MONTREAL PROTOCOL

ON SUBSTANCES THAT DEPLETE

THE OZONE LAYER

UNEP

REPORT OF THE

HALONS TECHNICAL OPTIONS COMMITTEE

DECEMBER 2014

VOLUME 1

2014 ASSESSMENT REPORT
ii

UNEP

REPORT OF THE HALONS TECHNICAL OPTIONS COMMITTEE

DECEMBER 2014

VOLUME 1

2014 ASSESSMENT REPORT
iii

Montreal Protocol

On Substances that Deplete the Ozone Layer

Report of the

UNEP Halons Technical Options Committee

December 2014

Volume 1

2014 ASSESSMENT REPORT

The text of this report is composed in Times New Roman

Co-ordination: Halons Technical Options Committee

Composition of the report: Halons Technical Options Committee

Reproduction: UNEP Ozone Secretariat

Date: December 2014

Under certain conditions, printed copies of this report are available from:

UNITED NATIONS ENVIRONMENT PROGRAMME

Ozone Secretariat, P.O. Box 30552, Nairobi, Kenya

This document is also available in portable document format from the UNEP Ozone Secretariat’s 

website:

http://ozone.unep.org/en/assessment_panels_bodies.php?committee_id=6

No copyright involved. This publication may be freely copied, abstracted and cited, with 

acknowledgement of the source of the material.

ISBN: 978-9966-076-04-5
iv

Disclaimer

The United Nations Environmental Programme (UNEP), the Technology and Economic 

Assessment Panel (TEAP) Co-chairs and members, the Technical and Economics Options 

Committees, Co-chairs and members, the TEAP Task Forces Co-chairs and members, and the 

companies and organisations that employ them do not endorse the performance, worker safety, or 

environmental acceptability of any of the technical or economic options discussed. Every 

industrial operation requires consideration of worker safety and proper disposal of contaminants 

and waste products. Moreover, as work continues - including additional toxicity evaluation -

more information on health, environmental and safety effects of alternatives and replacements 

will become available for use in selecting among the options discussed in this document.

UNEP, the TEAP Co-chairs and members, the Technical and Economic Options Committees Cochairs and members, and the TEAP Task Forces Co-chairs and members, in furnishing or 

distributing the information that follows, do not make any warranty or representation, either 

expressed or implied, with respect to the accuracy, completeness or utility; nor do they assume 

any liability of any kind whatsoever resulting from the use or reliance upon any information, 

material, or procedure contained herein, including but not limited to any claims regarding health, 

safety, environmental effect or fate, efficacy, or performance, made by the source of the material.

Mention of any company, association, or product in this document is for information purposes 

only and does not constitute a recommendation of any such company, association, or product, 

either expressed or implied by UNEP, the Technology and Economic Assessment Panel Cochairs or members, the Technical and Economics Options Committees Co-chairs or members, the 

TEAP Task Forces Co-chairs or members, and the companies and organisations that employ 

them.
v

Dedication

Since the last Assessment Report, a founding member of the Halons Technical Options 

Committee has passed away. This report is dedicated to the memory of:

Philip J. DiNenno

Acknowledgements

The UNEP Halons Technical Options Committee (HTOC) acknowledges with thanks the 

outstanding contributions from all individuals and organisations that provided technical support 

to Committee members. 

The opinions expressed are those of the Committee and do not necessarily reflect the views of 

any sponsoring or supporting organisations.

The following persons were instrumental in developing this report:

Committee Co-chairs

David Catchpole

PRA

United Kingdom

Dr. Sergey Kopylov

All Russian Research Institute for Fire Protection

Russian Federation

Dr. Daniel Verdonik

Hughes Associates, Inc.

USA

Committee Members

Tareq K. Al-Awad

King Abdullah II Design & Development Bureau

Jordan

Jamal Alfuzaie

Kuwait Fire Department

Kuwait

Seunghwan (Charles) Choi

Hanju Chemical Co., Ltd.

South Korea
vi

Adam Chattaway

UTC Aerospace Systems

UK

Dr. Michelle Collins

EECO, Inc.

USA

Salomon Gomez

Tecnofuego

Venezuela

Carlos Grandi

Embraer

Brazil

Andrew Greig

Protection Projects, Inc.

South Africa

H.S. Kaprwan

Consultant–Retired

India

John O’Sullivan, M.B.E.

Bureau Veritas

United Kingdom

Emma Palumbo

Safety Hi-tech srl

Italy

Erik Pedersen

Consultant–World Bank

Denmark

Donald Thomson

MOPIA

Canada

Filippo Tomasello

European Aviation Safety Agency

Italy

Robert Wickham

Consultant-Wickham Associates

USA
vii

Mitsuru Yagi

Nohmi Bosai Ltd. & Fire and Environment Protection Network

Japan

Consulting Experts

Tom Cortina

Halon Alternatives Research Corporation

USA

Matsuo Ishiyama

Nohmi Bosai Ltd. & Fire and Environment Protection Network

Japan

Dr. Nikolai Kopylov

All Russian Research Institute for Fire Protection

Russia

Dr. David Liddy

Consultant – Retired

United Kingdom

Steve McCormick

United States Army

USA

John G. Owens

3M Company

USA

Dr. Mark Robin

DuPont, Inc.

USA

Dr. Joseph Senecal

Kidde-Fenwal, Inc.

USA

Dr. Ronald Sheinson

Naval Research Laboratory – Retired

USA

Ronald Sibley

Consultant–Defence Supply Center

USA
viii

TEAP Senior Expert

Bella Maranion

United States Environmental Protection Agency

USA

Peer Reviewers

The Halons Technical Options Committee also acknowledges with thanks the following peer 

reviewers who took time from their busy schedules to review the draft of this report and provided 

constructive comments. At the sole discretion of the Halons Technical Options Committee, these 

comments may or may not have been accepted and incorporated into the report. Therefore, 

listing of the Peer Reviewers should not be taken as an indication that any reviewer endorses the 

content of the report, which remains solely the opinion of the members of the Committee.

Marie-Eve Brihaye - DGAC/DSAC NO/ST, France

Bradford Colton - American Pacific Corporation, USA

John Demeter - Wesco, USA

Brent Ehmke - Ehmke Associates, USA

Louise Jackman - Suppresion and Fire Safety, UK

Steve Montzka - NOAA, USA

Pete Mullenhard - Leidos, USA

Yoshio Ogawa - National Research Institute of Fire and Disaster, Japan

Milosh Puchovsky – Worcester Polytechnic Institute, USA

Michael Stevens – NASA, USA

Dawn Turner - Manitoba Hydro, Canada
ix

UNEP

REPORT OF THE HALONS TECHNICAL OPTIONS COMMITTEE

DECEMBER 2014

VOLUME 1

2014 ASSESSMENT REPORT

Table of Contents

Executive Summary.........................................................................................................................2

1.0 Global Estimated Inventories of Halons..............................................................................5

1.1 Emissions and Inventories of Halon 1301 ...............................................................5

1.2 Emissions and Inventories of Halon 1211 ...............................................................8

1.3 Emissions and Inventories of Halon 2402. ............................................................11

2.0 Civil Aviation .....................................................................................................................14

2.1 Introduction............................................................................................................14

2.2 Estimated Halon Installed Base and Emissions.....................................................14

2.3 Halon Banks...........................................................................................................14

2.4 Status of Halon Replacement Options...................................................................14

2.4.1 Lavatory Trash Receptacle.........................................................................15

2.4.2 Handheld Extinguishers.............................................................................15

2.4.3 Engine and APU Compartment..................................................................15

2.4.4 Cargo Compartments .................................................................................15

2.5 Regulatory Timelines.............................................................................................15

2.6 New Generation Aircraft........................................................................................16

2.7 Crash Rescue Vehicles...........................................................................................16

3.0 Military Applications.........................................................................................................17

3.1 Ground Vehicle Applications.................................................................................17

3.2 Military Aviation Applications...............................................................................18

3.3 Naval Applications.................................................................................................19

3.4 Conclusion .............................................................................................................19

4.0 Pipelines / Oil and Gas.......................................................................................................22

5.0 Global/Regional Supply and Demand Balance..................................................................23

6.0 Global Halon 1211, 1301, and 2402 Banking....................................................................24

7.0 Fire Protection Alternatives To Halons..............................................................................25

8.0 Climate Considerations for Halons and Alternatives.........................................................26
x

9.0 Recommended Practices for Recycling Halon and Halocarbon Agent Alternatives.........28

10.0 Halon Emission Reduction Strategies................................................................................29

11.0 Destruction.........................................................................................................................30

Appendix A: List of Acronyms and Abbreviations ...................................................... A-1

Appendix B: Definitions................................................................................................B-1
xi

List of Tables

Table 1-1: HTOC 2014 Assessment of Current Estimates of Inventories for Halon 1301 in MT.. 6

Table 1-2: HTOC 2014 Assessment of Current Estimates of Inventories for Halon1211 in MT... 9

Table 1-3: HTOC 2014 Assessment of Current Estimates of Inventories for Halon2402............ 12

Table 3-1: Continuing Uses of Halons and Examples of Implemented and Potential Alternatives 

in the Military Sector .................................................................................................. 20
Page 1 of 30

Preface

The December 2014 HTOC Report consists of three volumes:

Volume 1: 2014 Assessment Report

Volume 2: 2014 Supplementary Report #1 – Civil Aviation 

Volume 3: 2014 Supplementary Report # 2 – Global Halon 1211, 1301, and 2402 Banking

The HTOC has taken a different approach to the reporting of its 2014 Assessment than in 

previous years. In the past, the report was an accumulation of all the information that the HTOC 

had gathered – some that had not changed over the years - plus new, updated information. This 

made the report large and unwieldy to some readers, and the important messages that the HTOC 

wanted to convey were getting lost.

For 2014, the HTOC has decided to slim down the report so that the main body will concentrate 

on new/changed information and important messages for the Parties to consider. The background 

information for two topics that may be of particular interest to some Parties are included as 

Supplementary Reports, with only new and important information in the main body of this 

report. These are Civil Aviation, and Global Halon 1211, 1301 and 2402 Banking. In addition, 

information that has been reported on in the past, which has been updated, and which is 

considered useful reference material, will be found in one of five Technical Notes: Fire 

Protection Alternatives to Halons; Halon Emission Reduction Strategies; Explosion Protection –

Halon Use And Alternatives; Recommended Practices For Recycling Halon and Halocarbon 

Alternatives; and Halon Destruction. These technical notes may be further updated on an annual 

basis in conjunction with HTOC Progress Reports.
Page 2 of 30

Executive Summary

The HTOC is of the opinion that despite the introduction of new halon alternatives and the 

remarkable progress in switching to them, there is still an on-going need for halons for service, in 

particular legacy systems. As such, halon recycling is becoming even more important to ensure 

that adequate stocks of halons are available to meet the future needs of the Parties.

Inventories of Halons

1. The rates of halon emissions based on atmospheric measurements of halon concentrations 

are similar to the rates of emissions based on model estimates. The estimated size of the 

global halon banks in 2014 are: halon 1211 - 33,000 MT; halon 1301 - 43,000 MT; and 

halon 2402 - 9,000 MT.

2. The total quantities of inventories of halons are not necessarily available for 

redeployment for multiple reasons, e.g.:

a. It is often the case that the quantities, locations and availability of halons stocks are 

not known either within countries or regions;

b. Where halon quantities and locations are known it is because owners want to preserve 

these materials for their own use.

c. Many countries have no halon bank management programme for connecting 

recyclable halon to users.

d. Numerous reports have indicated halon quality is suspect due to lack of controls and 

infrastructure.

Thus, while the actual quantities of halons may be substantial, their use is jeopardized by 

political borders, suspect quality, and uncertain quantities in specific locations.

3. The 2010 HTOC report projected a 2014 halon 1211 bank of approximately 50,000 MT, 

while the 2014 HTOC report estimates a bank of 33,000 MT. This is because the HTOC 

has raised its assumed emission rates for halon 1211, based on a recent assessment of the 

likely emissions from retired portable extinguishers, particularly in A5 Parties.

4. Although the regional disparity in the distribution of halon itself does not constitute 

necessarily a regional problem, it is anticipated that regional imbalances may result in 

shortages in one country or region with excesses in other countries and regions.

5. The HTOC has a serious concern that many users are relying on halon imports for their 

most important uses, such as civil aviation and military.

6. Some A5 users are now encountering difficulties obtaining sufficient quantities of halon, 

with potential serious consequences.

7. Parties may wish to revisit the global strategic approach to halon bank management in 

order to avoid a severe supply disruption that would lead to an Essential Use Nomination. 

This could include development of updated training and awareness materials and 

programs, which address the harmonization of import and export regulations, purity and 

other halon bank management needs.
Page 3 of 30

Civil Aviation

1. The fact that alternatives are used only in the lavatory fire extinguishing systems of inproduction aircraft is a remarkably disappointing result, especially given the extensive 

research and testing efforts on aviation applications since 1993.

2. To date, the two low GWP candidates for engine nacelles have not passed all required 

tests by the civil aviation safety authorities. Airframe manufacturers have chosen not to 

pursue qualification and installation certification for HFC-125 owing to weight penalties 

and more recently, growing controls by individual jurisdictions.

3. The civil aviation industry has decided to develop a single agent/approach and has

formed the Engine/APU Halon Alternatives Industry Consortium (IC).

4. The International Coordinating Council of Aerospace Industries Associations (ICCAIA) 

has formed the Cargo Compartment Halon Replacement Working Group (CCHRWG) to 

begin to coordinate a single industry effort to find an alternative to halon 1301 in cargo 

bays.

5. While the halon requirements of civil aviation initially appear modest in comparison to 

the total inventory available today, civil aviation neither owns nor controls the ever 

reducing quantities of halons needed to support existing aircraft, much less new aircraft, 

for an additional 30 or more years.

6. Of all the sectors, civil aviation is the least prepared to deal with diminishing halon 

supplies and, with the ultimate exhaustion of supplies, this sector will most likely be the 

one to request an Essential Use Nomination in the future.

Military

1. Generally speaking, halon is only required to support legacy systems and their variants, 

and new military aircraft based on commercial designs with airworthiness certifications. 

Alternatives are available for all other new system designs.

2. The ultimate requirement of the military sector for halons cannot be calculated owing to 

the obvious uncertainty of future mission requirements. 

3. It is unclear how many military organizations have made provisions to secure long-term 

supplies of halons.

4. Some military organizations are known to be completely reliant upon sources of halons 

outside of their own countries.

5. Adverse geopolitical events might lead to increased rates of depletion of known halon 

stocks and loss of access to out-of-country supplies.

6. Unlike the civil aviation sector, the military sector has incorporated alternatives to halons 

on many of its newer platforms, reducing its future demand for the diminishing supplies 

of halons.

Oil & Gas Operations

1. Generally speaking, halon is only required to support legacy facilities; all new facilities 

are halon-free.

2. Legacy facilities in the far north will continue to require the use of halons in occupied 

spaces owing to severe ambient (very low temperature) conditions.

3. Facility owners neither own nor control the quantities of halons needed to support 

operations over the continually extended time horizons. This situation will continue to 
Page 4 of 30

place demands on the level of available halon stocks. However, owing to the adoption of 

alternatives in new facilities, this sector has reduced its future demand for the diminishing 

supplies of halons.

Alternatives Technologies

1. While no single alternative has been commercialized that covers the wide range of 

applications of halons, there are a multitude of alternatives that collectively can be used 

to meet the fire protection requirements of all non-aviation future applications, although 

with technical or economic penalties, or both and likely civil aviation future applications 

also with technical or economic penalties. Civil aviation has yet to try to validate and 

implement technically viable solutions with weight and/or space penalties.

2. Some applications, including those in the military, aviation, and oil & gas sectors, require 

use of high-GWP chemical alternatives or the original halon to meet the fire protection 

requirements.

3. Five new low-GWP chemicals are in various stages of evaluation as alternatives for 

halons; none of these prospective alternatives are expected to be commercially available 

for years, if at all.
Page 5 of 30

1.0 Global Estimated Inventories of Halons

As in previous assessment reports, the HTOC is providing the most current estimates of 

inventories for halon 1211 and halon 1301 based on modelling of reported production and 

estimated emissions. These models have been updated to reflect quantities that have been 

reported as destroyed and new emission patterns based on the latest information available. For 

halon 2402, open literature information has been found on production in the former Soviet 

Union. Based on that information, and other estimates, the HTOC has now developed a model 

for halon 2402 similar to the halon 1211 and 1301 models. 

1.1 Emissions and Inventories of Halon 1301

Table 1-1 provides the HTOC 2014 Assessment of estimates of total production, annual 

emissions, cumulative emissions and resulting inventories (bank) for halon 1301 from 2014 -

2044. The HTOC model emissions and bank estimates compare quite well with emissions 

derived from mixing ratios reported by the Science Assessment Panel (SAP) in Scientific 

Assessment of Ozone Depletion: 2014. The SAP estimated cumulative emissions through 2014 

of 108,000 MT, which would provide a remaining bank of 41,000 MT versus the HTOC model 

estimate of 106,000 MT of cumulative emissions and a remaining bank of 43,000 MT. The 

emissions and bank for Japan are consistent with those reported by the Japanese Fire and 

Environment Protection Network. The emissions for Europe are consistent with the latest 

estimates from O’Doherty et al., (2014) of North West Europe emissions from 1995 – 2013. This 

implies that a significant amount of halon 1301 is still contained within Europe. Figure 1-1 

provides the regional distribution of the global inventory of halon 1301 and shows that according 

to the HTOC Model for halon 1301, at the end of 2014 nearly 40% of the current inventory of 

halon 1301 is projected to be in Japan and 33% in North America. Although the regional 

disparity in the distribution of halon itself does not constitute necessarily a regional imbalance, it 

is anticipated that regional imbalances may result in shortages in one country or region with 

excesses in other countries and regions.
Page 6 of 30

Table 1-1: HTOC 2014 Assessment of Current Estimates of Inventories for Halon 1301 in MT

2014 2019 2024 2029 2034 2039 2044

CUMULATIVE PRODUCTION

North America, Western Europe and Japan 135,783 135,783 135,783 135,783 135,783 135,783 135,783

former Countries with Economies in Transition 1,385 1,385 1,385 1,385 1,385 1,385 1,385

Article 5 11,643 11,643 11,643 11,643 11,643 11,643 11,643

TOTAL CUMULATIVE PRODUCTION 148,781 148,781 148,781 148,781 148,781 148,781 148,781

ANNUAL EMISSIONS

North America 477 402 338 285 240 195 165

Western Europe and Australia 238 201 170 143 121 99 83

Japan 25 25 25 24 24 24 24

former Countries with Economies in Transition 69 56 45 36 29 22 18

Article 5 393 235 140 83 50 27 16

TOTAL ANNUAL EMISSIONS 1,203 918 718 572 464 367 306

CUMULATIVE EMISSIONS

North America 29,402 31,556 33,370 34,898 36,185 37,232 38,114

Western Europe and Australia 24,511 25,589 26,499 27,267 27,916 28,445 28,892

Japan 10,366 10,490 10,614 10,737 10,859 10,979 11,099

former Countries with Economies in Transition 6,613 6,916 7,161 7,358 7,516 7,638 7,736

Article 5 35,263 36,721 37,590 38,109 38,418 38,585 38,684

TOTAL CUMULATIVE EMISSIONS 106,154 111,272 115,234 118,369 120,893 122,879 124,525

INVENTORY (BANK)

North America 13,654 11,500 9,686 8,158 6,871 5,824 4,942

Western Europe and Australia 6,916 5,838 4,928 4,159 3,511 2,982 2,535

Japan 16,888 16,764 16,640 16,517 16,396 16,275 16,155

CEIT 1,556 1,252 1,008 811 653 531 433

Article 5 3,613 2,155 1,285 766 457 291 192

GLOBAL INVENTORY (BANK) 42,627 37,508 33,546 30,412 27,887 25,902 24,256
Page 7 of 30

Figure 1-1: Breakout of Global Inventories (Bank) of Halon 1301 by HTOC Model Regions

North America

North America North America North America

Western Europe 

and Australia

Western Europe 

and Australia Western Europe and 

Australia Western Europe and 

Australia

Japan

Japan

Japan

Japan

CEIT

A5(1)

A5(1)

0

5,000

10,000

15,000

20,000

25,000

30,000

35,000

40,000

45,000

2014 2024 2034 2044

Metric Tonnes of Halon 1301

Year
Page 8 of 30

1.2 Emissions and Inventories of Halon 1211

Table 1-2 provides the HTOC 2014 Assessment of estimates of total production, annual 

emissions, cumulative emissions and resulting inventories (bank) for halon 1211 from 2014 -

2044. The HTOC is concerned with the status of banking capabilities in some regions of the 

world and the handling of halon 1211. As a result, the HTOC is changing its assumptions on 

emissions as a percentage of the bank. It is believed that global emissions of halon 1211 are 

higher than previously proposed. The HTOC 2014 Assessment has increased the emissions, 

which results in a significantly smaller inventory (bank) as compared with the 2006 and 2010 

Assessments. The HTOC 2010 Assessment projected a 2014 halon 1211 bank of approximately 

50,000 MT while the HTOC 2014 Assessment estimates a bank of 33,000 MT. These lower 

estimates are consistent with emissions derived from mixing ratios reported by the Science 

Assessment Panel (SAP) in Scientific Assessment of Ozone Depletion: 2014. This is particularly 

true in light of the very large uncertainty in atmospheric measurement derived emissions and the 

sensitivity of atmospheric lifetime in estimating emissions. Newland et al., (2013) showed that 

changing the atmospheric lifetime of halon 1211 from 16 years to 14 years would reduce their

2010 bank estimates from 37,000 MT to 10,000 MT. Conversely, increasing the atmospheric 

lifetime would reduce the amount of resulting emissions and would increase the size of the bank. 

The SAP estimated cumulative emissions through 2014 of 291,000 MT and a remaining bank of 

22,000 MT versus the HTOC model estimate of 280,000 MT of cumulative emissions and a 

remaining bank of 33,000 MT. The HTOC emission estimates for North America are consistent 

with 600 MT average from 2004 – 2006 estimated by Millet et al. (2009) using aircraft 

measurements. The emissions and bank for Japan are consistent with those reported by the 

Japanese Fire and Environment Protection Network. The emissions for Europe are consistent 

with the latest estimates from O’Doherty et al., (2014) of North West Europe emissions from 

1995 – 2013, which implies that a significant amount of halon 1211 is still contained within 

Europe.

Figure 1-2 provides the regional distribution of the global inventory of halon 1211 and shows 

that according to the HTOC model approximately 25% of the current inventory of halon 1211 is 

projected to be in Article 5 Parties at the end of 2014. This is significantly lower than the more 

than 50% projected in the 2010 Assessment, which again is a reflection of HTOC concerns with 

halon 1211 bank management. Although the regional disparity in the distribution of halon itself 

does not constitute necessarily a regional imbalance, it is anticipated that regional imbalances 

may result in shortages in one country or region with excesses in other countries and regions.
Page 9 of 30

Table 1-2: HTOC 2014 Assessment of Current Estimates of Inventories for Halon1211 in MT

2014 2019 2024 2029 2034 2039 2044

CUMULATIVE PRODUCTION

North America, Western Europe and Japan 196,601 196,601 196,601 196,601 196,601 196,601 196,601

CEIT 1,040 1,040 1,040 1,040 1,040 1,040 1,040

Article 5(1) 115,817 115,817 115,817 115,817 115,817 115,817 115,817

TOTAL CUMULATIVE PRODUCTION 313,457 313,457 313,457 313,457 313,457 313,457 313,457

ANNUAL EMISSIONS

North America 457 375 308 253 207 170 140

Western Europe and Australia 538 436 371 301 258 211 160

Japan 12 10 8 6 5 4 3

CEIT 61 41 27 18 12 8 6

Article 5(1) 1,024 582 331 189 107 61 33

TOTAL ANNUAL EMISSIONS 2,092 1,445 1,045 767 591 454 342

591 454 342

CUMULATIVE EMISSIONS

North America 47,774 49,808 51,477 52,847 53,971 54,894 55,651

Western Europe and Australia 74,064 76,446 78,396 80,021 81,351 82,508 83,405

Japan 1,700 1,754 1,798 1,833 1,861 1,883 1,900

CEIT 10,163 10,403 10,564 10,672 10,745 10,793 10,826

Article 5(1) 146,654 150,350 152,453 153,649 154,329 154,717 154,931

TOTAL CUMULATIVE EMISSIONS 280,355 288,761 294,688 299,021 302,257 304,795 306,713

INVENTORY (BANK)

North America 11,342 9,308 7,639 6,270 5,145 4,223 3,466

Western Europe and Australia 12,186 9,804 7,853 6,229 4,899 3,741 2,845

Japan 271 216 173 138 110 88 70

CEIT 730 490 329 221 148 99 67

Article 5(1) 8,573 4,878 2,775 1,579 898 511 297

TOTAL INVENTORY (BANK) 33,102 24,696 18,769 14,436 11,200 8,663 6,744
Page 10 of 30

Figure 1-2: Breakout of Global Inventories (Bank) of Halon 1211 by HTOC Model Region

North America

North America

North America North America

Western Europe 

and Australia

Western Europe 

and Australia

Western Europe 

and Australia Western Europe 

and Australia

A5(1)

A5(1)

A5(1)

0

5,000

10,000

15,000

20,000

25,000

30,000

35,000

2014 2024 2034 2044

Metric Tonnes of halon 1211

Year
Page 11 of 30

1.3 Emissions and Inventories of Halon 2402.

Table 1-3 provides the HTOC 2014 Assessment of estimates of total production, annual 

emissions, cumulative emissions and resulting inventories (bank) for halon 2402 from 2014 -

2044. The HTOC model emissions are within about 20% of those derived from mixing ratios 

reported by the Science Assessment Panel (SAP) in Scientific Assessment of Ozone Depletion: 

2014. The SAP estimated cumulative emissions through 2014 of 41,000 MT versus the HTOC 

model estimate of 50,000 MT of cumulative emissions. It should be noted that this new 

assessment for halon 2402 was not completed in time for consideration by the SAP and is not 

included in Scientific Assessment of Ozone Depletion: 2014. The SAP did not have any 

information on the cumulative production of halon 2402. 

The HTOC estimated cumulative production of halon 2402 from Kopylov N.P., Nikolayev V.M., 

Zhevlakov A.F., Pivovarov V.V., Tselikov V.N., Russian National Strategy for Halon 

Management, Chimizdat, StPetersburg-Moscow, 2003, 39 pp. (in Russian) and by assuming the 

difference between total Article 7 production data for halon in non-Article 5 and the halon 1211 

and 1301 quantities used in the HTOC models, represents additional halon 2402 production 

outside of the former Soviet Union from the years 1986 - 2010. This difference represented 7% 

of the total quantity of halon produced over that period. To estimate the 1963 – 1985 production, 

the 7% factor was applied to the halon 1211 and 1301 production quantities per year. The 

resulting bank of halon 2402 in 2014 was 9,000 MT.
Page 12 of 30

Table 1-3: HTOC 2014 Assessment of Current Estimates of Inventories for Halon2402

2014 2019 2024 2029 2034 2039 2044

CUMMULATIVE PRODUCTION

North America, Western Europe and Japan 23,333 23,333 23,333 23,333 23,333 23,333 23,333

CEIT 35,558 35,558 35,558 35,558 35,558 35,558 35,558

Article 5(1) - - - - - - -

TOTAL CUMMULATIVE PRODUCTION 58,891 58,891 58,891 58,891 58,891 58,891 58,891

ANNUAL EMISSIONS

North America 57 42 31 23 17 12 9

Western Europe and Australia 134 94 66 47 33 23 16

Japan 12 10 8 7 6 5 -

CEIT 391 275 193 136 96 67 47

Article 5(1) 45 30 21 14 10 6 4

TOTAL ANNUAL EMISSIONS 639 451 319 227 162 113 76

CUMMULATIVE EMISSIONS

North America 4,930 5,168 5,344 5,473 5,568 5,638 5,690

Western Europe and Australia 8,662 9,208 9,591 9,861 10,050 10,184 10,278

Japan 860 915 959 996 1,026 1,051 1,064

CEIT 30,202 31,792 32,909 33,696 34,248 34,637 34,910

Article 5(1) 5,278 5,456 5,577 5,659 5,715 5,753 5,779

TOTAL CUMMULATIVE EMISSIONS 49,932 52,539 54,380 55,685 56,607 57,263 57,721

INVENTORY

North America 903 665 489 360 265 195 143

Western Europe and Australia 1,838 1,292 909 639 449 316 222

Japan 306 252 207 171 140 116 103

CEIT 5,356 3,766 2,649 1,862 1,310 921 648

Article 5(1) 556 377 256 174 118 80 54

TOTAL INVENTORY 8,959 6,352 4,510 3,206 2,282 1,628 1,170
Page 13 of 30

Figure 1-3: Breakout of Global Inventories (Bank) of Halon 2402 by HTOC Model Region

North America North America North America

Western Europe and 

Australia

Western Europe and 

Australia

Japan

Japan

CEIT

CEIT

CEIT

CEIT

Article 5(1)

Article 5(1)

0

1,000

2,000

3,000

4,000

5,000

6,000

7,000

8,000

9,000

10,000

2014 2024 2034 2044

Metric Tonnes of halon 2402

Year
Page 14 of 30

2.0 Civil Aviation

2.1 Introduction

Aviation applications of halon are among the most demanding uses of the agents, requiring their 

suppression effectiveness at an acceptable toxicity. For these reasons, it would be expected that 

civil aviation would place a high level of need on replacing halons for aviation uses. However, 

that is not evidenced in their efforts to date. Given the anticipated 25–30 year lifespan of a newly 

produced civil aircraft, halon 1301 dependency could continue beyond the time when recycled 

halon is readily available. A separate Supplementary Report on the status of halon and its 

alternatives in use in civil aviation has been produced, and is summarised below.

2.2 Estimated Halon Installed Base and Emissions

The halon 1301 and halon 1211 installed base estimates for mainline and regional aircraft were 

developed using activity data and fleet assumptions. The total worldwide fleet for 2014 is 

estimated to be approximately 21,000. In order to estimate the installed halon base, activity data 

for engine nacelles, cargo compartments, APUs, lavex systems, and handheld applications from 

previous analyses was used, as well as feedback from airframe manufacturers. It is estimated that 

for 2014, there is approximately 1,500 MT of halon 1301, and approximately 200 MT of halon 

1211 installed across the mainline and regional fleet. 

HTOC Supplemental Report #1: Civil Aviation, details the calculations used for these estimates, 

and also provides estimates for the years 2020, 2025 and 2030.

2.3 Halon Banks

At present, the halon demands of aviation are being met by recycling agent being withdrawn 

from applications in other industries and decommissioned aircraft. This source of supply will be 

dramatically reduced long before the aircraft now being built and fitted with halon systems are 

retired. Of all sectors, civil aviation is the least prepared to deal with diminishing halon supplies. 

Civil aviation has only instituted a halon replacement for its smallest use, lavatory trash 

receptacle extinguishing systems (lavex), estimated to be less than 0.5% of its total installed base 

on aircraft. Its two largest uses, engine nacelles/APUs and cargo compartments, continue to have 

no alternatives available to be approved by aviation authorities. With the ultimate exhaustion of 

supplies, this sector will most likely be the one to request an Essential Use Nomination in the 

future.

2.4 Status of Halon Replacement Options

With the exception of some lavatory trash receptacles, there has been no retrofit of halon systems 

or portable extinguishers with available alternatives in the existing worldwide fleet of aircraft.
Page 15 of 30

2.4.1 Lavatory Trash Receptacle

Research and testing has shown that there are suitable alternative suppression systems (using 

HFC-227ea or HFC-236fa).

2.4.2 Handheld Extinguishers

As of 2003, three halon alternatives, HFC-227ea, HFC-236fa and HCFC Blend B, have 

successfully completed all of the required Minimum Performance Standard (MPS) tests and

handheld extinguishers are commercially available. One other halon alternative, 2-BTP, is in the 

process of being commercialized. Qualification is needed prior to airline use, however, and to 

date this has not happened.

2.4.3 Engine and APU Compartment

HFC-125 has been used successfully as an alternative to halon for engine fire protection on US 

military aircraft developed since the early 1990s. In addition, HFC-125 is currently being 

specified for use on a military derivative of a large commercial aircraft currently under 

development (Boeing 767; military derivative KC-46). HFC-125 has increased space and weight 

characteristics that present installation and environmental concerns. Based on these issues, 

airframe manufacturers have chosen not to pursue qualification and installation certification for 

HFC-125 in engines/APUs.

The civil aviation industry has now decided to develop a single agent/approach and has formed 

the Engine/APU Halon Alternatives Research Industry Consortium (IC). The IC has mapped out 

a 3 phase multi-year approach for alternatives development.

2.4.4 Cargo Compartments

The International Coordinating Council of Aerospace Industries Associations (ICCAIA) has 

formed the Cargo Compartment Halon Replacement Working Group (CCHRWG) to begin to 

coordinate a single industry effort to find an alternative to halon 1301 in cargo bays. Current best 

estimates are that it will take somewhere between 31⁄2 and 6 years to transition from proof of 

concept to a point where a type certificate can be applied for.

2.5 Regulatory Timelines

ICAO Resolution A37-9 mandates halon replacement in ICAO standards in lavatory fire 

extinguishing systems used in aircraft produced after December 30, 2011; in hand-held fire 

extinguishers used in aircraft produced after December 30, 2016; and in engine and auxiliary 

power unit fire extinguishing systems used in aircraft for which application for type certification 

will be submitted after December 30, 2014. However, these are not requirements that states must 

follow. Instead, states can and have filed “differences” indicating that they will not meet these 

standards and will continue to use halons or allow the use of halons past these dates.

Within the European Union, all current on-board uses of halons in aviation are listed as critical 

uses in the current Annex VI to Regulation (EC) No. 1005/2009. Annex VI was revised in 2010 

as per Commission Regulation (EU) No 744/2010 of 18 August 2010 and contains “cut-off 
Page 16 of 30

dates” for the use of halons in new designs of equipment or facilities and “end dates” when all 

halon systems or extinguishers in a particular application must be decommissioned. 

2.6 New Generation Aircraft

The civil aviation regulatory authorities should closely monitor and ensure that the testing and 

approval of alternatives for engine nacelle and cargo compartment applications is completed in 

the near-term for new airframe designs. New airframe designs should take into account these

tested and approved alternative fire suppression agents and systems. However, this is not 

happening to date. The timing of the inclusion of the available halon alternatives in new aircraft 

designs remains uncertain, and unless the processes of designing, conforming, qualifying and 

certifying new extinguishing systems on civil aircraft are made a priority by the airframe 

manufacturers and approval authorities – and expedited accordingly – these are significant 

barriers to the transition away from halons and will place an increasing burden on the 

diminishing supplies of halons.

As reported in the 2010 HTOC Assessment, it is markedly disappointing that, given the extensive 

research and testing efforts that have been expended on aviation applications since 1993, 

alternatives are used only in the lavatory fire extinguishing systems of new Airbus, Boeing and 

Embraer aircraft systems and not yet for any engine/APU, cargo bay, or hand-held extinguisher 

applications.

2.7 Crash Rescue Vehicles

In addition to on-board civil aircraft applications, halon 1211 is used in some Aircraft Rescue 

and Fire Fighting (ARFF) or Crash Rescue vehicles on airport ramps. Since 1995 a significant 

number of airports in the United States have used HCFC Blend B as an alternative to halon 1211 

for this application. However, because HCFC Blend B is an ODS, national regulations may limit 

its use for this application in other countries.

The HTOC Supplementary Report #1: Civil Aviation, can be found on the Ozone Secretariat 

website at:

http://montreal-protocol.org/new_site/en/assessment_panels_bodies.php?committee_id=6

under the HTOC reports.
Page 17 of 30

3.0 Military Applications

Many Parties’ defence ministries and military organisations have invested substantial resources 

to minimize the inadvertent release of halons, recover and recycle these chemicals, and stockpile 

them for future use where alternatives cannot be implemented. These reserves are, in many 

cases, being carefully managed to support a number of weapon system applications for the 

remainder of their service lives or until alternatives can be fitted. At a time when many military 

budgets are decreasing in real terms, service life extension programmes are commonly being 

planned and implemented to maintain many of these weapon systems and equipment well past 

their originally intended design lives. This means that much of today’s fielded equipment will 

remain in operation, and their halon mission-critical fire protection systems will need to be 

supported, to 2050 and potentially beyond.

Military fire protection systems are unique in that, besides protecting against ‘peacetime’ fires

from routine use, including equipment failures, they must protect military personnel and 

platforms from the consequences of combat damage. Fires due to combat events are generally 

very fast-growing and relatively large and military fire protection systems are required to counter 

these, including in some cases also providing explosion protection for normally-occupied spaces.

Table 3-1 summarises where halons are being used in military applications and where and which 

alternatives have been implemented by various Parties, or could potentially be suitable, in new 

designs and to convert existing equipment and facilities. The status of alternatives remains 

largely unchanged from the 2010 HTOC Assessment report. 

There are no universal fire protection requirements for military applications. For example, some 

navies rely on halons as a key element of their fire protection strategies for submarines while 

others prohibit their use for this equipment due to the potential hazard from combustion byproducts (for example, acid gases including HF, HBr, and/or HCl as well as carbonyl species 

such as COF2, depending on the particular halon used) that are inevitably generated by thermal 

breakdown of the agent during fire suppression. Similarly, levels of these toxic combustion byproducts are a key consideration for agent selection for ground vehicle crew compartment fire 

extinguishing systems for some militaries while others have not established any limits for these 

potentially toxic compounds. These examples illustrate the fact that a suitable alternative for one 

Party may not be acceptable to another. 

3.1 Ground Vehicle Applications

In 2010 the US Army reported on an extensive research program that, among other results, 

demonstrated that drop-in replacements for halon 1301 and hybrid HFC-227ea / Sodium 

Bicarbonate (HFC-227BC) based crew protection systems were not feasible with currently 

available extinguishing agents and systems. These results were based on tests conducted in a 

vehicle mock-up. In 2011 the US Army completed that research with tests on a legacy vehicle 

protected by halon 1301 and similar results were obtained. 

In 2013 the US Army reported the development of a drop-in replacement unit for its halon 1301 

handheld fire extinguisher that is based on HFC-227ea in combination with nanoparticulate 

sodium bicarbonate, and has developed Military Specifications for the units. However, to date 

none have been deployed.
Page 18 of 30

Some Parties have made considerable progress since the 2010 HTOC Assessment Report. For 

example, the UK has converted the engine compartment fire protection systems of all its inservice armoured fighting vehicles to HFC alternatives and replaced halon portable extinguishers 

in the vehicle crew compartments. Additionally, several Parties have considered conversion 

programs that would replace halon 1301 in crew protection systems with a more environmentally 

friendly agent based upon an HFC/powder blend. Some continue to pursue this alternative 

because its performance has been shown to be comparable to halon 1301, while others have 

reservations about its use due to the short-term reduction in visibility and powder residue. 

Although this agent has a high-GWP, the Parties that have adopted it are not likely to be able to 

replace it in the foreseeable future due to the lack of other viable alternatives and the significant 

additional investment that would be required.

In general, vehicle halon replacement programmes have, to date, not proceeded further for a 

number of reasons including:

 There is concern that production or use of high-GWP HFCs may be limited in the future.

 An HFC or other alternative system generally requires more space and is heavier than the 

halon 1301 system it replaces.

 Potentially unacceptable levels of toxic combustion products may result from systems 

utilising fluorinated halocarbon alternatives.

 Converting a fielded platform to a new extinguishing system may be very expensive and 

demand considerable resources for a significant period of time.

3.2 Military Aviation Applications1

Halon replacement can only be achieved when there are technically and economically feasible 

alternatives available. To date, many military aviation applications have continued to rely on 

halons as the only viable option. As an example, the A400M military cargo aircraft has been 

ordered by eight European and Asian countries (Germany, France, Spain, United Kingdom, 

Turkey, Belgium, Luxembourg, and Malaysia) and entered service in late 2013 using halon 1301 

for its engine nacelle fire extinguishing system. The extinguishers are installed at the back of 

each engine nacelle using the very limited space available. Halon 1301 is used due to its fire 

extinguishing capability under the wide range of operating conditions that are likely to be 

experienced. The A400M and its halon 1301 extinguishing system are expected to have a 

minimum service life of 30 years; a retrofittable alternative is unlikely to be available for the 

foreseeable future due to the complex technical issues associated with the current aircraft design.

On the other hand, after substantial development effort, the halon systems initially used in the

protection of engines and auxiliary power units (APUs) in the prototype US F-22 stealth fighter 

have been replaced with an HFC-125 system for the production aircraft. The aircraft is designed 

to have a minimum service life of 30 years so support for the current system will be required 

beyond 2040; it is not likely this system will be converted to a lower-GWP agent in the 

foreseeable future.

 

1 Note: This section should be read in conjunction with Supplementary Report #1 on civil aviation.
Page 19 of 30

3.3 Naval Applications

The halons are no longer required or being installed in new designs of naval vessels. However, 

they continue to be used in critical legacy applications, including on some submarines and in 

certain ship areas.

 In naval vessels, HFC-227ea, fine water spray, hybrid HFC-227ea/water spray, foam or 

carbon dioxide systems are being used for the main machinery and other spaces of new 

vessels operated by some Parties. However, carbon dioxide systems are prohibited in all 

spaces on all new US naval vessels due to crew safety considerations. 

 On existing naval vessels operated by some Parties, conversion programs continue for 

normally-unoccupied spaces such as paint lockers and diesel or gas turbine modules. In 

these applications, carbon dioxide or HFC extinguishants have been found acceptable. 

Australia and Germany have converted some main machinery space halon systems to 

HFC-227ea and carbon dioxide, respectively. In Denmark, where HFCs are not 

acceptable because of national legislation, inert gas systems have been installed to protect 

the engine compartments of some surface ships. When considering inert gas systems for 

naval vessels, the weight and space occupied by the system must be considered. For the 

protection of identical spaces, inert gas systems require agent storage cylinders weighing 

over three times the cylinders’ weight of an HFC-227ea or FK-5-1-12 system. For those 

same systems, the inert gas storage cylinders occupy over three times the deck space of 

HFC-227ea or FK-5-1-12 cylinders.

3.4 Conclusion

Since the 2010 Assessment Report, the pace of research and development to evaluate and 

implement halon alternatives in military applications has slowed significantly. This is 

attributable, in large part, to the lack of potentially viable new alternatives being developed and 

marketed by industry. Most, if not all, commercially available extinguishing agents have been 

assessed against the range of unique military fire protection requirements. Alternatives have 

been adopted in some cases where they have been found to be technically and economically 

feasible, but applications remain where halons, and several of the high-GWP HFCs, are the only 

viable fire and explosion protection solution to maintain Parties’ levels of national security and 

the safety of their military personnel and equipment. This is likely to be the case for the 

foreseeable future.

While no blanket conclusions can be drawn regarding the viability of more environmentally 

benign replacement agents for these unique military fire protection applications, it is clear that, 

without major progress in the development of better alternatives, there will continue to be a need 

for recycled halons and high-GWP HFCs for a substantial number of military critical uses at least 

until the middle of the century. However, unlike the civil aviation sector, the military sector has 

incorporated alternatives to halons on many of its newer platforms, reducing its future demand 

for the diminishing supplies of halons.
Page 20 of 30

Table 3-1: Continuing Uses of Halons and Examples of Implemented and Potential Alternatives in the Military Sector

Application Protected Space

Primary Protected 

Risk Halon

Implemented & Potential Alternatives (1)

In conversions of 

Existing Equipment

In New Designs and 

Major Modifications of 

Equipment

Armoured 

Fighting 

Vehicle

Engine Compartment Class B 1301, 1211, 2402

HFC-227ea, HFC-236fa, 2-

BTP, Dry Chemical, Inert 

Gas

HFC-227ea, HFC-236fa, HFC125, 2-BTP, Dry Chemical

Crew Compartment Class B (explosion) 1301, 2402 HFC-227BC, HFC-236fa HFC-227BC HFC-236fa

Portable Extinguisher Class A, B, electrical 1211, 1301, 2402

CO2, 2-BTP, Dry Chemical, 

Water/Potassium Acetate, 

HFC-236fa, HFC-227ea

CO2, 2-BTP, Dry Chemical, 

Water/Potassium Acetate, HFC236fa, HFC-227ea

Aircraft

Engine Nacelle Class B 1301, 1211, 2402 None HFC-125, 2-BTP, FK-5-1-12, 

Powdered Aerosol F

APU Class B 1301, 1211, 2402 None HFC-125, 2-BTP, FK-5-1-12, 

Powdered Aerosol F

Dry Bay Class B (explosion) 1301, 2402 None IGG, Dry Chemical

Cargo Bay Class A (deep-seated) 1301, 2402 None Water Mist plus nitrogen (2)

Fuel Tank Inerting Class B 1301, 2402 None OBIGGS, Fire Suppression 

Foam

Cabin Portable Extinguisher Class A, B, electrical 1211, 1301, 2402 HFC-227ea, HFC-236fa, 2-

BTP, HCFC Blend B (3)

HFC-227ea, HFC-236fa, 2-BTP, 

HCFC Blend B (3)

Lavatory (waste bin) Class A 1301 HFC-227ea, HFC-236fa, FK5-1-12, 2-BTP

HFC-227ea, HFC-236fa, FK-5-

1-12, 2-BTP

Airfield

Hardened Aircraft Shelter Class B 1301 Foam Foam

Crash Rescue Vehicle Class B 1211 Dry Chemical, HCFC Blend 

B (3)

Dry Chemical, HCFC Blend B 

(3)

Fight Line (Portable) 

Extinguisher Class B 1211 CO2, Dry Chemical, Foam, HCFC Blend B (3)

Dry Chemical, Foam, HCFC 

Blend B (3)

Note 1: The listed alternatives are indicative only and may not be suitable for the applications in all examples of the equipment or facility concerned. 

Circumstances vary and the suitability of any alternative for any particular equipment or facility must be assessed by competent personnel on a case-bycase basis. Other unlisted alternatives may also prove to be suitable and the full range of options, as outlined in UNEP HTOC Technical Note #1, should 

be considered at the outset of any halon replacement activity.

Note 2: Water mist plus nitrogen has met the applicable FAA Minimum Performance Standard and a system is in the early stages of commercialization.

Note 3: HCFC Blend B is not an acceptable halon alternative under some jurisdictions because as an ODS it is being phased out under the Montreal Protocol.
Page 21 of 30

Application Protected Space

Primary 

Protected 

Risk Halon

Implemented & Potential Alternatives (1)

In conversions of Existing 

Equipment

In New Designs and Major 

Modifications of Equipment

Naval Vessel 

(Surface Ship)

Main Machinery Space 

(Normally Occupied) Class B 1301, 2402 HFC-227ea, CO2

, HFC-227ea/Water 

Spray

HFC-227ea, CO2, HFC-227ea/Water Spray, 

Water Mist, Foam

Engine Space/Module

(Normally Unoccupied) Class B 1301, 1211 HFC-227ea, 2-BTP, CO2

, Dry Chemical HFC-227ea, 2-BTP, CO2, PGA

Flammable Liquid Storeroom Class B 1301, 2402 Dry Chemical HFC-227ea, HFC-227ea/Water Spray, FK-5-1-

12

Electrical Compartment Class A, 

Electrical 1301, 2402 HFC-227ea, HFC-236fa, FK-5-1-12, Inert Gas HFC-227ea, HFC-236fa, FK-5-1-12, Inert Gas

Fuel Pump Room Class B 1301 None Foam, HFC-227ea FK-5-1-12

Command Centre Class A, 

Electrical 1301, 2402 None HFC-227ea, FK-5-1-12

Flight Line/Hangar (Portable 

Extinguisher) Class B 1211, 2402 Foam, Dry Chemical Foam, Dry Chemical

Naval Vessel 

(Submarine)

Machinery Space Class B 1301, 2402 None Foam, Water Mist

Diesel Generator Space Class B 1301, 2402 None Foam, Water Mist

Electrical Compartment Class A, 

Electrical 1301, 2402 None None

Command Centre Class A, 

Electrical 1301 None None

Facilities

Command Centre Class A, 

Electrical 1301, 2402 HFC-227ea, FK-5-1-12, CO2

Water Sprinkler, Inert Gas, HFC-227ea, FK-5-

1-12, CO2

Research Facility Class A, B, 

Electrical 1301 Water Sprinkler, CO2

, Inert Gas, HFC227ea, FK-5-1-12Water Sprinkler, Inert Gas, HFC-227ea, FK-5-

1-12, CO2

Computer Centre Class A 1301, 1211, 2402 Water Sprinkler, CO2

, Inert Gas, HFC227ea, FK-5-1-12Water Sprinkler, Inert Gas, HFC-227ea, FK-5-

1-12, CO2

Portable Extinguisher Class A, B, 

Electrical 1211, 2402 CO2

, Dry Chemical, Foam, FK-5-1-12, 

HFC-236fa, 2-BTP, HCFC Blend B (3)

CO2, Dry Chemical, Foam, FK-5-1-12, HFC236fa, 2-BTP, HCFC Blend B (3)
Page 22 of 30

4.0 Pipelines / Oil and Gas

In its 2010 Assessment, the HTOC detailed the status of the use of halons and their alternatives

in pipelines and the oil and gas industry. The primary need for halons is for the maintenance of 

legacy systems used to prevent explosions and to suppress fires in inhospitable locations such as 

the Alaskan North Slope in the United States and parts of the former Soviet Union. Essentially 

the situation remains unchanged.

In most cases, existing facilities were designed and constructed with halon 1301 fixed systems as 

an integral part of the safety system design as well as the physical layout of the facility. As with 

civil aviation, after extensive research, it has been determined that in some cases the retrofit of 

such facilities with currently available alternative systems is not economically feasible, and that 

current research is unlikely to lead to an economic solution. Thus, these facilities will likely rely 

on existing halon banks for their operating lifetimes.

For new facilities, companies are adopting an inherently safe design approach to the protection 

of their facilities. This means preventing the release of hydrocarbons and eliminating the 

availability of flammable or explosive materials. Only when all such measures have been 

considered, and a residual risk of the hazard still remains, are other risk reducing measures 

considered. In most cases, new technology detection systems are employed to shut-down and 

blow-down processes, and turn on high rate ventilation systems rather than closing up the space 

and trying to inert it with an extinguishing agent. However, where an inerting agent is still 

required in occupied spaces, halon 1301 has been replaced by HFC-23 or FK-5-1-12, if 

temperatures permit. Currently, HFC-23 is the only alternative that can be used in very cold 

climatic conditions.

Halon 1301 is also used for fire and explosion suppression systems that protect offshore oil 

exploration platforms in the tropical climatic zone in Asia.

Article 5 Parties in the Asia pacific region, including India, use halon 1301 systems in refineries, 

gas pumping stations and offshore oil platforms. Refineries and oil pumping stations have/are 

gradually switching over to dry powders in pumping stations, HFC-227ea, FK-5-1-12, and inert 

gases in refineries where it is technically feasible given space and weight concerns. For offshore 

oil platforms, space and weight are still a big concern and thus the replacement of old legacy 

systems and those systems on new platforms have been delayed. Thus for such applications 

halon requirements still exist. Oil companies are obtaining this halon from local sources of 

recovered halon, which they use to refill existing cylinders. However, there is no halon recycling, 

banking or quality testing facility for such recovered halon in this part of Asia. Therefore the 

quality and effectiveness of such recovered halon is currently a major concern. In land based 

halon 1301 systems, where a clean agent is important, some oil companies are hesitating to

switch over to HFCs because of their high GWP as they do not want to switch over twice. HFC23 has never been used in this region by the oil industry.

Owing to the adoption of alternatives in new facilities, this sector is reducing the burden on the 

ever reducing current supplies of halons.
Page 23 of 30

5.0 Global/Regional Supply and Demand Balance

As of January 1, 2010, all halon production and consumption, as defined by the Montreal 

Protocol, for fire protection ceased. Additionally, there has been no essential use halon 

production since 2000 (as authorised by Decision VIII/9). Nevertheless, halon 1301 (CF3Br) 

continues to be produced for use as a feedstock in the manufacture of the pesticide Fipronil.

With no global production of halons for fire protection uses, management of the remaining stock 

remains crucial for ensuring sufficient halons for applications that need them. There is currently 

no demand for new halons, which has been made possible through the availability of substitute 

fire extinguishing agents and alternatives for new systems, halon recycling programs to support 

mainly existing systems, and implementation of Best Practices to minimise emissions. Based on 

a review of the situation in a large number of Parties, with the exception of aviation and military,

it has been concluded that generally halons have been replaced by substitutes for all new 

applications where halons were traditionally used. Even so, the demand for recycled halons 

remains high for existing applications in some Parties. The global trade in recycled halons is 

robust, but difficulties have been reported in obtaining quantities beyond a few months’ supply 

by some Parties, and in obtaining the necessary government permits for import and export of 

halons.

In Decision XXI/7 the Parties were requested to report their projected needs for, and shortages 

of, halons to the Ozone Secretariat for use by the HTOC. To date the Parties have not indicated 

to the Ozone Secretariat that they are unable to obtain halons to satisfy their needs, although 

some Parties have expressed cost concerns to HTOC members. There are also indications that 

there are stocks of halons in some countries and regions that are not being recycled on the global 

market.

Based on current data reported to the Ozone Secretariat, and information from industry, the 

HTOC has concluded that there is no global halon imbalance at this time, i.e., demand is being 

satisfied by the available supply. Nevertheless, with many important halon users such as military 

and civil aviation relying on month to month supplies, the possibility of a supply disruption 

increases with time as the available supplies are depleted.

It has become apparent that for several uses, ready-to-use halons can only be obtained from a 

few countries in the world. However, without additional data on projected 

needs/shortages/surpluses, especially for civil aviation and military, from the Parties, the HTOC 

cannot quantify potential imbalances beyond noting that demand seems to remain steady and 

supply seems to remain available, but is only adequate for current needs. Therefore the HTOC is 

concerned that the likelihood of a supply disruption is increasing for those who must rely on 

halons for their most important uses. The lack of progress in implementing halon alternatives for 

the three largest (out of 4) civil aviation uses is troubling to the HTOC as the installed quantities 

of halon 1301 in civil aviation as a percentage of the available global quantities continues to 

increase annually.
Page 24 of 30

6.0 Global Halon 1211, 1301, and 2402 Banking

A Halon bank is defined as all halons contained in fire extinguishing cylinders and storage 

cylinders within any organisation, country, or region. Likewise, the ‘global halon bank’ is all 

halon presently contained in halon fire equipment plus all halon stored at halon recycling centres, 

at fire equipment companies, at halon users’ premises, etc., i.e., it is all halon that has been 

produced but has yet to be emitted or destroyed. The collection, reclamation, storage, and 

redistribution of halons are referred to as “Halon Banking”.

Many Parties have halon banking programs that are fully operational, but more Parties have not 

implemented any program nor planned for the needs of their remaining uses. Furthermore, it has 

become clear that historical knowledge has been lost and a significant number of individuals now 

responsible for halon management and phase out are unfamiliar with the issues surrounding 

halon use, recycling, and banking. In short, there is currently a systemic failure in organizational 

memory that has become evident to HTOC members as we attempt to collect information on 

halon banking and this failure is being seen by fire protection consultants as they work with 

various countries/organizations on issues related to acquiring halons to meet their continuing 

needs.

Halon 2402 is still being used in Europe, central Asia, and Japan. Russia is the largest user of 

halon 2402. The ‘market’ appears to be balanced. Most critical uses are in the military sector. 

Data shows no increase in demand and no increases expected in the future. Contaminated agent 

and mixtures have entered the market.

The HTOC Supplementary Report #2: Global Halon 1211, 1301, and 2402 Banking, provides 

guidance on these matters, and can be found on the Ozone Secretariat website at:

http://montreal-protocol.org/new_site/en/assessment_panels_bodies.php?committee_id=6

under the HTOC reports.
Page 25 of 30

7.0 Fire Protection Alternatives To Halons

Halons are fully-halogenated carbon-based molecules containing bromine. In a flame bromine 

atoms in a halon molecule readily detach to form bromine radicals (Br). Bromine radicals have 

unique chemical reactivity characteristics that result in the efficient deactivation of other radicals 

(especially OH, H, and O) that are essential to flame propagation. Reduction of the population 

of these flame-essential radicals from combustion gases leads to prompt flame extinguishment. 

For this reason some halon compounds were adopted into use, beginning in the 1950s, as fire 

extinguishing agents. Three halon compounds (halon 1301, halon 1211, and halon 2402) were 

adopted for use in a wide range of highly varied and critically important fire protection 

applications. Halon 1301, having a boiling point of -57.75 C, and which has low toxicity at use 

concentrations, became the “total-flooding” extinguishing agent of choice wherever fire 

extinguishing systems, that did not use water, were required in occupied spaces. Halon 1211, 

having a boiling point of -3.7 C, has acceptable toxicity characteristics that led to its wide 

adoption for use as an efficient “streaming” agent in portable or wheeled extinguisher units. 

Halon 2402, a liquid with a boiling point of 47.3 C, is a potent fire extinguishing agent that 

found use in some military and industrial explosion protection applications. 

The promulgation of the Montreal Protocol in 1987 meant that the manufacture of halons, which 

are potent ozone-depleting substances (ODSs), would eventually cease. By the 1980s the use of 

halons had become very important in fire protection applications world-wide. Manufacturers of 

halons promptly began research into new chemicals and gases that could serve as effective totalflooding and streaming fire extinguishants. An important attribute of halon alternatives was that 

they needed to have low toxicity to prevent injury to people who may be accidentally exposed to 

agent vapours. 

The subject of fire protection alternatives to halons was addressed at length in earlier editions of 

the HTOC Assessment Reports. For the 2014 Assessment Report the Halon Technical Options 

Committee elected to move the contents of this chapter to Technical Note #1: Fire Protection 

Alternatives to Halons, where it can be continuously updated as new alternatives are developed. 

Technical Note #1 can be found on the Ozone Secretariat website at:

http://ozone.unep.org/en/assessment_docs.php?committee_id=6&body_id=4&body_full=Halons 

Technical Options Committee&body_acronym=HTOC

under the HTOC reports.
Page 26 of 30

8.0 Climate Considerations for Halons and Alternatives

Hydrofluorocarbons (HFCs) have been commercialised as replacements for halons. The 

development of these and other alternatives for use in fire and explosion suppression 

applications, as outlined in Technical Note #1, was instrumental in achieving the halon 

production phase out mandated by the Montreal Protocol. 

Emissions of HFCs currently represent approximately 1-2% of total GHG emissions; however, 

there are projections that show emissions increasing to much higher levels in the future. 

Emissions of HFCs from fire protection are estimated at less than 1% of total HFC emissions 

from all sources. The impact on climate change of HFCs in fire protection is estimated to be 

0.015% and 0.05% of the impact of all GHGs in the US2and EU3, respectively.

The Technology and Economic Assessment Panel (TEAP) Decision XXIV/7 Task Force Report 

estimates that from 2008-2012 about 1% of global HFC sales were for fire protection 

applications4. Sales of HFCs in the fire protection sector are reported as growing in the Middle 

East and Asia regions, but are flat in North America, Latin America, and Europe.

The principal HFC used in total flooding fire protection systems is HFC-227ea, and annual 

emissions are estimated to be 3% of the installed base. Using HFC-227ea global emissions data 

reported by Laube et al. and Vollmer et al.5, and subtracting the estimated non-fire protection 

emissions, the TEAP Decision XXV/5 Task Force estimated that the installed base of HFC-227ea 

in fire protection, from the period 2006 – 2010, is in the low tens of thousands of metric tonnes 

(30,000 – 50,000 MT range). However, it should be noted that there are a lot of uncertainties 

associated with the various estimates and thus ultimately this estimate should be considered 

order-of-magnitude only. 

The principal HFC used in portable extinguishers is HFC-236fa, and annual emissions are 

estimated to be 4% of the installed base. As was the case for HFC-227ea, there are other non-fire 

protection uses of HFC-236fa. However, unlike HFC-227ea, there is little information available 

on the relative take-up of HFC-236fa in the fire protection market. The results of the total 

emissions of HFC-236fa provided in Vollmer et al. are only 160 MT in 2010 as compared with 

HFC-227ea total emissions of 2530 MT, more than one order of magnitude different. As it is not 

known how much of these emissions can be attributable to fire protection, the TEAP Decision 

XXV/5 Task Force decided the best that can be done is to bound the issue. If the fire protection 

installed base is responsible for 90% of these emissions, the fire protection installed base in 2010 

would be in the low thousands of metric tonnes (3000 - 4000 MT range), which is an order of 

magnitude less than for the HFC-227ea fire protection installed base. If the fire protection 

installed base is responsible for only 10% of these emissions, the fire protection installed base in 

 

2

Inventory of U.S. GHG Emissions and Sinks: 1990-2012, U.S. EPA, April 15, 2014

3 Annual European Union GHG Inventory 1990-2012 and Inventory Report 2014, 27 May 2014 

4 TEAP Decision XXIV/7 Task Force Report, September, 2013

5 TEAP Decision XXV/5 Task Force Report, September 2014.
Page 27 of 30

2010 would be in the low to mid hundreds of metric tonnes (300 - 500 MT range), which is two 

orders of magnitude less than for the HFC-227ea fire protection installed base.

In its response to Decision XXIV/7, the TEAP concluded that if an environmentally sound 

alternative agent works in any specific application there is no barrier to its adoption other than 

economic considerations. However there are a small number of fire protection applications that 

may still require halons, HCFCs, or HFCs such as oil and gas production facilities in very cold 

climates, crew bays of armoured vehicles, military and civilian flight lines, aircraft rescue and 

fire fighting vehicles, and systems/extinguishers on civil aircraft. Thus, from a total 

environmental impact perspective, is it better to reuse an already produced, recycled, halon or 

produce a high-GWP HFC for the application? This is a challenge that the Parties may wish to 

consider.
Page 28 of 30

9.0 Recommended Practices for Recycling Halon and Halocarbon Agent 

Alternatives

With the halt in production of halons, recycled halon became the sole replenishment source for 

the recharge of halon extinguishers and extinguishing systems. Indeed, the use of recycled 

halocarbons has emerged as the preferred source to recharge other halocarbon systems and 

extinguishers, even though these halocarbons continue to be manufactured.

Faced with this high reliance on recycled agents for the replenishment of agent in extinguishers 

and extinguishing systems, it is essential that “used” agents be properly processed in order to 

remove impurities and return the agent to a purity level consistent with newly manufactured 

agent. Furthermore, the participants in the agent resupply industry must have the technical ability 

to test and certify that the agents being offered for replenishment are indeed free of impurities. 

Without that ability rigorously applied, there can be no credible halon or halocarbon clean agent 

resupply industry.

Guidance on the practices for recycling halon was addressed in earlier editions of the HTOC 

Assessment Reports. For the 2014 Assessment Report the Halon Technical Options Committee 

elected to move the contents of this chapter to Technical Note #4: Recommended Practices for 

Recycling Halon and Halocarbon Agent Alternatives, where it can be continuously updated as 

necessary.

Technical Note #4 can be found on the Ozone Secretariat website at:

http://montreal-protocol.org/new_site/en/assessment_panels_bodies.php?committee_id=6

under the HTOC reports.
Page 29 of 30

10.0 Halon Emission Reduction Strategies

Historically, less than 5% of all halon emissions have been a result of using halons to extinguish 

fires. While most (it is presumed all) countries have discontinued system discharge testing and 

discharge of extinguishers for training purposes, additional significant reductions of halon 

emissions can be realised by improving maintenance procedures, detection, and control devices, 

recovery and recycling, recordkeeping, proper training, utilizing standardized procedures for 

halon transfers and storage, and implementation of policies and awareness campaigns.

In many cases, it has been found that an automatic halon fire suppression system would not have 

been necessary had a full risk assessment been performed, good fire protection design practices 

implemented, and the fire risks minimized or removed from the location being protected. There 

are many halon alternatives both in-kind and not-in-kind available to the designer; however, they 

should be considered only after the aforementioned “good practices” have been followed. The 

same strategies for halon emissions reductions should be employed with the halon alternatives.

The subject of halon emission reduction strategies was addressed at length in earlier editions of 

the HTOC Assessment Reports. For the 2014 Assessment Report the Halon Technical Options 

Committee elected to move the contents of this chapter to Technical Note #2: Halon Emission 

Reduction Strategies, where it can be continuously updated as necessary.

Technical Note #2 can be found on the Ozone Secretariat website at:

http://montreal-protocol.org/new_site/en/assessment_panels_bodies.php?committee_id=6

under the HTOC reports. 
Page 30 of 30

11.0 Destruction

With the worldwide end of halon production for fire protection uses at the end of 2009, global 

inventory management and responsible disposal practices become important considerations to 

prevent emissions during a critical period of ozone layer recovery. The options for avoiding 

emissions of unwanted stockpiles of halons include destruction and transformation (also referred 

to as conversion) to useful chemical products. Halons, more than some of the other ODSs, are 

readily accessible for collection, storage, and disposal or reuse. Owing to the continued global 

demand in applications such as aviation, the HTOC has recommended that destruction as a final 

disposition option should be considered only if the halons are cross-contaminated and cannot be 

reclaimed to an acceptable purity. Approved ODS destruction technologies and facilities can be 

found in many countries, and some already have experience destroying some types of ODS 

including, to a very limited extent, halons.

The subject of halon destruction was addressed at length in earlier editions of the HTOC 

Assessment Reports. For the 2014 Assessment Report the Halon Technical Options Committee 

elected to move the contents of this chapter to Technical Note #5: Halon Destruction, where it 

can be continuously updated as necessary.

Technical Note #5 can be found on the Ozone Secretariat website at:

http://montreal-protocol.org/new_site/en/assessment_panels_bodies.php?committee_id=6

under the HTOC reports.
A-1

Appendix A: List of Acronyms and Abbreviations

A5 Article 5 Party

APU Auxiliary Power Unit

2-BTP Bromotrifluoropropene

CFC Chlorofluorocarbons

CO2 Carbon Dioxide

EC European Commission

EU European Union

EUN Essential Use Nomination

FIC Fluoroiodocarbon

FK Fluoroketone

GHG Green House Gas

GWP Global Warming Potential

HBr Hydrogen Bromide

HCFC Hydrochlorofluorocarbons

HFC Hydrofluorocarbons

HTOC Halons Technical Options Committee

ICAO International Civil Aviation Organisation

IGG Inert Gas Generator

kg kilogrammes

MPS Minimum Performance Standards

MT Metric Tonnes

OBIGGS On-board Inert Gas Generating Systems

ODP Ozone Depletion Potential

ODS Ozone Depleting Substance

PFCs Perfluorocarbons

PGA Pyrotechnically Generated Aerosols

TEAP Technology and Economic Assessment Panel

UK United Kingdom

UNEP United Nations Environment Programme

US United States

USA United States of America
B-1

Appendix B: Definitions

Article 5 Parties: Parties to the Montreal Protocol whose annual calculated level of 

consumption is less than 0.3 kg per capita of the controlled substances in Annex A, and less than 

0.2 kg per capita of the controlled substances in Annex B, on the date of the entry into force of 

the Montreal Protocol, or any time thereafter. These countries are permitted a ten year "grace 

period" compared to the phase out schedule in the Montreal Protocol for developed countries. 

The Parties in this category are known as "countries operating under Article 5 of the Protocol”.

Atmospheric Lifetime: The total atmospheric lifetime or turnover time of a trace gas is the time 

required to remove or chemically transform approximately 63% (i.e., 1−1/e) of its global 

atmospheric burden as a result of either being converted to another chemical compound or being 

taken out of the atmosphere by a sink.

Consumption: Production plus imports minus exports of controlled substances.

Controlled Substance: Any ozone depleting substance that is subject to control measures under 

the Montreal Protocol. Specifically, it refers to a substance listed in Annexes A, B, C or E of the 

Protocol, whether alone or in a mixture. It includes the isomers of any such substance, except as 

specified in the relevant Annex, but excludes any controlled substance or mixture which is in a 

manufactured product other than a container used for the transportation or storage of that 

substance.

Essential Use: In their Decision IV/25, the Parties to the Montreal Protocol define an ODS use 

as “essential” only if: “(i) It is necessary for the health, safety or is critical for the functioning of 

society (encompassing cultural and intellectual aspects) and (ii) There are no available 

technically and economically feasible alternatives or substitutes that are acceptable from the 

standpoint of environment and health”. Production and consumption of an ODS for essential uses 

is permitted only if: “(i) All economically feasible steps have been taken to minimise the 

essential use and any associated emission of the controlled substance; and (ii) The controlled 

substance is not available in sufficient quantity and quality from existing stocks of banked or 

recycled controlled substances, also bearing in mind the developing countries' need for 

controlled substances”.

Essential Use Nomination (EUN): Decision IV/25 of the 4th Meeting of the Parties to the 

Montreal Protocol set the criteria and process for assessment of essential use nominations.

Feedstock: A controlled substance that undergoes transformation in a process in which it is 

converted from its original composition except for insignificant trace emissions as allowed by 

Decision IV/12.

Global Warming Potential (GWP): Global warming potential is defined as a cumulative 

radiative forcing effects of a gas over a specified time horizon resulting from the emission of a 

unit mass of gas relative to CO2. The TEAP has proposed the following classification: High 

>1000, Moderate 300 – 1000, and Low < 300, which has been used in this Assessment report.

Halocarbons: Halocarbons are compounds derived from hydrocarbons, where one or several of 

the hydrogen atoms are substituted with chlorine (Cl), fluorine (F), bromine (Br), and/or iodine 
B-2

(I). The ability of halocarbons to deplete ozone in the stratosphere is due to their content of 

chlorine, bromine, and/or iodine and their chemical stability). CFCs, HCFCs and HFCs are 

examples of halocarbons.

Halocarbon Fire Extinguishing Agents: Halogenated hydrocarbon chemicals, including 

HCFCs, HFCs, PFCs, and FICs, that are used for fire-fighting applications. Each of these 

chemicals is stored as a liquefied compressed gas at room temperature, is electrically nonconductive, and leaves no residue upon vaporisation.

Halon: The halon terminology system provides a convenient means to reference halogenated 

hydrocarbon fire extinguishants. Halogenated hydrocarbons are acyclic saturated hydrocarbons 

in which one or more of the hydrogen atoms have been replaced by atoms from the halogen 

series (that is, fluorine, chlorine, bromine, and iodine). By definition, the first digit of the halon 

numbering system represents the number of carbon atoms in the compound molecule; the second 

digit, the number of fluorine atoms; the third digit, the number of chlorine atoms; the fourth 

digit, the number of bromine atoms; and the fifth digit, the number of iodine atoms. Trailing 

zeros are not expressed. Unaccounted for valence requirements are assumed to be hydrogen 

atoms. For example, bromochlorodifluoromethane – CF2BrCl - halon 1211.

Halons exhibit exceptional firefighting effectiveness. They are used as fire extinguishing agents 

and as explosion suppressants.

Halon 1211: A halogenated hydrocarbon, bromochlorodifluoromethane (CF2BrCl). It is also 

known as "BCF". Halon 1211 is a fire extinguishing agent that can be discharged in a liquid 

stream. It is primarily used in portable fire extinguishers. Halon-1211 is an ozone depleting 

substance with an ODP of 3.0.

Halon 1301: A halogenated hydrocarbon, bromotrifluoromethane (CF3Br). It is also known as 

"BTM". Halon 1301 is a fire extinguishing agent that can be discharged rapidly, mixing with air 

to create an extinguishing application. It is primarily used in total flooding fire protection 

systems. Halon 1301 is an ozone depleting substance with an ODP of 10.

Halon 2402: A halogenated hydrocarbon, dibromotetrafluoroethane (C2F4Br2). Halon 2402 is a 

fire extinguishing agent that can be discharged in a liquid stream. It is primarily used in portable 

fire extinguishers or hand hose line equipment, and fire protection for specialised applications. 

Halon 2402 is an ozone depleting substance with an ODP of 6.0.

Halon Bank: A halon bank is all halons contained in fire extinguishing cylinders and storage 

cylinders within any organisation, country, or region.

Halon Bank Management: A method of managing a supply of banked halon. Bank 

management consists of keeping track of halon quantities at each stage: initial filling, 

installation, "recycling", and storage. A major goal of a halon bank is to re-deploy halons from 

decommissioned systems. Halon banks can be managed by a clearinghouse, i.e. an office that 

facilitates contact between halon owners and halon buyers.

Halons Technical Options Committee (HTOC): An international body of experts established 

under the Technology and Economic Assessment Panel (TEAP) to regularly examine and report 
B-3

to the Parties on the technical options and progress in phasing out halon fire extinguishants (see 

TEAP).

Hydrochlorofluorocarbons (HCFCs): A family of chemicals related to CFCs that contains 

hydrogen, chlorine, fluorine, and carbon atoms. HCFCs are partly halogenated and have much 

lower ODP than the CFCs.

Hydrofluorocarbons (HFCs): A family of chemicals related to CFCs that contains one or more 

carbon atoms surrounded by fluorine and hydrogen atoms. Since no chlorine or bromine is 

present, HFCs do not deplete the ozone layer.

Inert Gases: Fire extinguishing agents containing one or more of the following gases: argon,

carbon dioxide, and nitrogen. Inert gases have zero ODP and extinguish fires by reducing oxygen 

concentrations in the confined space thereby "starving" the fire.

Inert Gas Generator: A fire fighting technology that uses a solid material that oxidises rapidly, 

producing large quantities of carbon dioxide and/or nitrogen. The use of this technology to date 

has been limited to specialised applications such as engine nacelles and dry bays on military 

aircraft.

Montreal Protocol (MP): An international agreement limiting the production and consumption 

of chemicals that deplete the stratospheric ozone layer, including CFCs, halons, HCFCs, HBFCs, 

methyl bromide and others. Signed in 1987, the Protocol commits Parties to take measures to 

protect the ozone layer by freezing, reducing or ending production and consumption of 

controlled substances. This agreement is the protocol to the Vienna convention.

Non-Article 5 Parties: Parties to the Montreal Protocol that do not operate under Article 5 of the 

MP.

Ozone Depleting Substance (ODS): Any substance with an ODP greater than 0 that can deplete 

the stratospheric ozone layer. Most of ODS are controlled under the Montreal Protocol and its 

amendments, and they include CFCs, HCFCs, halons and methyl bromide.

Ozone Depletion Potential (ODP): A relative index indicating the extent to which a chemical 

product destroys the stratospheric ozone layer. The reference level of 1 is the potential of CFC-11 

and CFC-12 to cause ozone depletion. If a product has an ozone depletion potential of 0.5, a 

given mass of emissions would, in time, deplete half the ozone that the same mass of emissions 

of CFC-11 would deplete. The ozone depletion potentials are calculated from mathematical 

models, which take into account factors such as the stability of the product, the rate of diffusion, 

the quantity of depleting atoms per molecule, and the effect of ultraviolet light and other 

radiation on the molecules. The substances implicated generally contain chlorine or bromine.

Ozone Layer: An area of the stratosphere, approximately 15 to 60 kilometres (9 to 38 miles) 

above the earth, where ozone is found as a trace gas (at higher concentrations than other parts of 

the atmosphere). This relatively high concentration of ozone filters most ultraviolet radiation, 

preventing it from reaching the earth.
B-4

Ozone Secretariat: The secretariat to the Montreal Protocol and Vienna Convention, provided 

by UNEP and based in Nairobi, Kenya.

Party: A country that has ratified an international legal instrument (e.g., a protocol or an 

amendment to a protocol), indicating that it agrees to be bound by the rules set out therein. 

Parties to the Montreal Protocol are countries that have ratified the Protocol.

Perfluorocarbons (PFCs): A group of synthetically produced compounds in which the 

hydrogen atoms of a hydrocarbon are replaced with fluorine atoms. The compounds are 

characterised by extreme stability, non-flammability, low toxicity, zero ozone depleting potential, 

and high global warming potential.

Phase Out: The ending of all production and consumption of a chemical controlled under the 

Montreal Protocol.

Production: The amount of controlled substances produced, minus the amount destroyed by 

technologies to be approved by the Parties and minus the amount entirely used as feedstock in 

the manufacture of other chemicals. The amount recycled and reused is not to be considered as 

“production”.

Reclamation of Halons: To reprocess halon to a purity specified in applicable standards and to 

use a certified laboratory to verify this purity using the analytical methodology as prescribed in 

those standards. Reclamation is the preferred method to achieve the highest level of purity. 

Reclamation requires specialised machinery usually not available at a servicing company.

Recovery of Halons: To remove halon in any condition from an extinguisher or extinguishing 

system cylinder and store it in an external container without necessarily testing or processing it 

in any way.

Recycling of Halons: To extract halon from an extinguisher or system storage container and 

clean the halon for reuse without meeting all of the requirements for reclamation. In general, 

recycled halon is halon that has its super-pressurising nitrogen removed in addition to being 

processed to only reduce moisture and particulate matter.

Total Flooding System: A fire extinguishing system that protects a space by developing a 

critical concentration of extinguishing agent.

Water Mist: A fire fighting agent that uses relatively small water droplet sprays under low, 

medium, or high pressure to extinguish fires. These systems use specially designed nozzles to 

produce much smaller droplets than are produced by traditional water-spray systems or 

conventional sprinklers