L-Methionine

  • Acimetion
  • alpha-Amino-gamma-methylmercaptobutyric acid
  • L-alpha-Amino-gamma-methylmercaptobutyric acid
  • 2-Amino-4-methylthiobutanoic acid
  • L(-)-Amino-gamma-methylthiobutyric acid
  • 2-Amino-4-(methylthio)butyric acid
Formula
C5H11NO2S
Structure
Description
Minute hexagonal plates from dilute alcohol.
Uses
Feed additive, vegetable oil enrichment, single-cell protein dl mixt.

Registry Numbers and Inventories.
CAS
63-68-3
EC (EINECS/ELINCS)
200-562-9
RTECS
PD0457000
RTECS class
Mutagen; Reproductive Effector
Merck
13,6004
Beilstein/Gmelin
1722294
Beilstein Reference
4-04-00-03189
Canada DSL/NDSL
DSL
US TSCA
Listed
Austrailia AICS
Listed
New Zealand
Listed
Japan ENCS (MITI)
Listed
Korea ECL
Listed

Properties.
Formula
C5H11NO2S
Formula mass
149.21
Melting point, °C
136
Boiling point, °C
278
Decomposition point, °C
279 - 280
Vapor pressure, mmHg
0.0002 (25 C)
Critical temperature
484
Critical pressure
42.3
Density
1.373 g/cm3
Solubility in water
Very soluble
pKa/pKb
2.28 (pKa)
Partition coefficient, pKow
-0.56

Hazards and Protection.
Storage
Keep container closed when not in use. Store in a tightly closed container. Store in a cool, dry, well-ventilated area away from incompatible substances.
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
Clean up spills immediately, using the appropriate protective equipment. Sweep up or absorb material, then place into a suitable clean, dry, closed container for disposal. Avoid generating dusty conditions. Provide ventilation.
Stability
Stable under normal temperatures and pressures.
Incompatibilities
Strong oxidizing agents.
Decomposition
Nitrogen oxides, carbon monoxide, 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. Dusts at sufficient concentrations can form explosive mixtures with air. 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.
Health
1
 
Flammability
0
 
 
Reactivity
0
 

Health.
Exposure effects
Prolonged or repeated exposure may cause adverse reproductive effects. May cause fetal effects. Laboratory experiments have resulted in mutagenic effects.
   Ingestion
May cause irritation of the digestive tract. The toxicological properties of this substance have not been fully investigated.
   Inhalation
May cause respiratory tract irritation. The toxicological properties of this substance have not been fully investigated.
   Skin
May cause skin irritation.
   Eyes
May cause eye irritation.

First aid
 
   Ingestion
Never give anything by mouth to an unconscious person. 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.
HS Code
2930 40 10