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Guidelines for Air Emission Regulation

3. Recommended mass flow limits, emission limit values, and C-values

3.1 Terms, definitions, and explanations

The following is a description of the various types of limit values used in these Guidelines.

1. The mass flow limit is a limit used to determine when an emission must be limited. The mass flow is the measure of air pollution from installations prior to purification or abatement. Where the mass flow is greater than the mass flow limit and where the emission concentration is greater than the emission limit value, purification or abatement should be carried out, or production adjusted to comply with the emission limit value. Note that the mass flow limit is used as a criterion for when it may be relevant to limit emissions from installations. It does not in itself constitute a limit value that must be complied with.
2. The emission limit value is a limit value for the concentration of a given substance in the air emitted by installations through an outlet. Measurement is carried out for a period of time for control purposes, and only when the installation is in operation.
3. The AMS inspection limit is a limit for when an Automatic Measuring System must be installed, or when random testing must be carried out, as specified in chapter 5.
4. The C-value²⁶ is the total maximum permissible contribution from a single installation of one pollutant to the surrounding air, i.e. the ground-level concentration. The C-value must always be complied with when calculating according to the rules in these Guidelines.

Detailed explanation

3.1.1 Mass flow

The mass flow is the substance amount per time unit that would constitute the total emission of a given substance or substance class from an installation if no limitation of emissions were carried out. This means that the mass flow must be determined before the actual purification or abatement plant, but after the processing plant. The mass flow is measured as a mean value on the basis of a single working shift (7 hours).

If a mass flow limit is exceeded and if the emission concentration is greater than the emission limit value, emissions should be limited so that the specified emission limit value is complied with from each outlet.

No requirements regarding limitation of emissions should be made for installations that are only operated for relatively few hours per year, even if such installations exceed the mass flow limit and emission limit value.

Figure 1
shows how mass flow is determined.

Example of calculation of mass flow

3.1.2 Emission and reference condition

Emission means the emission into the atmosphere of polluting substances in solid, fluid, or gaseous form. The limit values also apply to aerosols, which are classified as dust within this context.

Figure 2
shows where emission to the atmosphere occurs from a single plant with a single outlet. See, however, figure 3.

Examples of other reference conditions

The reference condition should always be stated in the approval in connection with the emission requirements.

Usually, the polluted air is led from the plant to the stack through a flue duct as shown in Figure 3. The emission limit values apply to the polluted air in the flue duct.

Look here!

Figure 3
Example of an installation with emissions from different plants, showing where emission inspection is carried out.

Individual installations should not be allowed to comply with the emission limit values by means of "dilution", i.e. by using inordinately large quantities or air, e.g. through dilutions using indoor air or outlet air from other processes within the installation.

3.1.3 Ground-level concentration

This means the presence in outdoor air of solid, liquid, or gaseous pollutants – usually at a height of approximately 1.5 m above ground level. Where people live or stay in taller buildings (multi-storey homes, office buildings, factory premises, etc.), the ground-level concentration should be calculated at a height relevant to the building in question.

3.1.4 The C-value

The total maximum approved contribution from an installation to the concentration of a pollutant in the air at ground level is the "C-value". The C-value must be complied with everywhere outside the boundaries of the installation, regardless of the quantities emitted and the location of the installation.

The C-value must be compared to the results of an OML-model calculation. Such a calculation should be conducted for any outlet emitting pollutants into the air. The C-value must be complied with when taking the total emission from the installation into account, cf. chapter 4.

In these OML calculations, hourly average concentrations are computed. They may not exceed the C-value for more than 1 per cent of the time, ie. for more than 7 hours during a single month.

Figure 4
Drawing illustrating a ground-level concentration contribution

The size of the C-value, measured as mg/m³ air for each substance is determined by the Danish EPA in accordance with procedures and principles for determining limit values for chemical substances.

The C-values apply regardless of the background concentration.

The C-value must not be confused with air quality requirements as specified in section 14 of the Danish Environmental Protection Act or in the method to measure such values. Air quality requirements are currently specified in:

	Statutory Order No. 836 of 10 December 1986 on limit values for the atmospheric content of sulphur dioxide and suspended particulates.
	Statutory Order No. 119 0f 12 March 1987 on limit values for the atmospheric content of nitrogen dioxides.

Also of note in this connection are Council Directive 1999/30/EC of 22 April 1999 relating to limit values for sulphur dioxide, nitrogen dioxide and oxides of nitrogen, particulate matter and lead in ambient air, and European Parliament and Council Directive 2000/69/EC of 16 November 2000 relating to limit values for benzene and carbon monoxide in ambient air. These directives must be implemented in Denmark no later than 19 July 2001 and 13 December 2002, respectively.

The Danish EPA will assist the authorities by determining C-values for substances where no C-value has previously been set. For more information, please contact the Danish EPA.

The C-values stipulated are based upon the Danish EPA’s knowledge of the relevant substances at the time of publication.

The C-values for dust apply only to particles with a diameter of less than 10 m m.

For wood dust, however, the C-value applies to all particle sizes.

3.1.5 Relationship between mass flow limits, emission limit values, and C-values

3.1.5.1 Mass flow limits

The mass flow is a measure of the potential pollution of an installation.

3.1.5.1.1 Mass flow is smaller than the mass flow limit

If the mass flow for the relevant substance is smaller than the mass flow limit, no purification or abatement or adjustments to production in order to reduce emissions must be carried out. The emission should be determined by means of calculations, measurement, or similar. Outlets should be of such a height that the C-value can be complied with.

A dispersion calculation for the outlet, using the OML model²⁸ is then prepared to determine whether the C-value is complied with. This calculation is carried out with an emission corresponding to the emission limit value at the maximum flow rate. Where no emission limit value has been specified, the maximum hourly emission and the maximum flow rate are used instead. See also section 4.3.

Example where mass flow is smaller than the mass flow limit

3.1.5.1.2 Small emissions

For small emissions where the dispersion coefficient – i.e. the ratio between the emission measured in mg/sec. and the C-value in mg/m³ – is smaller than 250 m³/sec., there is no need to carry out a dispersion calculation. In this case, the outlet should be at least 1 m above roof level³⁰ and the air stream directed upwards in order to ensure compliance with the C-value, see chapter 4 on the calculation of outlet heights.

3.1.5.1.3 Mass flow is greater than the mass flow limit

If the mass flow is greater than the mass flow limit for a given substance, the emission limit value must be complied with. This means that where the emission concentration is greater than the emission limit value, purification or abatement should be carried out, or production at the installation should be adjusted to achieve compliance with the emission limit value. The outlet must be established in such a manner and with sufficient height to ensure that the C-value is complied with.

In order to determine whether the C-value is complied with, a dispersion calculation using the OML model must be carried out for the outlet. The emission limit value and maximum flow rate must be used in this calculation.

Example where the mass flow is greater than the mass flow limit

An example where mass flow is greater than the AMS limit can be found in chapter 5.

3.1.6 Classification of types of substance

For the purpose of these Guidelines, the pollutants are divided into two groups. These groups are in turn divided into substance groups and classes.

For more detailed information on groups, substance groups, and classes, please see the C-value Guidelines.

Chart illustrating this classification

3.1.7 Simultaneous emission of several substances. Average value C_r ³¹

Where an installation emits several substances at the same time, it is very difficult to assess the total health impact associated with exposure to the substances in question. In principle, a combination of substances in a mixture may affect each other’s mode of operation and effects in the following three ways:

1. the effects and mode of operation are independent of each other,
2. the substances mutually affect each other’s effects, either reinforcing or weakening each other,
3. the substances have identical effects and mode of operation.

Re. 1.

Where the substances act independently of each other, the C-values for each substance must be complied with separately. The outlet height must be determined on the basis of the substance with the greatest dispersion coefficient.

Re. 2.

If the substances affect each other’s effects and mode of operation, there is a risk that in certain mixtures, such substances may augment each other’s effects. However, animal tests indicate that such effects do not manifest themselves unless each substance is present in a concentration which would in itself entail effects, i.e. when a substance is present in a concentrations greater than its zero-effect concentration.

In this connection, a C-value for an individual substance will typically be determined on the basis of data concerning the zero-effect concentration (animal or human test). The C-value will be set at a level equal to or lower than this zero-effect level, so that no effects are anticipated at the C-value. Compliance with the individual C-values of such substances is thus assumed to ensure that there will be no interaction between the substances, including reinforcing effects. Accordingly, the outlet height must be determined on the basis of the substance with the largest dispersion coefficient.

Re. 3.

Where the substances have identical effects and mode of operation, this constitutes a valid reason to total the exposure contributions for the relevant substances.

In practice, C-values for substances with identical effects should be added up when:

	such substances are homologous (i.e. substances from the same chemical substance group, e.g. alcohols, ketones, ethers, etc.), and
	such substances belong to the same substance group within these Guidelines (Section 3.1.6), and
	such substances have health-related C-values (i.e. they are not marked L).

If all three of the above points are complied with, the outlet calculation should be made on the basis of the total substance emission. This may be done by determining the resulting C_r value (Equation 1). This C_r value represents a total C-value for the mixture, calculated on the basis of the source strength and C-values of the individual substances.

The procedure involving the use of a C_r value is correct when the substances are emitted from the same outlet, but it is excessively conservative if emissions come from several different outlets placed at some distance from each other, or of different heights. In such cases, an alternative method may be applied, as described in Section 4.4.2.2.

C_r is determined by means of Equation 1:

Equation 1

Please note that a C-value related to noxiousness, and therefore bearing an L label, cannot be converted into a health-related C-value.

3.1.8 C-value by intermittent³² operation

The C-value may be made less rigid for installations emitting Group 1 substances and sawdust or a quartz from Group 2 if the emissions from such installations are intermittent. If the intermittent operation is spread evenly throughout day and night and the annual cycle, a C-value for the intermittent operation, designated as C_i, may be used. This value is determined by means of Equation 2:

Equation 2

If the operation is not evenly distributed, Equation 3 is used instead:

Equation 3

If the C-value is relaxed in accordance with these regulations, the installation’s approved operation time must be specified in the requirements applying to the installation.

3.2 Mass flow limits and emission limit values

3.2.1 Introduction

Pollutants are divided into two groups (see section 3.1.6 on classification of substances).

Examples of Group 1 substances are listed in table 2 and table 2a.

Group 2 is divided into several substance groups. Some substance groups are divided into classes.

A recommended mass flow limit and a recommended emission limit value are indicated for each substance or substance class.

3.2.2 Group 1 substances

Group 1 includes chemical substances currently known to be especially harmful to health or the environment.

Various dangerous chemical substances are assigned to Group 1 on the basis of one of the following: their toxicity, their long-term impact on human health, and/or their unacceptable impact on nature.

The substances within Group 1 are divided into 2 classes (I and II) on the basis of the C-value.

Chart illustrating the division into classes

Table 2 features examples of particularly dangerous substances used in large quantities in Denmark (i.e. more than 1 tonne a year).

Table 2a features examples of particularly dangerous substances used in quantities smaller than 1 tonne per year in Denmark. C-values have been determined for these substances, depending on the risk class in which a given substance is included according to the provisions on labelling.

Basically, very potent biologically active substances are regarded as Group 1 substances. The final classification of these substances, and their C-values is carried out by the Danish EPA on the basis of a specific assessment of the toxicological and eco-toxicological documentation available.

3.2.3 Limiting emissions, Group 1 substances

3.2.3.1 Emissions of dust, Group 1 substances

For emissions of dust, pre-purification or abatement should normally be carried out, using filtering processes with a relatively low filter surface load. Subsequently, the filtered air should be purified in an absolute filter with a retention degree of at least 99.97 per cent for particles of 0.3 µm.

This purification or abatement technique means that emissions can be reduced to concentrations well below 0.01 mg/normal m³.

Please see chapter 5 regarding the inspection of filters.

3.2.3.2 Emissions of flammable substances, Group 1 substances

For emissions of flammable substances, purification or abatement should normally be carried out by means of thermal combustion or other, equally effective methods. Where necessary, this may be combined with absorption or adsorption methods.

By these means, such emissions can normally be brought to concentrations less than 0.1 mg/normal m³.

The installation is responsible for deciding which method to use to limit emissions.

The installation should be able to choose freely among other purification or abatement methods, as long as such methods are of a quality corresponding to that of the methods specified in these Guidelines.

The effectiveness of the purification or abatement methods chosen should be checked using appropriate means. See also chapter 5.

3.2.3.3 If neither absolute filtering nor combustion can be used

If neither absolute filtering nor combustion can be used, the mass flow limits and emission limit values specified in table 1 should be used instead.

Table 1
Mass flow limits and emission limit values for Group 1 substances when emission limitation by means of absolute filtering or combustion is impossible.

Some substances are, however, so unsafe that particularly low emission limit values should be used.

These substances are specified in sections 3.2.3.4 – 3.2.3.8 below.

3.2.3.4 PCB

PCB is subject to an emission limit value³³ of 0.0001 mg/normal m³.

3.2.3.5 Dioxins

Emissions of dioxins (polychlorinated dibenzodioxins and polychlorinated dibenzofuranes) should be limited as much as possible.

3.2.3.5.1 The CEN method

Emission limit values of dioxins should apply to measurements carried out using the CEN measurement method and the international toxicity factors that have now been implemented in Denmark. The CEN method is the measurement method given in the EU Waste Incineration Directive. Please refer to CEN standards EN 1948-1, EN 1948-2, and EN 1948-3.

3.2.3.5.2 Incineration of non-hazardous waste

Experience from waste-incineration plants shows that it is technically and financially feasible to limit emissions of dioxins to less than 0.1 ng I-TEQ/normal m³ air (11 per cent O₂)³⁴. This limit value is included in the protocol on limitation of persistent, organic compounds under the UN convention on Long-Range Transboundary Air Pollution, as well as in the new EU directive relating to waste incineration.

3.2.3.5.3 Incineration of dangerous waste

The Statutory Order on incineration of hazardous waste³⁵ sets an emission limit value for dioxins of 0.1 ng I-TEQ/normal m³(11% O₂). The new EU directive on waste incineration also extends in scope to incineration of dangerous waste.

3.2.3.5.4 Industrial installations

Steps should be taken to limit dioxin emissions from industrial installations if the annual mass flow of dioxins is greater than 0.01 g I-TEQ.

The emission limit value should be set at 0.1 ng I-TEQ/normal m³. In some cases, technical and financial considerations may render it necessary to accept an emission limit value of 0.2 ng I-TEQ/normal m³ for certain installation types.

3.2.3.6 Asbestos

Statutory Order No. 792 of 15 December 1988 on limitations of emissions of asbestos to air from industrial plants applies to emissions of asbestos³⁶.

3.2.3.7 Formaldehyde

An emission limit value of 5 mg/normal m³ at a mass flow greater than 25 g/hr applies to emissions of formaldehyde.

An emission limit value of 20 mg/normal m³ at a mass flow greater than 100 g/hr applies to rockwool and glasswool factories, and wood/furniture factories.

3.2.3.8 Polyaromatic hydrocarbons, PAH

A mass flow limit at 25 mg benzo[a]pyrene equivalents/hr applies to emissions of PAHs. The emission limit value for PAH substances is 0.005 mg benzo[a]pyrene equivalents/normal m³.

The list below of PAH substances specifies the PAH substances included in this requirement and how each PAH compound is weighted when calculating benzo[a]pyrene equivalents.

Overview of equivalence coefficients for PAH

The C-value for PAH compounds is set at 2.5 ng benzo[a]pyrene equivalents/ m³, by adding up all the contributions from the substances listed, measured as benzo[a]pyrene equivalents. The basis for this is that all of these substances are considered carcinogenic or are deemed to promote the carcinogenic process.

The PAH substances listed here were originally selected by the US EPA and are now widely used internationally in connection with characterisation and assessment of PAH mixtures.

The Danish Veterinary and Food Administration, Institute for Food Safety and Toxicology has prepared the equivalence coefficients in connection with efforts to update the existing equivalence systems developed for PAH substances.

For further information on the setting of emission limit values of PAH to air, please see the background document (June 2000) at the homepage of the Danish EPA reference laboratory.

http://www.dk-teknik.dk/ref-lab/Rapporter/tekniske-undersogelser.asp.

3.2.4 Examples of Group 1 substances

Table 2
Examples of chemical substances assigned to Group 1 that are used in significant quantities (greater than 1 tonne) in Denmark, and the C-value of such substances. See also the current Guidelines on C-values.

Table 2a
Examples of chemical substances belonging to Group 1 that are used in less significant quantities in Denmark, with C-value for these substances. See also the current Guidelines on C-values.

Example of approval for an installation producing proteolytic enzymes

3.2.5 Group 2

Group 2 encompasses substances that are harmful to human health or the environment other than those included in Group 1. Group 2 substances are divided into 6 substance groups, and some substance groups are sub-divided into classes.

1. Dangerous types of inorganic dust (Classes I, II, and III)
2. NO_X
3. SO₂
4. Vaporous or gaseous inorganic substances (Classes I, II, III, and IV) (except NO_x and SO₂)
5. Organic substances (Classes I, II, and III)
6. Other dust

The division into classes is based partly on knowledge of the health risk/harmful impact on the environment associated with a given substance, and partly on the technical and financial feasibility of emission limitation.

The following tables specify examples of mass flow limits, emission limit values, and C-values.

3.2.5.1 Dangerous types of inorganic dust

Table 3 includes examples of emission limit values, mass flow limits, and C-values for dangerous types of inorganic dust.

If a given outlet emits several substances within this substance group, and these substances belong to the same class, the emission limit value of this class applies to the sum of the concentrations of the substances emitted.

If a given outlet emits several substances that belong to several different classes, the emission limit value for each individual class should be complied with, and the total emission concentrations should not exceed 5 mg/normal m³.

Table 3
Examples of mass flow limits, emission limit values, and C-values for dangerous types of inorganic dust. The C-values apply to dust with a diameter of less than 10 m m. See also the current Guidelines on C-values.

*) Small amounts of the emission of Hg, Pb, etc., may occur in gas phase, but are included as dust.

3.2.5.2 NO_x

NO_x is a designation for the total sum of the following nitrogen oxides: nitrogen oxide, NO, and nitrogen dioxide, NO₂.

Table 4
Mass-flow limit, limit value for emission, and C-value for installations emitting NO_X ³⁷

The mass flow limit and the emission limit value apply to the emitted quantities of NO_X, calculated as NO₂.

The C-value applies to the part of the amount of NO_X that is emitted as NO₂.

The outlet height is calculated by counting all NO_X as NO₂ if no information on the distribution of the NO_x contents is available.

If less than half of a given amount of NO_X is NO₂, calculations should always be made on the assumption that at least half of the NO_X emitted is NO₂.

Example of conversion of NO_X to NO₂

The emission limit value for NO_X does not apply to cement kilns, rockwool and glasswool factories, moler works, leca works, tile works, or lime works. Emission limit values for

NO_X for such installations are set on the basis of BAT notes. Generally speaking, however, an emission limit value of 500 mg/normal m³ measured as NO₂ should be aimed for.

3.2.5.3 SO₂

Table 5
Mass-flow limit, emission limit value and C-value for installations emitting SO₂³⁸

The emission limit value for SO₂ must not, however, be used for installations with process plants using fuels and where there is direct contact between the flue gas and the product being manufactured if the relevant emission of SO₂ does not exceed the emission from any fuel used legally, irrespective of whether this leads to emission concentrations greater than what corresponds to 400 mg/normal m³ at 10 per cent O₂.

See also Statutory Order No. 901 of 31 October 1994 on the limitation of sulphur content in fuels for heating and transport, and Statutory Order No. 532 of 25 May 2001 on the limitation of sulphur content in certain liquid and solid fuels.

Special conditions apply to lime works, moler works, leca works, rockwool plants, and tile works, as the SO₂ emitted comes largely from the raw materials used. In these cases, a specific assessment must be carried out to determine the emission limit.

3.2.5.4 Other vaporous or gaseous inorganic substances

Table 6 presents examples of emission limit values, mass flow limits, and C-values for installations that emit vaporous or gaseous inorganic substances other than NO_X and SO₂.

Table 6
Examples of mass flow limits, emission limit values, and C-values for installations that emit vaporous or gaseous inorganic substances, except for NO_X and SO₂. See also the current guidelines on C-values for other substances.

3.2.5.5 Organic substances

Organic substances are divided into three classes, usually in accordance with the criteria outlined below:

Outline of the classification of organic substances

Mass-flow limits and emission limit values for organic substances can be found in table 7.

Table 8 features examples of C-values and classifications for organic substances.

If an installation emits substances that belong to several classes, and if the mass flow for all substances is > 6,250 g/hr, the emission limit value for each class should be complied with, and the sum of the emission concentrations should not exceed 300 mg/normal m³.

Table 7
Mass-flow limits and emission limit values for installations that emit organic substances

3.2.5.5.1 Thinner mixes

The definition of thinner mixes has been changed as a consequence of a review of the use and composition of thinner mixes.

A new C-value of 0.15 mg/m³ has been set for thinner mixes. Thinner mixes are still classified as belonging to Group 2, organic substances, class III.

Hereafter, "thinner mixes" include organic solvents in paint products used in paint shops (iron, metal, plastic), at car paint shops, in furniture manufacture, etc.

Thinner mixes are defined as a mixture of at least three organic solvents – or at least two organic solvents for water-based paints – of which the relative proportion of a single organic solvent does not exceed 80 per cent by weight.

If the mix contains three or more organic solvents, three of these organic solvents must each account for more than 2 per cent by weight³⁹. None of the organic solvents included in the mix may be substances belonging to Group 1 or Group 2, class I.

The C-value of 0.15 mg/m³ has been set on the basis of odour thresholds set for a representative selection of the thinner mixes currently available. For emissions of thinner mixes, requirements on outlet heights are based exclusively on the C-value. This means that there is no need to supplement this by requirements based on the concentration of substance odorants (LE/m³) in the surroundings of outlets emitting thinner mixes.

The C-value of 0.15 mg/m³ applies to new installations. This includes the establishment of new paint shops at existing installations that have not previously included a paint shop. As a general rule, the 0.15 mg/m³ C-value should also be complied with in connection with extensions to existing paint shops.

For existing paint shops where the outlets have been dimensioned on the basis of a C-value of 0.3 mg/m³, orders to increase outlet heights, etc., with a view to ensuring compliance with a 0.15 mg/m³ C-value should only be given if there are significant odour problems.

Detailed explanation

3.2.5.6 The VOC Statutory Order

On 11 March 1999, the European Council adopted Directive 1999/13/EC on the limitation of emissions of volatile organic compounds due to the use of organic solvents in certain activities and installations – (The VOC Directive). In Denmark, the VOC Directive will be implemented by means of a Statutory Order on limitations of emissions of volatile organic compounds from the use of organic solvents in certain installations and activities (the VOC Statutory Order). This Statutory Order applies to installations where one or more of the industrial processes and activities specified in appendix 1 are carried out and where the threshold values for use of organic solvents specified in appendix 2 A are exceeded.

As a point of departure, the VOC Statutory Order is exhaustively regulates emissions of volatile organic compounds from installations. It should, however, be observed whether an installation emits Group 1 substances which do not fall within the scope of the special provisions laid down in the VOC Statutory Order on substitution and limitation of emissions of certain substances that are particularly harmful to health, i.e. substances with the R phrases R45, R46, R49, R60 and R61. It should also be observed whether any emissions of organic substances that belong to Group 2, organic substances, class I, and which have a health-related C-value, are emitted from the installation. In these cases, the recommendations in these Guidelines should be followed. Such situations are expected to be rare, as installations often use thinner mixes.

3.2.5.6.1 Phenol

Phenol is a class I substance with an emission limit value of 5 mg/normal m³.

For rockwool and glasswool factories, special technical production conditions may mean that a higher emission limit value must be accepted, e.g. up to 20 mg/normal m³.

Table 8
Examples of classes and C-values for organic substances that belong to Group 2. The C-values are stated in mg/m³.
Substances marked "L" have an odour-related C-value (for such substances, the C-value is lower (by a factor of 10 or more) than the value that would be set if the assessment was purely health-related). See also the current guidelines on C-values for other substances.

3.2.5.7 Other dusts

General

The mass flow limits, emission limit values, and C-values specified in tables 9 and 9a apply to installations emitting types of dust that do not belong under any of the other sections in these Guidelines. Emission limit values for agricultural companies appear in the Danish EPA Guidelines No. 4/1991, Retningslinier for grovvarebranchen ("Guidelines for produce and foodstuffs companies").

3.2.5.7.1 Dry dusts

Table 9
Mass-flow limits, emission limits, and C-values for other dust
The C-value applies to dust with a diameter < 10 m m.

3.2.5.7.2 Wet dust

For a number of processes involving wet dust, reducing the relevant emission to a level below the specified emission limit values can be very problematic, either because the technology necessary to do so simply does not exist, or it is financially unfeasible for the relevant type of installation. For installations with mass flows greater than 0.5 kg/hr, a higher emission limit value for total dust emissions may be set within the framework specified below.

Table 9a
Emission limits for other dust, wet dust

The emission limit values specified in table 9a must apply where there is a valid reason for emissions not being brought below the normal emission limit.

The C-value for particles with a diameter of less than 10 mm is 0.08 mg/m³.

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