Annex 2: Potential Emissions

ANNEX 2

POTENTIAL EMISSIONS (FORMERLYTIER 1 FOR CONSUMPTION OF HFCs,PFCs, AND SF6)

2006 IPCC Guidelines for National Greenhouse Gas Inventories

A2.1

Volume 3: Industrial Processes and Product UseAuthors
Paul Ashford (UK) and Jochen Harnisch (Germany)

A2.2

2006 IPCC Guidelines for National Greenhouse Gas Inventories

Annex 2: Potential Emissions

ContentsAnnex 2

Potential Emissions (formerly Tier 1 for consumption of HFCs, PFCs, and SF6) ...........................A2.4

A2.1

Basic method to calculate potential emissions .............................................................................A2.4

A2.2

Additional calculations for estimating potential emissions according to the former Tier 1b .......A2.6

References....................................................................................................................................................A2.7

Equations
Equation A2.1 ............................................................................................................................................A2.4
Equation A2.2 ............................................................................................................................................A2.5
Equation A2.3 ............................................................................................................................................A2.5
Equation A2.4 ............................................................................................................................................A2.6
Equation A2.5 ............................................................................................................................................A2.6
Equation A2.6 ............................................................................................................................................A2.6
Equation A2.7 ............................................................................................................................................A2.7
Equation A2.8 ............................................................................................................................................A2.7

TablesTable A2.1

Calculation scheme for potential emissions according to the former Tier 1a.....................A2.5

2006 IPCC Guidelines for National Greenhouse Gas InventoriesA2.3

Volume 3: Industrial Processes and Product Use

ANNEX 2
A2.1

POTENTIAL EMISSIONS (FORMERLY TIER 1
FOR CONSUMPTION OF HFCs, PFCs, AND SF6)

BASIC METHOD TO CALCULATE POTENTIALEMISSIONS

The following approach, formerly the Tier 1 approach for estimating ‘potential’ emissions related to theconsumption of hydrofluorocarbons (HFCs), perfluorocarbons (PFCs) and sulphur hexafluoride (SF6), is nolonger recommended as a method for estimating HFCs, PFCs, or SF6 emissions. This is because it is likely togrossly overestimate emissions from sources in which stock is growing quickly and emissions are delayed fordecades, such as air conditioning and refrigeration equipment, foams, and electrical equipment. However, when
considered along with estimates of actual emissions, the potential emissions approach can assist in validation ofcompleteness of sources covered and as a QC check by comparing total domestic consumption as calculated inthis ‘potential emissions approach’ per compound with the sum of all activity data of the various uses. It may
also assist in monitoring the growth of banked greenhouse gases and thereby provide an indication of potential
future environmental burdens. Thus, the method is included here for reference purposes e.g., to facilitate
consistent time series.
Since net consumption of a chemical is equal to production plus imports minus exports, the calculation formulafor the basic method (former Tier 1) is as follows:

EQUATION A2.1
Potential SF6 emissions from all uses = Production + (Imports − Exports ) − Destruction

Production refers to production of new chemical. Reprocessing of recovered fluid should not be included.
Imports and exports include bulk chemicals and may or may not include the quantity of chemical contained inproducts, such as refrigerators, air-conditioners, packaging materials, insulating foams, fire extinguishers, etc.
Although destruction of HFCs, PFCs, and SF6 is currently not widely practised, and may be technically difficult
in some cases, it should be included as a potential option to reduce emissions. By-product emissions during
HFC, PFC, and SF6 production and fugitive emissions related to production and distribution have to becalculated separately.
There are two versions that formerly had been labelled Tier 1 (a and b) depending upon whether HFCs, PFCs,and SF6 in products are taken into account. In the former Tier 1a, chemicals contained in products are notconsidered. In the former Tier 1b, chemicals contained in products are considered. The reason for two versions
is that it is expected that there may be difficulties in many countries with the availability of data regarding
imports and exports of HFCs, PFCs, and SF6 in products, at least in the short term. The former Tier 1b
methodology is preferred if relevant data are available. As an alternative, alternative activity data can be used totake into account consumption (potential emissions) associated with the trade of products containing HFCs,PFCs, and SF6.
If countries choose to develop potential emission estimates, they are encouraged to track individual HFCs, PFCs,and SF6 separately. However, such tracking (particularly for imports and exports) is complicated by the fact thatmany of the commercial types of HFC/PFC refrigerants, blowing agents, solvents, etc. are mixtures of two or
more HFCs and/or PFCs. It is important to note that the composition of fluids for similar purposes may vary
according to individual formulas developed by the different chemical companies.

Former Tier 1aQuantities of HFCs, PFCs, and SF6 contained in various products imported into or exported from a country may
be difficult to estimate. In the former Tier 1a, only chemicals imported or exported in bulk are considered in thecalculation of potential emissions, which is a similar approach presently used to report Ozone Depleting
Substances (ODS) under the Montreal Protocol. The following definitions apply:A2.4

2006 IPCC Guidelines for National Greenhouse Gas InventoriesAnnex 2: Potential Emissions

EQUATION A2.2
Imports = Imported HFC/PFC/SF 6 in bulk
Exports = Exported HFC/PFC/SF 6 in bulk

The application of the former Tier 1a may lead to underestimation or overestimation of potential emissions,depending on whether the majority of products containing HFCs, PFCs, and SF6 is being imported or exported.
Data on production and exports of chemicals in bulk should be available from chemical companies. Information
on imports of chemicals in bulk may be available from customs services. National environmental protection
authorities may keep records of HFCs, PFCs, and SF6 destroyed, if any.
Potential emission data for each individual chemical should be calculated according to the scheme in Table A2.1:
TABLE A2.1
CALCULATION SCHEME FOR POTENTIAL EMISSIONSACCORDING TO THE FORMER TIER 1a
REPORTING YEAR:TYPE OF CHEMICAL (e.g., HFC-134a):
Production of chemical+ Import of chemical in bulk
– Export of chemical in bulk
– Destruction of chemical= Sum (potential emission of chemical)

Emissions related to production and distribution of HFCs, PFCs, and SF6 have to be taken into account as
described in Section 3.10, Fluorochemical Production.

Former Tier 1bThe former Tier 1b is an extension of the former Tier 1a and includes HFCs, PFCs, and SF6 contained in various
products which are imported and exported. The following definitions then apply:
EQUATION A2.3
Imports = Imported chemical in bulk
+ quantity of chemical imported in HFC/PFC/SF 6 containing products
Exports = Exported chemical in bulk
+ quantity of chemical exported in HFC/PFC/SF 6 containing products

Data on production and exports of HFCs, PFCs, and SF6 in bulk should be available from the chemicalcompanies to their national governments. Information on imports of bulk chemicals should be available fromcustoms services, as well as, in theory, imports and exports of products and equipment containing HFCs, PFCs,and SF6. However, in practice, tariff codes do not normally distinguish between those products and equipment
containing HFCs, PFCs, and SF6 and those which do not. Accordingly, the use of the alternative activity
estimates for HFCs, PFCs, and SF6 contained may be helpful. National environmental protection authorities may
keep records of HFCs, PFCs, and SF6 destroyed.
To calculate the potential emissions according to the former Tier 1b, the calculation scheme in Table A2.1 has tobe extended to include the import and export of chemicals in products. Section A2.2 demonstrates a possible
set-up, based on refrigeration equipment, foam products, fire extinguisher equipment, solvent and aerosols, forcalculation of emissions from exports/imports and the results should be added to the emissions calculated using
Table A2.1. In Section A2.2, HFC-xxx is used as an example to demonstrate the procedure, which in practicewill have to be performed for each individual HFC, PFC and for SF6.

2006 IPCC Guidelines for National Greenhouse Gas Inventories

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Volume 3: Industrial Processes and Product Use

A2.2

ADDITIONAL CALCULATIONS FOR
ESTIMATING POTENTIAL EMISSIONSACCORDING TO THE FORMER TIER 1b

REFRIGERATIONEQUATION A2.4
G HFC − xxx = G (Unit i ) • n(Unit i ) • FHFC − xxx (Unit i ) + L + G (Unit m ) • n(Unit m ) • FHFC − xxx (Unit m )Where:GHFC-xxx = total import (export) of HFC-xxx in pre-charged refrigeration units1
G(Unit i) = refrigerant charge in a refrigeration unit of type i (i = i → m)n(Unit i) = number of refrigeration units of type i imported (exported)
FHFC-xxx(Unit i) = fraction of component HFC-xxx2 in the refrigerant (mixture) of a unit of type i

FOAM PRODUCTS 3
EQUATION A2.5
G HFC − xxx = V (Foam i ) • J HFC − xxx (Foam i ) + L + V (Foam m ) • J HFC − xxx (Foam m )Where:
GHFC-xxx = total import (export) of HFC-xxx in foams (flexible and rigid)
V(Foam i) = volume of foam of type i imported (exported) (i = i → m)
JHFC-xxx(Foam i) = remaining amount of blowing agent HFC-xxx per volume unit of foam of type i

FIRE EXTINGUISHERS (PRE-CHARGED)
EQUATION A2.6
G HFC − xxx = G (Unit i ) • n(Unit i ) • FHFC − xxx (Unit i ) + L + G (Unit m ) • n(Unit m ) • FHFC − xxx (Unit m )Where:
GHFC-xxx = total import (export) of HFC-xxx in pre-charged fire extinguishers
G(Unit i) = charge of fire extinguishing agent in a fire extinguishing unit of type i (i = i → m)n(Unit i) = number of fire extinguishing units of type i imported (exported)
FHFC-xxx(Unit i) = fraction of component HFC-xxx4 in the fire extinguishing agent of a unit of type i

1‘Refrigeration units’ may be refrigerators, ice machines, AC window units, split-units, chillers etc.

2Many refrigeration units will contain HFC/PFC-mixtures. The fraction of each chemical (HFC-xxx) has to be considered.

3

Include insulating and non-insulating foams in a variety of products, like refrigerators, insulation panels, prefabricated pipe
section, PU formulated systems, etc.

4Many fire extinguishing units will contain HFC/PFC-mixtures. The fraction of each chemical (HFC-xxx) has to beconsidered.

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2006 IPCC Guidelines for National Greenhouse Gas Inventories

Annex 2: Potential Emissions

SOLVENTSEQUATION A2.7
G HFC − xxx = G (Solvent i ) • FHFC − xxx (Solvent i ) + L + G (Solvent m ) • FHFC − xxx (Solvent m )Where:
GHFC-xxx = total import (export) of HFC-xxx in solvents
G(Solvent i) = quantity of solvent of type i imported (exported) (i = i → m)
FHFC-xxx(Solvent i) = fraction of component HFC-xxx5 in solvent of type i

AEROSOLS
EQUATION A2.8
G HFC − xxx = G (Can i ) • n(Can i ) + L + G (Can m ) • n(Can m )Where:
GHFC-xxx = total import (export) of HFC-xxx in aerosol cans
G(Can i) = charge of HFC-xxx propellant in an aerosol can of type i (i = i → m)n(Can i) = number of aerosol cans of type i imported (exported)

References
IPCC (1997). Revised 1996 IPCC Guidelines for National Greenhouse Inventories. Houghton J.T., Meira Filho
L.G., Lim B., Tréanton K., Mamaty I., Bonduki Y., Griggs D.J. Callander B.A. (Eds). Intergovernmental
Panel on Climate Change (IPCC), IPCC/OECD/IEA, Paris, France.

5

Solvents will often not be pure HFCs or PFCs. The HFC/PFC fraction in the solvent composition (HFC-xxx) has to beconsidered.

2006 IPCC Guidelines for National Greenhouse Gas Inventories

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