COMMISSION OF THE EUROPEAN COMMUNITIES 
C0M(92) 236 final 
Brussels, 26 May 1992 
Amended proposal for a 
COUNCIL DIRECTIVE 
OS 
AIR KXIOTKH B* O0OME 
(presented by the Commission pursuant to Article 149(3) 
of the EEC-Treaty) 
EXPEAHKTOKr MBMnRAumK 
1. In June 1991 the Commission submitted a proposal for a Council 
Directive on air pollution by ozone (OOM(91)220 final) based on 
Article 130s of the Treaty establishing the European Economic 
Community. 
2. The European Parliament endorsed the Commission proposal on 14 Hay 1992 
subject to certain amendments which it wished the Commission to 
incorporate into its proposal in accordance with Article 149(3) of the 
Treaty. 
3. Of the 21 amendments tabled by Parliament, the Commission can accept 
five unreservedly (Nos 14, 15, 17, 19 and 20) and six others in part 
(Nos 1, 4, 6, 7, 9 and 22). 
4. The text on the following pages takes account of the changes entailed. 
5. The second recital and Article 6(1) and (2) and Article 8 have been 
amended to emphasize the need to take measures to limit the precursors 
of ozone, an Article 7a on this point has been added, and reference to 
the impossibility of adopting limit values has been deleted from the 
second recital. 
6. The need to specify criteria for the establishment of measuring 
stations in order to increase the comparability of measurements has 
also been taken into account and has resulted in the amendment of 
Article 3. 
7. The role of the European Environment Agency in the operational aspects 
of implementing the directive is also recognized and has been taken 
into account in Articles 4(3) and 6(1) (assuming that the agency is in 
operation by the time this directive comes into force.) 
8. The need for a sufficiently large number of measurement points for the 
purposes of the directive has been added in Article 4(3) and 
Annex II.2. 
9. Lastly, various practical points concerning the measurement of 
precursors and details regarding Information for the public have been 
added to Annexes III and IV. 
- 1 -
Amended proposal for a Council Directive 
on air pollution by ozone 
THE UUUNCJJL. OF THE EUROPEAN 
COMMUNITIES, 
Having regard to the Treaty 
establishing the European Economic 
Community, and in particular 
Article 130s thereof, 
Having regard to the proposal from 
the Commission, 
Having regard to the opinion of the 
European Parliament, 
Having regard to the opinion of the 
Economic and Social Committee, 
whereas the 1987 fourth Community 
action programme on the 
environment1 provides for the 
possibility of action on 
photochemical pollution, and in 
particular ozone, in view of its 
harmful effects and the state of 
knowledge concerning its Impact on 
human health and the environment; 
whereas, in order to protect human 
health, ozone concentrations in 
the air should be limited; 
whereas the scientific and 
technical information available 
and knowledge of the formation and 
transport of photochemical 
pollutants does not make it 
possible at present to adopt limit 
values for those concentrations; 
Whereas, however, as complete a 
knowledge as possible of ozone 
pollution levels is required in 
all Member States; Whereas, in order to protect human 
health, measures must be taken to 
limit ozone and its precursors where 
concentration thresholds are 
exceeded; whereas technical and 
scientific information must be used 
and promoted to enable limit values 
for these concentrations to be 
1 OJ No C 328, 7.12.1989, p. 1. 
/f> 
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Whereas to obtain this knowledge it 
is necessary to set up measurement 
stations to provide data on ozone 
concentrations in the air; 
Whereas, In order to obtain 
comparable results, the methods 
used by the Member States to 
determine concentrations should be 
equivalent; 
Whereas, In view of the special 
nature of photochemical pollution, 
the reciprocal exchange of 
Information between the 
Member States and the Commission 
including, once it is effectively 
set up, the European Environment 
Agency,2 is essential for a better 
understanding of the problem; 
Whereas the setting of warning 
levels at which precautions should 
be taken by the public will make it 
possible to limit the Impact of 
pollution episodes on health; 
Whereas the numerical values of 
these levels should be based on the 
findings of work carried out in the 
framework of the World Health 
Ctrga.n1 zatlon (WHO), in particular 
as regards the dose-effect 
relationships established for the 
pollutant in question; 
Whereas the information collected 
under this Directive will make it 
possible to monitor the development 
of air pollution by ozone and the 
impact of national and Community 
provisions to reduce pihotochemical 
precursors and establish in the 
future new provisions concerning 
ozone and air quality, 
2 OJNoL 120, 11.5.1990, p. 1. 
7T \ 
\ 
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HAS ADOPTED THIS DIRECTIVE: 
Article 1 
1. The purpose of this Directive is 
to establish a common procedure: 
- for monitoring, 
- for the exchange of 
information, 
- for warning, 
concerning air pollution by 
ozone in order to enable the 
competent authorities of the 
Member States and the Commission 
to obtain wider knowledge of 
this form of air pollution in 
the Community and guarantee a 
minimum amount of public 
information where concentration 
thresholds are exceeded and 
there may be a risk to human 
health or vegetation. 
2. For the purposes of this 
Directive: 
- "health protection th^eshold,, 
means the O3 concentration 
value given in Annex I, 
point 1 beyond which there Is 
a risk to human health in the 
event of prolonged pollution 
episodes; 
- "vegetation protection 
thresholds" means the O3 
concentration values given in 
Annex I, point 2 beyond which 
there is a risk to vegetation; 
- "warning threshold" means the 
Q3 concentration value given 
in Annex I, point 3 beyond 
which there is a risk to human 
health in the event of short 
exposure and at which steps 
must be taken by the 
Member States as specified in 
the following articles. 
- 4 -
Article 2 
Each Member State shall designate a 
central body responsible for 
problems concerning air pollution 
by ozone at national level, and 
shall forthwith inform the 
Commission thereof. 
Article 3 
Member States shall establish 
measuring stations to supply the 
data necessary for the application 
of this Directive. Such stations 
must meet the specifications in 
Annex II. 1. Member States shall establish 
measuring stations to supply the data 
necessary for the application of this 
Directive. Such stations must meet 
the specifications in Annex II. 
2. The Commission shall specify, as 
soon as possible, the conditions which 
must be fulfilled by networks of 
stations for measuring Og and its 
precursors and adapt these, as 
necessary . according to the 
information arising from the actions 
referred to in article 4.3. 
Article 4 
1. For the measurement of O3 
concentrations, Member States 
shall use: 
- either the reference method 
referred to in Annex V; 
- or any other method of 
analysis shown to produce 
measurement results equivalent 
to those obtained using the 
reference method. 
To this end, each Member State 
sha.11 designate one or more 
central laboratories responsible 
for evaluating the method used 
at national level in relation to 
the reference method. 
Furthermore, they shall organize 
at national level 
intercjomparisons between 
laboratories taking part in the 
collection and analysis of the 
data. 
- 5 -
2. Once the measuring stations have 
been established, Member States 
gTvUi provide the Commission 
with the following information: 
- the method used to determine 
O3 concentrations and, if it 
is different from the 
reference method, proof of its 
equivalence with the latter; 
- the geographical coordinates 
of the measuring stations, a 
description of the area 
covered by the stations, and 
the site-selection criteria; 
- the results of any indicative 
measurement programmes carried 
out under the provisions of 
Annex II, point 2. 
3. Ihe Commission may organize, on 
a Community scale, 
intercomparison programmes 
between central laboratories. 3. The Commission, with the assistance 
of the European Environment Agency, 
shall organize, at regular intervals, 
meetings with those responsible for 
measuring centres in the Member States 
with the aim of exchanging information 
and experience concerning 
photochemical pollution. 
Article 5 
Member States sha.ll make the 
necessary arrangements for 
informing the public in accordance 
with Annex IV by the most 
appropriate means (radio, 
television, newspapers) where the 
warning value given in Annex I, 
point 3 is exceeded. 
- 6 -
Article 6 
1. As from [1 January 1994], 
Member States shall provide the 
Commission with the following 
information no later than three 
months following the annual 
reference period: 
- the maximum, the median and 
the 98th percentile of the 
mean values over one hour and 
eight hours recorded during 
the year in each measuring 
station; the percentiles 
shall be calculated in 
accordance with the method 
given in Annex III; 
- the number, date and duration 
of periods during which the 
thresholds in Annex I, 
points 1 and 2 are exceeded. 
2. Where the warning threshold in 
Annex I, point 3 is exceeded, 
Member States shall Inform the 
Commission no later than seven 
days following the period in 
question of: 
- the date of the occurrence; 
- the duration of the 
cjocurrence; 
- the maximum hourly 
concentration recorded during 
this period. 
Where possible, this information 
should be supplemented by 
relevant data concerning sources 
of precursors and weather 
conditions which might explain 
the reasons for the occurrence. 1. As from [1 January 1994], Member 
States shall provide the Commission 
through the European Environment 
Agency with the following information 
no later than three months following 
the annual reference period: 
- the maximum, the median and the 98th 
percentile of the mean values over 
one hour and eight hours recorded 
during the year in each measuring 
station; the percentiles shall be 
calculated in accordance with the 
method given in Annex III; 
- the number, date and duration of 
periods during which the thresholds 
in Annex I, point 1 and 2, are 
exceeded; 
- the measures envisaged or taken to 
prevent the thresholds in Annex I. 
points 1 and 2. being exceeded. 
2. Where the warning threshold in 
Annex I, point 3, is exceeded, Member 
States shall inform the Commission no 
later than seven days following the 
period in question of: 
- the date of the occurrence; 
- the duration of the occurrenoe; 
- the maximum hourly concentration 
recorded during this period; 
- measures envisaged or taken to 
restrict concentrations of Qg. 
(...) This information should be 
supplemented by relevant data 
concerning sources of precursors and 
weather conditions which might explain 
the reasons for the occurrence. 
- 7 
3. Where the data referred to in 
paragraphs 1 and 2 above are 
available in the Member States 
for periods preceding the date 
referred to in Article 9 of this 
Directive, Member States shall 
send them to the Commission at 
the latest when they send the 
data relating to the first 
reference period. 
Article 7 
Member States and the Commission 
shall regularly exchange 
information conOerning: 
- the data collected under this 
Directive; 
- measures taken or planned and 
programmes established by the 
Member States to Improve air 
quality; 
- experience and knowledge 
concerning the problem of 
photochemical pollution. 
Article 7a 
The Member States shall lhfbrm the 
Commission of the means they propose 
to use to reduce Ozone precursors In 
'eneral and volatile organic compounds 
VOC) and oxides of nitrogen (MQx) in 
particular to an acceptable level. i 
- 8 -
Article 8 Article 8 
On the basis of the information On the basis of the information 
collected, the Commission shall collected and notably those Obtained 
submit to the Council no later than under the terms of article 7b above. 
[1 July 1997] a proposal on the the Commission shall submit to the 
control of air pollution by O3, Council no later than [1 July 1997] a 
including In particular limit proposal on the control of air 
values for O3 concentrations in pollution by O3, including in 
the air and time limits for particular limit values for O3 
compliance therewith. inol aiding in particular limit values 
for O3 concentrations In the air and 
time limits for compliance therewith. 
Article 9 and the measures to be taken to reduce 
Member States shall bring into 
force the laws, regulations and 
administrative provisions necessary 
to comply with this Directive no 
later than [31 December 1992]. 
They shall forthwith Inform the 
Commission thereof. 
When Member States adopt such 
provisions, they shall contain a 
reference to this Directive or 
shall be accompanied by such a 
reference at the time of their 
official, publication. The 
procedures for making such a 
reference shall be laid down by the 
Member States. 
Article 10 
This Directive is addressed to the 
Member States. 
Done at Brussels, 
For the Council 
The President air pollution by Og. 
- 9 -
ANNEX I 
Thresholds for ozone concentrations 
in the fyiT*^-
(The values are expressed In ug 
63/m3. The volume must be 
standardized at the following 
conditions of temperature and 
pressure: 293* K and 101.3 kPa). 
1 - Health protection threshold 
(Lengthy exposure) 
110 vg/m3 for the mean value over 
eight hours2 
2 - Vegetation protection 
thresholds 
200 ug/m3 for the mean value over 
one hour 
65 ug/m3 for the mean value over 
24 hours 
5 - Health protection warning value 
(Short exposure) 
175 ug/m3 for the mean value over 
one hour 
1 Concentrations must be measured continuously. 
2 The mean over eight hours is a simple moving average calculated each 
hour h from the eight hourly values between h and h-9. 
- 10 -
ANNEX II 
Monitoring of ozone concentrations 
1. The purpose of measuring ozone 
concentrations in ambient air is to 
assess: 
(i) as closely as possible the 
Individual risk of exposure of 
human beings to values In 
excess of the health 
protection thresholds; 
(11) the exposure of vegetation 
(e.g. forests, natural 
ecosystems, crops) to the 
values given in Annex I. 
2. The measurement points shall be 2. An adequate number of measurement 
located at geographically and points shall be located at 
ol 1 matologlcal ly representative geographically and cllmatologicallY 
sites where: representative sites where: 
(i) the risk of approaching or 
exceeding the thresholds in 
Annex I is the highest; 
(ii) it is likely that one of the 
targets mentioned in 
paragraph 1 is exposed. 
At places where the Member States 
do not have information concerning 
the sites mentioned under (1) and 
(il), they shall carry out 
indicative measurement programmes 
in order to determine the siting of 
the measurement points to supply 
the data necessary for the 
application of this Directive. 
- 11 -
3. Member States shall establish 
additional measurement points in 
order: 
(i) to contribute towards the 
identification and description 
of the formation and transport 
of ozone and its precursors; 
(ii) to monitor changes in ozone 
concentrations in areas 
affected by background 
pollution. 
Hi) to Identify concentrations or 
sources of natural emissions. 
Parallel measurement of 
pho1xx}hemioal precursors (oxides of 
nitrogen, volatile organic 
compounds) is recommended in order 
to make it possible to identify 
links between the different 
pollutants. 
4. The final reading of the 
measurement instruments must be 
carried out in such a way that the 
mean values over one hour and eight 
hours can be calculated, in 
accordance with the provisions of 
Annex III. In the measurement stations mentioned 
In points 1 and 2 above, the 
concentrations of oxides of nitrogen 
and, if possible, those of organic 
compounds will be measured in parallel 
with Og in order to make it possible 
to Identify links between the 
different pollutants. 
- 12 -
ANNEX III 
Calculation of the measurement 
results for the annual reference 
period 
1. Concentrations must be measured 
continuously. 
2. The annual reference period 
shall begin on 1 January and end 
on 31 December in any given 
calendar year. 
3. For the validity of the 
calculation of the percentiles* 
to be recognized, 75% of the 
possible values must be 
available and, as far as 
possible, distributed uniformly 
throughout the period in 
question for the particular 
measurement site. If that is not 
the case, this fact must be 
mentioned when the results are 
communicated. 
The calculation of the 50th 
(98th) percentile on the basis 
of the values recorded 
throughout the year shall be 
carried out as follows: the 
50th (98th) percentile must be 
calculated from the values 
actually measured. The measured 
values shall be rounded off to 
the nearest ug/m3. All the 
values are to be listed in 
increasing order for each site: 
Xl^Xg^Xg^ ±Xk 
± ± %-U. % 
The 50th (98th) percentile is the 
value of k, to be calculated from 
the following formula: 
k - 0.50 (0.98).N 
N being the number of values 
actually measured. The value of 
0.50 (0.98).N shall be rounded off 
to the nearest whole number. 
The median shall be calculated as the 50th percentile, 
- 13 -
ANNEX IV 
The information set out below must 
be circulated on a sufficiently 
large scale as soon as possible to 
enable the public to take all 
appropriate preventive protective 
action. 
Standard text for informing the 
public about a high level of ozone 
in the air 
Situation 
Today,1 at hrs, 
significant concentrations of ozone 
in the air were recorded. 
At the following measurement 
points: 
concentrations in excess of 
175 ug/m3 (European warning 
value) were recorded. 
The details of the recorded values 
are as follows: 
Station Time Concentration 
(hourly mean) 
Forecast: 
Since no significant change in 
weather conditions is foreseeable 
in the next few days, significant 
concentrations can still be 
expected tonight/tomorrow/this 
weekend between hrs and 
hrs 
or 
The most recent weather forecasts 
indicate an Improvement in the 
situation by hrs/ within 
days. 
Where information is provided in newspapers a reference to the previous 
day may be added. 
- 14 
Precautions: 
As a precaution, those people 
who are particularly at risk 
from air pollution (children, 
the elderly, people with 
respiratory problems, etc.) 
should avoid unaccustomed 
physical effort and all outdoor 
exercise during the next 
hours. - As a precaution, those people who 
are particularly at risk from air 
pollution (children, the elderly, 
people with respiratory problems, 
etc.) and persons particularly 
sensitive to ozone should avoid 
unaccustomed strenuous physical 
activity outdoors during the next 
... hours. 
In general, it is recommended 
that sustained physical effort 
Ce.g. jogging) should be avoided 
during this period. 
For the public in general, it is 
recommended that all physical, 
effort should be avoided. A 
number of symptoms such as eye 
irritations, headaches, 
respiratory difficulties and a 
reduction in physical capacities 
may occur.1 
Counter-measures 
While Og concentrations continue to 
exceed permissible levels, the 
following measures shall be taken to 
restrict Qg in the atmosphere: 
This paragraph is to be added in the event of concentrations in excess 
of 350 ug/m3. 
- 15 -
ANNEX V 
Reference method of analysis to be used for the purposes of +»^q TM-nftahira 
I. GKNKHAL 
The reference method of analysis used to determine ozone final! be the 
chemi 1 uminesoenoe method. This method Is being standardized by the ISO. 
Once the latter has published the standard in question, the method 
described therein shall constitute the reference method. 
The following points must be taken Into consideration when the measurement 
methods and instruments are used by the Member States In the field: 
1. The conformity of the operating characteristics of the measurement 
Instrument with those indicated by the manufacturer, In particular 
background noise, response time and linearity, must be verified in the 
laboratory. 
2. The instrument must be totally calibrated regularly, using ad hoc 
preconditioned standard gases. 
The potassium iodide method or the method based on gas titration using 
ND as reagent Is to be used in parallel In the laboratory to analyse 
the O3 content of the standard gases and/or the accuracy and 
precision of the other methods of measurement provided for in Article 4 
(double-checking principle). 
Special care must be taken with regard to Interferences Inherent In the 
method and the instrument in order to optimize flow rates and guarantee 
the condition of the apparatus during the calibration procedure. 
3. In the field, the instruments must be calibrated regularly, e.g. every 
23 or 25 hours. 
In addition, the validity of the calibration must be verified by 
regularly operating in parallel an instrument calibrated in accordance 
with paragraph 1. 
If the instrument Inlet filter is changed before calibration, 
calibration must be carried out after an appropriate period of exposure 
(from 30 minutes to several hours) of the filter to ambient O5 
concentrations. 
4. The sampling head must be placed at least 1 m away from buildings In 
order to avoid any screening effect. 
5. The sampling head opening must be protected against rain and insects. 
No prefilter is to be used. 
16 -
6. Sampling must not be influenced by adjoining installations (the 
air-conditioning or data-transmission equipment). 
7. The sampling line must be of inert material (e.g. glass, PTFE, 
stainless steel) which is not affected by the presence of O3. 
It must be exposed beforehand to appropriate O5 concentrations. 
8. The sampling HTV* between the sampling hea^i and the analysis Instrument 
must be as short as possible. In particular, the time taken for the 
gas volume sample to pass through the sampling line must be as short as 
possible (e.g. of the order of a few seconds in the presence of other 
reagents such as NO). 
9. Condensation In the sampling line must be avoided. 
10. The sampling line must be cleaned regularly, taking local conditions 
Into account. 
11. The sampling line must be tight and the flow rate must be Inspected 
regularly. 
12. Sampling must not be influenced by gas discharges from the instrument 
or from the calibration system. 
13. All necessary precautions must be taken to prevent temperature 
variations from producing measurement errors. 
ISSN 0254-1475 
COM(92) 236 final 
DOCUMENTS 
EN 14 
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Catalogue number t CB^CO-92-244-EN-C 
ISBN 92-77-44764-8 
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