1980L0779 — EN — 01.01.1995 — 002.001 — 1
This document is meant purely as a documentation tool and the institutions do not assume any liability for its contents
►B COUNCILDIRECTIVE
of15July1980
onairqualitylimit valuesandguidevaluesforsulphurdioxideandsuspendedparticulates
(80/779/EEC)
(OJ L 229, 30.8.1980, p. 30)
Amended by:
Official Journal
No page date
►M1Council Directive of 19 October 1981 (81/857/EEC) L 319 18 7.11.1981
►M2Council Directive of 21 June 1989 (89/427/EEC) L 201 53 14.7.1989
►M3Council Directive of 23 December 1991 (91/692/EEC) L 377 48 31.12.1991
Amended by:
►A1Act of Accession of Spain and Portugal L 302 23 15.11.1985
►A2Act of Accession of Austria, Sweden and Finland C241 21 29.8.1994
(adapted by Council Decision 95/1/EC, Euratom, ECSC) L 1 1 1.1.1995
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COUNCILDIRECTIVE
of15July1980
onairqualitylimitvaluesandguidevaluesforsulphurdioxideand
suspendedparticulates
(80/779/EEC)
THE COUNCIL OF THE EUROPEAN COMMUNITIES,
Having regard to the Treaty establishing the European Economic
Community, and in particular Articles 100 and 235 thereof,
Having regard to the proposal from the Commission,Having regard to the opinion of the European Parliament(
1),
Having regard to the opinion of the Economic and Social
Committee(2),
Whereas the European Communities' programmes of action on the
environment of 1973(3) and 1977(4) provide that priority is to be given
to measures against sulphur dioxide and suspended particulates because
of their toxicity and the current state of knowledge of their effects on
human health and the environment;
Whereas, since any discrepancy between the provisions already applic-
able or being prepared in the various Member States with regard tosulphur dioxide and suspended particulates could give rise to unequal
conditions of competition and could consequently directly affect the
functioning of the common market, the legislative provisions in thisarea should be harmonized as prescribed in Article 100 of the Treaty;
Whereas one of the basic tasks of the European Economic Community
is to promote throughout the Community a harmonious development of
economic activities and a continued and balanced expansion; whereas
such an achievement is inconceivable without measures to combatpollution, improve the quality of life and protect the environment;whereas, since the Treaty has not provided the necessary powers inthis field, Article 235 of the Treaty must be invoked;
Whereas, in order to protect human health in particular, it is necessary
to set for these two pollutants limit values which must not be exceededin the territory of the Member States during specified periods; whereasthese values should be based on the findings reached in the frameworkof the WHO, particularly with regard to the dose/effect relationships
established for sulphur dioxide and suspended particulates taken
together;
Whereas, despite the measures taken, it may not be possible to comply
with these limit values in certain zones; whereas the Member Statesmust therefore be allowed temporary derogations on condition that
they forward to the Commission plans for the progressive improvement
of the quality of the air in those zones;
Whereas guide values should also be set to serve as long-term precau-
tions for health and the environment and as reference points for theestablishment of specific schemes within zones determined by the
Member States;
Whereas the measures taken pursuant to this Directive must be
economically feasible and compatible with balanced development;
Whereas it is necessary to establish suitable monitoring of air quality
and particularly of observance of the limit values; whereas the Member
States should therefore be obliged to establish measuring stations tosupply the data necessary for the application of the Directive;1980L0779 — EN — 01.01.1995 — 002.001 — 2
(1) OJ No C 83, 4. 4. 1977, p. 44.
(2) OJ No C 204, 30. 8. 1976, p. 34.
(3) OJ No C 112, 20. 12. 1973, p. 1.
(4) OJ No C 139, 13. 6. 1977, p. 1.
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Whereas since different sampling and analysis methods are applied in
the Member States, it is necessary to permit, under certain conditions,the use of sampling and measurement methods other than the reference
methods laid down in the Directive;
Whereas, since some Member States use particular methods of
sampling and analysis which cannot easily be correlated with the refer-
ence methods, it is necessary that the Directive specify different limit
values which are to be respected where such methods are used;whereas the Member States concerned should also carry out parallelmeasurements at a series of representative stations using the referencemethods in addition to their own methods of measurement; whereas theCommission must make further proposals in the light of these parallel
measurements and of the need to avoid discriminatory provisions;
Whereas the subsequent development of reference methods of sampling
and analysis referred to in this Directive may be desirable in the lightof technical and scientific progress in this area; whereas in order to
facilitate implementation of the work necessary to this end, a procedure
should be set upto establish close coop eration between the MemberStates and the Commission within a Committee on Adaptation toScientific and Technical Progress,
HAS ADOPTED THIS DIRECTIVE:
Article 1
The purpose of this Directive is to fix limit values (Annex I) and guide
values (Annex II) for sulphur dioxide and suspended particulates in the
atmosphere and the conditions for their application in order to improve:
— the protection of human health,
— the protection of the environment.
Article 2
1. ‘Limit values’ means:
— the concentrations of sulphur dioxide and suspended particulates
considered simultaneously in accordance with Table A in Annex I,and
— the concentrations of suspended particulates considered separately
in accordance with Table B in Annex I,
which, in order to protect human health in particular, must not be
exceeded throughout the territory of the Member States during speci-fied periods and under the conditions laid down in the following
Articles.
2. ‘Guide values’ means the concentrations of sulphur dioxide and
suspended particulates over specified periods which are given in AnnexII and are intended to serve as:
— long-term precautions for health and the environment,
— reference points for the establishment of specific schemes within
zones determined by the Member States.
Article 3
1. Member States shall take appropriate measures to ensure that as
from 1 April 1983 the concentrations of sulphur dioxide and suspendedparticulates in the atmosphere are not greater than the limit values
given in Annex I, without prejudice to the following provisions.
2. Where a Member State considers that there is a likelihood that,
despite the measures taken, the concentrations of sulphur dioxide andsuspended particulates in the atmosphere might, after 1 April 1983,
exceed in certain zones the limit values given in Annex I, it shall
inform the Commission thereof before 1 October 1982.
It shall at the same time forward to the Commission plans for the
progressive improvement of the quality of the air in those zones. These1980L0779 — EN — 01.01.1995 — 002.001 — 3
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plans, drawn up on the basis of relevant information on the nature,
origin and evolution of the pollution, shall describe in particular themeasures taken or to be taken and the procedures implemented or to
be implemented by the Member State concerned. These measures and
procedures must bring the concentrations of sulphur dioxide andsuspended particulates in the atmosphere within these zones to valuesbelow or equal to the limit values given in Annex I as soon as possibleand by 1 April 1993 at the latest.
Article 4
1. In the zones in which the Member State concerned considers it
necessary to limit or prevent a foreseeable increase in pollution by
sulphur dioxide and suspended particulates in the wake of develop-ment, in particular urban or industrial development, the Member Stateshall, taking the guide values in Annex II as a reference point, fixvalues which must be lower than the limit values in Annex I.
2. In zones on its territory which the Member State concerned
considers should be afforded special environmental protection, the
Member State shall fix values which are generally lower than the guidevalues in Annex II.
3. Member States shall inform the Commission of the values, dead-
lines and timetables they have laid down for the zones referred to inparagraphs 1 and 2, and of any appropriate measures they have taken.
Article 5
In addition to the provisions referred to in Article 3 (1) and Article 4
(1), Member States shall, with the object of taking further precautions
for the protection of health and the environment, endeavour to move
towards the guide values in Annex II wherever the measured concen-trations are higher than these values.
Article 6
Member States shall establish measuring stations designed to supply
the data necessary for the application of this Directive, in particular inzones where the limit values referred to in Article 3 (1) are likely to be
approached or exceeded and in the zones referred to in Article 3 (2);
the stations must be located at sites where pollution is thought to begreatest and where the measured concentrations are representative oflocal conditions.
Article 7
1. Following the entry into force of this Directive, Member States
shall inform the Commission, not later than six months after the end(31 March) of the annual reference period, of instances in which the
limit values laid down in Annex I have been exceeded and of the
concentrations recorded.
2. They shall also notify the Commission, not later than one year
after the end of the annual reference period, of the reasons for suchinstances and of the measures they have taken to avoid their recur-rence.
3. In addition, Member States shall forward information to the
Commission, at its request, on the concentrations of sulphur dioxide
and suspended particulates in any zones they have designated pursuantto Article 4 (1) and (2).
4. The Commission shall each year communicate to the Member
States the information it has received pursuant to this Article.1980L0779 — EN — 01.01.1995 — 002.001 — 4
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Article 8
At intervals of three years the Member States shall send information to
the Commission on the implementation of this Directive, in the form ofa sectoral report which shall also cover other pertinent CommunityDirectives. This report shall be drawn up on the basis of a question-
naire or outline drafted by the Commission in accordance with the
procedure laid down in Article 6 of Directive 91/692/EEC(
1). The
questionnaire or outline shall be sent to the Member States six monthsbefore the start of the period covered by the report. The report shall besent to the Commission within nine months of the end of the three-yearperiod covered by it.
The first report shall cover the period from 1994 to 1996 inclusive.
The Commission shall publish a Community report on the implementa-
tion of the Directive within nine months of receiving the reports fromthe Member States.
Article 9
Application of the measures taken pursuant to this Directive must not
bring about a significant deterioration in the quality of the air wherethe level of pollution by sulphur dioxide and suspended particulates at
the time of implementation of this Directive is low in relation to the
limit values set out in Annex I.
Article 10
1. For the purposes of applying this Directive, Member States shall
use either the reference methods of sampling and analysis referred to in
Annex III for sulphur dioxide and for suspended particulates measuredby the black smoke method or in Annex IV for suspended particulatesmeasured by the gravimetric method, or any other method of samplingand analysis in respect of which they demonstrate to the Commission-
at regular intervals:
— either that it ensures satisfactory correlation of results with those
obtained using the reference method,
— or that measurements taken in parallel with the reference method at
a series of representative stations chosen in accordance with therequirements laid down in Article 6 show that there is a reasonably
stable relationshipbetween the results obtained using that method
and those obtained using the reference method.
2. Without prejudice to the provisions of this Directive, a Member
State may also use, pending the decision of the Council on the propo-
sals from the Commission referred to in paragraph 4, the sampling andanalysis methods laid down in Annex IV and the values associated withthese methods also laid down in Annex IV in substitution for the limitvalues set out in Annex I.
3. By way of derogation from Article 3, Member States which
decide to avail themselves of the provisions of paragraph 2 shall:
— inform the Commission, before 1 January 1991, of any zones where
they consider that there is a likelihood that the concentrations of
sulphur dioxide and suspended particulates in the air might exceedthe limit values set out in Annex IV after 1 January 1991,
— forward to the Commission, as from 1 April 1991, plans for the
progressive improvement of air quality in those zones. These plans,drawn upon the basis of relevant information on the nature, originand development of the pollution, shall describe in particular the1980L0779 — EN — 01.01.1995 — 002.001 — 5
(1) OJ No L 377, 31. 12. 1991, p. 48.▼M3
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measures taken or to be taken and the procedures implemented or to
be implemented by the Member States concerned. These measuresand procedures must bring the concentrations of sulphur dioxide
and suspended particulates in the air in these zones to values below
or equal to the limit values set out in Annex IV as soon as possibleand by 1 April 1993 at the latest.
4. To overcome the disadvantages of the dual approach currently
laid down in Annexes I and IV, which are not completely equivalent,by 31 December 1992 the Commission shall submit to the Council aproposal for a general review of this Directive. The proposal shalltake account of the experience acquired from the studies referred to in
paragraph 5 and of the results of subsequent measurements taken using
technical specifications or reference methods for determiningsuspended particulates and sulphur dioxide. These technical specifica-tions or reference methods must be finalized by the Commission, inagreement with the Member States, by 31 December 1990.
This proposal shall cover any other aspects in need of review in the
light of scientific knowledge and of the experience acquired over theperiod of application of this Directive. It shall take account of, inter
alia,aspects connected with the design of the networks for measuring
air pollution and with the installation of measuring equipment as well
as the quality and comparability of the measurements taken.
5. The Commission shall, in selected locations in the Member States
and in cooperation with the latter, carry out studies on the samplingand analysis of sulphur dioxide, and of black smoke and suspended
particulates. These studies shall be designed in particular to promote
the harmonization of methods of sampling and analysis of these pollu-tants.
Article 11
1. Where Member States fix in border regions values for concentra-
tions of sulphur dioxide and suspended particulates in the atmospherein accordance with Article 4 (1) and (2), they shall hold prior consulta-tions. The Commission may attend such consultations.
2. Where the limit values given in Annex I or the values referred to
in Article 4 (1) and (2), inasmuch as the latter values have been thesubject of consultations in accordance with paragraph 1, are or might
be exceeded following significant pollution which originates or may
have originated in another Member State, the Member States concernedshall hold consultations with a view to remedying the situation. TheCommission may attend such consultations.
Article 12
The procedure laid down in Articles 13 and 14 for the adaptation on
this Directive to technical progress shall cover the subsequent develop-ment of the reference methods of sampling and analysis referred to in
Annex III. This adaptation must not result in any direct or indirect
modification of effective concentration values given in Annexes I andII.
Article 13
1. For the purpose of Article 12 a Committee on the adaptation of
this Directive to scientific and technical progress, hereinafter called‘the Committee’, shall be set up; it shall consist of representatives of
the Member States, with a Commission representative as chairman.
2. The Committee shall adopt its own rules of procedure.
Article 14
1. Where the procedure laid down in this Article is invoked, the
Committee shall be convened by the chairman, either on his own initia-tive or at the request of the representative of a Member State.1980L0779 — EN — 01.01.1995 — 002.001 — 6
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2. The Commission representative shall submit a draft of the
measures to be taken to the Committee. The Committee shall give itsopinion on the draft within a time limit set by the chairman having
regard to the urgency of the matter. Decisions shall be taken by a
majority of ►
A262◄votes, the votes of the Member States being
weighted as provided in Article 148 (2) of the Treaty. The chairmanshall not vote.
3. The Commission shall adopt the proposed measures if they are
consistent with the opinion of the Committee.
Where the proposed measures are not consistent with the opinion of the
Committee, or if no opinion is delivered, the Commission shall without
delay submit to the Council a proposal on the measures to be taken.The Council shall decide by a qualified majority.
If within three months of the proposal being submitted to it the Council
has not acted, the proposed measures shall be adopted by the Commis-sion.
Article 15
1. Member States shall bring into force the laws, regulations and
administrative provisions necessary to comply with this Directive
within 24 months of its notification and shall forthwith inform the
Commission thereof.
2. Member States shall communicate to the Commission the texts of
the provisions of national law which they adopt in the field covered bythis Directive.
Article 16
This Directive is addressed to the Member States.1980L0779 — EN — 01.01.1995 — 002.001 — 7
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ANNEXI
LIMITVALUESFORSULPHURDIOXIDEANDSUSPENDEDPARTICULATES
(As measured by the black-smoke method)
TABLE A
Limit values for sulphur dioxide expressed in µg/m3with the associated values for suspended
particulates(asmeasuredbytheblack-smokemethod (1))expressedinµg/m3
Reference period Limit value for sulphur dioxideAssociated value for suspended parti-
culates
Year80
(median of daily mean values
taken throughout the year)>4 0
(median of daily mean values
taken throughout the year)
120
(median of daily mean values
taken throughout the year)≤40
(median of daily mean values
taken throughout the year)
Winter
(1 October to 31 March)130
(median of daily mean values
taken throughout the winter)>6 0
(median of daily mean values
taken throughout the winter)
180
(median of daily mean values
taken throughout the winter)≤60
(median of daily mean values
taken throughout the winter)
Year
(made upof units of
measuring periods of 24
hours)250(2)
(98 percentile of all daily mean
values taken throughout theyear)> 150
(98 percentile of all daily mean
values taken throughout the year)
350(
2)
(98 percentile of all daily mean
values taken throughout theyear)≤150
(98 percentile of all daily mean
values taken throughout the year)
(1) The results of the measurements of black smoke taken by the OECD method have been converted into gravi-
metric units as described by the OECD (see Annex III).
(2) Member States must take all appropriate steps to ensure that this value is not exceeded for more than three
consecutive days. Moreover, Member States must endeavour to prevent and to reduce any such instances in
which this value has been exceeded.
TABLE B
Limit values for suspendedparticulates (as measured by the black-smoke method (1)) expressed
inµg/m3
Reference period Limit value for suspended particulates
Year80
(median of daily mean values taken throughout the year)
Winter
(1 October to 31 March)130
(median of daily mean values taken throughout the winter)
Year
(made upof units of measuring
periods of 24 hours)250(2)
(98 percentile of all daily mean values taken throughout the
year)
(1) The results of the measurements of black smoke taken by the OECD method have been converted into gravi-
metric units as described by the OECD (see Annex III).
(2) Member States must take all appropriate steps to ensure that this value is not exceeded for more than three
consecutive days. Moreover, Member States must endeavour to prevent and to reduce any such instances inwhich this value has been exceeded.1980L0779 — EN — 01.01.1995 — 002.001 — 8
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ANNEXII
GUIDEVALUESFORSULPHURDIOXIDEANDSUSPENDEDPARTICULATES
(as measured by the black-smoke method)
TABLE A
(Guidevaluesforsulphurdioxideexpressedinµg/m3
Reference period Guide value for sulphur dioxide
Year40 to 60
(arithmetic mean of daily mean values taken throughout the
year)
24 hours100 to 150
(daily mean value)
TABLE B
Guidevaluesforsuspendedparticulates(asmeasuredbytheblack-smokemethod (1))expressed
inµg/m3
Reference period Guide value for suspended particulates
Year40 to 60
(arithmetic mean of daily mean values taken throughout the
year)
24 hours100 to 150
(daily mean value)
(1) The results of the measurements of black smoke taken by the OECD method have been converted into gravi-
metric units as described by the OECD (see Annex III).1980L0779 — EN — 01.01.1995 — 002.001 — 9
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ANNEXIII
REFERENCE METHODS OF SAMPLING AND ANALYSIS TO BE
EMPLOYEDWITHINTHECONTEXTOFTHISDIRECTIVE
A. SULPHUR DIOXIDE
The reference method of sampling for the determination of sulphur dioxide uses
the equipment described in International Standard ISO—4219, first edition
1979/09/15. The sampling period is normally 24 hours.
The reference method of analysis is that described in detail in Annex V; it is
based on Draft International Standard ISO DP—6767, revised February 1979:‘Air quality - determination of the mass concentration of sulphur dioxide in
ambient air - tetrachloromercurate (TCM)/pararosaniline’. This method of
analysis is based on the principle of the colorimetric reaction with pararosani-
line.
B. SUSPENDED PARTICULATES
For the determination of black smoke and its conversion into gravimetric units,
the method standardized by the OECD working party on methods of measuring
air pollution and survey techniques (1964) is considered to be the reference
method.
For the above-noted methods, standardized respectively by ISO and OECD, the
linguistic versions published by these organizations will be regarded as authentic
together with the other versions which the Commission will certify as being in
conformity therewith.1980L0779 — EN — 01.01.1995 — 002.001 — 10
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ANNEXIV
LIMIT VALUES FOR SULPHUR DIOXIDE AND SUSPENDED PARTI-
CULATES (AS MEASUREDBY A GRAVIMETRIC METHOD )
APPLICABLEWITHINTHECONTEXTOFARTICLE10(2)
TABLE A
Limit values for sulphurdioxide expressed in µg/m3, and associated values for suspendedparti-
culates(measuredbythegravimetric method)expressedinµg/m3
Reference period Limit value for sulphur dioxideAssociated value for suspended particu-
lates
Year80
(median of daily mean values taken
throughout the year)> 150
(median of daily mean values taken
throughout the year)
120
(median of daily mean values taken
throughout the year)≤150
(median of daily mean values taken
throughout the year)
Winter
(1.10. — 31.3.)130
(median of daily mean values taken
throughout the winter)> 200
(median of daily mean values taken
throughout the winter)
180
(median of daily mean values taken
throughout the winter)≤200
(median of daily mean values taken
throughout the winter)
Year
(made upof units
of measuring
periods of 24
hours)250(1)
(98th percentile of all daily mean
values taken throughout the year)> 350
(98th percentile of all daily mean
values taken throughout the year)
350(1)
(98th percentile of all daily mean
values taken throughout the year)≤350
(98th percentile of all daily mean
values taken throughout the year)
(1) Member States must take all appropriate steps to ensure that this value is not exceeded for more than three
consecutive days. Moreover, Member States must endeavour to prevent and to reduce any such instances inwhich this value has been exceeded.
TABLE B
Limitvaluesforsuspendedparticulates(asmeasuredbythegravimetricmethoddescribedin(ii)
below)expressedinµg/m3
Reference period Limit value for suspended particulates
Year150
(arithmetic mean of daily mean values taken throughout the
year)
Year
(made upof units of measuring
periods of 24 hours)300
(95 percentile of all daily mean values taken throughout the
year)
The methods of sampling and analysis applicable within the context of Article
10 (2) are with respect to:
(i)Sulphurdioxide
—Method of sampling:
The reference method in Annex III A.1980L0779 — EN — 01.01.1995 — 002.001 — 11
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—Method of analysis: the reference method of Annex III. The procedure
set out in Article 10 (1) applies.
(ii)Suspendedparticulates
—Method of sampling:
1. The suspended particulates are collected on a filter composed of
either membrane or glass-fibre.
2. The sampling system consists of:
— a filter,
— a filter support,
— a pump,
— a volumetric gasmeter.
3. The sampling system does not include a fractionating device.
4. The sampling duration is 24 hours.5. The filter is protected against direct deposition of particles by sedi-
mentation and against the direct influence of atmospheric conditions.
6. The filters used should have an efficiency of more than 99 % for
particles having an aerodynamic diameter of 0 3 µm.
7. The air velocity at the surface of the filter is between 33 and 55 cm/
sec inclusive. The reduction in the speed throughout the sampling
duration must not exceed 5 % if glass-fibre filters are used or 25 %
if membrane filters are used.
8. The number of samplings made throughout the year must be at least
100, uniformly spread throughout this period.
—Method of analysis:
(a) Analysis is by weighing.
(b) 1. Membrane filters are to be conditioned, before and after sampling,
by holding them at a constant temperature between 90 and l00 ºC
for two hours and subsequently storing them in a dessicator for
two hours before weighing.
(b) 2. Glass-fibre filters are to be conditioned, before and after
sampling, by holding them for a period of 24 hours in an atmo-
sphere at 20 ºC and 50 % relative humidity before weighing.1980L0779 — EN — 01.01.1995 — 002.001 — 12
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ANNEXV
REFERENCEMETHODOFANALYSISFORSULPHURDIOXIDE
Airquality-Determinationofthemassconcentrationofsulphurdioxidein
ambientair-Tetrachloromercurate (TCM)/pararosanilinemethod
1. SCOPE
This draft international standard specifies a spectrophotometric
method for the determination of the mass concentration of sulphur
dioxide in ambient air. The standard comprises methods for both
sampling and analysis.
2. FIELD OF APPLICATION
With the procedure described in this standard, atmospheric sulphur
dioxide concentrations between 7 and 1 150 µg/m3can be deter-
mined.
NoteIf higher concentrations have to be determined aliquots of the sample
solution or smaller air samples than specified in this standard can be
taken. In this case the absorption efficiency of the concentrations
under study.
Interferences from heavy metals, oxides of nitrogen, ozone and
reduced sulphur compounds (e.g. hydrogen sulphide and mercap-
tanes) are eliminated or minimized. Sulphuric acid and sulphates do
not interfere. No interference of sulphur trioxide has been experimen-
tally ascertained, since this presumably becomes hydrated to
sulphuric acid in the absorbing solution.
3. PRINCIPLE
A measured air sample is drawn through a solution of sodium tetra-
chloromercurate (TCM) and the sulphur dioxide present in the air is
absorbed by formation of a dichlorosulphitomercurate complex.
The sample solution is treated with a solution of sulphamic acid to
destroy the nitrite anion formed by the oxides of nitrogen present in
the air. It is then treated with solutions of formaldehyde and acid-
bleached pararosaniline containing phosphoric acid to obtain a pH
o f16±01 .
Pararosaniline, formaldehyde and the bisulphite anion react to form
the intensely coloured pararosaniline methyl sulphonic acid, which
behaves as a two-colour indicator ( λ
max= 548 nm at pH 1 6 ± 0 1).
The concentration of sulphur dioxide is taken from a calibration
graph prepared on the basis of calibration gas mixtures (6.3.1).
According to the equipment available in the laboratory it may be
convenient in certain cases, for routine checks to replace the calibra-
tion gas mixtures by sodium bisulphite solutions of known
concentration. However, this procedure should only be used after a
proper calibration with a permeation device.
4. REAGENTS4.1. All reagents shall be of analytical quality (pro analysi).
Unless otherwise indicated, references to water shall mean distilled
water. The water must be free from oxidants and should preferably
be double-distilled from an all-glass apparatus.
4.2. Absorbing solution: 0 04 moles/l sodium tetrachloromercurate
(TCM).
Dissolve 10 9 g of mercury (II) chloride, 4 7 g of sodium chloride
and 0 07 g of ethylendiamine tetracetic acid disodium salt (EDTA)
in water and dilute to 1 litre.
The solution is stable for several months and should be discarded if a
precipitate is formed.
Notes
1. The amount of EDTA added eliminates possible interferences
from heavy metals upto 60 µg of iron (III), 10 µg of manganese
(II), 10 µg of chromium (III), 10 µg of copper (II) and 22 µg of
vanadium (V) in 10 ml of absorbing solution.
2. The solution is highly poisonous and should be handled as such. A
method for recovering the mercury after the analysis is given in
Annex C. If any absorbing solution is spilt on the skin, it must
be flushed off with water immediately.1980L0779 — EN — 01.01.1995 — 002.001 — 13
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4.3.Hydrochloric acid,1mole/l
Dilute 86 ml of concentrated hydrochloric acid, HCl ( ρ= 1 19 g/ml,
to 1 litre.
4.4.Pararosaniline hydrochloride,02%stocksolution
Dissolve 0 2 g of pararosaniline hydrochloride, C19H17N3HCl in
100 ml of hydrochloric acid (4.3).
NotePararosaniline hydrochloride used in the preparation of the stock
solution must have a purity higher than 95 % (see Annex D) and
exhibit a maximum absorption at 540 nm in acetic acid - sodium
acetate buffer (0 1 moles/l). Furthermore, the absorbance of the
reagent blank should not exceed 0 10 when the blank is prepared
according to the procedure described in section 6.2.
Reagents that do not meet these requirements must be rejected or
purified. The purification can be achieved by crystallization or
extraction (see Annex D).
4.5.Phosphoricadd,3moles/l
Dilute 205 ml of concentrated phosphoric acid, H
3PO4,(ρ= 1 69 g/
ml) with water to 1 litre.
4.6.Pararosaniline reagentsolution
Pipet 20 ml of the pararosaniline hydrochloride stock solution (4.4)
and 25 ml of phosphoric acid (4.5) into a 250 ml volumetric flask
and make upto the mark with water.
This reagent is stable for several months if stored in the dark.
4.7.Formaldehyde,workingsolution
Pipet 5 ml of a 40 % formaldehyde solution, HCHO, into a 1 litre
volumetric flask and make upto the mark with water. Prep are daily.
4.8.Sulphamicadd,06%workingsolution
Dissolve 06go f sulphamic acid, NH2SO3H, in 100 ml water. This
solution is stable for a few days if protected from air.
4.9.Sodiumbisulphitesolution.Stocksolution
Dissolve 0 3 g of sodium metabisulphite, Na2S2O5, in 500 ml of
freshly boiled and cooled distilled water (double-distilled water that
has been deaerated is preffered (SIC! preferred)). The solution
contains from 320 to 400 µg of sulphur dioxide equivalents per milli-
litre. The actual concentration is determined by adding an excess of
iodine to an aliquot of the solution and back titrating with standar-
dized sodium thiosulphate solution (see Annex B).
The solution is unstable.
4.10.Sodiumbisulphitestandardsolution
Immediately after the standardization of the sodium bisulphite stock
solution (4.9), pipet 2 0 ml of the solution into a 100 ml volumetric
flask and make upto the mark with the sodium tetrachloromercurate
solution (4.2).
This solution is stable for 30 days if stored at 5 ºC. Stored at room
temperature, it will be stable for one day only.
5. APPARATUS
5.1.Samplingequipment
The equipment to be used for sampling is specified in ISO/DIS 4219,
Air Quality — Determination of gaseous compounds in ambient air
— Sampling equipment as shown in Figure 1.
Figure 1
Block diagram of sampling equipment
1980L0779 — EN — 01.01.1995 — 002.001 — 14
▼B
Alternatively to the gas meter a hypodermic needle can be used as a
critical orifice in a thermostated box. In this case, the pump must be
able to reach pd/pu≤05 ,pdand pubeing the pressures downstream
and upstream the needle respectively (see 5.5).
Figure 2
The equipment is shown in Figure 2.
5.2.Absorptionbottles
Satisfactory absorption bottles should have an absorption efficiency
for sulphur dioxide of at least 95 %. Examples of suitable absorption
bottles are given in Annex A.
The absorption efficiency varies with the geometry of the bottle, the
size of the gas bubbles and their contact time with the solution. It can
be determined by inserting a second absorption bottle in series to the
first one into the sampling system and relating the amount of sulphur
dioxide found in the first bottle to the sum of the sulphur dioxide
amount in the two bottles. When working with midget impingers
under the conditions described in section 6.1, the absorption effi-
ciency has been found to be better than 98 %.
The use of mixtures of sulphur dioxide and air for calibration, as
described in clause 6.3.1, automatically gives the absorption effi-
ciency of the system.
5.3.Hydrogensulphideabsorber
A glass tube filled with quarz wool impregnated with a solution
containing 0 5 % of silver sulphate, Ag2SO4, and 2 5 % of potassium
hydrogen sulphate, KHSO4. The impregnation is made by passing the
solution twice through the tube and then drying the quartz wool by
heating in a nitrogen stream.
5.4.Samplebottles
Polyethylene bottles, 100 ml, for transferring the exposed absorption
solutions to the laboratory.
5.5.Manometer
Two manometers accurate to 1000 Pa, for measurement of pressures
when using a critical orifice instead of a gas meter.
5.6.Spectrophotometerorcolorimeter
A spectrophotometer or colorimeter suitable for measuring the absor-
bance at about 550 nm. With a spectrophotometer, a wavelength of
548 nm should be used. If a colorimeter is used, the filter should
have its transmittance maximum at about 550 nm. Reagent blank
problems may occur with apparatus having a greater spectral band
width than 20 nm.
When measuring the absorbance use the same cell for samples and
standard solutions. If more than one cell is used, the cells must be
spectrophotometrically matched.
6. PROCEDURE6.1.Sampling
Transfer 10 ml of the TCM solution (4.2) to an absorption bottle and
insert it into the sampling system (Figure 1). Shield the absorbing
solution from direct sunlight during the sampling by covering the
absorption bottle with a suitable wrapping, such as aluminium foil,
to prevent decomposition. The duration and flow rate of the aspira-
tion depend on the concentration of sulphur dioxide in the air.
With midget impingers, the volume flow rate should be between 0 5 l/
min and 1 l/min. The minimum quantity of air aspirated should be 25
litres.
To obtain the best results, flow rate and sampling time should be
chosen to achieve an absorption of 0 5 to 3 0 µg (0 2 to 1 2 µl at
25 ºC and 101325 kPa) of sulphur dioxide per ml of absorbing solu-
tion.1980L0779 — EN — 01.01.1995 — 002.001 — 15
▼B
If the air is believed to contain hydrogen sulphide this must be
removed by a hydrogen sulphide absorber (5.3). Place the absorber
between the particulate filter and the absorption bottle.
After sampling, determine the volume of air sampled, and note the
atmospheric temperature and pressure (7.1, Note). If the sample
must be stored for more than 24 hours before analysis, keepit at 5 ºC.
NoteIf the sample solution shows a precipitate, it is probably due to the
reaction of Hg II with a reduced sulphur compound. Remove the
precipitate by filtration or centrifugation before the analysis.
6.2.Analysis
Samples must be left for at least 20 minutes after sampling to allow
trapped ozone to decompose. Then transfer the sample solution quan-
titatively to a 25 ml volumetric flask, using about 5 ml of water for
rinsing.
Prepare a blank by adding 10 ml of unexposed absorbing solution
(4.2) to a 25 ml volumetric flask, add the reagents as described below
and read the absorbance against distilled water using 10 mm cells.
Compare this value with the one recorded for the blank obtained
when preparing the calibration curve. Differences of more than 10 %
between the two values indicate contamination of the distilled water
or the reagents or decomposition of the latter, in which case fresh
reagents must be prepared.
Add 1 ml of the sulphamic acid solution (4.8) to each flask and allow
to react for 10 minutes to destroy the nitrate from oxides of nitrogen.
Then accurately pipet 2 ml of the formaldehyde solution (4.7) and
5 ml of the pararosaniline reagent (4.6) into the flasks. Make up to
the mark with freshly boiled and cooled distilled water and store in
a thermostat at 20 ºC. After 30 to 60 minutes measure the absorbance
of the sample and the blank with distilled water in the reference cell.
Do not let the coloured solution remain in the cell as a film of dye
will then be deposited on the walls.
NoteFixed time intervals between the addition of each reagent e.g. one
minute (SIC! reagent, e.g. one minute,) ensure a better reproducibility
of the colour development.
Solutions with absorbances exceeding that of the highest concentra-
tion used for calibration can be diluted upto sixfold with the
reagent blank in order to obtain an on-scale reading. This reading,
however, is only an indicative within ± 10 % of the true absorbance
value.
6.3.Calibration
6.3.1.Calibration with a mixture of sulphur dioxide and air
Mixtures of sulphur dioxide and air are prepared according to ISO/
DIS 6349.
In order to prepare the calibration graph, which is a plot of absor-
bance versus sulphur dioxide concentration, at least four different
concentration levels of sulphur dioxide within the range prescribed
in section 2 are needed.
The sampling procedure and the analytical procedure as described
under 6.1 and 6.2, respectively, are applied to each of the calibration
gas mixtures. The absorbance values are plotted against the given
sulphur dioxide concentrations, and a calibration graph is prepared.
6.3.2.Calibration with sodium bisulphite solution
Pipet graduated amounts of the sodium bisulphite standard solution
(4.10), 0, 1 0, 2 0, 3 0, 4 0 and 5 0 ml, into a series of 25 ml volu-
metric flasks. Add sufficient sodium tetrachloromercurate solution
(4.2) to each flask to bring the volume to approximately 10 ml.
Then add the reagents as described in 6.2. Measure the absorbances
with distilled water in the reference cell. For higher precision it is
necessary to use a constant-temperature bath. The temperature at the
calibration should not differ from the temperature at the analysis by
more than ± 1 ºC.
Plot the absorbances of the solutions (as ordinates) against the micro-
grammes of sulphur dioxide calculated according to Annex B. A
linear relationshipis obtained. The intercep t with the vertical axis of
the line best fitting the points is usually within 0 02 absorbance units
of the blank (zero standard) reading if 10 mm cells are used. Eval-
uate the calibration factor (reciprocal of the slope of the line). This1980L0779 — EN — 01.01.1995 — 002.001 — 16
▼B
calibration factor can be used for calculating the results, provided
there are no radical changes in temperature or pH. At least one
control sample is recommended per series of determinations to ensure
the reliability of this factor.
7. EXPRESSION OF RESULTS
7.1.Calculation
Calculate the mass concentration of sulphur dioxide as follows:
SO2¼fas/C0ab ðÞ
V
where
SO2= mass concentration of sulphur dioxide in micrograms per
cubic metre
f = calibration factor (see 6.3.2)a
s= Absorbance of the sample solution
ab= absorbance of the blank
V = volume of air sampled, in cubic metres
Note
If the mass sulphur dioxide concentration at reference conditions
(25 ºC, 1 bar) is needed, the volume of air sampled, V, must be
replaced by the corresponding value of volume under reference
conditions, VR:
VR¼298 V p
273þT
where
p= barometric p ressure, in bar
T = Temperature of air sample, in ºC.
7.2.Detectionlimit
The detection limit of sulphur dioxide in 10 ml of TCM sampling
solution is between 0 2 and 1 0 µg (based on twice the standard
deviation). This corresponds to mass concentrations of sulphur
dioxide of between 7 and 33 µg/m3(0 02 — 0 011 ppm) in air
sample of 30 litres (e.g. one hour sampling at 0 5 l/min).
7.3.Precision andaccuracy
The precision and accuracy of the method has not yet been deter-
mined to any degree of certainty over a variety of concentrations of
sulphur dioxide, nor is the absolute collection efficiency known for
the wide variety of possible systems of sampling and testing.
The relative standard deviation of a comparable TCM-method for
replication has been found to be 17 µg/m3at a concentration of
1 000 µg/m3(1).
8. LITERATURE
(1) H. C. McKee, R. E. Childers, O. Saenz: Collaborative Study of
Reference Method for Determination of Sulphur Dioxide in the
Atmosphere (Pararosaniline Method). Contract CPA 70—40,
SwRI Project 21—2811. Environmental Protection Agency,
Research Triangle Park, N. C., September 1971.1980L0779 — EN — 01.01.1995 — 002.001 — 17
▼B
ANNEXA
ABSORBERMODELS
1980L0779 — EN — 01.01.1995 — 002.001 — 18
▼B
ANNEXB
STANDARDIZATION OF THE SODIUM BISULPHITE STOCK SOLU-
TION(4.9)
B.1.Reagents
B.1.1.Iodine solution, 0 05 moles/l
Stock solution
Weigh 12 7 g of iodine, I2, into a 250 ml beaker, add 40 g of potas-
sium iodide, KI, and 25 ml of water. Stir until all is dissolved and
transfer the solution quantitatively to a 1 litre volumetric flask. Dilute
to the mark with water.
B.1.2.Iodine working solution, approximately 0 005 moles/l
Dilute 50 ml of the iodine stock solution (B.1.1) to 500 ml with
water.
B.1.3.Starch indicator solution, 0 2 %
Triturate 0 4 g of soluble starch and 0 002 g of mercury (II) iodide,
HgI2(preservative), with a little water, and add the paste slowly to
200 ml of boiling water. Continue the boiling until the solution is
clear, cool and transfer to a glass stoppered bottle.
B.1.4.Sodium thiosulphate solution, approximately 0 1 moles/l
Dissolve 25 g of sodium thiosulphate, Na2S2O35H2O, in 1 litre of
freshly boiled and distilled water and add 01go fsodium carbonate
to the solution. Allow the solution to stand for one day before stan-
dardizing.
To standardize, weigh 1 5 g of potassium iodate, KIO3, primary stan-
dard grade, dried at 180 ºC into a 500 ml volumetric flask and dilute
to the mark with water. To a 500 ml iodine flask, pipet 50 ml of the
iodate solution. Add 2 g of potassium iodide and 10 ml of a 1: 10
dilution of concentrated hydrochloric acid. Stopper the flask. After
five minutes titrate with sodium thiosulphate solution to a pale
yellow colour. Add 5 ml of the starch indicator and complete the
titration. Calculate the molarity of the sodium thiosulphate solution,
M, as follows
M¼g KIO3/C2103/C201
ml sodium thiosulphate solution /C235 67
B.1.5.Sodium thiosulphate solution, approximately 0 01 moles/l
Dilute 50 0 ml of the sodium thiosulphate solution (B.1.4) to 500 ml
with water and mix. The solution is not stable and must be prepared
fresh on the day it is to be used by diluting the standardized sodium
thiosulphate solution (B.1.4).
B.2.Procedure
Add 25 ml of water to a 500 ml flask and pipet 50 ml of the iodine
solution (B 1.2) (SIC! (B.1.2))into the flask (here designated flask A/
blank). Pipet 25 ml of the sodium bisulphite stock solution (4.9) to a
second 500 ml flask and pipet 50 ml of iodine solution (B.1.2) into
this flask (here designated B/sample). Stopper the flasks and allow to
react for five minutes. By means of a burette containing sodium thio-
sulphate solution (B.1.5), titrate each flask in turn to a pale yellow
colour. Then add 5 ml of starch solution (B.1.3) and continue the
titration until the blue colour disappears. Calculate the concentration
of sulphur dioxide in the sodium bisulphite stock solution (4.9):
SO2èmg=ml ðÞ ¼A/C0BðÞ /C2 M/C2K
V
A = volume of sodium thiosulphate solution (B.1.5) required for
the titration of the blank, in millilitres.
B = volume of sodium thiosulphate solution (B.1.5) required for
the titration of the sample, in millilitres.
M = Molarity of the sodium thiosulphate solution (= 0 01).
K = micro equivalent weight for sulphur dioxide = 32030.1980L0779 — EN — 01.01.1995 — 002.001 — 19
▼B
V = sodium bisulphite stock solution taken, in millilitres.
The concentration of sulphur dioxide in the bisulphite standard solu-
tion (4.10) is found by dividing the result by 50.1980L0779 — EN — 01.01.1995 — 002.001 — 20
▼B
ANNEXC
REMOVALOFMERCURYFROMRESIDUALSOLUTIONS
This Annex describes a method for the removal of mercury from the
residual solutions received when using the absorbing solution (4.2).
C.1.Reagents
C.1.1. Sodium hydroxide solution, approximately 400 g of NaOH per litreC.1.2. Hydrogen peroxide, H
2O2, approximately 30 %, technical quality
C.1.3. Sodium sulphide, Na2S9 H2O technical quality
C.2.Procedure
Collect in a polyethylene container with a volume of about 50 litres
the residual solutions, whose mercury content is too high to allow
them to be discarded through the sink. When the collected volume
reaches approximately 40 litres, add in the following order, while
stirring by means of air bubbling through the solution, a volume of
sodium hydroxide solution (C.1.1) sufficient for neutralizing followed
by 400 ml more. Add 100 g of sodium sulphide (C.1.3) and after 10
minutes, slowly 400 ml of hydrogen peroxide solution (C.1.2).
Leave the mixture for 24 hours and then draw off and discard the
clear liquid. Transfer the residue to another container.1980L0779 — EN — 01.01.1995 — 002.001 — 21
▼B
ANNEXD
PROPERTIES ANDPURIFICATION OF PARAROSANILINE HYD RO-
CHLORIDE
D.1.Testforthepurityofthereagent
Dilute 1 ml of the PRA solution (4.4) to 100 ml with distilled water.
Transfer 5 ml to a 50 ml volumetric flask and add 5 ml of a 0 1 M
acetic acid-sodium acetate buffer solution. Dilute to the mark with
water and mix.
Wait one hour and then measure the absorbance of the solution in a
spectrophotometer at 540 nm in a 10 mm cell.
Calculate the concentration of pararosaniline (PRA) as follows:
% PRA ¼absorbance /C2K
100 mg
where:
K = 21300.
If the purity of the pararosaniline is below 95 %, the reagent must be
purified by one of the procedures described in D.2 and D.3.
D.2.Purification byextraction
In a 250 ml separatory funnel, equilibrate 100 ml each of 1—butanol
and 1 M HCl. Weigh 0 1 g of pararosaniline hydrochloride (PRA)
into a beaker. Add 50 ml of the equilibrated acid and let stand for
several minutes. Add 50 ml of the equilibrated 1—butanol to a
125 ml separatory funnel. Transfer the acid solution containing the
dye to the funnel and extract. The violet impurity will transfer to
the organic phase. Transfer the lower (aqueous) phase into another
separatory funnel and add 20 ml portions of 1—butanol. This is
usually sufficient to remove almost all the violet impurity which
contributes to the reagent blank. If the violet impurity still appears
in the 1—butanol phase after five extractions, discard this batch of
dye.
After the final extraction, filter the aqueous phase through a cotton
plug into a 50 ml volumetric flask arid bring to volume with 1 M
HCl. This stock reagent will be yellowish red.
Note
Certain batches of 1—butanol contain oxidants that create a sulphur
dioxide demand. Check by shaking 20 ml of 1—butanol with 5 ml of
a 15 % potassium-iodide solution. If a yellow colour appears in the
alcohol phase, redistill the 1—butanol from silver oxide.
D.3.Purification byrecrystal1ization
Dissolve 1 g of pararosaniline hydrochloride in 250 ml of 2 5 M
hydrochloric acid. Let the solution stand for two hours at room
temperature. After filtration, the pararosaniline is reprecipitated by
addition of a small excess of 2 5 M sodium hydroxide solution.
Collect the precipitate on a filter funnel (porosity 3). The filtrate
should be colourless. Wash the precipitate with distilled water to
remove excess sodium hydroxide and the sodium chloride formed.
Dissolve the precipitate in 70 ml of methanol heated to boiling and
finally add 300 ml of water at 80 ºC. Let the solution stand at room
temperature. The pararosaniline reprecipitates slowly. The yield of
recrystallization is about 64 %. Pararosaniline gets dark between
200 and 205 ºC and decomposes at 285 ºC.
Literature
H. G. C. King and U. G. Pruden: The determination of sulphur
dioxide with rosaline dyes. Analyst 94, 43—48 (1969).1980L0779 — EN — 01.01.1995 — 002.001 — 22