Volatile organic compounds (VOCs) are a type of gases that can move through the air easily. They are organic compounds, which means they contain carbon. They have a high vapor pressure, so they become gas at a low temperature. Most scents that we can smell come from molecules of VOCs.
VOCs are often made through burning. For example, burning fossil fuels makes VOCs. They are a common type of air pollution. High levels of VOCs in the air can affect breathing, affect the immune system, and cause allergies. They can also react with other chemicals and make smog.