2-Butanone

78-93-3

Solvent or swelling agent for resins, intermediate in the
manufacture of ketones and amines, flush-off paint stripper,
extraction and production of wax from lube oil fractions of
petroleum, a solvent in nitrocellulose coatings and vinyl 
films.

Colourless liquid.

Quality: sweet, sharp
Hedonic tone: neutral to unpleasant
Threshold odour concentration
absolute: 2.0 ppm
50 % recognition: 5.5 ppm
100 % recognition: 6.0 ppm
Odour index 100 % recognition: 15 350
(Hellman & Small 1974).

72.12

Relative volatility (nBuAc=1) = 3.70

The half-life for evaporation from a river and lake will be 3
and 12 days respectively. 
Due to its high vapor pressure,
volatilation from soil will be rapid (Howard 1990).

Using the log Kow, a Koc value of 34 was estimated. 
Based on
this estimated Koc value, MEK will be expected to exhibit very
high mobility in soil and therefore may leach to the ground
water (Lyman et al. 1982) (Swann et al. 1983).

Soluble in organic solvents: alcohol, ether, acetone and
benzene (WPSREG 1994).

Self ignitiv temperature 404°C (WPSREG 1994).

MEK adsorbs radiation near the sort wavelength cutoff of the
solar spectrum at ground level; however the reaction with
photochemically produced hydroxyl radicals with a half-life of
2.3 days is the dominant atmospheric process. 
Acetaldehyde is
the primary product of this reaction (Cox et al. 1981).

Photooxidation half-life in air:
2.7hr - 26.7hr,
based upon mesured rate data for the vapor phase reaction with
hydroxyl radicals in air (Howard 1991).

Photooxidation half-life in water:
48.8yr - 81.4yr,
based upon measured rate data for hydroxyl radicals in aqueous 
solution (Howard 1991).

First-order hydrolysis half-life:
> 50yr (if at all),
unreactive towards hydrolysis from pH 5 to 9 at 15°C
(Howard 1991).

Aerobic half-life:
1d - 7d,
scientific judgement based upon unacclimated grab sample of 
aerobic fresh water and aerobic aqueous screening test data 
(Howard 1991).

Anaerobic half-life:
4d - 28d,
scientific judgement based upon estimated aqueous unacclimated 
aerobic biodegradation half-life (Howard 1991).

If 2-butanone is released to soil, it will partially evaporate
into the atmosphere from near-surface soil and may leach
into ground water. 
It will not significantly hydrolyze in soil
(Howard 1990).

If 2-butanone is released into water, it will evaporate into
the atmosphere with estimated half-lives of 3 and 12 days in
rivers and lakes, respectively. 
It will also biodegrade slowly
in both fresh and salt water. 
It may degrade slowly in
anaerobic systems after a long acclimation period (Howard 1990).

Complete removal and 87% mineralization in 5 days in screening
tests using municipal wastewater inocolum; complete removal in
9 days using activated sludge treatment (Dojlido 1979).

Percent theoretical BOD in 5 and 20 days were 76% and 89%,
respectively, using nonacclimated settled domestic wastewater
inocolum in fresh water and 32% and 69%, respectively, using
settled raw wastewater seed developed in actual seawater, with
the test being run in synthetic seawater (Price et al. 1974).

Percent theoretical BOD and COD were 76% and 79%, respectively,
after 5 days at 20°C using a standard dilution method with
filtered biological sanitary waste treatment plant seed (Bridie 
et al. 1979).

88% theoretical BOD in 5 days using sew seed in standard
dilution screening tests (Heukelekian & Rand 1955).

Degradation also occurs in anaerobic systems but time required
for acclimating degrading microorganisms is long (ca 1 wk)
(Chou et al. 1979).

Butan-2-one is readily absorbed by all routes of exposure; its
metabolism appears to follow both oxidative and reductive
pathways, the ketone undergoing omega-1 carbon atom oxidation
to the corresponding hydroxyketone which then undergoes
reduction to the diol. 
The secondary alcohol, butan-2-ole, is
formed by the reduction of the ketone, and is then eliminated
in the urine as O-sulfates and O-glucoronides, or may enter
intermediary metabolism to be eliminated as carbon dioxide, or
incorporated into tissues 
(Fawell & Hunt 1988, Williams 1959,Tadas et al. 1972, Munies 
1965, DiVincenco et al. 1976, Wurster & Munies 1965, Tsao & 
Pfeiffer 1957, Zlatkis et al. 1973, Loney et al. 1963, Leibman 
1971, Merritt & Tomkins 1959, Culp &McMahon 1968).

Using the log Kow a BCF of 1.0 was estimated. 
MEK will not be
expected to significantly bioconcentrate in aquatic organisms
(Howard 1990).

Few data are available concerning the long-term oral toxicity
of butan-2-one. 
Short-term studies suggest that this ketone is
of low oral toxicity. 
It also appears to have a low inhalation
toxicity, and although it has been widely reported not to be
neurotoxic itself, it does appear to potentiate polyneuropathy
caused by other solvents. 
It is also thought that it may
potentiate the hepatotoxicity of carbon tetrachloride, although
it does not cause any hepatotoxic effects itself. 
These effects
are believed to be due to induction of enzymes  by the ketone
(Carpenter 1954, Smyth et al. 1962, Kimura et al. 1971, Traiger
& Bruckner 1975, Krasavage et al. 1982, US EPA 1976, Patty et
al. 1935, Smyth 1956, La Belle & Brieger 1955, Garcia et al.
1978, Abdel-Rahman et al. 1976, DiVincenzo & Krasavage 1974,
NIOSH 1978, Moreno 1975, Carpenter 1949, Opdyke 1975, Spencer &
Schaumberg 1976, Saida et al. 1975, Duckett et al. 1974,
Shifman et al. 1981, Altenkirch et al. 1978, O'Donaghye et al.
1984, Hetland et al. 1976, Couri et al. 1977, Mellon Institute
1950, Clavender et al. 1983, Smith & Meyers 1944, Viader et al.
1975, Nakaaki 1974, Nelson et al. 1943, Elkins 1959, Malten et
al. 1968, Rowe & Wolf 1963).

Reproductive toxicity studies have proved rather inconclusive,
slight foetotoxic and embryotoxic effects being reported
(Fawell & Hunt 1988, Schwetz et al. 1974, Deacon et al. 1981).

Butan-2-one was found to be non-mutagenic in Salmonella
typhimurium TA98, TA100, TA1535, and TA1537, with and without
S-9 from arcolor-induced Sprague-Dawley rats. 
The Ames tests
were carried out at a concentration of 3 µmol/plate 
(Fawell & Hunt 1988, Florin et al. 1980).

Toxicity threshold (cell multiplication inhibition test):
bacteria (Pseudomonas putida): 1150 mg/l
(Bringmann & Kühn 1980a).

Removal/secondary treatment:
86% - 100%,
based upon % degraded in an 8 day period under acclimated 
aerobic semi-continuous flow conditions (Howard 1991).

Toxicity threshold (cell multiplication inhibition test):
green algae (Scenedesmus quadricauda): 4300 mg/l
protozoa (Entosiphon sulcatum): 190 mg/l
(Bringmann & Kühn 1980a)

20 g/l ihb biological degradation (WPSREG 1994).

1150 mg/l, Pseudomonas putida, ihb cell division (WPSREG 1994).