The Air Quality (Ozone) Regulations (Northern Ireland) 2003

PART IItarget values for ozone

ParameterTarget value for 2010 (a)
(a)

compliance with target values will be assessed as of this value. That is, 2010 will be the first year the data for which is used in calculating compliance over three or five years, as appropriate.

(b)

the maximum daily 8-hour mean concentration shall be selected by examining 8-hour running averages, calculated from hourly data and updated each hour. Each 8-hour average so calculated shall be assigned to the day on which it ends – that is, the first calculation period for any one day shall be the period from 17:00 on the previous day to 01:00 on that day; the last calculation period for any one day will be the period from 16:00 to 24:00 on that day.

(c)

if the three or five year averages cannot be determined on the basis of a full and consecutive set of annual data, the minimum annual data required for checking compliance with the target values shall be as follows:

(i)

for the target value for the protection of human health, valid data for one year; and

(ii)

for the target value for the protection of vegetation, valid data for three years.

1.  Target value for the protection of human health

Maximum daily 8-hour mean (b)120μg/m3 not to be exceeded on more than 25 days per calendar year averaged over three years (c)

2.  Target value for the protection of vegetation

AOT40, calculated from 1h values from May to July18,000μg/m3·h averaged over five years