Offgassed

Offgassed is the past participle of offgas, referring to the release of gas from a material as volatile compounds migrate to the surface and vaporize. Offgassing occurs when materials contain volatile organic compounds (VOCs) or other volatile additives and are exposed to environmental conditions such as heat, humidity, or vacuum. The rate of emission typically decreases over time as the most volatile substances are depleted.

Common sources include plastics, paints, coatings, adhesives, foams, textiles, wood products, carpets, and the housings of consumer electronics. In buildings, vehicles, and consumer products, offgassing is a major factor in indoor air quality, particularly in the period shortly after installation or manufacturing.

The emitted gases are often VOCs such as formaldehyde, acetaldehyde, toluene, benzene, and various alcohols or ketones. Some VOCs can irritate the eyes, nose, and throat or cause headaches; longer-term exposure has raised health concerns in certain contexts. Regulatory agencies in various regions set limits on VOC content and provide labeling or certification schemes to help manage exposure.

Measurement and management of offgassing rely on techniques such as dynamic emission testing, gas chromatography–mass spectrometry (GC-MS), or infrared spectroscopy to identify and quantify emitted compounds. Rates depend on factors including temperature, surface area, material composition, and ventilation.

Mitigation strategies include selecting low-VOC materials, increasing ventilation, and conditioning or “baking out” new products before use or occupancy. Manufacturers may provide emission data and labeling to inform users about potential offgassing and guide safer choices.