What is TVOC?

Volatile organic compounds (VOCs) are considered to be emitted harmful, carcinogenic gases from solids and liquids.

VOC concentrations are consistently higher indoors (up to 10 times, according to the U.S. EPA) than outdoors and are found in common household products and furnishings.

A metal-oxide-semiconductor(MOS) sensor is used to measure TVOC concentration. To ensure measurements remain accurate throughout the sensor’s lifetime, the sensor is continually self-calibrating: the lowest reading is used as a baseline, and all given TVOC reading is relative to this baseline. For the first 5 minutes of powering on, the Laser Egg 2+ will display the message: ‘TVOC sensor warming up.’ During this time, we recommend you bring the Laser Egg 2+ outside to set a baseline value.

TVOC (ppm) is the concentration of VOCs present in the air. The TVOC index uses TVOC (ppm) to communicate the level of VOCs in your surroundings. The device is calibrated to GB50325-2010 - China’s national standard for civil engineering indoor environmental pollution control.

The index and scale are as follows:



    TVOC Index










 Very unhealthy







The Laser Egg+ Chemical can detect the following VOCs:

  • Aldehydes
  • Aliphatic hydrocarbons
  • Aromatic hydrocarbons
  • CH4
  • Ketones
  • LPG
  • CO
  • Amines
  • Alcohols
  • Organic acids