What Are VOCs?
Volatile Organic Compounds (VOCs) are a broad group of carbon-based chemicals that evaporate easily at room temperature. They are released by a surprisingly wide range of household sources and can significantly affect indoor air quality.
Common Sources of Indoor VOCs
- New furniture and carpeting — off-gassing of formaldehyde and other chemicals
- Paint and varnish — even low-VOC paints release some compounds
- Cleaning products — bleach, disinfectants, and aerosol sprays
- Personal care products — perfume, hair spray, nail polish
- Cooking — especially at high temperatures
- Building materials — plywood, particleboard, insulation
- Printers and copiers — release ozone and VOCs during operation
Health Effects
Short-term exposure to elevated VOCs can cause:
- Eye, nose, and throat irritation
- Headaches and dizziness
- Fatigue and difficulty concentrating
Long-term exposure to certain VOCs (especially formaldehyde and benzene) is linked to:
- Respiratory disease
- Liver and kidney damage
- Cancer (classified carcinogens)
How VOC Sensors Work
Most consumer VOC sensors use a metal oxide semiconductor (MOx) element that changes resistance in the presence of VOC gases. These sensors report a Total VOC (TVOC) reading, which aggregates all detected compounds into a single number rather than identifying individual chemicals.
TVOC readings are less precise than CO2 measurements from NDIR sensors, but they provide useful trend data. A sudden spike in TVOC after painting or cleaning signals that ventilation is needed.
Monitoring Recommendations
- Use a multi-sensor monitor — devices like the Airthings View Plus measure VOCs alongside CO2, PM2.5, and humidity. See our best monitors guide.
- Track trends, not absolutes — TVOC numbers are most useful for spotting changes and identifying sources.
- Ventilate after introducing new items — new furniture, paint, and flooring off-gas most heavily in the first weeks. Open windows frequently.
- Choose low-VOC products — when renovating, select paints, adhesives, and furnishings labelled low-VOC or zero-VOC.
For more on how VOCs compare to other air quality metrics, read our PM2.5 vs CO2 comparison. Use the CO2 calculator to estimate ventilation needs that address both CO2 and VOC dilution.