Total Volatile Organic Compounds (TVOC) are a group of compounds containing carbon that have a high vapour pressure present in the air. There are abundant VOC emitted from everyday activities among which some are colourless and some odourless and some are toxic. TVOC monitoring is an efficient way to detect exposure to toxic VOCs. This article covers information on total volatile organic compounds, their sources in the ambient air, characteristics, health and environmental impact, possible corrective measures, need for TVOC monitors as well as different methods of TVOC monitoring. What is TVOC? Volatile organic compounds (VOC) are a group of compounds containing carbon that have a high vapor pressure i.e. easily convert into vapor or gases and have low water solubility. There are thousands of VOCs in the environment however, some may have short- and long-term adverse health effects when exposed to. The principal VOCs of interest include benzene, toluene, formaldehyde, ethylbenzene (BTEX), xylene, acetaldehyde, ethylene glycol, methylene chloride, acetone, styrene, etc. [Source: https://ere132.com/en/learn/for-a-healthy-home/volatile-organic-compounds-vocs.php] There are a large number of VOCs present in the environment making it difficult to continuously monitor them simultaneously. Hence, a common term TVOC (Total Volatile Organic Carbon) is used representing the total concentration of VOCs present in the air. Such a common term of measurement makes it easier to determine the overall presence of VOC and is cheaper than measuring individual VOCs. TVOC in Atmosphere We are in continuous contact with several products that contain and/or emit VOCs like disinfectants, paints and varnishes, solvents, semiconducting materials, rubber, vehicle exhaust, fuel, ink, adhesives, etc. Each VOC has its characteristic signature. For example, due to combustion, vehicle exhaust emits ethene while broadleaf trees emit isoprene. Different VOCs have different reaction rates and hence, have a large range of transport distances ones emitted. VOCs that have low creativity remain in the atmosphere for large durations of time are known as Persistent Organic Pollutants (POPs) and some VOCs are known as Hazardous Air Pollutants (HAPs) because of their toxicity.