Understanding VOC

What is a VOC?

VOC is an acronym (pronounced VEE-OH-CEE) that stands for Volatile Organic Compound. The scientific definition is an organic (carbon containing compound) that has a high vapor pressure at room temperature. The EPA defines this as “any organic compound having an initial boiling point less than or equal to 250°C at a standard atmospheric pressure”. The actual EPA definition of a VOC is:

“Volatile organic compounds (VOC) means any compound of carbon, excluding carbon monoxide, carbon dioxide, carbonic acid, metallic carbides or carbonates and ammonium carbonate, which participates in atmospheric photochemical reactions, except those designated by EPA as having negligible photochemical reactivity.

Volatile organic compounds, or VOCs are organic chemical compounds whose composition makes it possible for them to evaporate under normal indoor atmospheric conditions of temperature and pressure.” 1

The two paragraphs above are similar, but there is a key difference that shows there are two different focuses when discussing VOCs. The first paragraph concerns VOCs that may affect outdoor air quality. The concern is compounds that participate “in atmospheric photochemical reactions”. The focus for this definition is to minimize compounds that may cause ozone or smog generation. The second paragraph is more concerned about indoor air quality. This is generally more to do with health and safety.

Coating VOCs are usually measured and reported in terms of grams per liter (g/L), but you may see other measurements that will fall into the weight per volume mold (i.e. lbs/gal). The number that you see is essentially how many grams of VOC per liter of coating. Obviously, the smaller the number means less VOC in every container of coating.

Common Misunderstandings About VOCs

All VOCs are toxic and dangerous

From a purely scientific definition, VOCs are all around us and they are basically the smells that we smell. There are natural VOC sources (namely plants), as well as manmade VOC sources (paint, plastics, etc.). The pine scent of a Christmas tree is from a class of VOCs called terpenes. The smell of freshly cut grass or that “new car smell” are both the result of VOC emissions. Essentially, there are thousands upon thousands of chemicals that are classified as VOCs and they can be relatively harmless or extremely toxic. Essential oils are essentially all VOCs and are generally considered to be harmless. Other VOCs, like formaldehyde some plastics or benzene from car exhaust, can be toxic.

VOCs smell bad

As mentioned above, VOCs are usually identifiable by smell. Because of the negative connotation associated with VOCs, many people assume that VOCs smell bad. While that is true for some VOCs like car exhaust, petroleum based solvents (xylene, mineral spirits, isopropyl alcohol), other VOCs may smell pleasant. Some examples would be essential oils, citrus solvent (d-limonene), perfumes and even roses. A very common misunderstanding is that many people think that citrus solvent is better or safer because it smells like oranges, but it is just as much a VOC as something like paint thinner.

VOCs are permanent

To reiterate, VOC stands for volatile organic compound. The key word is volatile. The second part of the EPA definition states that these compounds “evaporate under normal indoor atmospheric conditions of temperature and pressure. This means that the compound turns into a gas which is why we are able to smell them. Other terms that you may see in VOC discussions would be off gassing or outgassing. These terms are basically describing the phenomenon of materials to emit gases (VOCs) that may cause unpleasant odors. Common examples of this would be unwrapping a new mattress, the “new car smell” or applying a fresh coat of paint. These products emit VOCs into the atmosphere around them in the form of a gas. If they were trapped in that area, the smell could linger for a long time, but with proper ventilation, VOC levels would drop quickly.

The way that VOCs affect indoor air quality is not a new subject or a new concern. Building materials, new furniture and paints/coatings are producers of VOCs. Immediately following construction or application, these levels will be the highest. Time and good ventilation will help to remove VOCs from the indoor environment.

Low or zero VOC products are Safe(r)

Just because a product is sold as Low VOC, Zero VOC or VOC Free does not make something non-toxic or mean that it will be low odor. The EPA and other organizations have examined and continue to examine thousands of VOCs to determine short and long-term affects. There are many compounds that from a purely scientific standpoint would be considered VOCs; however, they have also been found to be non-hazardous and therefore are exempt from VOC calculations done by coatings formulators.2 A good example of this is acetone. Acetone (nail polish remover) has a strong smell and is an organic compound that evaporates under normal indoor atmospheric conditions so, it is a VOC. However it is not considered in VOC calculations. Even if something is low odor or contains very little solvent (exempt or not), it may still be toxic. Toxicity usually has to do with the product in its liquid state, so while Low/Zero VOC products may impact the air quality less, you should still follow all safety instructions (ventilation, respirators, gloves, safety glasses, etc.). The takeaway is that almost all products will give off some level of VOCs. Lower VOC products will usually give off less of them, but the drying, curing and ventilation process is still important when using any product regardless of VOC levels. Regardless of initial VOC level, most products will probably get close to zero VOC after a sufficient amount of time with adequate ventilation.

VOCs and my project

VOC has become an important topic and is worthy of scrutiny and study; however, they do not need to be met with fear. With a better understanding of VOCs, any product, regardless of VOC levels, can be used safely with the proper precautions. If you would like more information on VOCs and Waterlox Products, please read our VOC Laws and Rules guides.