1,3-Dihydro-1-methyl-2H-imidazole-2-thione

  • Methimazole
  • 2-Mercapto-1-methylimidazole
Formula
C4H6N2S
Structure
Description
Beige powder. Stench.
Uses
In cyanide-free silver electroplating. Therap cat: antihyperthyroid.

Registry Numbers and Inventories.
CAS
60-56-0
EC (EINECS/ELINCS)
200-482-4
R 43 63
S 22 36/37
RTECS
NI8615000
RTECS class
Tumorigen; Drug; Mutagen; Reproductive Effector; Human Data
UN (DOT)
3335
Merck
13,6000
Beilstein/Gmelin
108646
Beilstein Reference
5-24-01-00305
Canada DSL/NDSL
DSL
US TSCA
Listed
Austrailia AICS
Listed
New Zealand
Listed
Japan ENCS (MITI)
Listed

Properties.
Formula
C4H6N2S
Formula mass
114.17
Boiling point, °C
155
Vapor pressure, mmHg
3 (25 C)
Density
1.36 g/cm3
Solubility in water
Soluble
pKa/pKb
11.64 (pKa)
Partition coefficient, pKow
-0.02
Heat of vaporization
39.2 kJ/mol

Hazards and Protection.
Storage
Keep container closed when not in use. Store in a cool, dry, well-ventilated area away from incompatible substances. Hormones and antibiotics room.
Handling
Wash thoroughly after handling. Remove contaminated clothing and wash before reuse. Use with adequate ventilation. Do not get in eyes, on skin, or on clothing. Keep container tightly closed. Do not ingest or inhale.
Protection
Eyes: Wear appropriate protective eyeglasses or chemical safety goggles as described by OSHA's eye and face protection regulations in 29 CFR 1910.133 or European Standard EN166. Skin: Wear appropriate protective gloves and clothing to prevent skin exposure. Clothing: Wear appropriate protective clothing to minimize contact with skin.
Respirators
A respiratory protection program that meets OSHA's 29 CFR 1910.134 and ANSI Z88.2 requirements or European Standard EN 149 must be followed whenever workplace conditions warrant a respirator's use.
Small spills/leaks
Wash area with soap and water. Clean up spills immediately, using the appropriate protective equipment. Sweep up, then place into a suitable container for disposal. Avoid generating dusty conditions. Provide ventilation.
Stability
Stable under normal temperatures and pressures. Light sensitive.
Incompatibilities
Strong oxidizing agents.
Decomposition
Nitrogen oxides, carbon monoxide, oxides of sulfur, carbon dioxide.

Fire.
Flash Point,°C
47
Fire fighting
Wear a self-contained breathing apparatus in pressure-demand, MSHA/NIOSH (approved or equivalent), and full protective gear. During a fire, irritating and highly toxic gases may be generated by thermal decomposition or combustion. To extinguish fire, use water, dry chemical, chemical foam, or alcohol-resistant foam.
Health
1
 
Flammability
1
 
 
Reactivity
0
 

Health.
Exposure effects
Chronic exposure may cause reproductive disorders and teratogenic effects. Laboratory experiments have resulted in mutagenic effects. Chronic exposure can affect thyroid function. Chronic exposure may cause blood effects.
   Ingestion
In high doses may cause gastric irritation, nausea, vomiting, fever, skin rashes, and blood abnormalities including anemia. May be harmful if swallowed. May cause pain and stiffness in joints, paresthesias, headache, and loss or depigmentation of hair.
   Inhalation
Causes irritation of the mucous membrane and upper respiratory tract. May cause sore throat, headache, and other effects similar to those of ingenstion.
   Skin
May cause skin irritation. May cause an allergic reaction in certain individuals.
   Eyes
May cause eye irritation.

First aid
 
   Ingestion
Never give anything by mouth to an unconscious person. Get medical aid immediately. Do NOT induce vomiting. If conscious and alert, rinse mouth and drink 2-4 cupfuls of milk or water.
   Inhalation
Remove from exposure to fresh air immediately. If not breathing, give artificial respiration. If breathing is difficult, give oxygen. Get medical aid.
   Skin
Get medical aid immediately. Flush skin with plenty of soap and water for at least 15 minutes while removing contaminated clothing and shoes. Wash clothing before reuse.
   Eyes
Immediately flush eyes with plenty of water for at least 15 minutes, occasionally lifting the upper and lower eyelids. Get medical aid immediately.

Transport.
UN number
3335
Response guide
HS Code
2933 29 90