Methacrylaldehyde

  • Methacrolein
  • 2-Methyl-2-propenal
  • Isobutenal
Formula
C4H6O
Structure
Description
Clear, colorless to slightly yellow liquid.
Uses
Chemical intermediate, comonomer in resin prodn.

Registry Numbers and Inventories.
CAS
78-85-3
EC (EINECS/ELINCS)
201-150-1
RTECS
OZ2625000
RTECS class
Mutagen; Primary Irritant
UN (DOT)
2396
Beilstein/Gmelin
1209258
Beilstein Reference
4-01-00-03455
Swiss Giftliste 1
G-2402
Canada DSL/NDSL
DSL
US TSCA
Listed
Austrailia AICS
Listed
Japan ENCS (MITI)
Listed

Properties.
Formula
C4H6O
Formula mass
70.10
Melting point, °C
-81
Boiling point, °C
69
Vapor pressure, mmHg
155
Vapor density (air=1)
2.4
Critical temperature
257
Critical pressure
43.0
Density
0.845 g/cm3 (20 C)
Solubility in water
60 g/L (20 C)
Viscosity
0.49 cp (20 C)
Refractive index
1.4156 (20 C)
Dipole moment
2.68 D
Heat of vaporization
29.0 kj/mol @ 101.3 kPa
Heat of combustion
-2293 kJ/mol

Hazards and Protection.
Storage
Keep away from heat, sparks, and flame. Keep away from sources of ignition. Keep container closed when not in use. Refrigerator/flammables. Do not expose to air. Store protected from light. Store under an inert atmosphere.
Handling
Wash thoroughly after handling. Remove contaminated clothing and wash before reuse. Use only in a well ventilated area. Ground and bond containers when transferring material. Use spark-proof tools and explosion proof equipment. Do not get in eyes, on skin, or on 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. Do not ingest or inhale. Store protected from light. Handle under an inert atmosphere. Store protected from air. Discard contaminated shoes. 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 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
Absorb spill with inert material, (e.g., dry sand or earth), then place into a chemical waste container. Avoid runoff into storm sewers and ditches which lead to waterways. Remove all sources of ignition. Use a spark-proof tool. Provide ventilation. Place under an inert atmosphere. A vapor suppressing foam may be used to reduce vapors.
Stability
Stable under normal temperatures and pressures. Air sensitive Light sensitive.
Incompatibilities
Air, direct light, strong bases, strong oxidizing agents, strong reducing agents.
Decomposition
Carbon monoxide, irritating and toxic fumes and gases, carbon dioxide.

Fire.
Flash Point,°C
2
Autoignition, °C
234
Upper exp. limit, %
14.6
Lower exp. limit, %
2.1
Fire fighting
Wear a self-contained breathing apparatus in pressure-demand, MSHA/NIOSH (approved or equivalent), and full protective gear. Will burn if involved in a fire. Use water spray to keep fire-exposed containers cool. Extremely flammable liquid. Containers may explode in the heat of a fire. Will be easily ignited by heat, sparks or flame. Runoff from fire control or dilution water may cause pollution. Runoff to sewer may create fire or explosion hazard. Extinguishing media: Use water spray to cool fire-exposed containers. Water may be ineffective. Use dry chemical, carbon dioxide, or alcohol-resistant foam. Do NOT use straight streams of water.
Fire potential
HIGHLY FLAMMABLE.
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 and poison hazard indoors, outdoors or in sewers. May polymerize explosively when heated or involved in a fire. Runoff to sewer may create fire or explosion hazard. Containers may explode when heated. Many liquids are lighter than water.
Combustion products
Fire will produce irritating, corrosive and/or toxic gases.
Health
3
 
Flammability
3
 
 
Reactivity
2
 

Health.
Poison_Class
3
Exposure effects
Effects may be delayed.
   Ingestion
Harmful if swallowed. Ingestion of large amounts may cause CNS depression. Causes gastrointestinal tract irritation. May cause burning sensations, coughing, wheezing, laryngitis, shortness of breath and headache.
   Inhalation
Exposure produces central nervous system depression. Aspiration may lead to pulmonary edema. Vapors may cause dizziness or suffocation. Harmful if inhaled. Inhalation may cause burning sensation, increased respiratory rate, bronchial constriction, choking and coughing.
   Skin
Causes severe skin irritation. May be fatal if absorbed through the skin. May cause cyanosis of the extremities.
   Eyes
Causes severe eye irritation. Lachrymator. May cause chemical conjunctivitis and corneal damage.

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
Get medical aid immediately. Remove from exposure to fresh air immediately. If breathing is difficult, give oxygen. Do not use mouth-to-mouth respiration if victim ingested or inhaled the substance; induce artificial respiration with the aid of a pocket mask equipped with a one-way valve or other proper respiratory medical device.
   Skin
Get medical aid immediately. Immediately flush skin with plenty of soap and water for at least 15 minutes while removing contaminated clothing and shoes. Remove contaminated clothing and shoes.
   Eyes
Immediately flush eyes with plenty of water for at least 15 minutes, occasionally lifting the upper and lower eyelids. Get medical aid immediately. Do NOT allow victim to rub or keep eyes closed.

Transport.
UN number
2396
Response guide
Hazard class
3
Packing Group
II
 
Std. Transport #
4907451