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What VOCs Are and How They Affect You

wwhere do VOCs come fromThe next time you’re out shopping, you may notice that some products have the words “low VOCs” on their label. An increasing amount of manufacturers are using this label because of the growing awareness of the harm that VOCs (i.e. volatile organic compounds) pose to human health.

VOCs Defined
Unfortunately, few people have ever heard of VOCs let alone know what they are. So, the first step in understanding what VOCs are and how they affect us is to break down the term itself. If you string each definition of the term together it becomes a “…substance that can easily evaporate and spread through the air, contains carbon in its molecular formula, and consists of two or more separate elements.” It should also be noted here that there are many different ways of classifying and categorizing VOCs, but that discussion is outside the scope of this article.

Now that you have a brief idea of what a VOC is, the next step is to understand how widespread VOCs are.  Many different consumer products contribute to indoor VOCs that people are exposed to, such as personal care products (nail polish, perfumes, hair spray), paints, fuels, cleaning products, and much more.  An example of a specific VOC would be Acetone (Chemical Formula: C3H6O) found in nail polish remover.  If you’ve used or been around nail polish remover before, you know how quickly the smell travels throughout a room.

VOC emissions from motor vehicles, factories, and manufacturing facilities are a large source of VOC emissions outdoors in the environment.  VOCs are also produced from naturally occurring sources, such as vegetation, bacteria, and fossil fuel deposits.

Why We Should Care About VOCs
At this point, you’re probably wondering why we care about VOCs?  The main concern for VOCs indoors are the adverse health effects that some of them have on people and animals.  VOCs from car emissions and other processes contribute to outdoor pollutants such as smog.  Outdoor VOC pollution is an important topic, however, this article focuses mainly on indoor air quality.

VOCs can have health effects such as irritation of the nose, throat, and eyes, headaches, nausea, dizziness, allergic skin reactions, damage to internal organs such as the liver and kidneys, cancer, and more.  One important thing to know is that the health effects vary greatly depending on the VOCs that you are exposed to, the length of exposure time, and the concentration of the VOCs.  Some VOCs are highly toxic and do not take long to have adverse health effects, some VOCs have no known adverse health effects at all.  OSHA and other safety administrations have developed occupational exposure limits for toxic VOCs that workers are not to exceed for safety reasons.  The exposure limits can vary from one organization to another.  Below are some examples of these types of exposure limits:

  • Time Weighted Average (TWA): The concentration in air of a substance that shall not be exceeded in an 8-hour work shift or a 40-hour work week. 
  • Short Term Exposure Limit (STEL): The time-weighted average exposure that should not be exceeded for any 15-minute period. 
  • Ceiling Limit (C): The exposure limit that shall at no time be exceeded.

This is why products containing potentially toxic VOCs recommend that you use them in a well ventilated area.  In an enclosed room, the more fresh air you add the less concentrated the VOCs become.

Measuring VOCs
So how do you measure VOCs?  Unfortunately, that is a complicated question.  This quote from the EPA website on VOCs provides useful information:

“All available measurement methods are selective in what they can measure and quantify accurately, and none are capable of measuring all VOCs that are present… The range of measurement methods and analytical instruments is large and will determine the sensitivity of the measurements as well as their selectivity or biases.”

For identifying the presence of VOCs, organic vapor analyzers such as photoionization detectors (PIDs), including the MiniRAE 3000 or ppbRAE 3000, can be used to measure Total Volatile Organic Compounds.  An important note about these meters is that they do not tell you the exact VOCs that you are measuring, just that VOCs are present.  Some VOCs require stronger lamps to be installed for detection, and others cannot be detected by PIDs (see our article on PID Lamp Selection).  If you know that only one VOC is present or if you know the exact mixture percentages of compounds where you are monitoring, then you can multiply the reading you get by a correction factor to get a more accurate reading for the compound(s). See RAE Systems Tech Note 106 for more details.

Other methods include colorimetric gas tubes that offer quick on-the-spot measurements of many different gases and vapors.  These tubes react with the compound in question and change color based on the concentration present.  The color can be compared to a color scale to get a value.

The most accurate method of testing VOCs involves collecting a sample using a SUMMA canister or air sampling pump with a tedlar bag and having it analyzed in a laboratory.  This method is best left to consultants who are trained professionals and know the correct sampling methodology.

Questions or Comments?
I hope this article answers some common questions that it may have about VOCs.  If you have any questions or comments, we would love to hear from you!  If you like to know more about VOCs, I recommend reading the following sources:


QT service station pumpThese days the service stations being built have quite the curb appeal.  I have noticed in the southeast QT® (i.e. Quick Trip) has built a number of facilities with quite a nice layout and beautiful landscaping.  These stores are very clean and have just about everything you need to get in a single stop.  I realize many of those reading this blog are environmental consultants who don’t own service stations, but you do have Clients who own them.

When a gasoline leak occurs at one of these new stations, the work that is required to fix the leak systematically destroys the appearance of these stations. There is no getting around doing the assessment to determine the impact of the release, but when it comes to remediation the choices are broad.

Some of the most successful cleanups I was involved in used Sparge\Vent technology.  This meant installing numerous Sparge wells and Vent wells, and cutting up that beautiful smooth pavement to install the underground lines between the wells and the equipment building.  These systems were quite effective, but noisy, smelly and not so pretty.  This is not what you want to see, hear and smell when you are pulling off the road to stretch, gets some gas, and a quick bite to eat.  The typical systems will be operated for a period of 2 to 5 years before being decommissioned.  But what if you didn’t have to install those wells and cut trenches through all that smooth pavement?

I know in the last two decades there have been a lot of snake oil salesmen offering to pour different concoctions into your monitoring wells to make your problems go away.  Most of the time all that happened good money was wasted, and in some cases, these concoctions made matters worse.  In some States, like South Carolina, pouring chemicals or bacteria into monitoring wells is not allowed.

However, what if you could remediate your site without using your monitoring wells for anything but monitoring?  You can – and it is not snake oil.  What I am talking about is cleaning up your site using a special blend of activated carbon in a carbon based injectate (CBI) and the indigenous bacteria.  This CBI is injected by direct push technology into the impacted formation to sequester the contaminants and allow the naturally occurring bacteria to do its job.  This is the way Mother Nature handles contaminants and does not require trenches, remediation wells and equipment compounds.  It is also relatively fast compared to other technologies and typically a lot cheaper.  It is not a solution for all sites, but no remediation technology is. If you are interested in getting more information about this technology contact ericchew@geologicrestoration.com

Brian E Chew Sr. P.G.
Principal Hydrogeologist


Inheriting Contaminated Property Not Always a Curse

What you need to know when inheriting contaminated propertyAs a Hydrogeologist with an interest in remediation of petrochemical impacted properties, I decided to do a Google search on the subject to see what I would find.  Surprisingly enough the first few pages were nothing but ads from lawyers telling you how to refuse your inheritance or risk being completely ruined financially.  Unfortunately these are the same folks who will turn around and buy the same property for next to nothing.

Also some inherited properties not worth owning due to excessive or extremely toxic contamination, but if you’ve been lucky enough to have been left a marketable tract of land that used to have a gas station or dry cleaner on the corner, you ought to consider remediation options before giving it away.  The key word here is marketable as 30 years ago, I inherited land in Georgia that was not contaminated but was a clear cut mess.  It was also out in the middle of nowhere.  I still have it and Atlanta is getting a lot closer to it every day.  Except in volcanic areas like Hawaii, there is no new land being made.  Remediation of impacted land can be expensive, but it can also be affordable.

There are numerous in-situ remediation methods available today that don’t require you to dig the whole place up and pay for expensive disposal.  There are even companies that will partner with you to clean up the property for a share of the sale price or in exchange for the property in more extreme cases (Yes, I am one of those guys).  A few of these remediation methods are as follows:

  • Bioremediation
    By injecting activated carbon into the impacted areas and allowing the indigenous bacteria to naturally degrade the contaminants into inert biomass and carbon dioxide. This is nature’s way of handling contamination, except a lot faster. A proprietary method of performing this method is called CleanInject®.
  • Air Sparging (AS) & Soil Vapor Extraction (SVE)
    This combination of methods is a lot more invasive but also very effective. It will require installation of equipment and remediation wells as well as trenching of underground piping. The equipment will have to be operated and maintained for a period of several years.

There are numerous other methods of cleaning up contaminated soil on property but these are some of the most popular.  If you have property that is worth more than $200,000 you may want to consider one of these methods.  Feel free and contact us to learn more by emailing Enviro-Equipment, Inc. at info@enviroequipment.com

Brian E Chew Sr PG

Principal Hydrogeologist