Organic chemical substances that are gaseous or can vaporize and enter the atmosphere under normal conditions. Methane, benzene, xylene, propane, and butane are examples of VOCs.
What gases are considered VOC?
VOCs (volatile organic compounds) are a class of chemicals found in many of the goods we use to construct and maintain our homes. These chemicals are released or “off-gas” into the indoor air we breathe once they are in our houses. They may or may not be odorable, and odor is not a reliable signal of health risk.
Benzene, ethylene glycol, formaldehyde, methylene chloride, tetrachloroethylene, toluene, xylene, and 1,3-butadiene are examples of VOCs that may be present in our daily life.
How do you determine if a chemical is a VOC?
Any carbon compound that participates in atmospheric photochemical reactions, excluding carbon monoxide, carbon dioxide, carbonic acid, metallic carbides or carbonates, and ammonium carbonate, is referred to as a volatile organic compound (VOC), with the exception of those designated by the Environmental Protection Agency as having negligible photochemical reactivity2.
Volatile organic compounds, or VOCs, are organic chemical molecules with a composition that allows them to evaporate at standard indoor temperature and pressure conditions3. This is the scientific literature’s broad definition of VOCs, which is similar to the definition used for indoor air quality. Because a compound’s volatility4 increases as its boiling point temperature decreases, the volatility of organic compounds is commonly characterized and categorised by their boiling points.
The European Union, for example, defines VOCs based on their boiling point rather than their volatility.
Any organic compound with an initial boiling point of less than or equal to 250° C measured at 101.3 kPa is classified as a VOC.
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VOCs are sometimes classified according to how easily they can be emitted. Indoor organic pollutants, for example, are classified by the World Health Organization (WHO) as follows:
The lower the boiling point of a substance, the more probable it is to be discharged into the air from a product or surface. Very volatile organic compounds are difficult to quantify because they exist almost exclusively as gases in the air, rather than in solids or on surfaces. The least volatile compounds found in air make up a small percentage of the total present indoors, with the majority being located in solids or liquids containing them, or on surfaces such as dust, furnishings, and building materials.
Are hydrocarbons VOC?
Hydrocarbons are organic molecules that are largely made up of carbon and hydrogen. Many of these compounds are volatile, meaning they can easily evaporate into the atmosphere at ambient temperature and pressure. They are known as Volatile Organic Compounds (VOCs). Many of the items we use every day, such as gasoline, paints and lacquers, cleaning products, pesticides, building materials, and glues and adhesives, contain VOCs, which can be released during the manufacturing or processing process. Many common VOCs are employed in a variety of industrial processes, including the production of Purified Terepthalic Acid (PTA), which is used to produce plastic bottles. Benzene, toluene, xylene, and tetrachloroethylene are some examples of VOCs commonly utilized in industry. Combustion operations also release volatile organic compounds (VOCs).
Indoor VOCs released by paints and adhesives are of special concern because a number of them are known to be carcinogenic.
Outdoor emissions of volatile organic compounds (VOCs) from big industrial processes are a source of worry not just because of their carcinogenic potential, but also because of their tendency to induce photochemical haze in the atmosphere.
By oxidizing these chemicals to carbon dioxide and water, Johnson Matthey offers many catalyst options to help eradicate them.
These catalysts can be precious metal-based, like our Oxidation Catalysts (2-way), or base-metal, like our SINOx mixed oxide catalyst pellets and honeycombs, and base-metal PTA emission control catalyst.
Is methane a VOC?
Do you ever wonder what some of your environmental department’s truncated technical terms mean? Do you work in the oil and gas business or in the storage of crude oil? If you answered yes, you should be familiar with the ABCs of VOCs.
VOC emissions are classified as organic molecules that participate in atmospheric photochemical processes, according to USEPA regulations.
40 CFR 51.100 contains the definition of VOCs (s).
A list of substances that aren’t classified as VOCs is included in the definition.
Methane and ethane are two chemical molecules that are not categorized as VOCs.
Photochemically reactive VOCs are controlled because, in the presence of sunlight, they chemically react with oxides of nitrogen (NOx a consequence of fossil fuel combustion) to generate ozone (O3) in the troposphere (lowest portion of the earth’s atmosphere).
VOCs are contaminants in the air that contribute to the development of ozone.
The management of VOCs is intended to avoid the release of one of the precursors to ozone production into the atmosphere.
Smog contains a lot of ozone, which is a potent oxidant.
Long-term exposure to ozone levels exceeding 75 parts per billion (ppb) can harm people’ mucous and respiratory tissues, as well as plants.
As a result, ozone is a significant human respiratory threat at ground level.
It’s worth noting that the earth’s so-called Ozone Layer (a part of the stratosphere with a greater ozone content) is advantageous to life on the planet.
This ozone layer in the stratosphere serves to keep harmful ultraviolet (UV) rays from reaching the Earth’s surface.
It’s crucial to remember that VOCs don’t include methane (CH4), ethane (C2H6), H2S, CO2, or N2 for the oil and gas industry to comply with the alphabet soup of air quality laws.
When determining the mass of VOCs in a vented natural gas stream, use the propane plus hydrocarbon (C3+) fraction in the natural gas as a starting point.
Of fact, because of the reporting requirements for greenhouse gases, methane in the natural gas stream is still significant.
This is crucial for air permits and NSPS OOOO/OOOOa compliance because venting from sources like storage tanks simply has to account for the VOC proportion in the gas.
Another factor to keep in mind is that the VOC level of storage tank vent gas is often substantially higher than that of HP separator gas.
VOC content in a storage tank vent may range from 35 percent to 50 percent by volume, whereas VOC content in an HP separator gas typically ranges from 80 percent to 98 percent by volume.
As a result, the mass (pounds) of VOC emissions from a volume of storage tank vent gas will be larger than the same volume of HP separator gas.
The ideal gas law is used to compute the mass of natural gas and the concentration of volatile organic compounds (VOCs).
We use the formula that one pound mole (lb-mole) of a gas occupies roughly 379.3 standard cubic feet at standard circumstances (60°F, 14.7 psia) (SCF).
The molecular weight of the gas stream or natural gas component is represented by the lb-mole.
This gas stream would emit over 731 tons of VOC per year if it were vented to the atmosphere at a rate of 500,000 SCF per day.
Many people believe that in the future, federal and state regulations on VOC emissions will get harsher and encompass more processes in the oil and gas industry.
The following are some examples:
- Collect data on current oil and gas production sites and emissions (prior to August 24, 2011). This includes facilities that aren’t affected by the NSPS OOOO and OOOOa.
- Reporting of greenhouse gases (GHG) from more facilities than the GHG reporting standards in 40 CFR Part 98 currently demand.
Capturing these vent gas streams and delivering the gas to sales, where possible, can help a facility enhance production and revenues.
How do you remove VOCs from indoor air?
VOCs build up if there isn’t enough ventilation, especially in dwellings that are more insulated. By opening a window, running the exhaust fan in your kitchen or bathroom, or having a mechanical ventilator built, you may get rid of VOCs and let some fresh air into your home. Heat or energy recovery ventilators remove stale indoor air while also bringing in the equivalent amount of new air. In the winter, they conserve energy by transferring heat from stale air to fresh air, and in the summer, they cool the fresh air.
Is acetone a VOC?
Acetone is a prevalent chemical in the body that is produced as a consequence of regular fat metabolism. The ketones created when the body consumes fat as a source of energy are the basis of the currently trendy ketogenic diet. When you follow a ketogenic diet, your body enters a state of ketosis “The liver turns fat into ketones, including acetone, and releases them into the bloodstream during ketosis. Cells that require energy transform the ketones into energy. Because acetone and other ketones provide a more consistent source of energy than sugar, the diet is expected to reduce the development of diabetes “Sugar crash” is a term used to describe a feeling that occurs after eating a big amount of carbs. It’s also supposed to help persons with epilepsy by stabilizing their sensitive neurons, allowing them to have fewer seizures.
Acetone is a less harmful industrial solvent when compared to other solvents. Because acetone is heavier than air and can accumulate in low regions, the largest concern of storing it in your house is its flammability. Lower amounts of heat, such as smoldering coals, do not ignite acetone, therefore a spark would be necessary for it to detonate.
Despite this, acetone can be hazardous. High-concentration inhalation depresses the central nervous system, resulting in lightheadedness, loss of balance, weariness, nausea, and other symptoms. Fortunately, these effects disappear as the source of exposure is removed, and there is no evidence of long-term harmful damage. Because acetone is not known to be carcinogenic or to produce long-term health problems, it is not classified as a hazardous volatile organic compound by the EPA (VOC). However, it is known to irritate the skin and eyes, and it can create a rash in some people, but it is still considered safe by regulatory organizations. The central nervous system can be depressed to the point of death at very high doses, but such high levels are only found in industrial settings.
What emits VOCs?
Certain solids or liquids emit volatile organic compounds (VOCs) as gases. VOCs are a group of compounds that can have both short- and long-term health consequences. Many VOC concentrations are continuously greater (up to ten times higher) indoors than outdoors. VOCs are emitted by a diverse range of items that number in the thousands.
Organic compounds are commonly employed in household products as ingredients. Organic solvents are found in paints, varnishes, and wax, as well as numerous cleaning, disinfecting, cosmetic, degreasing, and hobby items. Organic compounds are used to make fuels. All of these items can leak organic molecules when in use and, to a lesser extent, while being stored.
The “Total Exposure Assessment Methodology (TEAM) Study” (Volumes I through IV, completed in 1985) by the EPA’s Office of Research and Development found that levels of a dozen common organic pollutants were 2 to 5 times higher inside homes than outside, regardless of whether the homes were in rural or highly industrial areas. According to TEAM research, people who use goods containing organic compounds can expose themselves and others to extremely high pollutant levels, which can stay in the air long after the activity has ended.
How harmful are VOCs?
VOCs can irritate the eyes, nose, and throat, cause difficulties breathing and nausea, and harm the central nervous system and other organs when inhaled. Some VOCs have been linked to cancer. Although not all VOCs have all of these health impacts, many of them do.
The Agency for Toxic Substances and Disease Registry Toxic Substances Portal has information on the unique health impacts of each VOC.
VOCs can have similar health consequences outside, but they can also combine with nitrogen oxides to form ozone pollution, which is the most common outdoor air pollutant in the United States.
Is butane an air pollutant?
Different equipment and activities at oil and gas well sites, as well as processing and transmission infrastructure, emit pollutants into the environment. Visit the Oil and Gas Pollution page to learn more about the many sources of these specific toxins.
The most frequent air contaminants linked with oil and gas production are described on this page in broad terms. These are some of them:
The principal component of natural gas, methane (CH4), is linked to climate change. (Valuable hydrocarbons such as ethane, propane, butane, and pentanes are frequently present in natural gas and are sorted out during processing.) Methane is 86 times more potent as a greenhouse gas than carbon dioxide during a 20-year period. Natural gas is odorless when it is first produced; the chemical methyl mercaptan is added subsequently to odorize the gas so that leaks can be identified.
CO2 is the most common greenhouse gas linked to climate change, as well as the most persistent in the atmosphere. CO2 is emitted when fossil fuels are burned, including flaring, production, and processing, as well as any operations involving automobiles and engines. CO2 causes hypertension, migraines, disorientation, nerve damage, and skin and eye irritation, as well as reducing oxygen flow for breathing.
Many carbon-containing chemicals that quickly convert into gases or vapors and become airborne are classified as volatile organic compounds (VOCs) (volatilize). VOCs can react with nitrogen oxides and sunlight to generate ground-level ozone, which can lead to respiratory problems like asthma and a reduction in lung function.
Benzene, toluene, ethylbenzene, and xylene are the most common VOCs related with oil and natural gas development. These substances, often known as BTEX chemicals, have been linked to effects on the central nervous system, neurological systems, and reproductive systems. Benzene, as well as ethylbenzene and xylene, is a recognized carcinogen that can cause respiratory issues.
Another VOC that is causing concern in the oil and gas industry is formaldehyde. Formaldehyde is primarily thought of as a by-product of construction and household products, although it is also produced by industrial combustion processes. It’s a recognized carcinogen that’s linked to breathing issues and lung damage.
In some oil and gas formations, particularly in the western United States, hydrogen sulfide (H2S) occurs naturally. H2S can be released when gas is vented, when flared gas is incompletely burned, or when equipment emits fugitive emissions. During gas processing, it is frequently separated.
H2S is a poisonous gas with a rotten egg odor. At low doses, it can cause eye, skin, and respiratory problems, and at high amounts, it can be fatal. Oil and gas workers should avoid inhaling H2S fumes at production sites, according to a federal hazard advisory.
The US Environmental Protection Agency regulates the following five criteria pollutants connected with oil and gas under the Clean Air Act:
- When sunlight interacts with volatile organic molecules and nitrogen oxides, ozone (O3) is produced. Ozone is also known as smog when it is found at ground level, because it can cause or aggravate respiratory illnesses including asthma and emphysema.
According to a study, ozone produced by the oil and gas industry causes 750,000 asthma episodes in children throughout the summer and 2,600 asthma and respiratory emergency room visits nationwide.
- Particulate Matter (PM) is made up of microscopic particles that float in the air and gradually settle to the ground. Particulate matter is classified as PM10, which refers to small particles with a diameter of ten micrometers or less, or PM2.5, which refers to even smaller microscopic particles. Dust or soil entering the air during site or facility construction, traffic, and diesel exhaust from cars and equipment are the most typical sources of PM from oil and gas operations. During venting and flaring operations, PM can also be released.
Inhaling PM can induce respiratory and cardiovascular difficulties, as well as early death, depending on particle size and chemical composition. PM reduces visibility and air quality while suspended in the air.
- Carbon monoxide (CO) is a colorless, odorless, combustible gas created when carbon-based fuels are burned incompletely (i.e., oil, natural gas, coal, and wood). The oil and gas sector produces CO largely through flaring and the operation of machinery and equipment. CO has a number of negative health effects, including reducing the ability of the blood to carry oxygen and causing headaches, dizziness, and nausea. Inhalation can cause unconsciousness and death in some people.
- NOx is a set of gases generated when fossil fuels are burned, resulting in a chemical interaction between nitrogen (which occurs naturally in the atmosphere) and oxygen. NOx is produced during flaring operations and when fuel is consumed to power machinery such as compressor engines and other heavy equipment in the oil and gas industry. Ground-level ozone is formed when NOx and VOCs mix in the presence of sunshine. NOx has a variety of health effects, including irritation of the eyes, nose, and throat, respiratory difficulties, cardiac diseases, and lung damage.
- Sulfur Dioxide (SO2) is a colorless gas that has a pungent odor. It is created by the combustion of sulfur-containing fossil fuels (including oil, natural gas, and coal). SO2 is produced when natural gas is flared or fossil fuels are burnt to power pumpjack or compressor engines, as well as other equipment and vehicles at oil and gas operations. Sulfur dioxide is also produced by sour gas processing plants. SO2 is a major contributor to acid rain, alongside NOx.
SO2 causes irritation of the eyes, nose, and throat, as well as respiratory issues, nausea, headaches, and dizziness. SO2 can also combine with other chemicals to produce particulate matter, which can harm the lungs, cause respiratory and cardiovascular problems, and even cause death.
For More Information
- Endocrine Disruption Exchange research and information about chemicals in natural gas operations
- Toxic Substances Information Portal, US Centers for Disease Control and Prevention’s Agency for Toxic Substances and Disease Registry
