offgassing

Offgassing is the release of chemicals from materials or products as they age, cure, or weather. The term is most commonly used to describe the emission of volatile organic compounds, or VOCs, which can accumulate in indoor spaces and contribute to poor air quality.

Emissions result from solvents, residual monomers, additives, and other chemicals migrating from a solid or liquid product into the air. The rate of offgassing depends on temperature, humidity, surface area, air exchange, and the chemical properties of the substances involved. Warmer, drier conditions and more exposed surface area usually increase release.

Common sources include new furniture and cabinetry, pressed wood products, paints and varnishes, adhesives, carpets and textiles, foam insulation, plastics, and household cleaning products. New items typically offgas most heavily during the first days to weeks after installation, with rates diminishing over time but occasionally continuing for months.

Health effects are usually temporary, such as eye, nose, throat irritation, headaches, or dizziness, particularly in sensitive individuals or poorly ventilated spaces. Prolonged exposure to certain VOCs has raised concerns about chronic effects. Indoor air quality strategies focus on source control, ventilation, and filtration.

Mitigation includes increasing outdoor air exchange, using low-VOC or VOC-free products, allowing new items to offgas before occupancy, and using air cleaners with activated carbon. Emission testing typically reports VOC concentrations or emission rates in micrograms per square meter per hour (µg/m2·h).