The Air Quality Limit Values Regulations 2003

Regulation 18

SCHEDULE 11 INFORMATION TO BE OBTAINED AND COLLATED ON OZONE CONCENTRATIONS, AND CRITERIA FOR AGGREGATING DATA AND CALCULATING STATISTICAL PARAMETERS

PART I Information on ozone concentrations

The following information on ozone concentrations shall be obtained and collated—

	Type of station	Level	Averaging/accumulation time	Provisional data for each month from April to September	Report for each year
(a) In this Schedule, “AOT40” has the same meaning as in paragraph (d) of Part I to Schedule 2.
(b) Maximum daily 8-hour mean. Where they do not do so already, annual reports must also contain— (a) for ozone, nitrogen dioxide, oxides of nitrogen and the sums of ozone and nitrogen dioxide (added as parts per billion and expressed in µg/m3 ozone) the maximum, 99.9th, 98th and 50th percentiles and annual average and number of valid data from hourly series; and (b) the maximum, 98th and 50th percentile and annual average from a series of daily 8-hour ozone maxima. Data submitted in monthly reports are considered provisional and shall be updated where necessary in subsequent submissions.
Information threshold	Any	180µg/m3	1 hour	—for each day with any exceedance: date, total hours of exceedance, maximum 1 hour ozone and related NO2 values when required—monthly 1 hour maximum ozone	—for each day with any exceedance: date, total hours of exceedance, maximum 1 hour ozone and related NO2 values, when required
Alert threshold	Any	240µg/m3	1 hour	—for each day with any exceedance: date, total hours of exceedance, maximum 1 hour ozone and related NO2 values, when required	—for each day with any exceedance: date, total hours of exceedance, maximum 1 hour ozone and related NO2 values, when required
Health protection	Any	120µg/m3	8 hours	—for each day with any exceedance: date, 8 hours maximum (b)	—for each day with any exceedance: date, 8 hours maximum (b)
Vegetation protection	Suburban, rural, rural background	AOT40 (a) =6,000µg/m3.h	1 hour, accumulated from May to June		Value
Forest protection	Suburban, rural, rural background	AOT40 (a) =20,000µg/m3.h	1 hour, accumulated from April to September		Value
Materials	Any	40 µg/m3	1 year		Value

PART II Criteria for aggregating data and calculating statistical parameters

In this Part, percentiles are to be calculated using the method specified in Council Decision 97/101/EC establishing a reciprocal exchange of information and data from networks and individual stations measuring ambient air pollution within Member States(1).

The following criteria are to be used for checking validity when aggregating data and calculating statistical parameters—

Parameter	Required proportion of valid data
(a) In cases where all possible measured data are not available, the following factor shall be used to calculate AOT40 values: * being the number of hours within the time period of AOT40 definition (that is, 8:00 to 20:00 Central European Time from 1 May to 31 July each year, for vegetation protection and from 1 April to 30 September each year for forest protection).
1 hour values	75% (45 minutes)
8 hour values	75% of values (6 hours)
Maximum daily 8 hours mean from hourly running 8 hours averages	75% of the hourly running 8 hour averages(8 hours per day)
AOT40	90% of the 1 hour values over the time period defined for calculating the AOT40 value (a)
Annual mean	75% of the 1 hour values over summer (April to September) and winter (January to March, October to December) seasons separately
Number of exceedances and maximum values per month	90% of the daily maximum 8 hours mean value (27 available daily values per month) 90% of the 1 hour values between 8:00 and 20:00 Central European Time
Number of exceedances and maximum values per year	Five out of six summer months over the summer season (April to September)

(1)

OJ No. L035, 5.2.1997, p. 14.