Threshold Levels of Ozone

What is PPM?

PPM stands for one unit per million, and PPB stands for one unit per billion.

The concentration of ozone in air and water is expressed as “ppm” (parts per million). 1 ppm in air equals approximately 2.1 mg/m3 of ozone. Depending on the sun, season and geographical location, the ozone concentration increases as the altitude increases.

Ozone Concentration in Air:

  • 0.003 – 0.015 ppm: Smell level Concentration found at sea level in clean air
  • 0.005 – 0.010 ppm: Forest air
  • Disinfecting effects begin at 0.010 ppm levels. Although it depends on the sensitivity of the person, the smell starts to be felt at this level
  • 0.020 ppm destroys 90% of the bacteria in the air
  • 0.020 – 0.050 ppm: found in the air after lightning strikes. Can reach levels of 0.100 ppm immediately after a lightning storm
  • 0.050 ppm: Continuous inhalation FDA safety level. ( Unlimited time up to 0.050 ppm concentration .)
  • 0.100 ppm: Time limitation is given as 8 hours/day by FDA (0.1 ppm.) as safety level.
  • 0.120 ppm: determined by the EPA as the threshold level for city air.
  • 1,000 – 2.0 ppm: It is known as the human tolerance level (from this limit, reactions such as cough, dry throat, tearing, nasal burning, tearing occur). The body refuses to stay in an ozone environment. Asthmatic bodies are more affected by the ozone concentration in question. Even at this level, it cannot be said that ozone causes permanent damage to the body. Causes only local irritations. The body will repair itself in a few hours.
  • 5,000-10 ppm: Pulse beat, body pain, numbness can be observed. If exposure continues, pulmonary edema occurs.
  • 15.0 – 20.0 ppm: Small animals die within 2 hours.
  • 50. ppm: Human life is endangered for 1 hour