Acetone

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Not to be confused with Acetoin.
Acetone[1]
Full structural formula of acetone with dimensions Skeletal formula of acetone
Ball-and-stick model of acetone Space-filling model of acetone
Sample of acetone
Identifiers
Abbreviations DMK
CAS number 67-64-1 YesY
PubChem 180
ChemSpider 175 YesY
UNII 1364PS73AF YesY
EC number 200-662-2
UN number 1090
KEGG D02311 YesY
MeSH Acetone
ChEBI CHEBI:15347 YesY
ChEMBL CHEMBL14253 YesY
RTECS number AL3150000
Beilstein Reference 635680
Gmelin Reference 1466
3DMet B00058
Jmol-3D images Image 1
Properties
Molecular formula C3H6O
Molar mass 58.08 g mol−1
Appearance colorless liquid
Odor pungent, irritating, floral
Density 0.791 g cm−3
Melting point −95 to −93 °C; −139 to −136 °F; 178 to 180 K
Boiling point 56 to 57 °C; 133 to 134 °F; 329 to 330 K
Solubility in water miscible
Solubility miscible in benzene, diethyl ether, methanol, chloroform, ethanol[7]
log P -0.042
Vapor pressure 9.39 kPa (0 °C)
30.6 kPa (25 °C)
374 kPa (100 °C)
2.8 MPa (200 °C)[8]
Acidity (pKa) 19.2
Basicity (pKb) -5.2 (for conjugate base)
Refractive index (nD) 1.359
Viscosity 0.36 (10 °C)
0.295 cP (25 °C)[7]
Structure
Coordination
geometry
Trigonal planar at C2
Molecular shape Dihedral at C2
Dipole moment 2.91 D
Thermochemistry
Specific
heat capacity
C
125.45 J/mol·K
Std molar
entropy
So298
200.4 J/mol·K
Std enthalpy of
formation
ΔfHo298
-250.03-(−248.77) kJ/mol
Std enthalpy of
combustion
ΔcHo298
-1.772 MJ/mol
Hazards
MSDS External MSDS
GHS pictograms The flame pictogram in the Globally Harmonized System of Classification and Labelling of Chemicals (GHS) The exclamation-mark pictogram in the Globally Harmonized System of Classification and Labelling of Chemicals (GHS)
GHS signal word DANGER
GHS hazard statements H225, H319, H336
GHS precautionary statements P210, P261, P305+351+338
EU Index 606-001-00-8
EU classification Highly Flammable F Irritant Xi
R-phrases R11, R36, R66, R67
S-phrases (S2), S9, S16, S26
NFPA 704
Flammability code 3: Liquids and solids that can be ignited under almost all ambient temperature conditions. Flash point between 23 and 38 °C (73 and 100 °F). E.g., gasoline) Health code 1: Exposure would cause irritation but only minor residual injury. E.g., turpentine Reactivity code 0: Normally stable, even under fire exposure conditions, and is not reactive with water. E.g., liquid nitrogen Special hazards (white): no codeNFPA 704 four-colored diamond
Flash point −20 °C (−4 °F; 253 K)
Explosive limits 2.6–12.8%[9]
Threshold Limit Value 1185 mg/m3 (TWA), 2375 mg/m3 (STEL)
LD50 3000 mg/kg (oral, mouse), 20000 mg/kg (dermal, rabbit), LC50 = 19000 mg/m3 (inhalation)
Related compounds
Related compounds Butanone
Isopropanol
Supplementary data page
Structure and
properties
n, εr, etc.
Thermodynamic
data
Phase behaviour
Solid, liquid, gas
Spectral data UV, IR, NMR, MS
Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
 YesY (verify) (what is: YesY/N?)
Infobox references
This page refers to the chemical compound. For the slowcore band, see Acetone (band).

Acetone (systematically named propanone) is the organic compound with the formula (CH3)2CO. It is a colorless, volatile, flammable liquid, and is the simplest ketone.

Acetone is miscible with water and serves as an important solvent in its own right, typically for cleaning purposes in the laboratory. About 6.7 million tonnes were produced worldwide in 2010, mainly for use as a solvent and production of methyl methacrylate and bisphenol A.[10][11] It is a common building block in organic chemistry. Familiar household uses of acetone are as the active ingredient in nail polish remover and as paint thinner.

Acetone is produced and disposed of in the human body through normal metabolic processes. It is normally present in blood and urine. People with diabetes produce it in larger amounts. Reproductive toxicity tests show that it has low potential to cause reproductive problems. Pregnant women, nursing mothers and children have higher levels of acetone.[12] Ketogenic diets that increase acetone in the body are used to reduce epileptic attacks in infants and children who suffer from recalcitrant refractory epilepsy.

Metabolism[edit]

See also: ketosis

Biosynthesis[edit]

Small amounts of acetone are produced in the body by the decarboxylation of ketone bodies. Certain dietary patterns, including prolonged fasting and high-fat low-carbohydrate dieting, can produce ketosis, in which acetone is formed in body tissue. Certain health conditions, such as alcoholism and diabetes, can produce ketoacidosis, uncontrollable ketosis that leads to a sharp, and potentially fatal, increase in the acidity of the blood. Since it is a byproduct of fermentation, acetone is a byproduct of the distillery industry.

Metabolic use[edit]

Although some biochemistry textbooks and current research publications[13] indicate that acetone cannot be metabolized, there is evidence to the contrary, some dating back thirty years. Acetone can be produced from the oxidation of ingested isopropanol, or from the spontaneous/enzymatic breakdown of acetoacetate in ketotic individuals. It can then be metabolized either by CYP2E1 via methylglyoxal to D-lactate and pyruvate, and ultimately glucose/energy, or by a different pathway via propylene glycol to pyruvate, lactate, acetate (usable for energy) and propionaldehyde.[14][15][16]

Production[edit]

In 2010, the worldwide production capacity for acetone was estimated at 6.7 million tonnes per year.[17] With 1.56 million tonnes per year, the United States had the highest production capacity,[18] followed by Taiwan and mainland China. The largest producer of acetone is INEOS Phenol, owning 17% of the world's capacity, with also significant capacity (7–8%) by Mitsui, Sunoco and Shell in 2010.[17] INEOS Phenol also owns the world's largest production site (420,000 tonnes/annum) in Beveren (Belgium). Spot price of acetone in summer 2011 was 1100–1250 USD/tonne in the United States.[19]

Current method[edit]

Acetone is produced directly or indirectly from propylene. Approximately 83% of acetone is produced via the cumene process;[11] as a result, acetone production is tied to phenol production. In the cumene process, benzene is alkylated with propylene to produce cumene, which is oxidized by air to produce phenol and acetone:

Overview of the cumene process

Other processes involve the direct oxidation of propylene (Wacker-Hoechst process), or the hydration of propylene to give 2-propanol, which is oxidized to acetone.[11]

Older methods[edit]

Previously, acetone was produced by the dry distillation of acetates, for example calcium acetate in ketonic decarboxylation.

Ca(CH3COO)2 → CaO(s) + CO2(g) + (CH3)2CO (v)

Before that, during World War I acetone was produced using acetone-butanol-ethanol fermentation with Clostridium acetobutylicum bacteria, which was developed by Chaim Weizmann (later the first president of Israel) in order to help the British war effort[11] in the preparation of Cordite.[20] This acetone-butanol-ethanol fermentation was eventually abandoned when newer methods with better yields were found.[11]

Uses[edit]

About a third of the world's acetone is used as a solvent, and a quarter is consumed as acetone cyanohydrin a precursor to methyl methacrylate.[10]

Solvent[edit]

Acetone is a good solvent for many plastics and some synthetic fibers. It is used for thinning polyester resin, cleaning tools used with it, and dissolving two-part epoxies and superglue before they harden. It is used as one of the volatile components of some paints and varnishes. As a heavy-duty degreaser, it is useful in the preparation of metal prior to painting. It is also useful for high reliability soldering applications to remove rosin flux after soldering is complete; this helps to prevent the Rusty bolt effect.

Acetone is used as a solvent by the pharmaceutical industry and as a denaturant in denatured alcohol.[21] Acetone is also present as an excipient in some pharmaceutical drugs.[22]

Although itself flammable, acetone is used extensively as a solvent for the safe transporting and storing of acetylene, which cannot be safely pressurized as a pure compound. Vessels containing a porous material are first filled with acetone followed by acetylene, which dissolves into the acetone. One liter of acetone can dissolve around 250 liters of acetylene.[23][24]

Chemical intermediate[edit]

Acetone is used to synthesize methyl methacrylate. It begins with the initial conversion of acetone to acetone cyanohydrin:

(CH3)2CO + HCN → (CH3)2C(OH)CN

In a subsequent step, the nitrile is hydrolyzed to the unsaturated amide, which is esterified:

(CH3)2C(OH)CN + CH3OH → CH2=(CH3)CCO2CH3 + NH3

The third major use of acetone (about 20%)[10] is synthesizing bisphenol A. Bisphenol A is a component of many polymers such as polycarbonates, polyurethanes, and epoxy resins. The synthesis involves the condensation of acetone with phenol:

(CH3)2CO + 2 C6H5OH → (CH3)2C(C6H4OH)2 + H2O

Many millions of kilograms of acetone are consumed in the production of the solvents methyl isobutyl alcohol and methyl isobutyl ketone. These products arise via an initial aldol condensation to give diacetone alcohol.[11]

2 (CH3)2CO → (CH3)2C(OH)CH2C(O)CH3

Laboratory[edit]

In the laboratory, acetone is used as a polar, aprotic solvent in a variety of organic reactions, such as SN2 reactions. The use of acetone solvent is critical for the Jones oxidation. It does not form an azeotrope with water (see azeotrope (data)).[25] It is a common solvent for rinsing laboratory glassware because of its low cost and volatility. Despite its common use as a supposed drying agent, it is not effective except by bulk displacement and dilution. Acetone can be cooled with dry ice to −78 °C without freezing; acetone/dry ice baths are commonly used to conduct reactions at low temperatures. Acetone is fluorescent under ultraviolet light, and its vapor may be used as a fluorescent tracer in fluid flow experiments.[26]

Medical and cosmetic uses[edit]

Acetone is used in a variety of general medical and cosmetic applications and is also listed as a component in food additives and food packaging. Dermatologists use acetone with alcohol for acne treatments to peel dry skin.

Acetone is commonly used in chemical peeling. Common agents used today for chemical peels are salicylic acid, glycolic acid, 30% salicylic acid in ethanol, and trichloroacetic acid (TCA). Prior to chemexfoliation, the skin is cleaned and excess fat removed in a process called defatting. Acetone, Septisol, or a combination of these agents is commonly used in this process.[citation needed]

Domestic and other niche uses[edit]

Acetone is often the primary component in cleaning agents such as nail polish remover. Acetone is a component of superglue remover and easily removes residues from glass and porcelain. Make-up artists use acetone to remove skin adhesive from the netting of wigs and moustaches by immersing the item in an acetone bath, then removing the softened glue residue with a stiff brush.

This chemical is also used as an artistic agent; when rubbed on the back of a laser print or photocopy placed face-down on another surface and burnished firmly, the toner of the image transfers to the destination surface.[original research?]

Acetone can also be used in combination with automatic transmission fluid to create an effective penetrating oil. Brake fluid is sometimes used in place of ATF. These mixtures (usually 1:1) can be useful in loosening rusted or stuck bolts.[citation needed]

Safety[edit]

Flammability[edit]

The most hazardous property of acetone is its extreme flammability. At temperatures greater than acetone's flash point of −20 °C (−4 °F), air mixtures of between 2.5% and 12.8% acetone, by volume, may explode or cause a flash fire. Vapors can flow along surfaces to distant ignition sources and flash back. Static discharge may also ignite acetone vapors, though acetone has a very high ignition initiation energy point and therefore accidental ignition is rare. Even pouring or spraying acetone over red-glowing coal will not ignite it, due to the high concentration of vapour and the cooling effect of evaporation of the liquid.[27] It auto-ignites at 465 °C (869 °F). Auto-ignition temperature is also dependent upon the exposure time, thus at some tests it is quoted as 525 °C. Also, industrial acetone is likely to contain a small amount of water which also inhibits ignition.

Acetone peroxide[edit]

Main article: acetone peroxide

When oxidized, acetone forms acetone peroxide as a byproduct, which is a highly unstable, primary high explosive compound. It may be formed accidentally, e.g. when waste hydrogen peroxide is poured into waste solvent containing acetone. Due to its instability, it is rarely used, despite its easy chemical synthesis.

Health information[edit]

Acetone has been studied extensively and is generally recognized to have low acute and chronic toxicity if ingested and/or inhaled. Inhalation of high concentrations (around 9200 ppm) in the air caused irritation of the throat in humans in as little as 5 minutes. Inhalation of concentrations of 1000 ppm caused irritation of the eyes and of the throat in less than 1 hour; however, the inhalation of 500 ppm of acetone in the air caused no symptoms of irritation in humans even after 2 hours of exposure. Acetone is not currently regarded as a carcinogen, a mutagenic chemical or a concern for chronic neurotoxicity effects.[27]

Acetone can be found as an ingredient in a variety of consumer products ranging from cosmetics to processed and unprocessed foods. Acetone has been rated as a GRAS (generally recognized as safe) substance when present in beverages, baked foods, desserts, and preserves at concentrations ranging from 5 to 8 mg/L. Additionally, a joint U.S-European study found that acetone's "health hazards are slight".[citation needed]

Toxicology[edit]

Acetone is believed to exhibit only slight toxicity in normal use, and there is no strong evidence of chronic health effects if basic precautions are followed.[28]

At very high vapor concentrations, acetone is irritating and, like many other solvents, may depress the central nervous system. It is also a severe irritant on contact with eyes, and a potential pulmonary aspiration risk. In one documented case, ingestion of a substantial amount of acetone led to systemic toxicity, although the patient eventually fully recovered.[29] Some sources estimate LD50 for human ingestion at 1.159 g/kg; LD50 inhalation by mice is given as 44 g/m3, over 4 hours.[30]

Acetone has been shown to have anticonvulsant effects in animal models of epilepsy, in the absence of toxicity, when administered in millimolar concentrations.[31] It has been hypothesized that the high-fat low-carbohydrate ketogenic diet used clinically to control drug-resistant epilepsy in children works by elevating acetone in the brain.[31]

  • EPA EPCRA Delisting (1995). EPA removed acetone from the list of "toxic chemicals" maintained under Section 313 of the Emergency Planning and Community Right to Know Act (EPCRA). In making that decision, EPA conducted an extensive review of the available toxicity data on acetone and found that acetone "exhibits acute toxicity only at levels that greatly exceed releases and resultant exposures", and further that acetone "exhibits low toxicity in chronic studies".
  • Genotoxicity. Acetone has been tested in more than two dozen in vitro and in vivo assays. These studies indicate that acetone is not genotoxic.
  • Carcinogenicity. EPA in 1995 concluded, "There is currently no evidence to suggest a concern for carcinogenicity". (EPCRA Review, described in Section 3.3). NTP scientists have recommended against chronic toxicity/carcinogenicity testing of acetone because "the prechronic studies only demonstrated a very mild toxic response at very high doses in rodents".
  • Neurotoxicity and Developmental Neurotoxicity. The neurotoxic potential of both acetone and isopropanol, the metabolic precursor of acetone, have been extensively studied. These studies demonstrate that although exposure to high doses of acetone may cause transient central nervous system effects, acetone is not a neurotoxicant. A guideline developmental neurotoxicity study has been conducted with isopropanol, and no developmental neurotoxic effects were identified, even at the highest dose tested. (SIAR, pp. 1, 25, 31).
  • Environmental. When the EPA exempted acetone from regulation as a volatile organic compound (VOC) in 1995, EPA stated that this exemption would "contribute to the achievement of several important environmental goals and would support EPA's pollution prevention efforts". 60 Fed. Reg. 31,634 (June 16, 1995). 60 Fed. Reg. 31,634 (June 16, 1995). EPA noted that acetone could be used as a substitute for several compounds that are listed as hazardous air pollutants (HAP) under section 112 of the Clean Air Act.

Environmental effects[edit]

Although acetone occurs naturally in the environment in plants, trees, volcanic gases, forest fires, and as a product of the breakdown of body fat,[32] the majority of the acetone released into the environment is of industrial origin. Acetone evaporates rapidly, even from water and soil. Once in the atmosphere, it has a 22-day half-life and is degraded by UV light via photolysis (primarily into methane and ethane.[33]) Consumption by microorganisms contributes to the dissipation of acetone in soil, animals, or waterways.[32] The LD50 of acetone for fish is 8.3 g/L of water (or about 1%) over 96 hours, and its environmental half-life in water is about 1 to 10 days. Acetone may pose a significant risk of oxygen depletion in aquatic systems due to the microbial consumption.[34]

References[edit]

  1. ^ The Merck Index, 15th Ed. (2013), p. 13, Acetone Monograph 65, O'Neil: The Royal Society of Chemistry.(subscription required)
  2. ^ "Acetone". PubChem. USA: National Center for Biotechnology Information. 
  3. ^ a b c "Acetone". NIST Chemistry WebBook. USA: National Institute of Standards and Technology. 
  4. ^ Klamt, Andreas (2005). COSMO-RS: From Quantum Chemistry to Fluid Phase Thermodynamics and Drug Design. Elsevier. pp. 92–94. ISBN 978-0-444-51994-8. 
  5. ^ Ash, Michael; Ash, Irene (2004). Handbook of preservatives. Synapse Information Resources, Inc. p. 369. ISBN 1-890595-66-7. 
  6. ^ Myers, Richard L. (2007). The 100 Most Important Chemical Compounds: A Reference Guide. Greenwood. pp. 4–6. ISBN 978-0-313-08057-9. 
  7. ^ a b http://chemister.ru/Database/properties-en.php?dbid=1&id=27
  8. ^ Acetone in Linstrom, P.J.; Mallard, W.G. (eds.) NIST Chemistry WebBook, NIST Standard Reference Database Number 69. National Institute of Standards and Technology, Gaithersburg MD. http://webbook.nist.gov (retrieved 2014-05-11)
  9. ^ Working with modern hydrocarbon and oxygenated solvents: a guide to flammability American Chemistry Council Solvents Industry Group, pg. 7, January 2008
  10. ^ a b c Acetone, World Petrochemicals report, January 2010
  11. ^ a b c d e f Stylianos Sifniades, Alan B. Levy, "Acetone" in Ullmann's Encyclopedia of Industrial Chemistry, Wiley-VCH, Weinheim, 2005.
  12. ^ American Chemistry Council, Acetone VCCEP Submission, September 10, 2003, page 9
  13. ^ M Vujasinović; M Kočar; K Kramer; M Bunc; M Brvar. "Poisoning with 1-propanol and 2-propanol". Retrieved March 2014. 
  14. ^ Glew, Robert H. "You Can Get There From Here: Acetone, Anionic Ketones and Even-Carbon Fatty Acids can Provide Substrates for Gluconeogenesis". Retrieved August 2013. 
  15. ^ Miller DN, Bazzano G; Bazzano (1965). "Propanediol metabolism and its relation to lactic acid metabolism". Ann NY Acad Sci 119 (3): 957–973. Bibcode:1965NYASA.119..957M. doi:10.1111/j.1749-6632.1965.tb47455.x. PMID 4285478. 
  16. ^ Ruddick JA (1972). "Toxicology, metabolism, and biochemistry of 1,2-propanediol". Toxicol App Pharmacol 21: 102–111. doi:10.1016/0041-008X(72)90032-4. 
  17. ^ a b Camara Greiner, EO and Funada, C (June 2010). "CEH Marketing Research Report: ACETONE". Chemical Economics Handbook. SRI consulting. Retrieved March 2011. 
  18. ^ "Acetone Uses and Market Data". ICIS.com. October 2010. Retrieved 2011-03-21. 
  19. ^ Acetone (US Gulf) Price Report – Chemical pricing information. ICIS Pricing. Retrieved on 2012-11-26.
  20. ^ Wittcoff, M.M. Green ; H.A. (2003). Organic chemistry principles and industrial practice (1. ed., 1. reprint. ed.). Weinheim: Wiley-VCH. p. 4. ISBN 3-527-30289-1. 
  21. ^ Weiner, Myra L.; Lois A. Kotkoskie (1999). Excipient Toxicity and Safety. p. 32. ISBN 978-0-8247-8210-8. 
  22. ^ Inactive Ingredient Search for Approved Drug Products, FDA/Center for Drug Evaluation and Research
  23. ^ Mine Safety and Health Administration (MSHA) – Safety Hazard Information – Special Hazards of Acetylene. Msha.gov. Retrieved on 2012-11-26.
  24. ^ History – Acetylene dissolved in acetone. Aga.com. Retrieved on 2012-11-26.
  25. ^ What is an Azeotrope?. Solvent—recycling.com. Retrieved on 2012-11-26.
  26. ^ A. Lozano, B. Yip and R. K. Hanson (1992). "Acetone: a tracer for concentration measurements in gaseous flows by planar laser-induced fluorescence". Exp. Fluids 13 (6): 369–376. doi:10.1007/BF00223244. 
  27. ^ a b Acetone MSDS. Hazard.com (1998-04-21). Retrieved on 2012-11-26.
  28. ^ Basic Information on Acetone. Ccohs.ca (1999-02-19). Retrieved on 2012-11-26.
  29. ^ Canadian Centre for Occupational Health and Safety. "Health Effects of Acetone". Archived from the original on 17 October 2008. Retrieved 2008-10-21. 
  30. ^ Safety (MSDS) data for propanone. Msds.chem.ox.ac.uk. Retrieved on 2012-11-26.
  31. ^ a b Likhodii SS, Serbanescu I, Cortez MA, Murphy P, Snead OC 3rd, Burnham WM (2003). "Anticonvulsant properties of acetone, a brain ketone elevated by the ketogenic diet". Ann Neurol. 54 (2): 219–226. doi:10.1002/ana.10634. PMID 12891674. 
  32. ^ a b Acetone, Agency for Toxic Substances and Disease Registry ToxFAQs, 1995
  33. ^ Darwent, B. deB.; Allard, M. J.; Hartman, M. F.; Lange, L. J. (1960). "The Photolysis of Acetone". Journal of Physical Chemistry 64 (12): 1847. doi:10.1021/j100841a010. 
  34. ^ Safety Data Sheet Acetone. jmloveridge.com. Retrieved on 2012-11-26.

External links[edit]