Volatile Organic Compounds (VOCs) are a group of organic chemicals that have high vapor pressure at room temperature, meaning they easily evaporate into the air. They originate from various sources, including human activities and natural processes. VOCs are found in many common products such as paints, solvents, cleaning agents, fuels, pesticides, building materials, and personal care products.

While not all VOCs are harmful, some can have adverse effects on human health and the environment. These effects can vary depending on the specific VOC and the level of exposure. Short-term exposure to high concentrations of certain VOCs can cause irritation of the eyes, nose, and throat, headaches, dizziness, nausea, and exacerbation of asthma symptoms. Long-term exposure to some VOCs has been associated with more serious health effects, including damage to the liver, kidneys, and central nervous system, as well as an increased risk of cancer.

VOCs also contribute to the formation of ground-level ozone and particulate matter, which are components of smog and can have detrimental effects on air quality and human health. In addition, some VOCs can react with other pollutants in the atmosphere to form secondary pollutants such as formaldehyde and acrolein.

Due to their potential health and environmental impacts, there are regulations and guidelines in place to limit VOC emissions from various sources and to promote the use of low-VOC or VOC-free alternatives in products and processes.

The World Health Organization (WHO) provides guidelines regarding the different VOCs concentration thresholds. Based on global chemical pollution, VOC's should be best kept under 300 ppb (part per billion).