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Supplementary Guide for Reporting to the National Pollutant Release Inventory - Alternate Thresholds 2000

Section 5: Dioxins/Furans and Hexachlorobenzene (HCB)

5.1 Introduction, History and Intent

Polychlorinated dibenzo-p-dioxins (PCDD or dioxins), polychlorinated dibenzofurans (PCDF or furans) and hexachlorobenzene (HCB) are released primarily as by-products of industrial and combustion processes, but are also found as contaminants in certain pesticides or chlorinated solvents. HCB may also be found as a contaminant in ferric chloride used for water or wastewater treatment. These substances have been identified as Track 1 toxic substances under the CEPA (1999) (see Appendix 6) and as such are slated for virtual elimination* of releases to the environment. The Canada-Wide Standards for Dioxins and Furans target reductions of dioxin and furan emissions from pulp and paper boilers burning salt-laden wood, and waste incineration. Canada has international obligations under the UN ECE POPss Protocol to report releases of dioxins, furans and HCB.

Releases of substances classified as dioxins and furans are typically reported in units of toxic equivalent (TEQ) to the most toxic congener of this group, 2,3,7,8-tetrachlorodibenzo-p-dioxin. More information on the use of TEQ units is provided in section 5.4.4.

Environment Canada and the Work Group on Substances considered several options for addition of these substances to the NPRI. A release analysis was carried out using existing data gathered by Environment Canada. This analysis for dioxins/furans showed that a release-based reporting threshold of 0.1 g TEQ per year would capture about 98% of the known sources of facility-based releases of dioxins/furans in 1995. Similarly, a 0.5 kg per year release-based reporting threshold would capture about 99% of the known sources of facility-based releases of HCB in 1995.

While members of the Work Group supported the addition of dioxins/furans and HCB to the NPRI, they did not reach a consensus on selecting reporting criteria for these substances. Environmental groups supported the reporting of any release from specified sectors and processes. Industry associations supported setting a quantitative reporting threshold for all facilities reporting to the NPRI to capture almost 90% of known point-source releases, accompanied by guidance for reporting facilities on which sectors are expected to release dioxins/furans or HCB.

However, because of the persistent and bioaccumulative nature of dioxins/furans and HCB, and their classification as Track 1 substances, Environment Canada has enhanced the reporting requirements for these substances. Environment Canada must be able to set priorities, to implement short-term management strategies, to determine which sectors and which facilities have to virtually eliminate these substances, and to track progress toward the long-term goal of virtual elimination. A quantitative reporting threshold for dioxins/furans and HCB does not address the two requirements related to virtual elimination. To meet these information needs, Environment Canada has adopted a very different approach to reporting of these substances to the NPRI.

Environment Canada requires all facilities engaged in identified activities (see Tables 4 and 5) that have the potential to incidentally manufacture dioxins/furans or HCB, to submit a report to the NPRI. The identified activities were selected by Environment Canada to cover all main point sources of dioxins/furans and HCB releases being targetted by the Canada-Wide Standards (see Appendix 6) initiatives for dioxins, furans and HCB. Reporting by limited sectors known to release these substances will capture all significant releases from such facilities, while minimizing reporting burden on other facilities reporting to the NPRI.

However, if your facility is engaged in activities other than those identified in Tables 4 and 5, and you know that your facility has released or transferred dioxins/furans or HCB, you may submit substance reports to the NPRI using measured or estimated data. Environment Canada will re-examine the list of activities for which dioxins/ furans and HCB reports are required and consult with stakeholders to determine if any changes need to be made.

5.1.1 Wood Preservation

Environment Canada accepted the recommendation from the Issue Table for the Wood Preservation Sector Strategic Options Process, that any facility used for wood preservation using pentachlorophenol must submit a report for dioxins/furans and HCB, regardless of the quantity of dioxins/furans or HCB released or transferred. This activity is considered separately from other activities for which reporting for dioxins/furans and HCB is required, because dioxins/furans and HCB are present in pentachlorophenol as contaminants, rather than being incidentally manufactured.

5.2 Substances

5.2.1 Dioxins/Furans

Dioxins/furans are listed in Schedule 1, Part 4, of the 2000 Canada Gazette notice as "polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans". There is no CAS number provided for the dioxin/furan group since the listing includes the 17 most toxic dioxin and furan congeners. A congener is a compound belonging to a family of compounds having similar chemical skeletons, but differing in the number and position of hydrogen substitutes. The 17 congeners and their CAS numbers are referenced in Schedule 1, Part 4, of the 2000 Canada Gazette notice in a footnote to the "polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans" listing, and below in Table 3.

Table 3: Dioxin and Furan Congeners Included in the NPRI Dioxins/Furans Group
CAS No.Name of Congener
1746-01-62,3,7,8-Tetrachlorodibenzo-p-dioxin
40321-76-41,2,3,7,8-Pentachlorodibenzo-p-dioxin
39227-28-61,2,3,4,7,8-Hexachlorodibenzo-p-dioxin
19408-74-31,2,3,7,8,9-Hexachlorodibenzo-p-dioxin
57653-85-71,2,3,6,7,8-Hexachlorodibenzo-p-dioxin
35822-46-91,2,3,4,6,7,8-Heptachlorodibenzo-p-dioxin
3268-87-9Octachlorodibenzo-p-dioxin
51207-31-92,3,7,8-Tetrachlorodibenzofuran
57117-31-42,3,4,7,8-Pentachlorodibenzofuran
57117-41-61,2,3,7,8-Pentachlorodibenzofuran
70648-26-91,2,3,4,7,8-Hexachlorodibenzofuran
72918-21-91,2,3,7,8,9-Hexachlorodibenzofuran
57117-44-91,2,3,6,7,8-Hexachlorodibenzofuran
60851-34-52,3,4,6,7,8-Hexachlorodibenzofuran
67562-39-41,2,3,4,6,7,8-Heptachlorodibenzofuran
55673-89-71,2,3,4,7,8,9-Heptachlorodibenzofuran
39001-02-0Octachlorodibenzofuran

Because these 17 congeners have related toxic effects that are cumulative, report on-site releases and off-site transfers of dioxins/furans together as a group, in grams of toxicity equivalent (TEQ) to the most toxic congener of dioxin (2,3,7,8-tetrachlorodibenzo-p-dioxin). You estimate the quantity in grams of TEQ of dioxins/furans released or transferred by adding the individual units of TEQ for each congener. A more detailed description of TEQ and its calculation is in section 5.4.4.

5.2.2 Hexachlorobenzene (HCB)

Hexachlorobenzene (HCB) has the CAS No. 118-74-1 and is listed in Schedule 1, Part 4, of the 2000 Canada Gazette notice.

5.3 Reporting Criteria

The reporting criteria for dioxins/furans and HCB are outlined in Schedule 2, Part 4, of the 2000 Canada Gazette notice, and are summarized in the flowchart in Figure 4.

If a facility was "used for" one of the activities not required to meet the 20 000-hour employee threshold, that facility was used primarily or exclusively for that activity.

If a facility was "engaged in" an activity, then that facility was engaged in the activity at any time during the year, regardless of extent or the primary purpose of the facility.

Figure 4: Reporting Criteria for Dioxins/Furans and HCB

You must submit substance reports for dioxins/furans and HCB if your facility met one or more of the following criteria, regardless of the quantity of dioxins/furans or HCB released on site or transferred off site:

  • your facility was used for one or more of the activities in Table 4, regardless of the 20 000-hour employee threshold
  • your facility engaged in one or more of the activities in Table 4 or 5, and your facility met the 20 000-hour employee threshold, and/or
  • your facility was used for wood preservation using pentachlorophenol, regardless of the 20 000-hour employee threshold.

The NAICS codes listed in Tables 4 and 5 are provided to help identify facilities that may engage in these activities. However, it is the activity and not the NAICS code that determines whether a facility is required to submit substance reports to the NPRI for dioxins/furans and HCB.

Table 4 lists the activities for which substance reports are required for dioxins/furans and HCB, regardless of the total number of hours worked by employees at the facility in the 2000 calendar year.

If your facility was used for one or more of the activities set out in Table 4, you must submit substance reports for dioxins/furans and HCB. Only report on-site releases and off-site transfers that resulted from the incidental manufacture of dioxins/furans or HCB while engaging in the listed activities. A description of the activities listed in Table 4 is provided in section 5.3.1.

Table 4: Activities for Which Dioxins/Furans and HCB Reports are Required (20 000-Hour Employee Threshold Does Not Apply)
ActivityNAICS Code
a)Non-hazardous solid waste incineration of 100 tonnes or more of waste per year, including small combustion units, teepee burners and beehive burners5622
b)Biomedical or hospital waste incineration of 100 tonnes or more of waste per year5622
c)Hazardous waste incineration5622
d)Sewage sludge incineration5622

If your facility is engaged in one or more of the activities set out in Table 5, and your facility met the 20 000-hour employee threshold in the 2000 calendar year, you must submit substance reports for dioxins/furans and HCB. A description of the activities listed in Table 5 is provided in section 5.3.1.

Table 5: Activities for Which Dioxins/Furans and HCB Reports are Required (20 000-Hour Employee Threshold Applies)
ActivityNAICS Code
a)Non-hazardous solid waste incineration of 100 tonnes or more of waste per year, including small combustion units, teepee burners and beehive burners5622
b)Biomedical or hospital waste incineration of 100 tonnes or more of waste per year5622
c)Hazardous waste incineration5622
d)Sewage sludge incineration5622
e)Base metals smelting (this refers to copper, lead, nickel and zinc)3314
f)Smelting of secondary lead3314
g)Smelting of secondary aluminum3313
h)Manufacturing of iron using a sintering process3311
i)Operation of electric arc furnaces in steel manufacturing3311
j)Operation of electric arc furnaces in steel foundries3315
k)Production of magnesium3314
l)Manufacturing of portland cement3273
m)Production of chlorinated organic solvents or chlorinated monomers3251
n)Combustion of fossil fuel in a boiler unit, for the purpose of producing steam for the production of electricity, with a generating capacity of 25 megawatts or greater of electricity2211
o)Combustion of hog fuel originating from logs that were transported or stored in salt water in the pulp and paper sector(not available)
p)Combustion of fuel in kraft liquor boilers used in the pulp and paper sector(not available)

A description of what and how you must report is given in Sections 5.4 and 5.5; examples of estimation methods and reporting scenarios are provided in Chapter 7.

5.3.1 Description of Activities Listed in Tables 4 and 5

The first four activities listed in Tables 4 and 5 are forms of waste incineration. Waste incineration, for the purposes of the NPRI, only includes incineration that takes place in a waste incinerator. Waste incineration does not include open burning of wastes.

A waste incinerator is a device, mechanism or structure constructed primarily to thermally treat (e.g., combust or pyrolyze) a waste for the purpose of reducing its volume, destroying a hazardous chemical present in the waste, or destroying pathogens present in the waste. This includes facilities where waste heat is recovered as a by-product from the exhaust gases from an incinerator (e.g., energy-from-waste incinerators). This also includes conical (or teepee) burners and beehive burners. This does not include industrial processes where fuel derived from waste is fired as an energy source, such as industrial boilers. Refer to Table 5 if you combust wastes in industrial boilers, as your facility may meet dioxins/furans and HCB reporting criteria for another activity.

a) Non-hazardous solid waste incineration of 100 tonnes or more of waste per year, including small combustion units, teepee burners and beehive burners

Non-hazardous solid waste means any waste, regardless of origin, which might normally be disposed of in a non-secure manner, such as at a sanitary landfill site, if not incinerated. It includes clean wood waste, i.e., waste from woodworking or forest product operations, including bark, where the wood waste has not been treated with preservative chemicals (e.g., pentachlorophenol) or decorative coatings. Non-hazardous solid waste incineration includes incineration of residential and other municipal wastes in conical (or teepee) burners, and clean wood waste in beehive burners.

A facility engaged in the incineration of 100 tonnes or more of non-hazardous solid waste per year must submit substance reports for dioxins/furans and HCB.

b) Biomedical or hospital waste incineration of 100 tonnes or more of waste per year

Biomedical waste is defined fully in Appendix 4. Biomedical or hospital waste refers to waste that is generated by:

  • human or animal health-care facilities
  • medical or veterinary research and testing establishments
  • health-care teaching establishments
  • clinical testing or research laboratories, and
  • facilities involved in the production or testing of vaccines.

Biomedical or hospital waste includes human anatomical waste and animal waste. It also includes microbiology laboratory waste, human blood and body fluid waste, and waste sharps that have not been disinfected or decontaminated. It does not include waste from animal husbandry, or waste that is controlled in accordance with the Health of Animals Act (Canada).

Wastes that are household in origin, or that are generated in the food production, general building maintenance and office administration activities of those facilities to which this definition applies are not considered to be biomedical or hospital waste but rather to be non-hazardous solid waste.

A facility engaged in the biomedical or hospital waste incineration of 100 tonnes or more of waste per year must submit substance reports for dioxins/furans and HCB.

c) Hazardous waste incineration

Hazardous waste is defined fully in Appendix 5. Hazardous waste includes those wastes that are potentially hazardous to human health and/or the environment because of their nature and quantity, and that require special handling techniques. Hazardous waste incinerators must be licensed by the responsible jurisdiction. Hazardous waste incinerated in a mobile incinerator temporarily located at your facility must be included as part of this activity.

A facility engaged in the incineration of hazardous waste must submit substance reports for dioxins/furans and HCB, regardless of the quantities incinerated.

d) Sewage sludge incineration

Sludge means a semi-liquid mass removed from a liquid flow of wastes. Sewage sludge means sludge from a facility treating wastewater from a sanitary sewer system.

A facility engaged in the incineration of sewage sludge must submit substance reports for dioxins/furans and HCB, regardless of the quantities incinerated.

e) Base metals smelting

Base metals refers to copper, lead, nickel and zinc. This activity does not include smelting of aluminum or any other metals. It also does not include the smelting of secondary lead, which is a separate activity in Table 5 (see description below). The Canada Gazette notice of December 25, 1999, limited reporting to base metals smelters using chlorinated plastics or other chlorinated substances in their feeds but, at the request of the sector, this qualifier was removed in an amendment to the Canada Gazette notice.

f) Smelting of secondary lead

Secondary lead refers to lead-bearing scrap or lead-bearing materials, other than lead-bearing concentrates derived from a mining operation. Facilities engaged in smelting of lead-bearing concentrates derived from a mining operation are considered to be base metals smelters (see description above).

g) Smelting of secondary aluminum

Secondary aluminum refers to aluminum-bearing scrap or aluminum-bearing materials. Secondary aluminum smelting involves two processes - pre-cleaning and smelting - both of which may produce emissions of dioxins/furans.

h) Manufacturing of iron using a sintering process

Sintering is the welding together and growth of contact area between two or more initially distinct particles at temperatures below the melting point, but above one-half of the melting point (in degrees Kelvin). In sintering operations, dioxins/furans may be formed as unwanted by-products during high-temperature decomposition and combustion of raw materials containing chlorine and organic compounds.

i) Operation of electric arc furnaces in steel manufacturing

In an electric arc furnace, material is heated by the heat energy released from an electric arc. The electric arc is a component of an electric circuit, like a resistor, but with its own peculiar characteristics. Dioxins/furans may be formed as unwanted by-products during high-temperature decomposition and combustion of raw materials containing chlorine and organic compounds.

j) Operation of electric arc furnaces in steel foundries

In an electric arc furnace, material is heated by the heat energy released from an electric arc, during which dioxins/furans and HCB may be formed.

k) Production of magnesium

Production of magnesium from magnesium chloride by electrolysis may result in the generation of dioxins/furans and HCB.

l) Manufacturing of portland cement

Portland cement is a fine greyish powder consisting of four basic materials - lime, silica, alumina and iron compounds. Cement production involves heating (pyroprocessing) the raw materials to a very high temperature in a rotating kiln to induce chemical reactions that produce a fused material called clinker. The cement clinker is further ground into a fine powder, then mixed with gypsum to form portland cement.

m) Production of chlorinated organic solvents or chlorinated monomers

This activity is limited to the intentional manufacturing of chlorinated organic solvents or chlorinated monomers, and does not include coincidental production.

n) Combustion of fossil fuel in a boiler unit, for the purpose of producing steam for the production of electricity, with a generating capacity of 25 megawatts or greater of electricity

Fossil fuel includes solid or liquid fuel (e.g., coal, petroleum or any liquid or solid fuel derived from such). This clearer definition of electric power generation is provided in the 2000 Canada Gazette amendment. It includes electric power generation utilities and large industrial facilities co-generating electric power using waste heat from industrial processes. It does not include combustion of natural gas or other fuels that are gaseous in form at ambient pressure and temperature. It also does not include diesel generators, which are not boiler units.

o) Combustion of hog fuel originating from logs that were transported or stored in salt water in the pulp and paper sector

Pulp and paper boilers burning salt-laden wood are unique to British Columbia. Dioxins/furans are emitted from the burning of salt-contaminated hog fuel. Logs transported and stored in salt water take up chlorine into the bark. The bark is stripped from logs and ground up with other waste wood to produce hog fuel. The material is then used as boiler fuel to produce heat and electrical energy for pulp and paper processes. The Canada-Wide Standards for Dioxins and Furans state that every boiler covered by the Standards will be tested twice each year to determine the emissions of dioxins/furans to air for the years prior to 2003, and annually for the year 2003 and beyond.

p) Combustion of fuel in kraft liquor boilers used in the pulp and paper sector

A kraft liquor boiler burns black liquor, composed mostly of lignin, the residue from the digester in a kraft (sulphate) pulping process. The boiler recovers chemical products from the combusted black liquor, which are later recycled, and also produces steam which is used in mill process operations.

5.3.2 Wood Preservation Using Pentachlorophenol

Wood preservation means the preservation of wood using heat or pressure treatment, or both. If your facility was used for wood preservation using pentachlorophenol, you must submit substance reports for dioxins/furans and HCB, regardless of the number of hours worked by employees.

5.4 What You Must Report - Overview

This section provides an overview of the types of information you will be required to report for dioxins/furans or HCB, if your facility met the reporting criteria set out in Section 5.3. Section 5.5 provides details of the types of information that you will be required to report. Chapter 7 provides some sample calculations for facilities that must report on-site releases or off-site transfers of dioxins/furans and HCB.

With the exception of facilities used for wood preservation using pentachlorophenol, a facility should only consider quantities of dioxins/furans or HCB that were incidentally manufactured as the result of the activities listed in Tables 4 or 5. Wood-preservation facilities using pentachlorophenol must consider all sources of releases or transfers of dioxins/furans or HCB arising from the use of pentachlorophenol for the purpose of wood preservation.

5.4.1 Special Reporting Criteria

A facility that met the criteria set out in Section 5.3 must provide substance reports for dioxins/furans and HCB. However, what you report for releases and transfers may differ from a typical NPRI substance report. The dioxins/furans or HCB substance report submitted to the NPRI will indicate, for on-site releases to each environmental medium and for each off-site transfer activity:

  • the quantity released on site or transferred off site as the result of incidental manufacture during an activity listed in Tables 4 or 5
  • the quantity released on site or transferred off site resulting from wood preservation using pentachlorophenol
  • that directly-measured releases to a specific medium or transfers off site were at concentrations above, equal to or below the Level of Quantification (LoQ) concentrations set out in Table 8 (this option is available only if estimates were based on direct measurements)
  • that there were no releases to a specific medium or no transfers off site, or
  • that no information was available on which to base an estimate.

5.4.2 "Basis of Estimate" and "Detail" Codes

Basis of Estimate Codes

When you report on-site releases to each environmental medium and off-site transfer for disposal or recycling, you will enter a "Basis of Estimate" code in the NPRI reporting software. There are four methods of estimating releases.

The following are the "Basis of Estimate" codes, listed in declining order of expected accuracy:

  • monitoring or direct measurement (Code M)
  • mass balance (Code C)
  • emission factors (Code E)
  • engineering estimates (Code O)

Selecting Code "NA" (Not applicable) as the "Basis of Estimate" indicates that there were no releases from your facility to this medium, or no transfers off site.

A new "Basis of Estimate" code (Code NI) was added for the 2000 reporting year only for dioxins/furans and HCB for instances when no information is available. You should enter "NI" as your "Basis of Estimate" code if your facility met reporting criteria for dioxins/furans or HCB, but you have no information available on which to base an estimate of the quantity released or transferred.

Detail Codes

For dioxins/furans and HCB substance reports only, a "Detail" code field is available in the NPRI reporting software adjacent to the "Basis of Estimate" field. There are three "Detail" codes:

  • concentrations at or above LoQ (Code AL)
  • concentrations below LoQ (no quantity entered) (Code BL), andv
  • concentrations below LoQ (enter a quantity) (Code BQ).

These "Detail" codes only apply to data from monitoring or direct measurements (Code "M" in the "Basis of Estimate" field). If you enter the "AL" Detail code, you must enter the quantities released or transferred. If your concentrations are below LoQ, then reporting of quantities released or transferred is optional - you must select one of two Detail codes. If you enter the "BL" Detail code for concentrations below LoQ, you have chosen not to report the quantities released or transferred. If you enter the other Detail code for concentrations below LoQ (Code "BQ"), you have chosen to report the quantities released or transferred.

The use of "Basis of Estimate" and "Detail" codes is discussed in the following sections and summarized in Table 6. More information on completing an NPRI report using the NPRI reporting software is provided in the Guide for Reporting.

Table 6: How to Report Releases and Transfers of Dioxins/Furans and HCB
Basis of Estimate CodeDetail CodeQuantity Field
Monitoring or Direct Measurement (Code M)At or above LoQ (Code AL)you must enter quantity released or transferred
Monitoring or Direct Measurement (Code M)Below LoQ (no quantity entered) (Code BL)not applicable
Monitoring or Direct Measurement (Code M)Below LoQ (quantity entered) (Code BQ)you must enter quantity released or transferred
Mass Balance (Code C)not applicableyou must enter quantity released or transferred
Emission Factors (Code E)not applicableyou must enter quantity released or transferred
Engineering Estimate (Code O)not applicableyou must enter quantity released or transferred
No Information Available (Code NI)not applicablenot applicable
Not Applicable (Code NA)not applicablenot applicable


5.4.3 Units

Dioxins/Furans

Report quantities of dioxins/furans released on site and transferred off site in units of grams of toxic equivalents (g TEQ) of the 17 congeners listed in Table 3. Units of grams TEQ are further discussed in Section 5.4.4.

HCB

You must report the quantities of HCB released on site and transferred off site in units of grams (g).

5.4.4 What Are Toxic Equivalents (TEQs) of Dioxins/Furans?

You must report on-site releases and off-site transfers of dioxins/furans in units of grams TEQ of the 17 congeners listed in Table 3. Dioxins and furans are often found in complex mixtures, typically at extremely low concentrations, making it difficult to determine the cumulative toxicity of the mixture. Accordingly, scientists have assigned toxic equivalency factors (TEFs) to each dioxin/furan congener as weighting factors. These TEFs are assigned relative to the toxicity of 2,3,7,8-TCDD, the most toxic congener, which is assigned a TEF of 1.

To apply and compare TEQs, the values must be calculated using the same set of TEFs. Most release data on dioxins/furans currently available in Canada are in units of international TEQs (North Atlantic Treaty Organization/Committee on the Challenges of Modern Society, NATO/CCMS, 1989). More recent work undertaken for the World Health Organization (van den Berg, 1998) has resulted in a revised set of TEFs, not just for humans, but for mammals, fish and birds. However, since most of the emission factors currently available are in international TEQs, these TEF values (NATO/CCMS, 1989), listed in Table 7, must be used for reporting to the NPRI.

Table 7: Toxic Equivalency Factor (TEF) Values for Dioxins and Furans
CAS No.CongenerAbbreviationTEF
Dioxins
1746-01-62,3,7,8-Tetrachlorodibenzo-p-dioxin2,3,7,8-TCDD1
40321-76-41,2,3,7,8-Pentachlorodibenzo-p-dioxin1,2,3,7,8-PeCDD0.5
39227-28-61,2,3,4,7,8-Hexachlorodibenzo-p-dioxin1,2,3,4,7,8-HxCDD0.1
57653-85-71,2,3,6,7,8-Hexachlorodibenzo-p-dioxin1,2,3,6,7,8-HxCDD0.1
19408-74-31,2,3,7,8,9-Hexachlorodibenzo-p-dioxin1,2,3,7,8,9-HxCDD0.1
35822-46-91,2,3,4,6,7,8-Heptachlorodibenzo-p-dioxin1,2,3,4,6,7,8-HpCDD0.01
3268-87-9Octachlorodibenzo-p-dioxinOCDD0.001
Furans
51207-31-92,3,7,8-Tetrachlorodibenzofuran2,3,7,8-TCDF0.1
57117-31-42,3,4,7,8-Pentachlorodibenzofuran2,3,4,7,8-PeCDF0.5
57117-41-61,2,3,7,8-Pentachlorodibenzofuran1,2,3,7,8-PeCDF0.05
70648-26-91,2,3,4,7,8-Hexachlorodibenzofuran1,2,3,4,7,8-HxCDF0.1
72918-21-91,2,3,7,8,9-Hexachlorodibenzofuran1,2,3,7,8,9-HxCDF0.1
57117-44-91,2,3,6,7,8-Hexachlorodibenzofuran1,2,3,6,7,8-HxCDF0.1
60851-34-52,3,4,6,7,8-Hexachlorodibenzofuran2,3,4,6,7,8-HxCDF0.1
67562-39-41,2,3,4,6,7,8-Heptachlorodibenzofuran1,2,3,4,6,7,8-HpCDF0.01
55673-89-71,2,3,4,7,8,9-Heptachlorodibenzofuran1,2,3,4,7,8,9-HpCDF0.01
39001-02-0OctachlorodibenzofuranOCDF0.001

(NATO/CCMS, 1989)

To calculate the TEQ of a mixture, you must first multiply the concentration of an individual congener by its respective TEF, or weighting factor, to obtain the congener specific TEQ concentration. The sum of the TEQ concentrations for the individual congeners is the TEQ concentration for the mixture.

Example of a TEQ Calculation

The following table shows the different concentrations of four dioxin and furan congeners in an ash sample. If these concentrations were simply summed together, the sample would be reported as containing 80 nanograms (ng) of dioxins/furans in each kilogram (kg) of ash. However, 1,2,3,4,7,8-HxCDF is 10 times less toxic than 2,3,7,8-TCDD. By applying the TEFs to each congener and summing the values, the resulting toxic equivalent (TEQ) for the mixture is 25 ng TEQ of dioxins/furans in each kg of ash, or 25 ng TEQ/kg.

Dioxins/Furans CongenerSample Concentration (ng/kg)Toxic Equivalency Factor (TEF)Toxic Equivalent
(ng TEQ/kg ASH)
2,3,7,8-TCDD10110
1,2,3,7,8-PeCDD200.510
1,2,3,4,7,8-HxCDF300.13
1,2,3,6,7,8-HxCDF200.12
Total Concentration  25


5.5 What You Must Report - Details

First, determine whether you must report quantities released on site to each environmental medium and transferred off site. You must report quantities released on site and transferred off site unless:

  • you directly measure dioxins/furans and HCB resulting from incidental manufacture from an activity listed in Tables 4 or 5, and the concentrations are below the LoQ values defined below, or
  • you have no information available on which to base estimates of on-site releases and off-site transfers.

Use the flowchart in Figure 5 to determine what you must report to the NPRI for dioxins/furans and HCB. Read the flowchart for on-site releases to each environmental medium (i.e., air, water, land and underground injection) and for each type of off-site transfer. You must account for total releases of dioxins/furans and HCB from your facility to each environmental medium. Explanations of the terms used in the flowchart are provided in sections 5.5.1 to 5.5.4.

Figure 5: What You Must Report for Dioxins/Furans and HCB

5.5.1 Direct Measurements

As defined in the Guide for Reporting, a direct measurement is based on measured concentrations of the substance in a waste stream and the volume/flow rate of that stream. Direct measurements should be made of on-site releases and off-site transfers representative of the facility's normal operating conditions or production levels.

If your facility has made direct measurements of dioxins/furans or HCB, then you should use these data to determine which releases and transfers, if any, you must report to the NPRI. Enter Code "M" in the "Basis of Estimate" field in the NPRI reporting software. Chapter 7 provides examples of how to estimate releases using measured data.

The following sections will help you determine if your measured concentrations are above, equal to or below the LoQ for each type of material that you release on site and transfer off site.

Level of Quantification (LoQ)

The level of quantification is defined in Section 65.1 of the CEPA (1999) as "the lowest concentration that can be accurately measured using sensitive but routine sampling and analytical methods". Environment Canada determines LoQ values by carrying out statistical analyses of several sets of measurements from a variety of emission sources. The LoQ is calculated as 10 times the standard deviation of replicated measurements. The standard deviation is the variability of the test data associated with the sampling, analysis and actual source emission changes during testing, using standard test methods (Environment Canada, 1989).

Table 8 provides estimated LoQs for dioxins/furans and for HCB for three types of material or waste streams that may be released on site or transferred off site - gaseous, liquid and solid. The LoQ values listed include both final and draft values published by Environment Canada. You must compare your measured concentrations to the appropriate LoQ for each type of on-site release and off-site transfer that you report to the NPRI. Containment in an off-site landfill is an example of a type of off-site transfer for disposal. Recovery of pollution-abatement residues is an example of a type of off site transfer for recycling.

Table 8: Estimated LoQ Values for Concentrations of Dioxins/Furans and HCB
State of MaterialEstimated LoQ for Concentrations of Dioxins/FuransEstimated LoQ for Concentrations of HCB
Gaseous32 pg TEQ/m36 ng/m3
Liquid20 pg TEQ/L70 ng/L
Solid9 pg TEQ/g2 ng/g

Environment Canada published estimated LoQ values for dioxin/furan and HCB concentrations in gaseous releases (Environment Canada, 1999). You should use these values to determine whether concentrations in releases to air from stacks and other sources are above, equal to or below the LoQ.

Environment Canada has not published an LoQ for dioxin/furan concentrations in liquids, but has extrapolated a draft LoQ for dioxins/furans in liquids from the effective LoQ for 2,3,7,8-TCDD in the Pulp and Paper Mill Effluent Chlorinated Dioxins and Furans Regulations. Facilities should use 20 pg TEQ/L as the LoQ for concentrations of dioxins/furans in liquids.

Environment Canada has developed an estimated LoQ for concentrations of HCB in chlorinated solvents. Facilities should use 70 ng/L as the estimated LoQ for concentrations of HCB in all liquids.

Environment Canada published proposed LoQ values for dioxins/furans and HCB in soil in early 2000 (Environment Canada, 2000). You should use LoQ values of 9 pg TEQ/g for dioxins/furans and 2 pg/g for HCB to determine whether concentrations of dioxins/furans or HCB in solid materials are equal to or above the LoQ. Incinerator bottom ash, pollution-abatement residues and sludges are examples of solid materials containing dioxins/furans or HCB that may be released on site or transferred off site.

Are Your Measured Concentrations Equal to or Above LoQ?

When comparing measured concentrations to LoQ values, measurements should be made of on-site releases and off-site transfers representative of your facility's normal operating conditions or production levels. If you determine that your measured concentrations are equal to or above the LoQ, then you must estimate and report the quantities of on-site releases and off-site transfers for the 2000 calendar year using these concentrations. Enter Code "AL" (At or above LoQ) in the "Detail" code field in the NPRI reporting software.

Are Your Measured Concentrations Below LoQ?

When comparing measured concentrations to LoQ values, measurements should be made of on-site releases and off-site transfers representative of your facility's normal operating conditions or production levels. If you directly measure dioxins/furans and HCB in an on-site release or off-site transfer resulting from incidental manufacture from an activity listed in Tables 4 or 5, and the concentrations are below LoQ, reporting the quantities released on site and transferred off site is optional. You must select one of two Detail codes. If you enter Code "BL" for concentrations below LoQ, you are not required to enter the quantities released or transferred. If you enter Code "BQ" for concentrations below LoQ, you have chosen to report the quantities released or transferred.

Example

A facility has directly measured dioxins/furans resulting from incineration of non hazardous solid waste (incidental manufacture of dioxins/furans from an activity listed in Table 4). The facility determined that dioxins/furans were released to air from a stack at a concentration of 20 pg TEQ/m3 . The measured concentration is below the LoQ of 32 pg TEQ/m3, so the facility does not need to report the quantities of dioxins/furans released on site from stacks. The facility will report that releases to air of dioxins/furans from the stack are below LoQ (Detail code "BL").

Dealing with Multiple Data Points and Non-detected Values

If you have several sets of directly measured concentrations for a given release or transfer, you should compare the average or mean value of all the concentrations with the appropriate LoQ. The method detection limit (MDL) is the smallest concentration of the substance under analysis (analyte) that produces an instrumental response and that meets all analyte detection and identification criteria of a specified test method. If some of the concentration data are below the MDL (i.e., they are non-detected), you should use a value of one-half the MDL to calculate the mean concentration for comparison with the LoQ and to calculate the quantities of dioxins/furans and HCB released on site or transferred off site.

5.5.2 Emission Factors

As defined in the Guide for Reporting, an emission factor is based on average measured emissions from several similar processes. Emission factors usually express releases as a ratio of quantity released to process or equipment throughput. In the absence of data from direct measurements, your facility should estimate on-site releases or off-site transfers of dioxins/furans or HCB as a result of incidental manufacture, using emission factors that you possess or to which you have reasonable access. Enter Code "E" in the "Basis of Estimate" field in the NPRI reporting software.

Emission factors may be developed for one or more facilities using measured data under similar process conditions. Environment Canada compiled many emission factors for activities in Tables 4 and 5 in the Emission Factor Database for Alternate-Threshold Substances (see Appendix 9). You should indicate, in the "Comments" field of the NPRI reporting software, the source of any emission factor used. If Environment Canada has included an emission factor for your activity in the Emission Factor Database for Alternate-Threshold Substances, but you choose not to use it, you should provide your reason in the "Comments" field.

If you use emission factors to estimate on-site releases and off-site transfers, you must report the quantities released or transferred. You cannot report that your concentrations for a specific on-site release or off-site transfer are below the LoQ.

5.5.3 No On-site Releases to a Specific Medium or Transfers Off Site

If there are no dioxins/furans or HCB released on site to a given medium or transferred off site from the facility for the specified activity, the facility should report "Not applicable" for that medium or transfer category for that substance. Enter Code "NA" in the "Basis of Estimate" field in the NPRI reporting software, indicating that there were no releases to the given medium or transfers off site for that category.

For example, if dioxins/furans were only released to air from a combustion process of an activity listed in Table 4 or 5, and there was no related process with releases to water as a result of that activity, the facility reports "Not applicable" for on-site releases of dioxins/furans to water. Similarly, if there were no off-site transfers of material from the activity that generates the dioxins/furans, report "Not applicable" for each off-site transfer category.

5.5.4 No Information Available

If information is not available for releases to a specific medium or for an off-site transfer, either through direct measurements, emission factors or some other source to which the facility possesses or may reasonably be expected to have access, then the facility should report "No information available" for on-site releases to that medium or for that type of off-site transfer. Enter Code "NI" in the "Basis of Estimate" field in the NPRI reporting software. If you report "No information available" for an activity for which Environment Canada has included an emission factor in the Emission Factor Database for Alternate-Threshold Substances, you should provide your reason for not using the values in the emission factor database in the "Comments" field of the NPRI reporting software.

* Virtual elimination of a toxic substance released into the environment as a result of human activity, is defined in subsection 65(1) of the CEPA (1999) as "the ultimate reduction in the quantity or concentration of the substance in the release below the level of quantification (LoQ)".