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What are the different ways to measure VOCs?

iaq testing instrument taking VOC measurements

You may have just recently undergone a renovation in your home and noticed that the fresh paint odor seems to be very strong and lingers months after you finished. Maybe you had some new furniture delivered, and ever since you have been suffering from headaches in your home. These are just two examples of common issues that could be related to an issue with volatile organic compounds, otherwise known as “VOCs”1. VOCs are a common concern in indoor air quality and depending on the situation, it can be confusing for someone without technical knowledge to navigate the different ways to test. This blog will discuss some of the methods professionals like us use to measure VOCs.

What is a VOC?

Let’s start at the beginning, a VOC is a very broad classification of chemicals which are carbon-based and expected to be airborne in typical indoor conditions. There are hundreds of different chemicals which can be called a VOC. Common VOCs in typical indoor environments include compounds like ethanol, acetone, formaldehyde, and many more. VOCs come from a wide range of sources such as cleaning products, personal care products, building materials, and surface coatings, and even living things like mold and our own bodies!

Consumer Based VOC Detectors

Recently with the development of low priced sensors, consumer focused devices have become available over the past few years. These devices are relatively affordable (~$100-200), and often come paired with other low cost air quality sensors such as carbon dioxide or particulate matter. Usually driven by the price point, glowing reviews on Amazon, and convincing marketing, many consumers have been gravitating towards these devices to help them assess their air quality. However, these consumer based devices typically cannot be calibrated or serviced, and they use a very low cost sensor which means the reliability, accuracy, and precision of these devices can be questionable. I have seen two of the exact same devices placed next to each other with readings which are drastically different. We have had countless calls from people who have alarming levels from their device and want professional help to assess the issues, only to hire us and discover the only issue in their home is an unreliable device. With most technology these days, things develop rapidly, and I don’t doubt that in time there may be very reliable consumer based monitors but the current generation of sensors are just not reliable enough in our experience.

Professional VOC Devices

The most common tool used by professionals to measure VOCs in a property is a photoionization detector, or PID. These instruments typically are handheld and approximate the total level of VOCs in the air. If you like knowing the details, they work by using a UV lamp to energize electrons in a molecule, eventually causing electrons to be ejected from the molecule which produces an electrical current which is detected by the device. PIDs are nearly instantaneous and handheld, meaning we can use these devices to take many measurements quickly. These instruments are great screening tools to assess a home to determine if the overall levels of VOCs are high before deciding to collect expensive laboratory tests. There are some drawbacks; for example, the device is calibrated to a known gas (typically isobutylene) so the readings are only an approximation of the total. These devices cannot identify the compounds in the air, and can be blind to some compounds (such as formaldehyde) in their approximations.

Laboratory Analysis

Laboratory analysis is the most conclusive way to measure VOCs, but due to its expense and turn around time it is not always the best option. Many labs can analyze a sample for a panel of hundreds of VOCs, which can be very helpful in situations where the irritant is unknown, or if there are many different target compounds. Some VOCs, such as formaldehyde, require specific laboratory analysis and can not be detected by the panel analyses. Samples are typically collected on sorbent tubes, passive badges, or in evacuated canisters. Depending on the exact situation, the air quality professional will decide the best way to sample and the most appropriate laboratory analysis.

In this blog, I only scratch the surface on the many different techniques air quality professionals use to evaluate VOCs, and this article is mainly focused on residential properties (commercial and industrial settings pose many more variables!). If you have VOC or air quality concerns, please reach out to us to discuss what options for testing we would suggest for you!

  1. https://www.epa.gov/indoor-air-quality-iaq/volatile-organic-compounds-impact-indoor-air-quality

Ian Cull

Ian Cull is a nationally recognized expert in the field of indoor air quality. He is the Chief Science Officer of Indoor Science, a company he started in 2004. He speaks around the world on air quality topics and is a training provider of the Indoor Air Quality Association. Mr. Cull is a Licensed Professional Engineer (PE) and Certified Industrial Hygienist (CIH). His degree is in Environmental Engineering from the University of Illinois - Urbana Champaign. Mr. Cull has developed 50 air quality related courses for the IAQA University and is the author of the book, “Fundamentals of Mold Remediation”. In his words… “Besides being passionate about indoor air quality, I enjoy cycling, music, the Chicago Bulls, and having fun with my three kids.”

8 thoughts on “What are the different ways to measure VOCs?

    I live in a studio apt and have a downstairs neighbor who uses air freshener fragrance plug ins and harsh cleaners & the VOC come directly up through the vinyl flooring & electric outlets causing me headaches, nausea, heart palpitations, itching skin. So So I would by curious to know the concentrations of whatever it is as I also have a sensitivity.

    Nick,

    You could check out pro.iaqa.org to find an air quality professional near you who can help assess your VOC concerns.

    I’ve been worried about VOCs we had new mattresses and furniture delivered along with carpet installed. I left windows opened but never really knew the harms of Off gassing we also have a new car and I’m trying to reduce our exposure as we have already been exposed

    Mimi,

    The best thing to do is to increase ventilation as much as possible. The easiest way to do that is to crack windows (or open them up all the way if weather allows). Typically, levels from mattresses, furniture, and carpet will dissipate within a week or so.

    Hi Dylan – this info was very interesting as my adult son (50) has been having very difficult issues particularly at work. He’s been diagnosed with Sjogrens Syndrome and at first was given all kinds of meds but the meds were terrible for him – it wasnt helping at all. He works as an IT civilian
    with the National Guard in a very old building. He told me his problem was also related to VOCs. He has brought this problem to the attention of the person in charge but is not the least bit interested in doing anything to help. He is worried he may have to quit his job as his symptoms are getting worse. When he is home he feels better but has trouble sleeping. In reading about VOCs I see they are very where and in your own home you can control that by opening windows and using fans. But at the work place its a different issue. He says there are no odors. Do you have any suggestions? thanks for your help.

    Martha,

    In an older building like you describe, there are not many VOC sources that I can think of that could cause a general VOC elevation. There could be specific VOCs your son is sensitive to that could be triggering his symptoms.

    One thing to test out, your son could wear a respirator with an organic vapor cartridge while at work for a day to see if that provides some relief. This could help also confirm that his issue is with a VOC in the space or something else.

    He could see if he would be able to move to a workspace closer to a door, window, or HVAC register. There are air purifiers that can filter VOCs, but depending on the size of the space he works it, it may not be efficient enough to low the levels by any meaningful amount.

    Hi, I had a curious question asked of me; wondering if you can comment.
    This weekend I’ve been tinkering with an air quality monitor that I bought to monitor smoke and I’ve discovered that our master bedroom has really high and unhealthy TVOC levels. I can’t figure it out. It’s 5x higher than the cabinet where I keep my cleaning supplies and the area of the garage where we store paint / solvents.

    Mira,

    Things like candles, air fresheners, and perfumes can have large effects on VOCs. Also, if you have any new furniture, bedding, carpet, drapes, etc those could be contributing to the higher levels in the space. For the most part, cleaning supplies and paints are stored in very tight sealing containers, so we do not often see major issues in areas where these are stored (as long as they are stored properly).

    A reliable DIY test that you can do is Home Air Check, they have laboratory VOC tests that you can buy and sample to get a reliable reading on the VOCs in the room.