Paragraph 3 InterpretationI1

A maximum daily running 8-hour mean is calculated on a daily basis. The maximum daily running 8-hour mean for a particular substance at a particular location for a particular day is the maximum of the running 8-hour means ending during that day.

For the purpose of sub-paragraph (1) a “running 8-hour mean” is a mean, which is calculated on an hourly basis, yielding one running 8 hour mean per hour. The running 8-hour mean for the relevant substance at the relevant location for a particular hour is the mean of the hourly means for the substance at the location for the hour and the preceding 7 hours.