The source of VOCs can be natural or artificial. The most common natural source is methane, a greenhouse gas, generated by the decomposition of organic matter, by the burning of biomass "Biomass (energy)") or by ruminant animals such as cows. Other VOCs of natural origin are essential oils made up of terpenes.

Artificial sources of volatile organic compounds originate mainly from industrial activities such as the paint, footwear or steel industries, solvents from the dry cleaning industry, the evaporation of organic solvents, automobiles and even tobacco smoke.

Inside the home, you can find numerous sources of VOCs, such as cleaning products, personal hygiene products, cosmetics, paints, plastics, etc.

• - Steel industry.

• - Plastics and rubber industry").

• - Footwear industry.

• - Paints, varnishes and lacquers.

• - Food industry.

• - Wood industry.

• - Pharmaceutical industry.

• - Cosmetic industry").

• - Dry cleaning industry.

• - Hydraulic fracturing.

• - Sanitary landfills "Landfill (garbage)").

The health effects are varied, depending on the compound and the period to which one has been exposed. Volatile organic compounds are fat-soluble, and thanks to their affinity for fats, they accumulate in various parts of the human body. In the short term they can cause:

• - Irritation of eyes and throat, nose.

• - Nausea, throat irritation.

• - Headache, vomiting blood.

• - Allergic reactions, swelling.

• - Dizziness, stomach and intestinal pain.

• - Fatigue, skin spots.

And, in the long term, they can damage the liver, kidneys or central nervous system. They can also be carcinogens, such as benzene, which also damages the small intestine to the point that holes are created that cause death.

VOCs can be classified, according to their danger, into 3 groups:

• - Extremely dangerous compounds for health: Benzene, vinyl chloride and 1,2 dichloroethane and sulfur.

• - Class A compounds: These are compounds that can cause significant damage to the environment, such as acetaldehyde, aniline, carbon tetrachloride "Carbon(IV) chloride"), 1,1,1-trichloroethane, trichloroethylene, trichlorotoluene, etc.

• - Class B compounds: with less impact on the environment such as acetone, ethanol and fossil fuels.

Volatile organic compounds are also found in hospitals and health care centers. In these environments, these chemical substances are widely used for cleaning, disinfection, and hygiene tasks in different areas.[5]​ Thus, health professionals such as nurses, doctors, healthcare personnel, etc., may present adverse health effects such as asthma; however, further studies are required to determine the exact levels, as well as the determinants that influence exposure to these compounds.[5]​[6]​[7]​.

Studies have shown that the concentration levels of different VOCs such as halogenated and aromatic hydrocarbons differ substantially between areas of the same hospital. However, one of these studies reported that ethanol, isopropanol, ether "Ether (chemistry)"), and acetone were the main compounds within the site.[8]​[9]​ Along the same lines, in a study conducted in the United States, it was established that nursing assistants are the population most exposed to compounds such as ethanol, while medical equipment preparers are most exposed to 2-propanol.[8]​[9]​.

Regarding VOC exposure from cleaning and personal hygiene, a study conducted in 4 hospitals in the United States established that disinfection and sterilization workers are associated with exposures to d-limonene and 2-propanol, while those responsible for cleaning with chlorine-containing products are more likely to have higher levels of exposure to α-pinene and chloroform.[7] For their part, personnel who perform cleaning tasks on floors and other surfaces (for example, waxing soils) and that uses products based on quaternary ammonium, alcohol and chlorine is associated with a higher exposure to VOCs than the previous two groups, that is, it is especially linked to exposure to acetone, chloroform, α-pinene, 2-propanol or d-limonene.[7]​.

Other medical and health care settings such as nursing homes or gerontological centers have hardly been the subject of study, despite the fact that the elderly and vulnerable populations can spend considerable time in these indoor environments, where they could be exposed to VOCs, derived from the habitual use of cleaning products, sprays and air fresheners.[10][11]​ In a study carried out in France, a team of researchers developed an online questionnaire for different social care centers for the elderly, in which they asked about cleaning practices, products used and the frequency of these activities. As a result, more than 200 chemicals were identified, of which 41 are known to have adverse health effects, 37 of them being VOCs. Health effects include skin sensitization, reproductive and specific organ toxicity, carcinogenicity, mutagenicity, and endocrine disruption.[10] Likewise, in another study conducted in the same European country, it was discovered that there is a significant association between respiratory distress in the elderly population and high exposure to VOCs such as toluene and o-xylene, unlike the rest of the population.[12]​.

It is very important to avoid the entry of these compounds that are harmful to health into IVF laboratories since they may contain embryotoxic compounds that harm the embryos. However, these compounds have the difficulty that they cannot be eliminated through normal filters and cause death.

To eliminate these VOCs in IVF laboratories, active carbon filters with different concentrations of potassium permanganate are used. These filters are placed at all gas inlets in the laboratory, such as in the air conditioning systems and the gas inlet to the incubator. However, these filters are not capable of completely eliminating these compounds and must be renewed from time to time depending on their absorption power.

Since the air outside the IVF room does contain VOCs, a pressure gradient is established between the IVF room and the outside so that the pressure in the IVF room is greater and if a door is opened the air escapes, preventing the entry of external compounds. In addition, recirculation systems for this purified air are established.

In Spain there are currently several royal decrees whose main objective is the prevention and reduction of atmospheric pollution due to the emission of volatile organic compounds in various industrial activities.

Royal Decree 117/2003 transposes Directive 1999/13/EC[3]​ and is based on the limitation of emissions of volatile organic compounds due to the use of solvents in certain activities. It defines VOC as any organic compound that has a vapor pressure of 0.01 kPa or more at 293.15 K, or that has an equivalent volatility under the particular conditions of use. It includes the obligation to have the Integrated Environmental Authorization of Law 16/2002 on Integrated Pollution Prevention and Control.[13]​.

Royal Decree 227/2006 transposes Directive 2004/42/EC of the European Parliament and of the Council, of April 21, 2004, and its main objective is to limit the VOC content in paints, varnishes and vehicle refinishing products.

Subsequently, Royal Legislative Decree 1/2016, of December 16, was published, approving the consolidated text of the Law on Integrated Pollution Prevention and Control[14]​, which updates the regulations on these compounds.

There are two royal decrees that regulate VOC emissions from gasoline: Royal Decree 2102/1996, of September 20, on the control of VOC emissions resulting from the storage and distribution of gasoline from terminals to service stations and Royal Decree 1437/2002, of December 27, which adapts gasoline tankers to the Royal Decree 2102/96.

• - Persistent organic pollutant.

• - Photochemical smog.

• - Air pollution.

• - Organic compound.

• - Health effects of VOCs Archived April 7, 2010 at the Wayback Machine.

• - Royal Decree 117/2003.

• - Royal Decree 227/2006.

• - VOC emissions from the printing industry and European legislation.

The source of VOCs can be natural or artificial. The most common natural source is methane, a greenhouse gas, generated by the decomposition of organic matter, by the burning of biomass "Biomass (energy)") or by ruminant animals such as cows. Other VOCs of natural origin are essential oils made up of terpenes.

Artificial sources of volatile organic compounds originate mainly from industrial activities such as the paint, footwear or steel industries, solvents from the dry cleaning industry, the evaporation of organic solvents, automobiles and even tobacco smoke.

Inside the home, you can find numerous sources of VOCs, such as cleaning products, personal hygiene products, cosmetics, paints, plastics, etc.

• - Steel industry.

• - Plastics and rubber industry").

• - Footwear industry.

• - Paints, varnishes and lacquers.

• - Food industry.

• - Wood industry.

• - Pharmaceutical industry.

• - Cosmetic industry").

• - Dry cleaning industry.

• - Hydraulic fracturing.

• - Sanitary landfills "Landfill (garbage)").

The health effects are varied, depending on the compound and the period to which one has been exposed. Volatile organic compounds are fat-soluble, and thanks to their affinity for fats, they accumulate in various parts of the human body. In the short term they can cause:

• - Irritation of eyes and throat, nose.

• - Nausea, throat irritation.

• - Headache, vomiting blood.

• - Allergic reactions, swelling.

• - Dizziness, stomach and intestinal pain.

• - Fatigue, skin spots.

And, in the long term, they can damage the liver, kidneys or central nervous system. They can also be carcinogens, such as benzene, which also damages the small intestine to the point that holes are created that cause death.

VOCs can be classified, according to their danger, into 3 groups:

• - Extremely dangerous compounds for health: Benzene, vinyl chloride and 1,2 dichloroethane and sulfur.

• - Class A compounds: These are compounds that can cause significant damage to the environment, such as acetaldehyde, aniline, carbon tetrachloride "Carbon(IV) chloride"), 1,1,1-trichloroethane, trichloroethylene, trichlorotoluene, etc.

• - Class B compounds: with less impact on the environment such as acetone, ethanol and fossil fuels.

Volatile organic compounds are also found in hospitals and health care centers. In these environments, these chemical substances are widely used for cleaning, disinfection, and hygiene tasks in different areas.[5]​ Thus, health professionals such as nurses, doctors, healthcare personnel, etc., may present adverse health effects such as asthma; however, further studies are required to determine the exact levels, as well as the determinants that influence exposure to these compounds.[5]​[6]​[7]​.

Studies have shown that the concentration levels of different VOCs such as halogenated and aromatic hydrocarbons differ substantially between areas of the same hospital. However, one of these studies reported that ethanol, isopropanol, ether "Ether (chemistry)"), and acetone were the main compounds within the site.[8]​[9]​ Along the same lines, in a study conducted in the United States, it was established that nursing assistants are the population most exposed to compounds such as ethanol, while medical equipment preparers are most exposed to 2-propanol.[8]​[9]​.

Regarding VOC exposure from cleaning and personal hygiene, a study conducted in 4 hospitals in the United States established that disinfection and sterilization workers are associated with exposures to d-limonene and 2-propanol, while those responsible for cleaning with chlorine-containing products are more likely to have higher levels of exposure to α-pinene and chloroform.[7] For their part, personnel who perform cleaning tasks on floors and other surfaces (for example, waxing soils) and that uses products based on quaternary ammonium, alcohol and chlorine is associated with a higher exposure to VOCs than the previous two groups, that is, it is especially linked to exposure to acetone, chloroform, α-pinene, 2-propanol or d-limonene.[7]​.

Other medical and health care settings such as nursing homes or gerontological centers have hardly been the subject of study, despite the fact that the elderly and vulnerable populations can spend considerable time in these indoor environments, where they could be exposed to VOCs, derived from the habitual use of cleaning products, sprays and air fresheners.[10][11]​ In a study carried out in France, a team of researchers developed an online questionnaire for different social care centers for the elderly, in which they asked about cleaning practices, products used and the frequency of these activities. As a result, more than 200 chemicals were identified, of which 41 are known to have adverse health effects, 37 of them being VOCs. Health effects include skin sensitization, reproductive and specific organ toxicity, carcinogenicity, mutagenicity, and endocrine disruption.[10] Likewise, in another study conducted in the same European country, it was discovered that there is a significant association between respiratory distress in the elderly population and high exposure to VOCs such as toluene and o-xylene, unlike the rest of the population.[12]​.

It is very important to avoid the entry of these compounds that are harmful to health into IVF laboratories since they may contain embryotoxic compounds that harm the embryos. However, these compounds have the difficulty that they cannot be eliminated through normal filters and cause death.

To eliminate these VOCs in IVF laboratories, active carbon filters with different concentrations of potassium permanganate are used. These filters are placed at all gas inlets in the laboratory, such as in the air conditioning systems and the gas inlet to the incubator. However, these filters are not capable of completely eliminating these compounds and must be renewed from time to time depending on their absorption power.

Since the air outside the IVF room does contain VOCs, a pressure gradient is established between the IVF room and the outside so that the pressure in the IVF room is greater and if a door is opened the air escapes, preventing the entry of external compounds. In addition, recirculation systems for this purified air are established.

In Spain there are currently several royal decrees whose main objective is the prevention and reduction of atmospheric pollution due to the emission of volatile organic compounds in various industrial activities.

Royal Decree 117/2003 transposes Directive 1999/13/EC[3]​ and is based on the limitation of emissions of volatile organic compounds due to the use of solvents in certain activities. It defines VOC as any organic compound that has a vapor pressure of 0.01 kPa or more at 293.15 K, or that has an equivalent volatility under the particular conditions of use. It includes the obligation to have the Integrated Environmental Authorization of Law 16/2002 on Integrated Pollution Prevention and Control.[13]​.

Royal Decree 227/2006 transposes Directive 2004/42/EC of the European Parliament and of the Council, of April 21, 2004, and its main objective is to limit the VOC content in paints, varnishes and vehicle refinishing products.

Subsequently, Royal Legislative Decree 1/2016, of December 16, was published, approving the consolidated text of the Law on Integrated Pollution Prevention and Control[14]​, which updates the regulations on these compounds.

There are two royal decrees that regulate VOC emissions from gasoline: Royal Decree 2102/1996, of September 20, on the control of VOC emissions resulting from the storage and distribution of gasoline from terminals to service stations and Royal Decree 1437/2002, of December 27, which adapts gasoline tankers to the Royal Decree 2102/96.

• - Persistent organic pollutant.

• - Photochemical smog.

• - Air pollution.

• - Organic compound.

• - Health effects of VOCs Archived April 7, 2010 at the Wayback Machine.

• - Royal Decree 117/2003.

• - Royal Decree 227/2006.

• - VOC emissions from the printing industry and European legislation.