Technical Guidance Note (Monitoring) M16. Monitoring volatile organic compounds in stack gas emissions. Environment Agency Version 2

Transcription

1 Technical Guidance Note (Monitoring) M16 Monitoring volatile organic compounds in stack gas emissions Environment Agency Version 2 September 2009

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3 Foreword Purpose This Technical Guidance Note (TGN) is one of a series providing guidance to our staff, monitoring contractors, industry and other parties interested in emissions and regulatory monitoring. This note provides information on the sampling, monitoring and measuring of volatile organic compounds (VOCs) to air from industrial processes. This TGN does not cover methods for monitoring VOCs in ambient air. These are covered in a separate TGN, M9 Monitoring Methods for Ambient Air. Feedback Any comments or suggested improvements to this TGN should be ed to Rupert Standring at rupert.standring@environment-agency.gov.uk.

4 Status of this document M16: Monitoring volatile organic compounds in stack gas emissions This Guidance Note may be subject to review and amendment following publication. The latest version of this note is available from Record of changes Version Date Change 1 July 05-2 September 09 Major revision

5 Contents 1. Introduction Industrial sources of VOC emissions Classification of VOCs Regulatory requirements Specifying the concentration of VOCs Pollution Prevention and Control Regulations Environmental Permitting Regulations Waste Incineration Directive (WID) The Solvent Directive Techniques for monitoring TOCs Flame ionisation detectors Electron capture detection Catalytic oxidation Techniques for monitoring individual VOCs Sorbent tube followed by gas chromatography (GC) separation Non-dispersive infrared (NDIR) detection Fourier transform infrared (FTIR) Differential optical absorption spectrometry (DOAS) Mass Spectroscopy Hierarchy of monitoring standards European periodic standard reference methods BS EN FID method for low concentrations of TOC BS EN FID method for high concentrations of TOC BS EN charcoal tube method for individual VOCs CEMs References Glossary of terms and abbreviations...12 Appendix 1. Toxic VOCs...13

6 1. Introduction The term volatile organic compounds (VOCs) covers an enormous range of classes of chemicals, such as aliphatic, aromatic and halogenated hydrocarbons, aldehydes, ketones, esters, ethers, alcohols, acids and amines. It is recognised that certain VOCs are involved in the generation of photochemical oxidants, in particular ozone, in the troposphere. VOCs are an important class of pollutants commonly found in the atmosphere at ground level in urban and industrial centres. There are various definitions of VOCs. We have adopted the United Nations Economic Council for Europe (UNECE) definition, which defines a VOC as any organic compound which is emitted from non-natural processes and has a photochemical ozone creation potential (POCP). We interpret this as any organic compound released to the atmosphere from an operator s plant or process, excluding releases of naturally produced VOCs from within the plant boundary and methane. A large number of industries emit VOCs. These emissions have two main types of impact: a direct impact, where some VOCs can have direct effects on human health; indirect impacts through the creation of photochemical pollutants such as ozone, which is a secondary pollutant. Ozone has direct effects on human health, plants and materials. It is also a greenhouse gas. A variety of primary and secondary legislation has been introduced to impose limits on industrial VOC emissions. We ensure industries comply with these legislative requirements. Therefore, operators of regulated industries need to assure us that they are carrying out the following: determining the types of VOCs which they emit, together with data on VOC concentrations, dispersion routes and fates; reporting which categories of VOCs are emitted, taking into account factors such as the photochemical ozone creation potential; using appropriate monitoring to demonstrate that they are controlling their emissions within the required limits. 2. Industrial sources of VOC emissions VOCs are emitted by wide range of different industries. For example emissions can arise through the evaporation of organic compounds used as solvents; from processes which use oil or organic chemicals; through incomplete combustion of fuels; and through biological degradation of organic matter as in fermentation processes. Emissions also occur over a wide range of concentrations. For example, stack emissions of solvents from coating processes can range between less than 20 mg/m 3 up to several thousand g/m 3. M16, Version 2, September 2009 Page 1 of 13

7 3. Classification of VOCs VOCs are categorised according to their potential environmental harmfulness, so that an assessment can be made of the degree of control needed on their release from a process. Specific industry sector guidance notes provide advice on appropriate abatement and achievable levels of control of releases according to the category of VOC concerned. Substances such as benzene, vinyl chloride and 1,2 dichloroethane pose serious health risks to humans and are regarded as highly harmful. Emissions of these compounds must either be prevented or minimised by setting very low emission limits in permits. Appendix 1 shows a selection of the most toxic VOCs. Other VOCs carry a lower, albeit significant health risk. Such VOCs may also contribute substantially to the creation of photochemical ozone, depletion of stratospheric ozone or global warming. These are considered as having a medium degree of harmfulness. This category includes the substances listed in the Montreal Protocol. Examples include acetaldehyde, aniline, benzyl chloride, carbon tetrachloride, chlorofluorocarbons (CFCs), ethyl acrylate, halons, maleic anhydride, 1,1,1-trichloroethane, trichloroethylene and trichlorotoluene. The remaining majority of VOCs are considered as having a lower degree of harmfulness. However, these VOCs are also regulated substances whose releases must be prevented or minimised. Examples include butane and ethyl acetate. The research report The Categorisation of Volatile Organic Compounds 1 provides a method of categorisation, information on the properties of some 500 VOCs and a summary table of resulting categorisations. When categorising VOCs, the first step is to search the summary tables in The Categorisation of Volatile Organic Compounds. If the VOC is not included, then the method and decision tree given in the above report can be used to determine the appropriate category. 4. Regulatory requirements 4.1 Specifying the concentration of VOCs There are three commonly used ways of stating the concentrations of VOCs: as total organic carbon (TOC), which is the concentration of carbon in the gas stream, and usually expressed in milligrams per cubic metre (mg/m 3 ); as TOC expressed in terms of the equivalent concentration of a specified VOC, such as toluene; the sum of the concentrations of specific, individual VOCs in a sample. M16, Version 2, September 2009 Page 2 of 13

8 Both speciated and TOC monitoring is often required when characterising industrial emissions. The targeted VOCs to be monitored should take into account factors such as their POCPs, toxicities and concentrations. The limits set by us are expressed in terms of concentration. They depend upon the VOCs being emitted or the abatement technology being used. Emission limits are sector specific, and typical examples can range from 5 mg/m 3 for specific VOCs such as formaldehyde, 10 mg/m 3 of TOC from waste incineration, or 50 mg/m 3 of TOC from solvent-using processes. 4.2 Pollution Prevention and Control Regulations 2000 The Pollution Prevention and Control (PPC) Regulations created the UK national framework for implementing the European Community directive on Integrated Pollution Prevention and Control 3 (IPPC). 4.3 Environmental Permitting Regulations The Environmental Permitting (England and Wales) Regulations came into force in April The new regulations replaced Pollution Prevention Control (PPC) and Waste Management Licensing (WML) regimes in England and Wales. All PPC Permits and WML automatically became environmental permits. 4.4 Waste Incineration Directive (WID) The Directive on the incineration of waste 4 (2000/76/EC) specifies limit values for several determinands, which include gaseous organic vapours measured as total organic carbon (TOC). The limit value for TOC is 10 mg/m 3 expressed as a daily average. 4.5 The Solvent Directive The Solvent Directive 5 (1999/13/EC) aims at reducing emissions of organic solvents within certain processes and industrial installations. VOCs are targeted in this Directive because organic solvents are commonly used in adhesives, inks, paints and cleaning agents, such as degreasers. Solvents are also used extensively to clean surfaces before coating and to remove greases and oils, such as during manufacturing. Specialist applications such as pharmaceuticals manufacturing, vegetable-oil extraction from seeds, and the impregnation of wood with preservatives also make use of solvents. 5. Techniques for monitoring TOCs 5.1 Flame ionisation detectors Flame ionisation detector (FID) techniques work by a gas being passed into a measurement chamber, which uses a flame to create ions from the VOCs. More specifically, FID analysers make use of the chemi-ionisation of organically bound M16, Version 2, September 2009 Page 3 of 13

9 carbon atoms in a hydrogen flame (Figure 1) to provide measurements. The measurement cell contains a pair of electrodes, which the instrument applies a current between. If there are ions present in the cell, then a current can pass between the electrodes. The ionisation current measured by the FID depends upon the number of carbon-hydrogen bonds of the organic compounds burning in the fuel gas flame and the ability with which these compounds ionise. The more ions present in the cell, the greater the current. As the abundance of ions within the cell depends on the concentration of the gas, then FID provides an effective means of measuring the concentrations of gases. Figure 1 Generic design of a flame ionisation detector HEATED LINE & PUMP SUPPLY VOCS + METHANE PUMP HEATED BYPASS VALVE NON-METHANE VOC CONVERTER FLAME RESTRICTOR AIR CATALYTIC AIR CLEANER HYDROGEN/HELIUM SUPPLY ELECTRO- METER FLAME ELECTRODE HEATED FID UNIT FIDs do not differentiate between different compounds since they respond to carbonhydrogen bonds, rather than specific compounds. They also have low to no responses to chlorinated compounds and reduced sulphur compounds. Therefore, a user must know how a FID responds to different VOCs. The differences between these responses can be compared by means of a relative response factor, which is based on the ratio of the responses between different VOCs and a principal VOC used as a calibrant. The main strength of the FID is that it is a useful instrument for measuring total carbon in a gas stream. As a general rule, the response of a FID is mostly influenced by the number of carbon atoms in a sample. Furthermore, FIDs only respond to gaseous or vapour phase molecules which contain carbon-hydrogen bonds. Table 1 shows the relative responses of FIDs to organic compounds. M16, Version 2, September 2009 Page 4 of 13

10 Table 1: Responsiveness of FIDs CLASS OF COMPOUND EXAMPLE SENSITIVITY Aromatics Benzene, toluene, xylene Excellent Alkanes Butane Excellent Alkenes/Alkynes Ethene/Ethyne Excellent Chlorinated compounds Dichloromethane Very poor Ketones MEK Good Alcohols Butyl alcohol Good Aldehydes Formaldehyde Poor If the stack gas is relatively hot and wet, or the VOCs are concentrated, then there is a high probability of condensation when the gas sample touches a surface cooler than that in the stack. The only way to overcome this is to dry the gas stream, dilute it, or maintain the temperature of the sample such that the chances of condensation are reduced. A FID for stack monitoring should, therefore, have a means of preventing condensation of either moisture or VOCs in the sample line (i.e. be equipped with a heated-line, heated detector and a heated by-pass). Where continuous or periodic sampling is carried out with an analyser close to the duct and the sampled gases are above ambient temperature, then the line (and its filter) carrying the sample to the analyser must be heated to prevent condensation and reduce adsorption losses. The lines within an analyser also need to be heated, while all gas chromatographs must have heated injection ports, ovens to heat the column and detectors in heated housings (issues with using heated equipment to measure flammable gases are outlined in Box 1). Box 1: Intrinsic safety Many industrial areas pose a risk of an explosion due to the presence of flammable gases. The use of equipment in such areas is controlled by EC Directives. Potentially explosive areas have three categories based on the risk of explosion, which are: Zone 0: Explosive atmosphere present continuously or for long periods of time. Zone 1: Explosive atmosphere present occasionally under normal operating circumstances. Zone 2: Explosive atmosphere not normally present and then only for short periods. Equipment which is to be used in such areas should not pose a risk of explosion, and must either be certified to the applicable standards, or verified on site as safe. Certified equipment is classed according to their applicability in the three zones, and termed as intrinsically safe. Some FIDs are certified as intrinsically safe. However, no FID can be certified for Zone 0 use. Many simple, unheated, portable FIDs have been designed for applications in health and safety screening, landfill gas monitoring, contaminated land measurements, and fugitive emissions monitoring. The simpler FIDs also usually have a wider spectrum of response factors, so their accuracy and precision will never be as great as the highly engineered, complex, heated FIDs. M16, Version 2, September 2009 Page 5 of 13

11 5.2 Electron capture detection The electron capture detector (ECD) works on the opposite principle to FIDs. Instead of creating ions by fragmenting a molecule, the ECD creates ions by bombarding the sampled gases with electrons. It works well with compounds which do not ionise easily in a flame or ultraviolet (UV) light, i.e. compounds which have a strong affinity for electrons. It was developed as a GC-detector for chlorinated compounds, such as pesticides. 5.3 Catalytic oxidation An instrument called a catalytic oxidiser is an alternative way of measuring total carbon, although the technique is not used as widely as FID. A sample of VOCs enters a combustion chamber which contains a catalyst, and within this, the carbon in the VOCs is oxidised to carbon dioxide (CO 2 ). The instrument then measures the concentration of CO 2 using an infra-red gas analyser. This method has two disadvantages. First, the catalysts can be poisoned by some components of the gas stream and secondly, the conversion of carbon to CO 2 is not always completely efficient. 6. Techniques for monitoring individual VOCs 6.1 Sorbent tube followed by gas chromatography (GC) separation Solid adsorbents are versatile media for collecting hundreds of types of VOCs. They work by collecting the VOC on the surface of the medium, which is usually contained within a tube. Prior to analysis, the sampled VOCs are removed by either thermal desorption, or by solvent extraction. There is no universal sampling sorbent, each tends to be suited for monitoring different categories of organic compound. For example, solid absorbents such as charcoal are typically used for VOCs, while polymeric sorbents are used for semi- VOCs. Organic polymeric sorbents include porous, polymeric resins such as 2,4-diphenyl-pphenylene oxide (e.g Tenax GC) and styrene di-vinylbenzene co-polymer resins (e.g XAD). These materials are hydrophobic, so they usually collect minimal amounts of water during the sampling. This means they can be used to sample very large samples of air, which is important if the target analytes are present in very small concentrations. On the other hand, these resins are not well suited to collecting highly volatile compounds, or certain polar materials, such as alcohols and ketones. Inorganic sorbents include magnesium aluminium silicate (e.g. Florosil), silica gel and molecular sieves. These are usually very polar adsorbents, so they are efficient for collecting high-polarity compounds. However, they are also efficient at collecting water, which tends to degrade the adsorbents, thus decreasing their efficiency. Carbon sorbents have a polarity in between the inorganic and organic, polymeric adsorbents, so water is less of a problem. However, collection of water can still inhibit M16, Version 2, September 2009 Page 6 of 13

12 some sampling programmes. Carbon based sorbents have a much stronger adsorption than organic polymers, so they are very efficient for collecting a vast array of VOCs. However, VOCs, which adhere strongly to carbon sorbents are also difficult to desorb. There are two ways of desorbing VOCs from carbon sorbents, thermal desorption and solvent extraction. Thermal desorption is preferable because solvent extraction complicates the subsequent analysis. However, solvent extraction may result in a greater recovery of the adsorbed VOCs if they have boiling points above 150 C. Apart from the versatility of the technique, its strength is that it effectively immobilises the sample on the adsorbent. However, there are caveats when using solid sorbents: the media often collect VOCs other than the target analytes, so the user must employ a means of separating the different VOCs once they have been removed from the medium; each medium has a saturation point, known as the breakthrough concentration. The user must therefore know when this occurs, which in turn means having some idea of the range of concentrations in the sampled gas. This can usually only be determined reliably by pre-surveys and some experimentation; there is no universal adsorbent for all VOCs; some VOCs cannot be entirely removed from the adsorbent medium once they have adsorbed onto it. The proportion of desorbed target analyte is known as the recovery rate, and the user must know this rate for the target VOCs and the media used to collect them; to apply this method correctly for compliance monitoring against an ELV, it is essential that the species of VOCs present in the stack gas is known beforehand. If they are not known, they may be determined by using this technique to carry out semi-quantitative screening. Once the species are known it is possible for the GC-FID analysis stage to be carried out quantitatively. Besides solid tubes a canister, which is coated with an inert surface, such as PTFE can be used. Alternatively, the sample can be drawn into a canister which has been evacuated. Once taken, the samples can then be analysed using methods such as GC- FID or GC-MS. The technique is suitable for emissions where the VOCs are highly concentrated and relatively free of particulates and moisture. Also, many VOCs can be selectively trapped in liquid media. The VOC sample is passed through an impinger containing a solution, after which the target determinand is analysed. The above techniques require a sample to be extracted from a stack or duct and transported to a laboratory for subsequent analysis. For sources at ambient temperature this is relatively straightforward. If the stack contains water vapour and is at an elevated temperature, condensation in the sample container may cause problems. The water vapour can be dealt with by diluting the sample or drying the gas stream with a drying agent or a permeation tube drier. M16, Version 2, September 2009 Page 7 of 13

13 In terms of analysis, GC is a straightforward and accurate means of separating the components of even quite complex mixtures. The FID is a very useful detector because of its cost, sensitivity, wide dynamic range, reliability, response to all carbon compounds, and linearity. 6.2 Non-dispersive infrared (NDIR) detection All VOCs absorb electromagnetic radiation, while different compounds absorb energy at different frequencies. This means that VOCs have an electromagnetic finger-print which is known as a spectrum. This feature can be exploited for measurements by targeting a peak or peaks in a compound's spectrum. The diatomic bonds in VOCs absorb infrared (IR) radiation and vibrate. This fact is exploited in the simplest and most widely used spectroscopic analysers. A source of radiation generates a beam which is then focused through a cell and a filter is placed in front of the beam in order to create a single wavelength beam of IR radiation. The wavelength is selected to coincide with an exclusive absorption peak in the spectrum of the target compound. The advantage of this technique is that most VOCs absorb strongly in the IR. However, if there is a mixture of VOCs, then the spectra can overlap. Therefore, the technique is suited best to single compounds or simple mixtures where there are no interferences. For some applications, infra-red analysers are well suited to long term monitoring of VOCs. Acetylene, ethylene, ethane, propane, propylene, butene-1, butane, pentane and hexane can all be measured at concentrations below ppm. 6.3 Fourier transform infrared (FTIR) FTIR uses the same basic principle as simple infra red (IR) analysers, but resolves interfering spectra by splitting the beam into two. One beam is then bounced off a fixed mirror while the other is bounced off a moving mirror. This causes the beams to be slightly out of phase. The beams are then directed by mirrors to collide, and the resulting new spectrum creates both constructive and destructive interference in such a way that software can carry out a Fourier transform calculation to identify distinct compounds. 6.4 Differential optical absorption spectrometry (DOAS) This technique was originally developed as an open-path monitor for atmospheric research. Most DOAS instruments use either UV or IR absorption to distinguish between different species. The technique can measure a selected handful of VOCs, such as benzene, toluene, ethylbenzene, xylene and formaldehyde. 6.5 Mass Spectroscopy In Mass Spectrometry (MS), organic molecules are bombarded with electrons and converted to energetic, positively charged ions, which can break up into smaller ions. M16, Version 2, September 2009 Page 8 of 13

14 The molecular ions are separated by deflection in a variable magnetic field according to their mass and charge. They generate a current at a detector in proportion to their relative abundance. A mass spectrum is a plot of the relative abundance against the mass-charge ratio. This detection system is usually coupled with gas chromatography, and serves as a definitive technique for analysing hundreds of VOCs. In recent years, developments in this technique have resulted in on-line instruments, which can take direct readings from stacks. The benefits of the technique is that it has very rapid response times (typically in milliseconds) and a wide dynamic range, from ppb levels to 100% concentrations. The technique can also monitor several compounds at once, although there is also the possibility of interference. Mass spectrometry is very useful for identifying unknown compounds in a mixture but is less suited to long-term routine monitoring of emissions - largely on grounds of capital cost and maintenance. 7. Hierarchy of monitoring standards A list of relevant standards for monitoring VOCs is given in the index of methods in TGN M2 6. The standards in this index are selected from the following hierarchy: Comité Européen de Normalisation 7 (CEN) International Standardisation Organisation 8 (ISO) National standards, such as US EPA 9. If the VOC cannot be monitored using standards covered by the above, then a method from the following may be specified in TGN M2: Method for the Determination of Hazardous Substances 10 (MDHS) series published by the Health and Safety Executive (HSE) National Institute of Occupational Safety and Health 11 (NIOSH) Occupational Safety and Health Administration 12 (OSHA). 8. European periodic standard reference methods 8.1 BS EN FID method for low concentrations of TOC CEN developed BS EN as a standard reference method (SRM) for monitoring TOC from incinerators. It has been validated as suitable for measuring low level gaseous or vapour phase TOC emissions over a range of 0-20 mg/m 3. It specifies a set of minimum performance requirements for an instrument using a FID, together with procedures for its calibration and operation. The system comprises a probe with a filter connected to a heated sample line, which is in turn connected to a heated FID. M16, Version 2, September 2009 Page 9 of 13

15 8.2 BS EN FID method for high concentrations of TOC BS EN is similar to BS EN 12619, except that it has been validated for higher concentrations of TOC found in emissions from processes which use solvents. BS EN was developed for processes covered by the Solvent Directive. The standard has been validated as suitable for measuring emissions up to 500 mg/m 3, although FIDs can be used to measure higher concentrations. 8.3 BS EN charcoal tube method for individual VOCs BS EN was developed for monitoring individual VOC emissions from solvent using processes. It specifies procedures for the sampling, preparation and analysis. The VOCs are expressed as concentrations of individual species, averaged over a sampling period. The standard has been validated as suitable for use in the range from 0.5 mg/m 3 up to 2000 mg/m 3. The standard is based on the principles of sampling onto adsorption media followed by desorption and analysis by gas chromatography. The standard specifies desorption by solvent extraction, however, thermal desorption may also be used. There are several analytical methods which have been developed for monitoring concentrations of VOCs in workplace atmospheres (MDHS, NIOSH, OSHA). These analytical methods can be adapted for use in stack emissions monitoring. However, it is important that the sampling part of the method follows the framework given in BS EN CEMs If a process operator s permit requires TOC to be measured continuously, the CEMs used must be MCERTS certified. Information on our monitoring certification scheme is available from Once a CEM has been installed, it should be checked for functionality and its performance verified. Typical performance checks include: leak test response time linearity interference, particularly any substances which could cause bias zero and span drift comparison with a SRM. The European standard, EN , for the quality assurance of CEMs and TGN M20 17 provide further information on this. EN was developed to implement requirements of applicable Directives, such as the WID and LCPD. Therefore it is a legal requirement for installations regulated by such Directives. For other processes, the general principles of EN are applied, albeit in a simplified way. M16, Version 2, September 2009 Page 10 of 13

16 10. References 1. The Categorisation of Volatile Organic Compounds (DOE/HMIP/RR/95/009). HMIP (1996). 2. Pollution Prevention and Control Regulations (England and Wales) 2000, (SI 2000, No.1973.) 3. Directive 96/61/EC. A European Community System for Integrated Pollution Prevention and Control (IPPC). Official Journal No. L257, /76/EC. Directive on the incineration of waste. Official Journal L332/91, 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. Official Journal L85/1, Technical Guidance Note M2, Monitoring stack emissions to air, Environment Agency 7. Committee for European Normalisation, CEN International Standards Organisation, ISO United States Environmental Protection Agency, USEPA MDHS methods are available from the HSE website at NIOSH methods are available from the NIOSH website at The OSHA methods are available from the OSHA website at BS EN (1999) - Stationary source emissions - Determination of the mass concentration of total organic carbon at low concentrations in flue gases - continuous flame ionisation detector method. 14. BS EN (2001) - Stationary source emissions - Determination of the mass concentration of total gaseous organic carbon at high concentrations in flue gases - Continuous flame ionisation detector method. 15. BS EN (2002) Stationary source emissions Determination of the mass concentration of individual gaseous organic compounds Activated carbon and solvent desorption method. 16. BS EN (2000) Stationary source emissions -Quality assurance of automated measuring systems. 17. Technical Guidance Note M20, Quality assurance of continuous emissions monitoring systems, Environment Agency. M16, Version 2, September 2009 Page 11 of 13

17 11. Glossary of terms and abbreviations Glossary of acronyms AST Annual surveillance test BS British standard CEMs Continuous emission monitoring system CEN Comité Européen de Normalisation DIAL Differential absorption light detection and ranging DOAS Differential optical absorption spectroscopy EC European commission ECD Electron capture detection ELV Emission limit value EN European standard EU European Union FID Flame ionisation detector FTIR Fourier transform infrared spectrometry GC Gas chromatography HPLC High performance liquid chromatography HSE Health and Safety Executive IR Infrared IPPC Integrated pollution and prevention control LIDAR Light detection and ranging MCERTS Monitoring certification scheme MDHS Method for the Determination of Hazardous Substances NIOSH National Institute of Safety and Health OSHA Occupational Safety and Health Administration POCP Photochemical ozone causing potential PPC Pollution and prevention control PTFE Polytetrafluoroethylene SRM Standard reference method TCD Thermal conductivity detector TGN Technical guidance note TOC Total organic carbon UNECE United Nations economic council of Europe US EPA United States Environmental Protection Agency UV Ultraviolet VOC Volatile organic compound WID Waste incineration directive WML Waste management licence M16, Version 2, September 2009 Page 12 of 13

18 Appendix 1. Toxic VOCs Table A2-1 - Alphabetical list of VOCs identified to be of importance due to their toxicity Compound acrylamide acrylonitrile azinphos-methyl benzene benzo(a)anthracene benzo(b)fluoranthene benzo(k)fluoranthene benzo(j)fluoranthene benzo(a)pyrene butadiene carbon disulphide 1-chloro-2,3-epoxypropane chloroethene (vinyl chloride) dibenzo(a,h)anthracene 1,2-dichlorethane dichlorvos dieldrin diethyl sulphate dimethyl sulphate dnoseb endosulfan endrin 1,2-epoxypropane 2-ethoxyethanol 2-ethoxyethyl acetate 4,4 -methylenebis(2-chloroanaline) 4,4 -methylenediphenyl diisocyanate nitrobenzene 2-nitropropane phenol phorate phosgene polychlorinated biphenyls 2-propen-1-ol pyrene 1,1,2,2-tetrachloroethane Category and mutagen cat.1 carcinogen, mutagen and teratogen cat.2 teratogen cat.1 carcinogen and mutagen cat.2 teratogen cat.2 teratogen cat.2 teratogen (inhalation) (inhalation) IARC group 2A (inhalation) M16, Version 2, September 2009 Page 13 of 13