Is ozone 172 normal?

Not normal. An ozone index between 0 and 50 is considered a normal level, between 50 and 100 is considered a moderate pollution level, and above 100 is considered a severe pollution level. Ozone 172 has reached a serious pollution level and is therefore abnormal. The ozone index is an indicator used to express the concentration of ozone in the air. The specific ozone index standard will vary depending on the region, season and weather changes.