OpenLegislation

Division 1 Definitions

United Kingdom

Original text. Later amendments are not shown.

AOT40 (expressed in (μg/m3) · hours) means the sum of the difference between hourly concentrations greater than 80 μg/m3 (= 40 parts per billion) and 80 μg/m3 over a given period using only the one-hour values measured between 8.00 and 20.00 Central European Time (CET) each day.