वाष्पशील कार्बनिक यौगिक का स्रोत देखें

{{हिन्दी नहीं|1=अंग्रेजी|date=दिसम्बर 2015}}
'''वाष्पशील कार्बनिक यौगिक(Volatile organic compounds)''' या 

('''VOCs''') वे कार्बनिक रसायन है जिनमे कमरे के समान्य ताप पर भी उच्च वाष्प दाब होता है। इनका उच्च वाष्प दाब, उनके कम क्वथनांक की वजह से garmi  अधिक अणुओं के ठोस या द्रव वाष्पीकृत या ऊर्ध्वपतित होकर यौगिक बनाने व आस पास की वायु में मिलने के कारण होता है। निम्न क्वथनांक के कारण इनमे उच्च वाष्प दाब होता है, अधिक अणुओ का जल या ठोस अवस्था से वाष्पीकरण या ऊर्ध्वपातन होता है तथा यौगिक बनकर वायुमंडल में मिश्रित हो जाता है। जैसे कि निम्न क्वथनांक के paint- 19&nbsp;°C (–2&nbsp;°F) से formaldehyde का वाष्पीकरण।

VOCs, कई अलग अलग, और सर्वव्यापी हैं। इनमे दोनों मानव निर्मित और स्वाभाविक रूप से होने वाली रासायनिक यौगिक शामिल है। अधिकतर सुगंधिया VOCs है। VOCs पौधों के मध्य सम्प्रेषण में महत्वपूर्ण भूमिका निभाते हैं,<ref>{{cite web |url=http://content.yudu.com/Library/A1og25/PlantsADifferentPers/resources/73.htm |title=Plants: A Different Perspective |publisher=Content.yudu.com |date= |accessdate=2012-07-03 |archive-url=https://web.archive.org/web/20170217195618/http://content.yudu.com/Library/A1og25/PlantsADifferentPers/resources/73.htm |archive-date=17 फ़रवरी 2017 |url-status=live }}</ref> तथा पौधों से जीवो को संदेश भेजते हैं। कुछ VOCs मानव स्वास्थ्य के लिए खतरनाक होते हैं व वातावरण को हानी पहुंचाते हैं। [[Anthropogenic behaviour|Anthropogenic]] VOCs are regulated by law, especially indoors, where concentrations are the highest. Harmful VOCs typically are not acutely [[toxic]], but have compounding long-term health effects. Because the concentrations are usually low and the symptoms slow to develop, research into VOCs and their effects is difficult.

== Definitions ==
Diverse definitions of the term VOC<ref>{{cite web |url=http://www.eurofins.com/voc.aspx |title=What does VOC mean? |publisher=Eurofins.com |date= |accessdate=2012-07-03 |archive-url=https://web.archive.org/web/20120530034011/http://www.eurofins.com/voc.aspx |archive-date=30 मई 2012 |url-status=dead }}</ref> are in use.

The definitions of VOCs used for control of precursors of photochemical smog used by the EPA, and states in the US with independent outdoor air pollution regulations include exemptions for VOCs that are determined to be non-reactive, or of low-reactivity in the smog formation process. EPA formerly defined these compounds as reactive organic gases (ROG) but changed the terminology to VOC.{{citation needed|date=अक्टूबर 2013}}

In the USA, different regulations vary between states - most prominent is the VOC regulation by [[SCAQMD]] and by the [[California Air Resources Board]].<ref>{{Cite web |url=http://www.eurofins.com/carb-consumer-products-voc.aspx |title=California ARB |access-date=11 सितंबर 2015 |archive-url=https://web.archive.org/web/20150924003305/http://www.eurofins.com/carb-consumer-products-voc.aspx |archive-date=24 सितंबर 2015 |url-status=dead }}</ref> However, this specific use of the term VOCs can be misleading, especially when applied to [[indoor air quality]] because many chemicals that are not regulated as outdoor air pollution can still be important for indoor air pollution.

===Canada===
[[Health Canada]] classes VOCs as organic compounds that have boiling points roughly in the range of {{Convert|50|to|250|C|F}}. The emphasis is placed on commonly encountered VOCs that would have an effect on air quality.<ref>[http://www.hc-sc.gc.ca/ewh-semt/pubs/air/office_building-immeubles_bureaux/organic-organiques-eng.php Health Canada] {{Webarchive|url=https://web.archive.org/web/20090207142918/http://www.hc-sc.gc.ca/ewh-semt/pubs/air/office_building-immeubles_bureaux/organic-organiques-eng.php |date=7 फ़रवरी 2009 }} <!-- retrieved January 22, 2009 --></ref>

===European Union===
A VOC is any organic compound having an initial boiling point less than or equal to {{Convert|250|C|F}} measured at a standard atmospheric pressure of 101.3 kPa<ref>[http://eur-lex.europa.eu/LexUriServ/LexUriServ.do?uri=CELEX:32004L0042:EN:NOT Directive 2004/42/CE of the European Parliament and of the Council of 21 April 2004 on the limitation of emissions of volatile organic compounds due to the use of organic solvents in certain paints and varnishes and vehicle refinishing products] {{Webarchive|url=https://web.archive.org/web/20131121053510/http://eur-lex.europa.eu/LexUriServ/LexUriServ.do?uri=CELEX:32004L0042:EN:NOT |date=21 नवंबर 2013 }} ''EUR-Lex'', European Union Publications Office. Retrieved on 2010-09-28.</ref>

===US===
VOCs (or specific subsets of the VOCs) are legally defined in the various laws and codes under which they are regulated. Other definitions may be found from government agencies investigating or advising about VOCs.<ref>{{Cite web |url=http://toxics.usgs.gov/definitions/vocs.html |title=USGS definition |access-date=11 सितंबर 2015 |archive-url=https://web.archive.org/web/20150905205650/http://toxics.usgs.gov/definitions/vocs.html |archive-date=5 सितंबर 2015 |url-status=dead }}</ref> The [[United States Environmental Protection Agency]] (EPA) regulates VOCs in the air, water, and land. The [[Safe Drinking Water Act]] implementation includes a list labeled "VOCs in connection with contaminants that are organic and volatile."<ref>40CFR141</ref> The EPA also publishes testing methods for chemical compounds, some of which refer to VOCs.<ref>{{cite web |url=http://www.epa.gov/waterscience/methods/method/files/524_2.pdf |title=Clean Water Act Analytical Methods &#124; CWA Methods &#124; US EPA |publisher=Epa.gov |date= |accessdate=2012-07-03 |archive-url=https://web.archive.org/web/20101224053356/http://www.epa.gov/waterscience/methods/method/files/524_2.pdf |archive-date=24 दिसंबर 2010 |url-status=live }}</ref>

In addition to drinking water, VOCs are regulated in discharges to waters (sewage treatment and stormwater disposal), as hazardous waste,<ref>[[CERCLA]] and RCRA</ref> but not in non industrial indoor air.<ref>{{cite web |url=http://www.epa.gov/iaq/voc.html |title=Volatile Organic Compounds &#124; Indoor Air &#124; US Environmental Protection Agency |publisher=Epa.gov |date=2010-11-17 |accessdate=2012-07-03 |archive-url=https://web.archive.org/web/20150909090046/http://www.epa.gov/iaq/voc.html |archive-date=9 सितंबर 2015 |url-status=live }}</ref> The [[United States Department of Labor]] and its Occupational Safety and Health Administration (OSHA) regulate VOC exposure in the workplace. Volatile organic compounds that are [[hazardous material]] would be regulated by the [[Pipeline and Hazardous Materials Safety Administration]] while being transported.

==Biologically generated VOCs==
Not counting [[methane]], biological sources emit an estimated 1150 [[Orders of magnitude (mass)#106 to 1011 kg|teragrams]] of [[carbon]] per year in the form of VOCs.<ref name="unexplored">{{cite journal |doi=10.1021/es072476p |title=Known and Unexplored Organic Constituents in the Earth's Atmosphere |year=2007 |last1=Goldstein |first1=Allen H. |last2=Galbally |first2=Ian E. |journal=Environmental Science & Technology |volume=41 |issue=5 |pages=1514–21 |pmid=17396635}}</ref> The majority of VOCs are produced by plants, the main compound being [[isoprene]]. The remainder are produced by animals, microbes, and [[fungi]], such as [[molds]].

The strong odor emitted by many plants consists of [[green leaf volatiles]], a subset of VOCs. Emissions are affected by a variety of factors, such as temperature, which determines rates of volatilization and growth, and sunlight, which determines rates of [[biosynthesis]]. Emission occurs almost exclusively from the leaves, the [[stomata]] in particular. A major class of VOCs is <!--Predicate agrees in number with its subject.-->[[terpene]]s, such as [[myrcene]].<ref>{{cite journal |doi=10.1016/j.tplants.2004.02.006 |title=Physiological and physicochemical controls on foliar volatile organic compound emissions |year=2004 |last1=Niinemets |first1=Ülo |last2=Loreto |first2=Francesco |last3=Reichstein |first3=Markus |journal=Trends in Plant Science |volume=9 |issue=4 |pages=180–6 |pmid=15063868}}</ref> Providing a sense of scale, a forest 62,000&nbsp;km<sup>2</sup> in area (the U.S. state of Pennsylvania) is estimated to emit 3,400,000 kilograms of terpenes on a typical August day during the growing season.<ref>{{cite journal |doi=10.1002/cssc.200900186 |title=Myrcene as a Natural Base Chemical in Sustainable Chemistry: A Critical Review |year=2009 |last1=Behr |first1=Arno |last2=Johnen |first2=Leif |journal=ChemSusChem |volume=2 |issue=12 |pages=1072–95 |pmid=20013989}}</ref> VOCs should be a factor in choosing which trees to plant in urban areas.<ref>{{cite web|last1=Xie|first1=Jenny|title=Not All Tree Planting Programs Are Great for the Environment|url=http://www.citylab.com/weather/2014/06/not-all-tree-planting-programs-are-great-for-the-environment/372849/|website=[[The Atlantic Cities#CityLab|City Lab]]|publisher=[[Atlantic Media]]|accessdate=20 June 2014|archive-url=https://web.archive.org/web/20140620032819/http://www.citylab.com/weather/2014/06/not-all-tree-planting-programs-are-great-for-the-environment/372849/|archive-date=20 जून 2014|url-status=live}}</ref> Induction of genes producing volatile organic compounds, and subsequent increase in volatile terpenes has been achieved in maize using (Z)-3-Hexen-1-ol and other plant hormones.<ref>{{cite journal |doi=10.1007/s00425-004-1404-5 |title=(Z)-3-Hexenol induces defense genes and downstream metabolites in maize |year=2004 |last1=Farag |first1=Mohamed A. |last2=Fokar |first2=Mohamed |last3=Abd |first3=Haggag |last4=Zhang |first4=Huiming |last5=Allen |first5=Randy D. |last6=Paré |first6=Paul W. |journal=Planta |volume=220 |issue=6 |pages=900–9 |pmid=15599762}}</ref>

==Anthropogenic sources==

[[Anthropogenic]] sources emit about 142 [[Orders of magnitude (mass)#106 to 1011 kg|teragrams]] of [[carbon]] per year in the form of VOCs.<ref name="unexplored"/>

===Specific components===

====Paints and coatings====
A major source of man-made VOCs are coatings, especially paints and protective coatings. Solvents are required to spread a protective or decorative film. Approximately 12 billion litres of paints are produced annually. Typical solvents are aliphatic hydrocarbons, [[ethyl acetate]], glycol ethers, and [[acetone]]. Motivated by cost, environmental concerns, and regulation, the paint and coating industries are increasingly shifting toward [[aqueous solution|aqueous solvents]].<ref>{{citation | last1 = Stoye | first1 = D. | last2 = Funke | first2 = W. | last3 = Hoppe | first3 = L. | last4 = Hasselkus | first4 = J. R. | last5 = Curtis | first5 = L. G. | last6 = Hoehne | first6 = K. | last7 = Zech | first7 = H. J. | last8 = Heiling | first8 = P. | last9 = Yamabe | first9 = M. | last10 = Dören | first10 = K. | last11 = Schupp | first11 = H. | last12 = Küchenmeister | first12 = R. | last13 = Schmitthenner | first13 = M. | last14 = Kremer | first14 = W. | last15 = Wieczorrek | first15 = W. | last16 = Gempeler | first16 = H. | last17 = Schneider | first17 = W. | last18 = White | first18 = J. W. | last19 = Short | first19 = A. G. | last20 = Blank | first20 = W. J. | last21 = Calbo | first21 = L. J. | last22 = Plath | first22 = D. | last23 = Wagner | first23 = F. | last24 = Haller | first24 = W. | last25 = Rödder | first25 = K. M. | last26 = Streitberger | first26 = H. J. | last27 = Urbano | first27 = E. | last28 = Laible | first28 = R. | last29 = Meyer | first29 = B. D. | last30 = Bagda | first30 = E. | title = Ullmann's Encyclopedia of Industrial Chemistry | year = 2006 | pmid = | pmc = | doi = 10.1002/14356007.a18_359.pub2 | isbn = 3527306730 | chapter = Paints and Coatings | displayauthors = 3 }}</ref>

====Chlorofluorocarbons and chlorocarbons====
[[Chlorofluorocarbon]]s, which are banned or highly regulated, were widely used cleaning products and refrigerants. Tetrachloroethene is used widely in dry cleaning and by industry.

====Fossil fuels====
The use of [[fossil fuels]] produces VOCs either directly as products (e.g., [[gasoline]]) or indirectly as byproducts (e.g., automobile [[exhaust gas]]).{{citation needed|date=अगस्त 2013}}

====Benzene====
{{main|Benzene}}
One VOC that is a known human carcinogen is benzene, which is a chemical found in environmental tobacco smoke, stored fuels, and exhaust from cars. Benzene also has natural sources such as volcanoes and forest fires. It is frequently used to make other chemicals in the production of plastics, resins, and synthetic fibers. Benzene evaporates into the air quickly and the vapor of benzene is heavier than air allowing the compound to sink into low-lying areas. Benzene has also been known to contaminate food and water and if digested can lead to vomiting, dizziness, sleepiness, rapid heartbeat, and at high levels, even death may occur.{{citation needed|date=अगस्त 2013}}

====Methylene chloride====
[[Methylene chloride]] is another VOC that is highly dangerous to human health. It can be found in adhesive removers and aerosol spray paints and the chemical has been proven to cause cancer in animals. In the human body, methylene chloride is converted to carbon monoxide and a person will suffer the same symptoms as exposure to carbon monoxide. If a product that contains methylene chloride needs to be used the best way to protect human health is to use the product outdoors. If it must be used indoors, proper ventilation is essential to keeping exposure levels down.{{citation needed|date=अगस्त 2013}}

====Perchloroethylene====
[[Perchloroethylene]] is a volatile organic compound that has been linked to causing cancer in animals. It is also suspected to cause many of the breathing related symptoms of exposure to VOCs.{{citation needed|date=अप्रैल 2013}} Perchloroethylene is used mostly in dry cleaning. While dry cleaners recapture perchloroethylene in the dry cleaning process to reuse it, some environmental release is unavoidable. Studies show that people breathe in low levels of this VOC in homes where dry-cleaned clothes are stored and while wearing dry-cleaned clothing.{{citation needed|date=अप्रैल 2013}}

====MTBE====
[[MTBE]] was banned in the US around 2004 in order to limit further contamination of drinking water [[aquifers]] ([[groundwater]]) primarily from leaking underground gasoline storage tanks where MTBE was used as an octane booster and oxygenated-additive.{{citation needed|date=अगस्त 2013}}

===Indoor air===
{{Main|Indoor air quality}}
Since many people spend much of their time indoors, long-term exposure to VOCs in the indoor environment can contribute to [[sick building syndrome]].<ref name="Wang, S. 2007" /> In offices, VOC results from new furnishings, wall coverings, and office equipment such as photocopy machines, which can [[Outgassing|off-gas]] VOCs into the air.<ref name="test" /><ref>{{cite journal |doi=10.1016/S0360-1323(97)00055-3 |title=A review of the emission of VOCs from polymeric materials used in buildings |year=1998 |last1=Yu |first1=Chuck |last2=Crump |first2=Derrick |journal=Building and Environment |volume=33 |issue=6 |pages=357–74}}</ref> Good ventilation and air-conditioning systems are helpful at reducing VOCs in the indoor environment.<ref name="test" /> Studies also show that relative [[leukemia]] and [[lymphoma]] can increase through prolonged exposure of VOCs in the indoor environment.<ref>{{cite journal |doi=10.1016/j.biopha.2007.10.006 |title=Lifestyle-related factors and environmental agents causing cancer: An overview |year=2007 |last1=Irigaray |first1=P. |last2=Newby |first2=J.A. |last3=Clapp |first3=R. |last4=Hardell |first4=L. |last5=Howard |first5=V. |last6=Montagnier |first6=L. |last7=Epstein |first7=S. |last8=Belpomme |first8=D. |journal=Biomedicine & Pharmacotherapy |volume=61 |issue=10 |pages=640–58 |pmid=18055160}}</ref>

In the United States, there are two standardized methods for measuring VOCs, one by the [[National Institute for Occupational Safety and Health]] (NIOSH) and another by [[Occupational Safety and Health Administration]] (OSHA). Each method uses a single component solvent; [[butanol]] and [[hexane]] cannot be sampled, however, on the same sample matrix using the NIOSH or OSHA method.<ref>{{Cite web |url=http://galsonlabs.com/services/referenceinfo/technical_bulletins.php?tb_id=42 |title=Who Says Alcohol and Benzene Don't Mix? |access-date=11 सितंबर 2015 |archive-url=https://web.archive.org/web/20080415162950/http://galsonlabs.com/services/referenceinfo/technical_bulletins.php?tb_id=42 |archive-date=15 अप्रैल 2008 |url-status=dead }}</ref>

The aromatic VOC compound [[benzene]], emitted from exhaled cigarette smoke is labeled as carcinogenic, and is ten times higher in smokers than in nonsmokers.<ref name="test">{{cite journal |doi=10.1503/cmaj.070359 |title=Quality of indoor residential air and health |year=2008 |last1=Dales |first1=R. |last2=Liu |first2=L. |last3=Wheeler |first3=A. J. |last4=Gilbert |first4=N. L. |journal=Canadian Medical Association Journal |volume=179 |issue=2 |pages=147–52 |pmid=18625986 |pmc=2443227}}</ref>

The United States Environmental Protection Agency (EPA) has found concentrations of VOCs in indoor air to be 2 to 5 times greater than in outdoor air and sometimes far greater. During certain activities indoor levels of VOCs may reach 1,000 times that of the outside air.<ref>{{Cite web |url=http://www.epa.gov/iaq/voc.html |title=An Introduction to Indoor Air Quality |access-date=11 सितंबर 2015 |archive-url=https://web.archive.org/web/20150909090046/http://www.epa.gov/iaq/voc.html |archive-date=9 सितंबर 2015 |url-status=live }}</ref> Studies have shown that individual VOC emissions by themselves are not that high in an indoor environment, but the indoor total VOC (TVOC) concentrations can be up to five times higher than the VOC outdoor levels.<ref>{{cite journal |doi=10.1016/S1352-2310(99)00272-1 |title=Indoor air quality and health |year=1999 |last1=Jones |first1=A.P. |journal=Atmospheric Environment |volume=33 |issue=28 |pages=4535–64}}</ref> New buildings especially, contribute to the highest level of VOC off-gassing in an indoor environment because of the abundant new materials generating VOC particles at the same time in such a short time period.<ref name="Wang, S. 2007">{{cite journal |doi=10.1016/j.envint.2007.02.011 |title=Volatile organic compounds in indoor environment and photocatalytic oxidation: State of the art |year=2007 |last1=Wang |first1=Shaobin |last2=Ang |first2=H.M. |last3=Tade |first3=Moses O. |journal=Environment International |volume=33 |issue=5 |pages=694–705 |pmid=17376530}}</ref> In addition to new buildings, we also use many consumer products that emit VOC compounds, therefore the total concentration of VOC levels is much greater within the indoor environment.<ref name="Wang, S. 2007"/>

VOC concentration in an indoor environment during winter is three to four times higher than the VOC concentrations during the summer.<ref>{{cite journal | last1 = Barro | first1 = R. | last2 = Regueiro | first2 = J. | last3 = Llompart | first3 = M. A. | last4 = Garcia-Jares | first4 = C. | title = Analysis of industrial contaminants in indoor air: Part 1. Volatile organic compounds, carbonyl compounds, polycyclic aromatic hydrocarbons and polychlorinated biphenyls | journal = Journal of Chromatography A | volume = 1216 | issue = 3 | pages = 540–566 | year = 2009 | pmid = 19019381 | pmc = | doi = 10.1016/j.chroma.2008.10.117 | displayauthors = 1 }}</ref> High indoor VOC levels are attributed to the low rates of air exchange between the indoor and outdoor environment as a result of tight-shut windows and the increasing use of humidifiers.<ref>{{cite journal |doi=10.1016/j.atmosenv.2003.11.003 |title=Seasonal cycle of indoor-VOCs: Comparison of apartments and cities |year=2004 |last1=Schlink |first1=U |last2=Rehwagen |first2=M |last3=Damm |first3=M |last4=Richter |first4=M |last5=Borte |first5=M |last6=Herbarth |first6=O |journal=Atmospheric Environment |volume=38 |issue=8 |pages=1181–90}}</ref>

=== Regulation of indoor VOC emissions ===
In most countries, a separate definition of VOCs is used with regard to indoor air quality that comprises each organic chemical compound that can be measured as follows: Adsorption from air on Tenax TA, thermal desorption, gas chromatographic separation over a 100% nonpolar column (dimethylpolysiloxane). VOC (volatile organic compounds) are all compounds that appear in the gas chromatogram between and including n-hexane and n-hexadecane. Compounds appearing earlier are called VVOC (very volatile organic compounds) compounds appearing later are called SVOC (semi-volatile organic compounds). See also these standards: ISO 16000-6, ISO 13999-2, VDI 4300-6, German [https://web.archive.org/web/20090818001614/http://www.umweltbundesamt.de/building-products/agbb.htm AgBB evaluating scheme], German [https://web.archive.org/web/20150924003255/http://www.eurofins.com/agbb.aspx DIBt approval scheme], GEV testing method for the [https://web.archive.org/web/20150924003316/http://www.eurofins.com/emicode.aspx EMICODE].
Some overviews over VOC emissions rating schemes<ref>{{cite web |url=http://www.eurofins.com/ecolabels.aspx |title=Ecolabels, Quality Labels, and VOC emissions |publisher=Eurofins.com |date= |accessdate=2012-07-03 |archive-url=https://web.archive.org/web/20150924003314/http://www.eurofins.com/ecolabels.aspx |archive-date=24 सितंबर 2015 |url-status=dead }}</ref> have been [https://web.archive.org/web/20150924003312/http://www.eurofins.com/ecolabels-comparison.aspx collected and compared].

[[फ़्रान्स|France]], [[जर्मनी|Germany]] and [[Belgium]] have enacted regulations to limit VOC emissions from commercial products, and industry has developed numerous voluntary ecolabels and rating systems, such as EMICODE,<ref>{{Cite web |url=http://www.eurofins.com/emicode.aspx |title=EMICODE |access-date=11 सितंबर 2015 |archive-url=https://web.archive.org/web/20150924003316/http://www.eurofins.com/emicode.aspx |archive-date=24 सितंबर 2015 |url-status=dead }}</ref> M1,<ref>{{Cite web |url=http://www.eurofins.com/m1.aspx |title=M1 Finnish label |access-date=11 सितंबर 2015 |archive-url=https://web.archive.org/web/20150924003357/http://www.eurofins.com/m1.aspx |archive-date=24 सितंबर 2015 |url-status=dead }}</ref> Blue Angel<ref>{{Cite web |url=http://www.eurofins.com/blue-angel.aspx |title=Blue Angel German ecolabel |access-date=11 सितंबर 2015 |archive-url=https://web.archive.org/web/20150924003302/http://www.eurofins.com/blue-angel.aspx |archive-date=24 सितंबर 2015 |url-status=dead }}</ref> and Indoor Air Comfort<ref>{{Cite web |url=http://www.indoor-air-comfort.com/ |title=Indoor Air Comfort |access-date=15 जून 2020 |archive-url=https://archive.today/20120908070151/http://www.indoor-air-comfort.com/ |archive-date=8 सितंबर 2012 |url-status=dead }}</ref> In the [[संयुक्त राज्य अमेरिका|United States]], several standards exist; California Standard CDPH Section 01350<ref>{{Cite web |url=http://www.eurofins.com/section-1350.aspx |title=CDPH Section 01350 |access-date=11 सितंबर 2015 |archive-url=https://web.archive.org/web/20150924003428/http://www.eurofins.com/section-1350.aspx |archive-date=24 सितंबर 2015 |url-status=dead }}</ref> is the most popular one. Over the last few decades, these regulations and standards changed the marketplace, leading to an increasing number of low-emitting products: The leading voluntary labels report that licenses to several hundreds of low-emitting products have been issued (see the respective webpages such as [https://web.archive.org/web/20150801201451/http://mascertifiedgreen.com/ MAS Certified Green].- Certified Products<ref>{{Cite web |url=http://www.mascertifiedgreen.com/certified_products.asp |title=IAQ Certified Products |access-date=11 सितंबर 2015 |archive-url=https://web.archive.org/web/20151220034432/http://mascertifiedgreen.com/certified_products.asp |archive-date=20 दिसंबर 2015 |url-status=live }}</ref>).

===Formaldehyde===
Many building materials such as paints, adhesives, wall boards, and ceiling tiles slowly emit [[formaldehyde]], which irritates the mucous membranes and can make a person irritated and uncomfortable.<ref name="test">{{cite journal |doi=10.1016/j.jaci.2007.10.045 |title=The health effects of nonindustrial indoor air pollution |url=https://archive.org/details/sim_journal-of-allergy-and-clinical-immunology_2008-03_121_3/page/585 |year=2008 |last1=Bernstein |first1=Jonathan A. |last2=Alexis |first2=Neil |last3=Bacchus |first3=Hyacinth |last4=Bernstein |first4=I. Leonard |last5=Fritz |first5=Pat |last6=Horner |first6=Elliot |last7=Li |first7=Ning |last8=Mason |first8=Stephany |last9=Nel |first9=Andre |last10=Oullette |first10=John |last11=Reijula |first11=Kari |last12=Reponen |first12=Tina |last13=Seltzer |first13=James |last14=Smith |first14=Alisa |last15=Tarlo |first15=Susan M. |journal=Journal of Allergy and Clinical Immunology |volume=121 |issue=3 |pages=585–91 |pmid=18155285}}</ref> Formaldehyde emissions from wood are in the range of 0.02 – 0.04 ppm. Relative humidity within an indoor environment can also affect the emissions of formaldehyde. High relative humidity and high temperatures allow more vaporization of formaldehyde from wood-materials.<ref>{{cite journal |doi=10.1016/j.envint.2007.04.004 |title=The dichotomy of relative humidity on indoor air quality |year=2007 |last1=Wolkoff |first1=Peder |last2=Kjaergaard |first2=Søren K. |journal=Environment International |volume=33 |issue=6 |pages=850–7 |pmid=17499853}}</ref>

==Health risks==
Respiratory, allergic, or immune effects in infants or children are associated with man-made VOCs and other indoor or outdoor air pollutants.<ref>{{cite journal |doi=10.1111/j.1600-0668.2007.00478.x |title=Indoor residential chemical emissions as risk factors for respiratory and allergic effects in children: A review |year=2007 |last1=Mendell |first1=M. J. |journal=Indoor Air |volume=17 |issue=4 |pages=259–77 |pmid=17661923}}</ref>

Some VOCs, such as [[styrene]] and [[limonene]], can react with [[nitrogen oxides]] or with ozone to produce new oxidation products and secondary aerosols, which can cause sensory irritation symptoms.<ref name="test" /><ref>{{cite journal |doi=10.1111/j.1600-0668.2005.00393.x |title=Organic compounds in office environments - sensory irritation, odor, measurements and the role of reactive chemistry |year=2006 |last1=Wolkoff |first1=P. |last2=Wilkins |first2=C. K. |last3=Clausen |first3=P. A. |last4=Nielsen |first4=G. D. |journal=Indoor Air |volume=16 |pages=7–19 |pmid=16420493 |issue=1}}</ref> Unspecified VOCs are important in the creation of [[Photochemical smog|smog]].<ref>"What is Smog?", Canadian Council of Ministers of the Environment, [http://www.ccme.ca/assets/pdf/pn_1257_e.pdf CCME.ca] {{Webarchive|url=https://web.archive.org/web/20110928160543/http://www.ccme.ca/assets/pdf/pn_1257_e.pdf |date=28 सितंबर 2011 }}</ref>

Health effects include eye, nose, and [[throat irritation]]; headaches, loss of coordination, nausea; damage to liver, kidney, and central nervous system. Some organics can cause cancer in animals; some are suspected or known to cause cancer in humans. Key signs or symptoms associated with exposure to VOCs include conjunctival irritation, nose and throat discomfort, headache, allergic skin reaction, [[dyspnea]], declines in serum [[cholinesterase]] levels, nausea, vomiting, nose bleeding, fatigue, dizziness.{{citation needed|date=अगस्त 2013}}

The ability of organic chemicals to cause health effects varies greatly from those that are highly toxic, to those with no known health effects. As with other pollutants, the extent and nature of the health effect will depend on many factors including level of exposure and length of time exposed. Eye and respiratory tract irritation, headaches, dizziness, visual disorders, and memory impairment are among the immediate symptoms that some people have experienced soon after exposure to some organics. At present, not much is known about what health effects occur from the levels of organics usually found in homes. Many organic compounds are known to cause cancer in animals; some are suspected of causing, or are known to cause, cancer in humans.<ref>{{Cite web |url=http://www.epa.gov/iaq/voc.html |title=EPA -- An Introduction to Indoor Air Quality Pollutants and Sources of Indoor Air Pollution Volatile Organic Compounds (VOCs) |access-date=11 सितंबर 2015 |archive-url=https://web.archive.org/web/20150909090046/http://www.epa.gov/iaq/voc.html |archive-date=9 सितंबर 2015 |url-status=live }}</ref>

===Reducing exposure===

To reduce exposure to these toxins, one should buy products that contain Low-VOCs or No VOCs. Only the quantity which will soon be needed should be purchased, eliminating stockpiling of these chemicals. Use products with VOCs in well ventilated areas. When designing homes and buildings, design teams can implement the best possible ventilation plans, call for the best mechanical systems available, and design assemblies to reduce the amount of infiltration into the building. These methods will help improve indoor air quality, but by themselves they cannot keep a building from becoming an unhealthy place to breathe.{{citation needed|date=अगस्त 2013}}

===Limit values for VOC emissions===
[https://web.archive.org/web/20150901035955/http://www.eurofins.com/lci-cli-nik-crel.aspx Limit values for VOC emissions into indoor air] are published by e.g. AgBB, AFSSET, California Department of Public Health, and others. These regulations have prompted several companies to adapt with VOC level reductions in products that have VOCs in their formula, such [[Benjamin Moore & Co.]] in the paint industry and [[Weld-On]] in the adhesive industry.{{citation needed|date=अगस्त 2013}}

==Chemical fingerprinting==
The exhaled human breath contains a few hundred volatile organic compounds and is used in breath analysis to serve as a VOC [[biomarker]] to test for diseases such as [[lung cancer]].<ref name="doi: 10.1002/bmc.835">{{cite journal | last1 = Buszewski | first1 = B. A. | last2 = Kesy | first2 = M. | last3 = Ligor | first3 = T. | last4 = Amann | first4 = A. | title = Human exhaled air analytics: Biomarkers of diseases | journal = Biomedical Chromatography | volume = 21 | issue = 6 | pages = 553–566 | year = 2007 | pmid = 17431933 | pmc = | doi = 10.1002/bmc.835 | displayauthors = 1 }}</ref> One study has shown that "volatile organic compounds ... are mainly blood borne and therefore enable monitoring of different processes in the body."<ref>{{cite journal | last1 = Miekisch | first1 = W. | last2 = Schubert | first2 = J. K. | last3 = Noeldge-Schomburg | first3 = G. F. E. | title = Diagnostic potential of breath analysis—focus on volatile organic compounds | journal = Clinica Chimica Acta | volume = 347 | pages = 25 | year = 2004 | pmid = | pmc = | doi = 10.1016/j.cccn.2004.04.023 }}</ref> And it appears that VOC compounds in the body "may be either produced by metabolic processes or inhaled/absorbed from exogenous sources" such as [[environmental tobacco smoke]].<ref name="doi: 10.1002/bmc.835"/><ref>{{cite journal | last1 = Mazzone | first1 = P. J. | title = Analysis of Volatile Organic Compounds in the Exhaled Breath for the Diagnosis of Lung Cancer | journal = Journal of Thoracic Oncology | volume = 3 | issue = 7 | pages = 774–780 | year = 2008 | pmid = 18594325 | pmc = | doi = 10.1097/JTO.0b013e31817c7439 }}</ref> Research is still in the process to determine whether VOCs in the body are contributed by cellular processes or by the cancerous tumors in the lung or other organs.

==VOC sensors==
{{Main|VOC sensors}}
VOCs in the environment or certain atmospheres can be detected based on different principles and interactions between the organic compounds and the sensor components. There are electronic devices that can detect ppm concentrations despite the non-selectivity. Others can predict with reasonable accuracy the molecular structure of the volatile organic compounds in the environment or enclosed atmospheres<ref>{{cite journal |doi=10.1021/la102693m |title=Holographic Detection of Hydrocarbon Gases and Other Volatile Organic Compounds |year=2010 |last1=MartíNez-Hurtado |first1=J. L. |last2=Davidson |first2=C. A. B. |last3=Blyth |first3=J. |last4=Lowe |first4=C. R. |journal=Langmuir |volume=26 |issue=19 |pages=15694–9 |pmid=20836549}}</ref> and could be used as accurate monitors of the Chemical Fingerprint and further as health monitoring devices.

[[Solid-phase microextraction]] (SPME) techniques are used to collect VOCs at low concentrations for analysis.<ref>{{cite journal |doi=10.1016/j.chroma.2003.11.069 |title=Identification of volatile organic compounds emitted by a naturally aged book using solid-phase microextraction/gas chromatography/mass spectrometry |year=2004 |last1=Lattuati-Derieux |first1=Agnès |last2=Bonnassies-Termes |first2=Sylvette |last3=Lavédrine |first3=Bertrand |journal=Journal of Chromatography A |volume=1026 |pages=9–18 |pmid=14870711 |issue=1–2}}</ref>

Direct injection [[mass spectrometry]] techniques are frequently utilized for the rapid detection and accurate quantification of VOCs.<ref>{{cite journal |doi=10.1016/j.trac.2011.04.005 |title=Direct-injection mass spectrometry adds the time dimension to (B)VOC analysis |year=2011 |last1=Biasioli |first1=Franco |last2=Yeretzian |first2=Chahan |last3=Märk |first3=Tilmann D. |last4=Dewulf |first4=Jeroen |last5=Van Langenhove |first5=Herman |journal=Trends in Analytical Chemistry |volume=30 |pages=1003-1017 |issue=7}}</ref> [[Proton-transfer-reaction mass spectrometry|PTR-MS]] is among the methods that have been used most extensively for the on-line analysis of biogenic and antropogenic VOCs.<ref>{{cite book |last1=Ellis |first1=Andrew M. |last2=Mayhew | first2=Christopher A. |date=2014 |title=Proton Transfer Reaction Mass Spectrometry - Principles and Applications |location=Chichester, West Sussex, UK |publisher=John Wiley & Sons Ltd |isbn=978-1-405-17668-2}}</ref> Recent PTR-MS instruments based on [[time-of-flight mass spectrometry]] have been reported to reach [[detection limit]]s of 20 pptv after 100 ms and 750 ppqv after 1 min measurement (signal integration) time. The [[Resolution (mass spectrometry)|mass resolution]] of these devices is between 7000 and 10,500 m/Δm, thus it is possible to separate most common isobaric VOCs and quantify them independently.<ref>{{cite journal |doi=10.1016/j.ijms.2014.05.004 |title=A Proton Transfer Reaction-Quadrupole inferface Time-Of-Flight Mass Spectrometer (PTR-QiTOF): High speed due to extreme sensitivity |year=2014 |last1=Sulzer |first1=Philipp |last2=Hartungen |first2=Eugen |last3=Hanel |first3=Gernot |last4=Feil |first4=Stefan |last5=Winkler |first5=Klaus |last6=Mutschlechner |first6=Paul |last7=Haidacher |first7=Stefan |last8=Schottkowsky |first8=Ralf |last9=Gunsch |first9=Daniel |last10=Seehauser |first10=Hans |last11=Striednig |first11=Marcus |last12=Jürschik |first12=Simone |last13=Breiev |first13=Kostiantyn |last14=Lanza |first14=Matteo |last15=Herbig |first15=Jens |last16=Märk |first16=Lukas |last17=Märk |first17=Tilmann D. |last18=Jordan |first18=Alfons |journal=International Journal of Mass Spectrometry |volume=368 |pages=1–5 }}</ref>

==See also==
* [[Aroma compound]]
* [[Criteria air contaminants]]
* [[Dutch standards]]
* [[Fugitive emissions]]
* [[Non-methane volatile organic compound]] (NMVOC)
* [[NoVOC]] (classification)
* [[NTA (company)]]
* [[Organic compound]]
* [[Ozone]]
* [[Photochemical smog]]
* [[VOC contamination of groundwater]]
* [[Volatile Organic Compounds Protocol]]
* [[Volatility (chemistry)]]

==References==
{{Reflist|2}}

==External links==
 <!--titles of links need to be cleaned up-->
* [https://web.archive.org/web/20040928231843/http://www.ec.gc.ca/nopp/voc/EN/index.cfm Volatile Organic Compounds (VOCs) web site of the Chemicals Control Branch of Environment Canada]
* [https://web.archive.org/web/20150909090046/http://www.epa.gov/iaq/voc.html An Introduction to Indoor Air Quality, US EPA website]
* [https://web.archive.org/web/20150221165440/http://www.toolbase.org/Technology-Inventory/Interior-Partitions-Ceilings/low-voc-paints VOC in paints, finishes and adhesives]
* [https://web.archive.org/web/20150924003434/http://www.eurofins.com/voc-testing.aspx VOC emissions testing]
* [https://web.archive.org/web/20090105071705/http://www.epa.gov/region01/airquality/ EPA NE: Ground-level Ozone (Smog) Information]
* [https://web.archive.org/web/20080406100730/http://sea.helcom.fi:15037/dps/docs/documents/Maritime%20Group/HELCOM%20MARITIME%204,%202005/6-3.pdf#search=%22VOC%20reduction%20crude%20oil%22VOC emission from crude oil tankers]
* [https://web.archive.org/web/20160109004119/http://www.envmodels.com/cov.php VOC emissions and calculations]
* [https://web.archive.org/web/20190119054007/http://www.ownyourair.org/ VOCs, ozone and air pollution information from the American Lung Association of New England]
* [https://web.archive.org/web/20160303183321/http://www.test-lab.eu/en/tests/voc/ VOC Tests]
* [https://web.archive.org/web/20111008013646/http://www.fondazioneedmundmach.it/sperimentazione_context2.jsp?ID_LINK=3173&area=6 Post doc in Volatile organic compound in Food]
* [https://web.archive.org/web/20131219031219/http://www.vocemission.com/solvent-emission-voc-control.html VOC emissions from printing processes, European legislation and biological treatment]
* [https://web.archive.org/web/20150924003314/http://www.eurofins.com/ecolabels.aspx Examples of product labels with low VOC emission criteria]
* [https://web.archive.org/web/20160921213637/http://www.aquateklabs.com/drinkingwater/vocprofile/about.html Information about VOCs in Drinking Water]
* [https://web.archive.org/web/20150318040157/http://www.entechinst.com/technical-info/library/formaldehyde-and-vocs-in-iaq-determinations-gc-ms Formaldehyde and VOCs in Indoor Air Quality Determinations by GC/MS]

{{Authority control}}

{{DEFAULTSORT:Volatile Organic Compound}}
[[श्रेणी:Building biology]]
[[श्रेणी:Organic compounds]]
[[श्रेणी:Pollutants]]
[[श्रेणी:Smog]]
[[श्रेणी:Flavors]]
[[श्रेणी:Perfumes]]