Methyl tert-butyl ether

  • 2-Methoxy-2-methylpropane
  • tert-Butyl methyl ether
  • MTBE
  • Methyl 1,1-dimethyl ethyl ether
Formula
(CH3)3COCH3
Structure
Description
Clear, colorless liquid with a characteristic ethereal or terpene-like odor.
Uses
Octane booster in gasoline.

Registry Numbers and Inventories.
CAS
1634-04-4
EC (EINECS/ELINCS)
216-653-1
EC Index Number
603-181-00-X
EC Class
highly flammable
R 11 38
S 9 16 33 37
RTECS
KN5250000
RTECS class
Tumorigen; Mutagen; Reproductive Effector
UN (DOT)
2398
Merck
12,6111
Beilstein/Gmelin
1730942
Beilstein Reference
4-01-00-01615
Swiss Giftliste 1
G-9533
Canada DSL/NDSL
DSL
US TSCA
Listed
Austrailia AICS
Listed
New Zealand
Listed
Japan ENCS (MITI)
Listed
Korea ECL
Listed

Properties.
Formula
C5H12O
Formula mass
88.15
Melting point, °C
-108.6
Boiling point, °C
55.2
Vapor pressure, mmHg
252 (25 C)
Saturation Concentration
26.5% at 20 C
Evaporization number
8.5 (n-butyl acetate = 1)
Critical temperature
224
Critical pressure
33.26
Density
0.7405 g/cm3 (20 C)
Solubility in water
48 g/L (20 C)
Viscosity
0.34 cp (25 C)
Surface tension
19.4 g/s2 (24 C)
Refractive index
1.3765 (17.5 C)
Dipole moment
1.23 D
Partition coefficient, pKow
0.94
Heat of vaporization
27.94 kJ/mol
Heat of combustion
-3361 kJ/mol

Hazards and Protection.
Storage
Keep away from heat, sparks, and flame. Keep away from sources of ignition. Store in a tightly closed container. Store in a cool, dry, well-ventilated area away from incompatible substances.
B2 D2B
Handling
Use with adequate ventilation. Ground and bond containers when transferring material. Use spark-proof tools and explosion proof equipment. Avoid contact with eyes, skin, and clothing. Empty containers retain product residue, (liquid and/or vapor), and can be dangerous. Keep container tightly closed. Avoid contact with heat, sparks and flame. Avoid ingestion and inhalation. Do not pressurize, cut, weld, braze, solder, drill, grind, or expose empty containers to heat, sparks or open flames.
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 half-face organic vapor respirator may be worn for up to ten times the exposure limit, or the maximum use concentration specified by the appropriate regulatory agency or respirator supplier, whichever is lowest. A full-face piece organic vapor respirator may be worn up to 50 times the exposure limit, or the maximum use concentration specified by the appropriate regulatory agency or respirator supplier, whichever is lowest. For emergencies or instances where the exposure levels are not known, use a full-face piece positive-pressure, air-supplied respirator.
Small spills/leaks
Avoid runoff into storm sewers and ditches which lead to waterways. Remove all sources of ignition. Absorb spill using an absorbent, non-combustible material such as earth, sand, or vermiculite. Provide ventilation. A vapor suppressing foam may be used to reduce vapors.
Stability
Stable under ordinary conditions of use and storage. Unstable in acid solutions.
Incompatibilities
Oxidizing agents, acids.
Decomposition
Carbon monoxide, carbon dioxide, formic acid, butyl formate, methyl radicals, acetone.

Fire.
Flash Point,°C
-28
Autoignition, °C
435
Upper exp. limit, %
8.4
Lower exp. limit, %
1.6
Fire fighting
Wear a self-contained breathing apparatus in pressure-demand, MSHA/NIOSH (approved or equivalent), and full protective gear. Use water spray to keep fire-exposed containers cool. Containers may explode in the heat of a fire. Extinguishing media: For small fires, use dry chemical, carbon dioxide, water spray or alcohol-resistant foam. For large fires, use water spray, fog, or alcohol-resistant foam. Use water spray to cool fire-exposed containers. Water may be ineffective. Do NOT use straight streams of water. Cool containers with flooding quantities of water until well after fire is out.
Fire potential
Extremely flammable liquid and vapor. Vapor may cause flash fire.
Hazards
Vapors may form explosive mixtures with air. Vapors may travel to source of ignition and flash back. Most vapors are heavier than air. They will spread along ground and collect in low or confined areas (sewers, basements, tanks). Vapor explosion hazard indoors, outdoors or in sewers.
Combustion products
May contain irritating and toxic gases.
Health
2
 
Flammability
3
 
 
Reactivity
0
 

Health.
Poison_Class
5
Exposure effects
Acute symptomsmay be produced by cumulative exposure.
   Ingestion
May cause nausea, vomiting. Other symptoms similar to inhalation may occur. Laryngeal, ocular, and respiratory muscles are affected in severe poisoning.
   Inhalation
Inhalation of vapor can irritate respiratory tract. Causes central nervous system effects. Breathing high concentrations in air can cause lightheadedness, dizziness, weakness, nausea, headache.
   Skin
A mild skin irritant which causes loss of natural oils. May be a route of absorption into the body.
   Eyes
Vapors can irritate eyes; splashes may cause damage to eye tissue.

First aid
 
   Ingestion
If victim is conscious and alert, give 2-4 cupfuls of milk or water. Never give anything by mouth to an unconscious person. Get medical aid immediately.
   Inhalation
Remove from exposure to fresh air immediately. If not breathing, give artificial respiration. If breathing is difficult, give oxygen. Get medical aid.
   Skin
Immediately flush skin with plenty of soap and water for at least 15 minutes while removing contaminated clothing and shoes. Get medical aid if irritation develops or persists. 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
2398
Response guide
Hazard class
3
Packing Group
II
 
USCG CHRIS Code
MBE
 
HS Code
2909 19 00
 
Std. Transport #
4908224
 
IMO Chemical Code
18
IMO Pollution Category
D