 0.2 mg/m3 complained of cough and chest discomfort. [ACGIH] Corrosive to skin and eyes; May cause respiratory sensitization; [Sigma-Aldrich MSDS]

Reference Link

EPA Pesticide Chemical Search

Exposure Assessment
Skin Designation (ACGIH)

Insufficient data

TLV (ACGIH)

0.2 mg/m3

STEL (ACGIH)

0.4 mg/m3

PEL (OSHA)

0.2 mg/m3

IDLH (NIOSH)

5 mg/m3

Excerpts from Documentation for IDLHs

Based on health considerations and acute oral toxicity data in animals [Kay 1961/62; Korolev et al. 1982], a value of about 500 mg/m3 would have been appropriate for 1,3dichloro5,5dimethylhydantoin. However, the revised IDLH for 1,3dichloro5,5dimethylhydantoin is 5 mg/m3 based on being 25 times the NIOSH REL and OSHA PEL of 0.2 mg/m3 (25 is an assigned protection factor for respirators and was used during the Standards Completion Program for deciding when the "most protective" respirators should be used for 1,3dichloro5,5dimethylhydantoin).

Vapor Pressure

2.4E-5 mm Hg

Odor Threshold Low

0.01 mg/m3

Lethal Concentration

LCLo (rat) = 20,000 mg/m3/1H

Explanatory Notes

Odor threshold from "Quick Guide: The Electronic NIOSH Pocket Guide to Chemical Hazards"; Flash point = 346 deg F;

Adverse Effects
Toxic Pneumonitis

Yes

Dermatotoxin

Skin Burns

Links to Other NLM Databases
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Toxicity Information

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Processes

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