|Chemical Abstract Number (CAS #)||
|Synonyms||4-Methyl-2-pentanone||MIBK||Methyl isobutyl ketone||2-Pentanone, 4-methyl
||EPA Method 524.2||EPA Method 8015
||EPA Method 8260
Link to the National Library of Medicine's Hazardous Substances
Database for more details
on this compound.
|Use|| Denaturant for rubbing alcohol
SOLVENT FOR PAINTS, VARNISHES, NITROCELLULOSE, LACQUERS, MFR OF
METHYL AMYL ALCOHOL; ORGANIC SYNTHESIS, EXTRACTION PROCESSES, INCL
EXTRACTION OF URANIUM FROM FISSION PRODUCTS, ORGANIC SYNTHESIS
SOLVENT FOR PROTECTIVE COATINGS & IN RARE METALS EXTRACTION,
DEWAXING OF MINERAL OILS & IN MFR OF ANTIBIOTICS
USED IN DRYCLEANING PREPARATIONS, SYNTHESIS OF METHYL ISOBUTYL
SYNTHETIC FLAVORING ADJUVANT: FLAVOR USEFUL IN FRUIT FLAVORS, RUM
|Consumption Patterns|| 65% AS SOLVENT FOR PROTECTIVE COATINGS, 5% AS SOLVENT FOR RARE
METAL EXTRACTION; 5% EXPORTED; 25% FOR MISC APPLICATIONS INCLUDING
DEWAXING OF MINERAL OILS AND IN THE MANUFACTURE OF ANTIBIOTICS (1971)
NITROCELLULOSE LACQUERS, 25%; OTHER COATINGS, INKS, LACQUERS, 30%;
SOLVENT EXTRACTION, 10%; MIBC, 10%; METALURGICAL, 5%; EXPORT, 15%;
MISC, 5% (1980)
CHEMICAL PROFILE: Methyl isobutyl ketone. Demand: 1986: 145 million lb; 1987: 148
million lb; 1991 projected/: 155 million lb. (Includes exports; in addition, 12.5 million lb were
imported in 1986).
|Apparent Color|| COLORLESS LIQUID
|Odor|| PLEASANT ODOR ; HAS FAINT, KETONIC AND CAMPHOR ODOR
|Boiling Point|| 116.8 DEG C AT 760 MM HG
|Melting Point|| -84.7 DEG C
|Molecular Weight|| 100.16
|Density|| 0.7978 AT 20 DEG C
|Odor Threshold Concentration|| 0.10 ppm
Air: 0.68 ul/l; water: 1.3 mg/l; odor safety class B; B= 50-90% of distracted persons perceive
warning of TLV
Odor detection limit in air: 9.70x10-6 g/l (gas).
0.410 mg/cu m (odor low) 192.7 mg/cu m (odor high).
|Sensitivity Data|| AT 100 PPM METHYL ISOBUTYL KETONE MAY IRRITATE EYES OF MORE
Vapors cause irritation of nose .
Chemical safety information sheet. Toxicity: irritation of eyes, nose and throat.
|Environmental Impact|| Methyl isobutyl ketone (MIBK) is released to the environment in effluent and emissions
from its manufacturing and use facilities, in exhaust gas from vehicles, and from land disposal and
ocean dumping of consumer products and industrial wastes which contain this compound. A large
number of industries may release or dispose of this compound including: rare metal extracters and
manufactures of coatings (ie lacquers, varnishes, paints), pharmaceuticals, pesticides, rubber
processing chemicals, and adhesives. If released to soil, MIBK may be removed by direct
photolysis on soil surfaces, volatilization, or aerobic biodegradation. This compound is also
susceptible to extensive leaching and has been detected in landfill leachate. Chemical hydrolysis is
not expected to be environmentally significant. If released to water, the primary removal
mechanisms for MIBK are expected to be volatilization (t1/2 15-33 hours) and direct photolysis.
Aerobic biodegradation may be of minor importance. MIBK is not expected to undergo chemical
oxidation or chemical hydrolysis, bioaccumulate in aquatic organisms or adsorb significantly to
suspended solids or sediments in water. In the atmosphere, methyl isobutyl ketone (MIBK) will be
subject to direct photolysis (t1/2 15 hours in sunlight) and reaction with hydroxyl radical (t1/2
16-17 hours). In photochemical smog situations, MIBK may also react with nitrogen oxides.
Acetone is a major photooxidation product of MIBK, and in the presence of nitrogen oxides,
peroxyacetylnitrate (PAN) and methyl nitrate will also be formed. The most probable routes of
exposure to MIBK by the general population are inhalation and dermal contact during use of
consumer products which contain this compound. Such products would include coatings,
adhesives, rubber cements, pesticides, as well as a variety of other products. Some segments of
the general population may also be exposed to MIBK by inhalation of contaminated air in source
dominated areas or areas near landfills and by ingestion of contaminated drinking water.
|Environmental Fate|| TERRESTRIAL FATE: If released to soil, methyl isobutyl ketone (MIBK) may be
removed by direct photolysis on soil surfaces, volatilization, or aerobic biodegradation. MIBK is
also susceptible to extensive leaching and has been detected in landfill leachate . This compound
is not expected to undergo chemical hydrolysis.
Rathbun RE, Tai DY; Water Air Soil Poll 17: 281-93 (1982)] AQUATIC FATE: If released
to water, the primary removal mechanisms for methyl isobutyl ketone (MIBK) are expected to be
volatilization (t1/2 15-33 hours(1,SRC) and direct photolysis. Aerobic biodegradation may be of
minor importance. MIBK is not expected to undergo chemical oxidation or chemical hydrolysis,
bioaccumulate in aquatic organisms or adsorb significantly to suspended solids or sediments in
ATMOSPHERIC FATE: In the sunlit atmosphere, methyl isobutyl ketone (MIBK) will be subject
to direct photolysis (t1/2 15 hours) and reaction with hydroxyl radicals (t1/2 16-17 hours)(2-4). In
photochemical smog situations MIBK may also react with nitrogen oxides. Acetone is a major
photooxidation produce of MIBK, and in the presence of nitrogen oxides, peroxyacetylnitrate
(PAN) and methyl nitrate will also be formed .
|Drinking Water Impact|| SURFACE WATER: Methyl isobutyl ketone was qualitatively identified in Cuyahoga
River . Identified, but not quantified, in 1 out of 204 samples of surface water collected near
heavily industrialized areas across the US . Qualitatively identified in 1 out of 17 samples of
Delaware River water collected between Aug 1976 to March 1977 at river mile 78 and 132 .
DRINKING WATER: Methyl isobutyl ketone was detected in 4 out of 14 drinking water supplies
sampled between 1977 and 1979 .
GROUNDWATER: Leachate collected from the Southington, CT municipal landfill during
1982-1983 contained methyl isobutyl ketone (MIBK) at a concn ranging from 172-263 ug/l .
During 1981-82 MIBK was detected in leachate from Granby, CT municipal landfill, concn range
25-150 ppb . During 1984 after an attempt to abate groundwater contamination by capping the
landfill and diverting stormwater, MIBK was not detected in leachate, detection limit not
reported . Qualitatively identified in leachate from Maxy Flats, KY low-level radioactive waste
disposal site .
EFFL: Methyl isobutyl ketone (MIBK) detected in aqueous condensate from low-Btu gasification
of rosebud coal at a concn of 78 ppm. Detected in Omega-9 retort water from in situ oil shale
processing at a concn of 105 ppm . MIBK has been identified in the final effluent from at least
one plant in each of the following industries: printing and publishing, coal mining, electronic, and
organic chemicals . Detected at a concn of 190 ug/L in formation water discharged from an
offshore (Shell Oil) production operation in the Gulf of Mexico . MIBK was not detected in air
samples taken from the Allegheny Tunnel during 1979, detection limit not reported .