Best VOC Gas Detector (Volatile Organic Compounds for Indoor Air Quality)

VOC Detector, Volatile Organic Compounds -

Best VOC Gas Detector (Volatile Organic Compounds for Indoor Air Quality)

Volatile organic compounds are a common indoor pollutant. They are released from common household products such as paints, furniture, carpet and plastics. They can cause many negative health effects such as headaches, fatigue, nausea. VOCs are problematic gas pollutant indoor air, car, bus, home and office/work settings. VOC gas detectors are used to monitor the presence of VOCs and provide a quantitative measure of VOCs in ppm.

Pros

Cons

  • VOCs are a common indoor air pollutant that come from, solvents, aerosols and synthetic materials
  • VOCs can be hazardous air pollutants that are of particular concern in indoor air for people who may come into contact with it
  • VOC gas detectors are used to detect harmful levels of VOCs in the parts per million levels and common calibrated to isobutylene
  • VOCs are harmful to humans. They off gas from solvents included in perfumes.
  • Hundreds of VOCs exist, which make it confusing
  • VOC gas detectors need to be regularly calibrated to operate accurately
  • Hard to pin point a specific VOC that is giving the indoor pollution problem

What Is the Best VOC Gas Detector?

The VOC gas detector brands we recommend include the following:

Which VOC Gas Detectors to Avoid?

There are many "junk" VOC detectors on the market using low cost and non-specific sensors (ranging from $20 to $200). These product use low cost metal oxide sensors (MOS). They are small and inexpensive sensors. Humidity sensitivity, non-linear response, and long-term drift are all negative performance issues with MOS sensors.

Also, they react to inorganic gases as well, so don't use them if you're trying to test low levels of VOCs in an environment where gases like NO, NO2, or CO are present. When using MOS technology for VOC are made for the "non serious" user that is looking for a cheap "quick fix" option.

We recommend avoiding VOC detectors with MOS sensors since:

  • they are not calibrated to a national standard
  • do not use high quality specific gas sensors
  • large sensor drift and give unstable, non repeatable readings
  • made with low cost metal oxide sensors (MOS) that have high cross sensitivity to temperature and humidity
  • do not come with a calibration certificate signed by a engineer

What Is the Best VOC Gas Sensor Choice?

More reliable VOC detectors cost over $300 and come in two distinct sensor varieties -- PID Sensors and Electrochemical Sensors.

The most important part of any gas detector is the actual sensing element. Hence, it is important to understand the sensor options, the pros and cons and understanding the quality of the sensor and the specific manufacturer of the actual gas sensing element.

For VOCs, the two best sensor options are:

  • Superior and Expensive: PID sensor type, that includes a photoionization sensor. These usually can detect down to 0.001ppm and are very sensitive, but more expensive. A PID sensors works by breaks down VOCs in the air into positive and negative ions using an ultraviolet (UV) light source. The charge of the ionized gas is then detected or measured by the PID, with the charge being a function of the concentration of VOCs in the air. PIDs have a high sensitivity (ppb), a wide dynamic range (can detect several thousand ppm), and can monitor VOCs at ppb-low ppm levels and are made in small sensor packaging form factor as shown below here.

  • Satisfactory and Affordable: Electrochemical type sensors, that detect down to 0.01ppm, not as sensitive as PID type, but are more affordable and readily available in small form factor.

    What is the Best Continuous VOC Monitor?

    VOC Detectors are also designed for permanent indoor mounting and continuous monitoring. These are called wall mount VOC monitors. These units are popular for indoor business, manufacturing, public facilities, construction sites, process control and chemical industries.



    What is the Exposure Limit of VOC?

    They are non existent.

    There are different exposure limits for different VOCs. Many people are surprised to find that there are no federal or state standards for home VOC levels.

    Also one finds, that there is not one generic limit for VOC or TVOC which makes it a bit confusing. This can be explained because the word Volatile Organic Compounds is a generic word which describes a plethora of different gases and chemical compounds.

    When using a VOC detector, it may be responding to many organic compounds and giving you the representative ppm reading or the summation of the various compounds it is detecting.

    However, to provide some guidance, OSHA does have exposure limits on specific VOC chemical compounds and their recommended permissible exposure limit. Some examples include:

    Acetone Exposure Limits

    • 1000ppm TWA 8 hours OSHA
    • 500ppm TWA 8 hours Cal OSHA
    • 250ppm TWA 10 hours NIOSH

    Ethanol Exposure Limits

    • 1000ppm TWA 8 hours OSHA
    • 1000ppm TWA 8 hours Cal OSHA
    • 1000ppm TWA 10 hours NIOSH

    Formaldehyde Exposure Limits

    • 0.75ppm TWA 8 hours OSHA
    • 0.75ppm TWA 8 hours Cal OSHA
    • 0.016ppm TWA 10 hours NIOSH

    Benzene Exposure Limits

    • 10ppm TWA 8 hours OSHA
    • 1ppm TWA 8 hours Cal OSHA
    • 0.1ppm TWA 10 hours NIOSH

    Methylene Chloride (Dichloromethane) Exposure Limits

    • 25ppm TWA 8 hours OSHA

    Isopropanol (Isopropyl alcohol) Exposure Limits

    • 400ppm TWA 8 hours OSHA
    • 400ppm TWA 8 hours Cal OSHA
    • 400ppm TWA 10 hours NIOSH

    Toluene Exposure Limits

    • 200ppm TWA 8 hours OSHA

    What Are Volatile Organic Compounds?

    Volatile organic compounds, VOCs, are organic (means they have "carbon") chemical compounds that are known to possess certain properties including high vapor pressure, low boiling point and low water solubility.

    For example, VOCs are found in a variety of fuels, including diesel, petrol, gasoline, heating oil, and aviation fuel. VOC gases from these liquids include benzene, toluene, ethylene, xylene, and formaldehyde.

    Some example of VOCs compared to H2O are here:

    Examples of VOCs in the Home?

    Commonly, VOC come to exist in indoor air by off-gas from a solid or liquid material very easily.

    New car smell: Off-gassing from new autos can be significant. Many automotive parts, especially when the car is new, are constructed with polystyrene and other organic chemical compounds that emit VOCs. VOCs will off-gas at higher concentrations in vehicles that are subjected to high temperatures and poor airflow.

    Carpet Smell: That fresh, clean carpet fragrance that so many people associate with it may not be as benign as you assume. Toxic organic chemicals can be found in carpet glue and foam pads, which then off-gas as VOCs in your house. As a result, some states have passed legislation establishing VOC emission limitations for all new carpet installations.

    Mattress Smell: When purchasing a new mattress for their child's crib, parents should exercise caution because baby mattresses can be important sources of newborn VOC exposure. Infant mattresses, particularly those produced with polyurethane foam, which includes the chemical toluene, have been identified as a major source of off-gassing.

    Where do VOCs come from?

    Indoor VOC Sources

    Building materials:

    • Paint, paint strippers
    • Varnishes and finishes
    • Caulks and sealants
    • Adhesives
    • Flooring, carpet, pressed wood products

    Home & personal care products:

    • Cleaners and disinfectants
    • Furniture
    • Pesticides
    • Air fresheners
    • Cosmetics and deodorants
    • Fuel oil, gasoline
    • Tobacco smoke
    • Dry-cleaned clothing
    • Arts and crafts products: glues, permanent markers, etc.
    • Wood burning stoves
    • Office printers and copiers

    Outdoor VOC Sources

    • Gasoline
    • Diesel emissions
    • Wood burning
    • Oil and gas extraction and processing
    • Industrial emissions

    Are Volatile Organic Compounds Harmful?

    Yes. VOCs are a problem for both human health and overall air pollution.

    VOCs can cause a number of health concerns seen in humans. High levels of exposure to VOCs can lead to a number of short-term symptoms such as:

    • Eye irritation
    • Throat irritation
    • Nose irritation
    • Headache
    • Nausea
    • Vomiting
    • Dizziness

    Additionally, high exposure may lead to certain chronic problems of cancer, liver damage, kidney damage, or central nervous system damage.

    How Can I Test for VOCs at Home?

    There are two primary ways that people test for VOCs at their homes.

    One way to test for VOCs in the home is to use a sorbent tube for air capture. This then gets sent to a lab for analysis. Due to having to send the test elsewhere for results, this method can be time-consuming.

    The other way to test for VOCs at home is to use a VOC gas detector capable of detecting the presence of VOCs. Often, these devices are simply called VOC gas detectors. They may also be called Total Volatile Organic Compound TVOC Detectors. 

    What Are VOC Gas Detectors?

    VOC gas detectors are essential components of Personal Protective Equipment (PPE). They are electronic monitoring devices used to detect the presence of VOCs in air so that people are not put in unnecessary danger. 

    What Do VOC Sensors Detect?

    VOC sensors detect the presence of VOCs in a given environment. Most VOCs are human-produced chemical compounds that feature high vapor pressure and low water solubility. Since there are many hundreds of gases that fall into the technical definition of VOC, gas detectors termed VOC gas detectors are commonly calibrated to isobutylene. Isobutylene is used because it is near the midpoint ionization point of most VOCs and is not flammable or toxic at low concentrations used in calibration. 

    Which VOCs does my Sensor Detect?

    The VOC sensor used by Forensics Detectors in all the VOC detectors sold has a cross sensitivity profile to various VOCs which is shown in the table below.

    Gas Formula Test Gas Concentration Sensor Reading
    Isobutylene
    (CH3)2C=CH2
    5ppm
    5ppm
    Isobutene  
    C4H8
    5ppm 5ppm
    Formaldehyde
    HCHO 5ppm 5.5ppm
    Acetaldehyde  
    C2H4O
    5ppm
    3.84ppm
    Methanol 
    CH4O
    5ppm
    5.96ppm
    Styrene   
    C8H8
    0.5ppm
    7.5ppm
    Benzene   
    C6H6
    5ppm
    1.1ppm
    Toluene   
    C7H8
    5ppm
    0.81ppm
    P-xylene   
    C8H10
    5ppm
    0.59ppm
    Ethylene   
    C2H4
    5ppm
    0.59ppm
    Butadiene   
    C4H6
    5ppm
    8.68ppm
    Ethanol
    C2H6O
    5ppm 1.83ppm

    How Do VOC Gas Detectors Work?

    VOC gas detectors are made up of a VOC sensor and digital electronics. The gas interacts with the sensor that changes the output electrical signal. The electronics converts this signal to a meaningful quantitative measure in parts per million (ppm).

    How Do You Use a VOC Gas Detector?

    In most cases, VOC gas detectors are used as handheld devices. As long as the device has been properly calibrated, has enough energy (typically in the form of battery power), and has been turned on, it is able to detect the instantaneous presence of VOCs in the nearby air environment that the sensor "smells".

    How Do You Select a VOC Gas Detector?

    There are a number of different types of VOC gas detectors available on the market. Some include personal gas detectors, portable gas detectors, fixed gas detectors, and semi-portable gas detectors. For assessing indoor air quality, a portable gas detector or fixed gas detector may be best.

    Can You Smell VOCs?

    Yes.

    Many VOCs carry a distinct smell. As such, many of them can be smelled by the human nose. With that said, smell alone is not an effective way to detect the presence of VOCs. VOC gas detectors are a more effective way to detect the presence of VOCs and reduce the chance of error.

    Why Do People Use VOC Gas Detectors?

    Many people in industries that regularly produce VOCs use VOC gas detectors to prevent the gas from reaching hazardous levels. By monitoring the amount of gas in the environment, these people can make effective decisions intended to lower the amount of VOCs in that specific area.

    Who Uses a VOC Gas Detector?

    Many people may find a use for VOC gas detectors. Most notably, industrial complexes should consider using VOC gas detectors to protect their workers from hazardous levels of VOCs. Companies may find mounted devices particularly useful as these can be mounted in areas of particular concern.

    Are VOCs Air Pollutants?

    Yes.

    VOCs are known as air pollutants that have been shown to have adverse impacts on human health in the past. As such, it is best practice to limit them as much as possible.

    How Do VOCs Affect Indoor Air?

    VOCs are common indoor air pollutants. This means that they have a negative effect on overall air quality and may have acute effects to humans. When using products that emit VOCs, people may unintentionally expose themselves and others to hazardous levels of air toxins. 

    Can VOCs Be Removed From the Air?

    Yes.

    Consumer-grade air cleaners are designed to trap and/or destroy VOCs. While the efficacy of these cleaners is questionable, their intention is to remove VOCs from the air.

    Some do this by physically trapping VOCs within the air cleaner. This prevents them from remaining in the air and potentially poisoning people.

    Others remove VOCs from the air by destroying VOCs through chemical means. This may include photocatalytic oxidation or ionization with ultraviolet light.

    Final Words

    • The phrase VOC stands for volatile organic compound where different VOC has different permissible exposure ppm levels by OSHA
    • A VOC gas detector can be used to identify the presence of VOCs in a given area
    • Be careful, there are many "junk" VOC gas detectors sold for less than $100. We do not recommend these units. Our testing has shown they are not specific (sensitive to many factors) and not calibrated to any national gas standard (like using NIST Traceable Isobutylene)
    • VOC gas detectors are often used to assess home air quality and used in industrial capacities where employers can ensure their employees are kept safe from potential toxins
    • VOC gas detectors may function through different means- the most common are photoionization detectors and electrochemical cells. 

    About the Author

    Dr. Koz is the President of FORENSICS DETECTORS, where the company operates from the scenic Palos Verdes Peninsula in Los Angeles, California. He is a subject matter expert on gas sensor technology, gas detectors, gas meters, and gas analyzers. He has been designing, building, manufacturing, and testing toxic gas detection systems for over 20 years.

    gas detector expert

    Every day is a blessing for Dr. Koz. He loves to help customers solve their unique problems. Dr. Koz also loves spending time with his wife and his three children going to the beach, grilling burgers, and having a cold beer. 

    Read more about Forensics Detectors here.

    Email:  drkoz@forensicsdetectors.com
    Phone: +1 424-341-3886


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