Toxicty of Ozone to Humans
This graph shows an indication of the ozone concentration and exposure time.
At an ozone concentration of 0.1 ppm (100 ppb), 1000 minutes of exposure causes no symptoms.
At an ozone concentration of 1 ppm (1000 ppb), 100 minutes of exposure can cause Nontoxic Symptomatic symptoms.
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Source: Toxicity of ozone to humans (Langewerf, 1963; cited in Dimitriou, 1990)