Methylthiouracil

  • 4-Hydroxy-2-mercapto-6-methylpyrimidine
  • 6-Methyl-2-thiouracil
Formula
C5H6N2OS
Structure
Description
White crystalline powder with an odor of onions and a bitter taste. A saturated aqueous solution is neutral or slightly acidic.
Uses
Medication.

Registry Numbers and Inventories.
CAS
56-04-2
EC (EINECS/ELINCS)
200-252-3
EC Class
harmful
R 45 22
RTECS
YR0875000
RTECS class
Tumorigen; Drug; Mutagen; Reproductive Effector; Human Data
UN (DOT)
2811
Merck
12,6210
Beilstein/Gmelin
115648
Beilstein Reference
5-24-07-00049
RCRA
U164
Canada DSL/NDSL
NDSL
US TSCA
Listed
Austrailia AICS
Listed
New Zealand
Listed
Japan ENCS (MITI)
Listed

Properties.
Formula
C5H6N2OS
Formula mass
142.18
Boiling point, °C
351
Decomposition point, °C
280 - 290
Density
1.519 g/cm3
Solubility in water
Slightly soluble
Partition coefficient, pKow
0.27

Hazards and Protection.
Storage
Store in a tightly closed container. 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. Minimize dust generation and accumulation. Avoid contact with eyes, skin, and clothing. Keep container tightly closed. Avoid ingestion and inhalation.
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 to prevent skin exposure. Clothing: Wear appropriate protective clothing to prevent skin exposure.
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
Vacuum or sweep up material and place into a suitable disposal container. Clean up spills immediately, using the appropriate protective equipment. Avoid generating dusty conditions. Provide ventilation.
Stability
Stable under normal temperatures and pressures.
Incompatibilities
Strong oxidizing agents.
Decomposition
Carbon monoxide, oxides of nitrogen, oxides of sulfur, irritating and toxic fumes and gases, carbon dioxide.

Fire.
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. Extinguishing media: Use agent most appropriate to extinguish fire. In case of fire use water spray, dry chemical, carbon dioxide, or appropriate foam.
Fire potential
This material is probably combustible.
Health
2
 
Flammability
0
 
 
Reactivity
0
 

Health.
Exposure limit(s)
OSHA: Possible Select carcinogen
Carcinogin
I-2B, CP65
Exposure effects
May cause cancer according to animal studies. May cause thyroid abnormalities. Reproductive effects have been reported in humans.
   Ingestion
May cause irritation of the digestive tract. May be harmful if swallowed. Mercaptans may cause nausea and headache. Exposure to high concentrations of mercaptans can produce unconsciousness with cyanosis, cold extremities and rapid pulse. May cause thyroid abnormalities.
   Inhalation
May cause respiratory tract irritation. The toxicological properties of this substance have not been fully investigated. Exposure to high concentrations of mercaptans can produce unconsciousness with cyanosis, cold extremities and rapid pulse. Mercaptans may cause nausea and headache.
   Skin
May cause skin irritation.
   Eyes
May cause eye irritation.

First aid
 
   Ingestion
Get medical aid. 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. Flush skin with plenty of soap and water for at least 15 minutes while removing contaminated clothing and shoes. Wash clothing before reuse.
   Eyes
Flush eyes with plenty of water for at least 15 minutes, occasionally lifting the upper and lower eyelids. Get medical aid.

Transport.
UN number
2811
Response guide
USCG CHRIS Code
MTR
 
HS Code
2933 59 95