Toolkit for Identification and Quantification of Releases of Dioxins, Furans and Other Unintentional POPs
PART II Emission Factors
Source Group 8 Miscellaneous
This category comprises five processes, shown in Table II.8.1, that were not placed in other source groups for various reasons. For example, two of the processes – drying of green fodder and smoke houses – are included here even though they are combustion processes that might be considered to be similar to processes addressed in source category 1f Waste wood combustion or source category 3d Household heating and cooking. These are shown in Table II.8.1.
Table II.8.1. Overview of source categories included in group 8 - Miscellaneous
8 - Miscellaneous Potential release route Source categories Air Water Land Product Residue a Drying of biomass x x x b Crematoria x X c Smoke houses x x X d Dry cleaning residues x x x e Tobacco smoking x x
With relevance to the provisions of Article 5, sources in this category can be classified as follows:
Table II.8.2. Relevance to Article 5, Annex C of the Stockholm Convention
No Toolkit source category Part II Part III Relevant source category in Annex C 8b Crematoria X Crematoria
An example of elaborating a source inventory and release estimate for this source group is included in the example inventory 9.
Drying of woody or herbaceous biomass, e.g. wood chips or green fodder, occurs either with or without containment, in which the combustion gases contaminated with unintentional POPs enter in contact with the material being dried.
Other processes that use direct heating methods (e.g. for foodstuffs) should be addressed under source category 8c smoke houses. Processes without contact should be addressed in Source Group 3 Power Generation and Heating.
Under controlled conditions, clean fuels such as wood are used. The drying of green fodder using poor fuels, e.g., treated wood, used textiles, carpets, etc., may lead to PCDD/PCDF formation and contamination of the fodder. For example, in 2005, in Germany, it was shown that the use of contaminated wood as fuel had resulted in very high concentrations of PCDD/PCDF in the fodder. When such contaminated fodder is fed to livestock, PCDD/PCDF can be transferred to the human food chain.
PCDD/PCDF emission factors for three source classes are listed in Table II.8.3. Revised or newly added emission factors are highlighted in red. Detailed information on how these emission factors have been derived can be found in Annex 52.
Table II.8.3 PCDD/PCDF emission factors for source category 8a Drying of Biomass
|8a||Drying of Biomass||Emission Factors (µg TEQ/t dry product)||Concentration
(µg TEQ/t ash)
|1||Highly contaminated fuel (PCP- or otherwise treated material)||10||NA||ND||0.5||2,000|
|2||Moderately contaminated fuel||0.1||NA||ND||0.1||20|
* For herbaceous biomass being dried, use an EFProduct of 1 µg TEQ/t dry product.
Class 1 is applied when using highly contaminated fuel (PCP- or otherwise treated material).
Class 2 is applied when using moderately contaminated fuel.
Class 3 is applied when using clean fuel.
The emission factors for this source category have been assigned a low level of confidence based on the scarcity of data and limited accessibility of activity information. Expert judgment has also been used in deriving these emission factors.
Cremation, reducing human bodies to ashes by burning, is a common practice in many societies. The essential components for cremation are the coffin (and the corpse), the main combustion chamber, and where applicable the afterburning chamber and air pollution control system. The cremation process is described in detail in the BAT&BEP Guidelines. The Guidelines equally provide information on PCDD/PCDF emissions from this process.
PCDD/PCDF emission factors for three source classes are listed in Table II.8.4. Detailed information on how these emission factors have been derived can be found in Annex 52.
Table II.8.4 PCDD/PCDF emission factors for source category 8b Crematoria
|8b||Crematoria||Emission Factors (µg TEQ per cremation)|
Class 1 includes facilities with poor combustion conditions, e.g., temperatures below 850°C, uncontrolled combustion air flow, etc., if plastic or other decoration materials are burned together with the coffin, if the wood of the coffin has been treated with wood preservatives, or if there is no flue gas cleaning system in place.
Class 2 includes facilities where the combustion conditions are better – temperatures securely above 850°C, controlled combustion air flow, no plastics or other problematic input materials - and some dust removal is in place. This class also includes open air cremations.
Class 3 includes state-of-the-art facilities with sophisticated air pollution control systems.
Class 1 emission factors are assigned a low level of confidence due to the low stability of the process, and only a limited number of measurements being available. Class 2 emission factors are assigned a medium level of confidence due to the larger range of the data. Finally, Class 3 emission factors are assigned a high level of confidence due to availability of consistent datasets from measurements with high geographical coverage.
Smoking food for preservation of meat and fish is a common practice in many countries. Smoke houses are commonly small installations that use wood as fuel and have sub-optimal combustion conditions.
PCDD/PCDF emission factors for three source classes are listed in Table II.8.5. For smoking foodstuffs in open air, use the EFAir from source category 3d, class 5 (open fire three stone stoves). Detailed information on how these emission factors have been derived can be found in Annex 52.
Table II.8.5 PCDD/PCDF emission factors for source category 8c Smoke Houses
|8c||Smoke Houses||Emission Factors (µg TEQ/t product)||Concentration
(ng TEQ/kg ash)
|2||Clean fuels, no afterburner||6||NA||NA||ND||20|
|3||Clean fuels, afterburner||0.6||NA||NA||ND||20|
Class 1 should be applied if treated wood or other contaminated biomass is used as fuel.
Class 2 should be used if clean wood is being used as fuel.
Class 3 should be applied if clean wood or other biomass is used as fuel and there is a state-of-the-art air pollution control system in operation.
The emission factors for this source category have been assigned a low level of confidence based on the scarcity of available data. Expert judgment has also been used in deriving these emission factors.
PCDD/PCDF have been detected in the distillation residues from dry cleaning (cleaning of textiles with organic solvents, not washing with water). The PCDD/PCDF sources have been identified as the use of contaminated biocides, such as PCP, to protect textiles or raw materials – wool, cotton, etc. – and the use on textiles of PCDD/PCDF-contaminated dyes and pigments. The dry cleaning process itself does not generate PCDD/PCDF, but rather redistributes PCDD/PCDF already present in the textiles via prior contamination.
During the dry cleaning process, PCDD/PCDF are extracted from the textiles and transferred into the cleaning solvent. When the solvent is distilled for recovery and reuse, PCDD/PCDF are concentrated in distillation residues, which normally are disposed of. Detailed research has shown that PCDD/PCDF concentrations in the distillation residues do not depend on the solvent present in the dry cleaning process (Fuchs et al. 1990, Towara et al. 1992). Therefore, the influence of the solvent used is negligible; typical solvents are perchloroethylene, petrol, or fluorocarbons.
PCDD/PCDF emission factors for two source classes are listed in Table II.8.6. Detailed information on the derivation of these emission factors can be found in Annex 52.
Table II.8.6 PCDD/PCDF emission factors for source category 8d Dry Cleaning Residues
|8d||Dry Cleaning Residues||Emission Factors (µg TEQ/t)||Concentration in distillation
residue (µg TEQ/t)
|1||Heavy textiles, PCP treated, etc.||NA||NA||ND||ND||3,000|
Class 1 includes dry cleaning of highly contaminated textiles, e.g. carpets or heavy curtains suspected to be treated with PCP (the country of origin may be an indicator) or clothing of workers or other textiles from dioxin-polluted environments.
Class 2 includes cleaning of uncontaminated clothing and other textiles.
As an indication, 15g of residues are formed per kilogram of treated clothes (data from the French Technical Center on Cleaning - CTTN). Activity data can be retrieved from competent authorities that license the dry cleaning shops, and waste collectors.
The emission factors for this source category have been assigned a low level of confidence due to changes and complexity in the textile and leather manufacturing.
As any other thermal process, “combustion” of cigarettes and cigars produces PCDD/PCDF. The quantity of tobacco in cigarettes varies but is commonly less than 1 gram per cigarette. Cigars vary both in their size and their tobacco load. Large cigars may contain as much tobacco as an entire pack of 20 cigarettes, while small cigars (cigarillos) may be similar in size and tobacco content to that of one cigarette.
PCDD/PCDF emission factors for two source classes are listed in Table II.8.7. Revised or newly added emission factors are highlighted in red. Detailed information on how these emission factors have been derived can be found in Annex 52.
Table II.8.7 PCDD/PCDF emission factors for source category 8e Tobacco Smoking
|8e||Tobacco Smoking||Emission Factors (µg TEQ/ million cigars or cigarettes)|
NB: The emission factors for tobacco smoking are applied to total cigarette numbers, not to the weight of tobacco.
Class 1 should be applied to cigar smoking.
Class 2 applies to cigarette smoking.
The activity rate can be assessed by the following mass-balance equation: Production - Export + Import. While cigarette data are available as numbers of cigarettes, loose tobacco and cigars are usually reported in weight. A conversion factor of 1 g of tobacco per cigarette may be used to estimate the number of cigarettes, i.e. 1 ton of loose tobacco is equivalent to 1,000,000 cigarettes.
The level of confidence assigned to these emission factors is low due to limited data available and difficult experimental design.