Volatile Organic Compounds

What it is

Volatile organic compounds (VOCs) are carbon-based chemicals that evaporate into the air at room temperature. The category covers thousands of different molecules, from familiar ones like formaldehyde, benzene, toluene, and xylene to fragrance compounds like limonene and pinene.

Some are short-lived irritants. Others are known or suspected human carcinogens. Indoor VOC concentrations typically run 2 to 10 times higher than outdoors, and during activities like painting or stripping floors, levels can spike 1,000 times above background.

Where it comes from

Indoor sources are everywhere once you start looking. Paints, varnishes, stains, paint strippers, and adhesives. Pressed-wood furniture and cabinets that off-gas formaldehyde from urea-formaldehyde glue. New carpet, vinyl flooring, and upholstery. Cleaning products, disinfectants, air fresheners, and scented candles. Personal care products like nail polish, perfume, and hairspray. Printers, copiers, and dry-cleaned clothes.

Combustion adds more: gas stoves emit benzene, tobacco smoke is a major source, and wood fires release dozens of VOCs. Outdoors, the main contributors are vehicle exhaust, gas stations, oil and gas operations, industrial solvents, and trees (which emit natural VOCs that combine with NOx to form ozone).

Health effects

Short-term symptoms include eye, nose, and throat irritation, headache, dizziness, nausea, and worsening asthma. Sensitive people often notice these symptoms when they walk into a freshly painted or newly carpeted room.

Long-term risks depend on the specific compound. Benzene is a known human carcinogen linked to leukemia. Formaldehyde is classified as a human carcinogen by the IARC and linked to nasopharyngeal cancer. Chronic exposure to some VOCs can damage the liver, kidneys, and central nervous system. Children and pregnant people face elevated risk.

How it's measured and typical levels

Total VOCs (TVOC) is reported in micrograms per cubic meter (µg/m³) or parts per billion (ppb). Individual compounds get tested in laboratory analysis of air samples. Low-cost sensors give a rough TVOC index, useful for spotting trends but not for regulatory accuracy.

Benchmarks vary by compound and country. Useful reference points:

Indoor formaldehyde, WHO 30-minute guideline: 100 µg/m³ (about 80 ppb)
CARB indoor target for formaldehyde: 9 ppb (chronic)
Benzene: no safe level identified; ATSDR minimal risk level for chronic inhalation is 3 ppb
TVOC guidance, "low concern" (German UBA): below 300 µg/m³
TVOC, "uncomfortable": above 1,000 µg/m³

The US EPA does not set NAAQS for individual indoor VOCs.

What you can do

The fastest fix is source control. Choose low-VOC or zero-VOC paints, adhesives, and finishes (look for GREENGUARD Gold or similar third-party certifications). Let new furniture and flooring air out in a garage or open room for a few days before bringing inside. Avoid air fresheners and scented candles; they add VOCs rather than remove them.

Ventilate aggressively during and after painting, sanding, or using strong cleaners. Open windows, run bathroom and kitchen exhaust fans, or use a fresh-air HVAC setting.

For ongoing exposure, an air purifier with a substantial activated carbon stage (not just a token sleeve) removes many VOCs. HEPA filters alone do not. Test your home for formaldehyde if you have new pressed-wood cabinets or have noticed persistent irritation.

Sources

This article is for educational purposes only. Canairy does not provide medical advice, diagnosis, or treatment. Talk to a qualified health professional about your specific situation.