SVOCs: Allergy Season’s Least Understood Contributor May Be Its Most Dangerous

AllergiesJanuary 8, 2019

  You have probably heard the term VOC in the past. It is an acronym for Volatile Organic Compound. They are chemicals that exist as gasses at room temperature, and are considered a very serious air quality issue. The EPA and others in the know have linked them to a number of respiratory and cardiac diseases. Today, you will be able to expand your chemistry vocabulary even further, and we are going to introduce you to the SVOC. This stands for Semi-Volatile Organic Compound. A mouthful to be sure, but something you need to be aware of 2019. More Dangerous To Your Health Than Common VOCs. SVOCs are not like traditional VOCs in that they don’t always exist as a gas you can inhale. Usually you have to get up to temperatures over 200 degrees to get these things into the air. Most people like their home a bit cooler than that, so no one can blame you for not having SVOCs at the top of your mind. However, many plastic products are formed using these chemicals. Because they are not bound to the surface of the plastic during the manufacturing, the SVOCs are free to vaporize into the air. Take a look around your living room or kitchen or bedroom. How many plastic items do you see? Maybe it is your television set, or window frame, or the garbage bag protruding from beneath a lid. You can be sure that most of them are pumping SVOCs into your living space.  Lawrence Berkeley National Laboratory, one of the nation’s most prestigious producers of scientific knowledge have done a whole study on SVOCs. The news isn’t good. The risk is not simply an SVOC  released from the edge of your television set andyou breathe it in, and that’s that. Not at all. These gasses are persistent. They become attached to dust, which can lie dormant in a carpet until a vacuum or stampede of kids comes through. They can also be absorbed through the skin. SVOCs are long lasting. Berkeley claims that even if the emission source is removed, they can last for years.  As allergy season gets going, the topic of SVOCs becomes very important. While VOCs are certainly malignant, they have been around humans for a long time. Many VOC sources are completely natural, like trees and plants. We have evolved for tens of thousands of years with these VOCs, and have had a chance to develop immunity. Not so with SVOCs. Human exposure to them can be measured in decades not millennia. So, there is no built up immunity to them. That makes them more dangerous to us than VOCs are.     aps 2.5   A VOC Air Purifier For The SVOC Problem A VOC air purifier is a device capable of removing both VOCs and SVOCs from indoor air in excess of ninety percent of the baseline concentration. However, not all air purifiers are VOC air purifiers. Forget about anything that uses a filter. Even the highest grade HEPA filters (which will not be in your home) are too permeable to trap individual SVOC molecules. They are just too small, having a diameter measured in millionths of a meter. Some filtration systems contain charcoal or activated carbon. However, most of these have what is called a honeycomb geometry – it is shaped like a diamond. This construct does not provide a large absorbent surface area. The consequence is rapid saturation. And, with high CFM fan  this problem is only enhanced. Ozone will react with VOCs in the air, and remove them. However, Ozone Generators (also referred to as “Ionizers”) do not have any mechanism to control what the Ozone reacts with. It is just released into the environment. Ozone damages furniture and fabrics, and has been linked to many health problems itself. In fact, it is outright banned in many legal jurisdictions. There is one promising technology however that is both safe and effective in removing VOCs. It is called Photocatalytic Oxidation (PCO). The phenomenon was discovered by Japanese researchers, and later used by NASA to remove VOCs from spacecraft. Air is passed through a reaction chamber, where an activated catalyst produces a chemical species called a hydroxyl radical. The radical never leaves the surface, so it will not create another indoor air quality issue the way Ozone does. It works by chemically reacting with the SVOC. The products are harmless carbon dioxide and water. Of course, the trick to making this process as effective as NASA did, is to maximize the surface area where radicals can form. The results of a good PCO system are very promising, and have the potential to reverse the public health controversy SVOCs are responsible for. Note that not all PCO air purifiers are created equal. There is a lot of science and engineering that goes into the manufacture of a proper PCO reactor. If radical producing surface area is not maximized, chemistry not perfect, or air flow too rapid, the system can actually produce the VOCs formaldehyde and acetylaldehyde. Both are carcinogens. This was observed in a 2006 Lawrence Berkeley National Laboratory study with a PCO reactor transiting air at 300 CFM. Fortunately, there are PCO systems that avoid these problems, and are outstanding.  PCO technology has a great history. It has been around. It has been vetted. And, it has been associated with some of the greatest institutions science and technology has to offer. It is the solution to the SVOC problem. Allergy season is just around the corner. As you begin to make preparations to keep you and your loved one’s safe and symptom free, consider a PCO air purifier for your home to keep it SVOC free.