Ozone is a colourless toxic gas. It is irritating to eyes and mucous membranes and can cause respiratory complaints. An ozone content of 180 μg/m³ is considered as critical value above which sensitive persons should avoid stronger physical exertion. The ozone values published by public media like press, radio or TV represent the ozone concentrations in the vicinity of the measuring stations. However, actual ozone values in other locations can considerably deviate from these published values due to meteorological and chemical influences such as wind, solar radiation, exhaust gases from vehicles etc. For this reason a local measurement of ozone concentrations is recommended.

Ozone test sticks are a convenient test for orienting determination of the ozone concentration in air. Similar to the QUANTOFIX^® test sticks they consists of plastic strips 10 mm wide, onto which a test paper has been sealed at the lower end. This allows easy handling of the test.