Ozone Test Paper, Pack of 12
<ul><li>Quick and easy to use<li>Suitable for indoor and outdoor testing<li>Economical pricing for classroom labs and science projects</li></ul> Analyze these strips after only 10 minutes of exposure. Simply compare the stick's color with the color chart on the container for semi-quantitative results ranging from < 90 to > 210 µg/m<sup>3</sup> O<sub>2</sub>. An ozone content of 180 µg/m3 is considered a critical value above which sensitive persons should avoid strong physical exertion.