VOC (volatile organic compounds) refers to organic compounds that can evaporate and enter the air at room temperature. VOCS is the plural form of VOC, which refers to a variety of volatile organic compounds. TVOC (total volatile organic compounds) is the total amount obtained after measuring all individual VOCS in the air. SVOC (semi-volatile organic compounds) refers to organic compounds that can exist in both gaseous and particulate matter at room temperature. These compounds participate in chemical and physical processes in the atmosphere and may have an impact on human health and the environment. https://www.renkeer.com/what-is-tvoc/