Halon General Info

Halon recovery for safe environmental disposal

The Ministry for the Environment has issued an invitation for submissions on “Priority Waste Streams for Product Stewardship Intervention”. This consultation’s scope includes Greenhouse Gas Refrigerant Materials, Halon 1211 (BCF), and Halon 1301 (BTM). We, as Halon recovery, have prepared and placed a submission to the Ministry. 

On the basis our proposal is acceptable, we may yet continue to focus on Halon recovery throughout New Zealand. 

While the Ministry acknowledges that FPANZ-owned Halon Recycling NZ Ltd has been active, they have not yet acknowledged the substantial progress made to date which is the safe environmental destruction of 48,000kg of Halon, and the recovery of 13,000kg of Halon 1301 for essential-use recycling. 

There is now no Halon material or transfer plant available in New Zealand to sustain any “Servicing Operation”, nor any remaining system hardware. 

The bad news for residual Halon owners is that future shipments for destruction will be at increased cost due to the relocation of the Australian destruction plant and a new Contractor. 

On the bright side, however, we do have strong support from the Australian Ministry for the Environment to continue our efforts to safely dispose of all residual Halon. 

Further Proof of the contribution from our two Industries (Fire Protection & Refrigeration) in Australia & New Zealand, was no hole developed in the Ozone Layer over Antarctica last summer. 

All Halon hand operated fire extinguishers and Gas Flood systems will need to be decommissioned to meet proposed new regulations, with disposal by “safe environmental“ destruction. This is only available through Halon Recycling Ltd using the unique destruction process provided in Australia.

Depletion of the Ozone Layer

The earth's stratospheric ozone layer plays a critical role in absorbing ultraviolet radiation emitted by the sun. In the last thirty years, it has been discovered that stratospheric ozone is depleting as a result of anthropogenic pollutants. There are a number of chemical reactions that can deplete stratospheric ozone; however, some of the most significant of these involves the catalytic destruction of ozone by halogen radicals such as chlorine and bromine.

Introduction

The atmosphere of the Earth is divided into five layers. In order of closest and thickest to farthest and thinnest the layers are listed as follows: troposphere, stratosphere, mesosphere, thermosphere and exosphere. The majority of the ozone in the atmosphere resides in the stratosphere, which extends from six miles above the Earth’s surface to 31 miles. Humans rely heavily on the absorption of ultraviolet B rays by the ozone layer because UV-B radiation causes skin cancer and can lead to genetic damage. The ozone layer has historically protected the Earth from the harmful UV rays, although in recent decades this protection has diminished due to stratospheric ozone depletion.

Figure 1. These images from the Total Ozone Mapping Spectrometer (TOMS) show the progressive depletion of ozone over Antarctica from 1979 to 1999. This "ozone hole" has extended to cover an area as large as 10.5 million square miles in September 1998. The previous record of 10.0 million square miles was set in 1996. Figure courtesy of NASA.

History of Ozone Depletion

Ozone depletion is largely a result of man-made substances. Humans have introduced gases and chemicals into the atmosphere that have rapidly depleted the ozone layer in the last century. This depletion makes humans more vulnerable to the UV-B rays which are known to cause skin cancer as well as other genetic deformities. The possibility of ozone depletion was first introduced by scientists in the late 1960's as dreams of super sonic transport began to become a reality. Scientists had long been aware that nitric oxide (NO) can catalytically react with ozone (O 3 ) to produce O 2 molecules; however, NO molecules produced at ground level have a half life far too short to make it into the stratosphere. It was not until the advent of commercial super sonic jets (which fly in the stratosphere and at an altitude much higher then conventional jets) that the potential for NO to react with stratospheric ozone became a possibility. The threat of ozone depletion from commercial super sonic transport was so great that it is often cited as the main reason why the US federal government pulled support for its development in 1971. Fear of ozone depletion was abated until 1974 when Sherwood Rowland and Mario Molina discovered that chlorofluorocarbons could be photolyzed by high energy photons in the stratosphere. They discovered that this process could releasing chlorine radicals that would catalytically react with O 3 and destroy the molecule. This process is called the Rowland-Molina theory of O 3 depletion.

The Chapman Cycle

The stratosphere is in a constant cycle with oxygen molecules and their interaction with ultraviolet rays. This process is considered a cycle because of its constant conversion between different molecules of oxygen. The ozone layer is created when ultraviolet rays react with oxygen molecules (O2) to create ozone (O3) and atomic oxygen (O). This process is called the Chapman cycle.

It is important to keep in mind that ozone is constantly being created and destroyed by the Chapman cycle and that these reactions are natural processes, which have been taking place for millions of years. Because of this, the thickness the ozone layer at any particular time can vary greatly. It is also important to know that O2 is constantly being introduced into the atmosphere through photosynthesis, so the ozone layer has the capability of regenerating itself.

Chemistry of Ozone Depletion

CFC molecules are made up of chlorine, fluorine and carbon atoms and are extremely stable. This extreme stability allows CFC's to slowly make their way into the stratosphere (most molecules decompose before they can cross into the stratosphere from the troposphere). This prolonged life in the atmosphere allows them to reach great altitudes where photons are more energetic. When the CFC's come into contact with these high energy photons, their individual components are freed from the whole. The following reaction displays how Cl atoms have an ozone destroying cycle:

Chlorine is able to destroy so much of the ozone because it acts as a catalyst. Chlorine initiates the breakdown of ozone and combines with a freed oxygen to create two oxygen molecules. After each reaction, chlorine begins the destructive cycle again with another ozone molecule. One chlorine atom can thereby destroy thousands of ozone molecules. Because ozone molecules are being broken down they are unable to absorb any ultraviolet light so we experience more intense UV radiation at the earths surface. 



Figure 2. Much like sunscreen for the Earth, the ozone layer shields the Earth from the sun’s damaging UV-B radiation, which can adversely affect human health and ecosystems. Figure courtesy of NOAA.

The Ozone Hole

From 1985 to 1988, researchers studying atmospheric properties over the south pole continually noticed significantly reduced concentrations of ozone directly over the continent of Antarctica. For three years it was assumed that the ozone data was incorrect and was due to some type of instrument malfunction. In 1988, researchers finally realized their error and concluded that an enormous hole in the ozone layer had indeed developed over Antarctica. Examination of NASA satellite data later showed that the hole had begun to develop in the mid 1970's.

The ozone hole over Antarctica is formed by a slew of unique atmospheric conditions over the continent that combine to create an ideal environment for ozone destruction.

  • Because Antarctica is surrounded by water, winds over the continent blow in a unique clockwise direction creating a so called "polar vortex" that effectively contains a single static air mass over the continent. As a result, air over Antarctica does not mix with air in the rest of the earth's atmosphere. 
  • Antarctica has the coldest winter temperatures on earth, often reaching -110 F. These chilling temperatures result in the formation of polar stratospheric clouds (PSC's) which are a conglomeration of frozen H2O and HNO3. Due to their extremely cold temperatures, PSC's form an electrostatic attraction with CFC molecules as well as other halogenated compounds

As spring comes to Antarctica, the PSC's melt in the stratosphere and release all of the halogenated compounds that were previously absorbed to the cloud. In the antarctic summer, high energy photons are able to photolyze the halogenated compounds, freeing halogen radicals that then catalytically destroy O3. Because Antarctica is constantly surrounded by a polar vortex, radical halogens are not able to be diluted over the entire globe. The ozone hole develops as result of this process.

Resent research suggests that the strength of the polar vortex from any given year is directly correlated to the size of the ozone hole. In years with a strong polar vortex, the ozone hole is seen to expand in diameter, whereas in years with a weaker polar vortex, the ozone hole is noted to shrink

References

  1. Dessler, Andrew. The Chemistry and Physics of Stratospheric Ozone. San Diego, Ca: Academic Press, 2000
  2. Hoffman, Matthew J. Ozone Depletion and Climate Change. Albany, NY: State University of New York Press, 2005
  3. Parson, Edward A. Protecting the Ozone Layer: Science and Strategy. New York: Oxford University Press, 2003.
  4. Petrucci, Ralph H., William S. Harwood, and Geoff E. Herring. General Chemistry : Principles and Modern Applications. 9th ed. Upper Saddle River: Prentice Hall, 2006.Dynamic Equilibrium#
  5. Varotsos, Costas, Kirill Ya. Kondratyev. Atmospheric Ozone Variability: Implications for Climate Change, Human Health and Ecosystems. Chichester, UK: Praxis Publishing Ltd, 2000
  6. Godish, Thad. Air Quality. 4th ed. Florida: CRC Press LLC, 2004.
  7. United States Clean Air Act: as of June 3rd, 2010.

How long will the supply of Halon last?

While the production of Halon ceased on January 1, 1994, under the Clean Air Act, it is still legal to purchase and use recycled Halon and Halon fire extinguishers. In fact, the FAA continues to recommend Halon fire extinguishers for aircraft.

At H3R Clean Agents, we are certain that the eventual demise of Halon will come not from insufficient supply, but from the development of an equally effective agent that does not damage the ozone layer and is relatively inexpensive.

What is Halon and How Does it Work?

Halon is a "Clean Agent." The National Fire Protection Association defines, a "Clean Agent" as "an electrically non-conducting, volatile, or gaseous fire extinguishant that does not leave a residue upon evaporation."

Halon is a liquefied, compressed gas that stops the spread of fire by chemically disrupting combustion. Halon 1211 (a liquid streaming agent) and Halon 1301 (a gaseous flooding agent) leave no residue and are remarkably safe for human exposure. Halon is rated for class "B" (flammable liquids) and "C" (electrical fires), but it is also effective on class "A" (common combustibles) fires. Halon 1211 and Halon 1301 are low-toxicity, chemically stable compounds that, as long as they remain contained in cylinders, are easily recyclable.

Halon is an extraordinarily effective fire extinguishing agent, even at low concentrations. According to the Halon Alternative Research Corporation: "Three things must come together at the same time to start a fire. The first ingredient is fuel (anything that can burn), the second is oxygen (normal breathing air is ample) and the last is an ignition source (high heat can cause a fire even without a spark or open flame). Traditionally, to stop a fire you need to remove one side of the triangle - the ignition, the fuel or the oxygen. Halon adds a fourth dimension to fire fighting - breaking the chain reaction. It stops the fuel, the ignition and the oxygen from dancing together by chemically reacting with them."

A key benefit of Halon, as a clean agent, is its ability to extinguish fire without the production of residues that could damage the assets being protected. Halon has been used for fire and explosion protection throughout the 20th century, and remains an integral part of the safety plans in many of today's manufacturing, electronic and aviation companies. Halon protects computer and communication rooms throughout the electronics industry; it has numerous military applications on ships, aircraft and tanks and helps ensure safety on all commercial aircraft.

Because Halon is a CFC, production of new Halon ceased in 1994. There is no cost effective means of safely and effectively disposing of the Halon. Therefore, recycling and reusing the existing supply intelligently and responsibly to protect lives and property is the wisest solution.

Where can I get more information about Halon and other clean agents?

www.nafed.org - National Association of Fire Equipment Distributors

www.fssa.net - Fire Suppression Systems Association

www.harc.org - Halon Alternatives Research Corporation

www.nist.gov - National Institute of Standards & Technology

The Montreal Protocol on Substances that Deplete the Ozone Layer

FAA AC 20-42C, Hand Fire Extinguishers for Use in Aircraft dated 03/07/84

EPA - RULE 40 CFR Part 82 Protection of Stratospheric Ozone: Manufacture of Halon Blends, Intentional Release of Halon, Technician Training and Disposal of Halon and Halon-Containing Equipment. 

FINAL RULE SUMMARY EPA BAN ON HALON MARCH 5, 1998 (63FR 11084)

Halon information: Q & A on Halon and Their Substitutes 

The information contained in these pages was compiled from a variety of sources, including Halon Alternatives Research Corporation, Halon Recycling Corporation, National Fire Protection Association, Environmental Protection Agency, and others.

How Damaging Is Halon to the Ozone Layer?

A compound's ability to destroy ozone depends on many factors, including the amount of chlorine and/or bromine that it contains. To aid in comparing compounds, scientists have developed a relative scale called the ozone depletion potential (ODP). Common refrigerants, like those found in refrigerators and in automobile air conditioners, have been assigned the value 1 as a reference. Halon 1301 has the value between 10 and 16, meaning it has 10-16 times the more potential for destroying the ozone layer.

Halon's Role in Stratospheric Ozone Depletion

The Halon covered by EPA Rule 40 CFR Part 82, Subpart H contains the chemical element bromine (Br) and also, in the case of Halon 1211 specifically, chlorine (Cl). Br and Cl both contribute to stratospheric ozone destruction. The earth's stratosphere is a layer of the atmosphere that begins between 5 and 11 miles above the earth's surface and extends up to about 30 miles above the earth's surface. Ninety percent of the ozone in the earth's atmosphere is found in the stratosphere. The characteristics of Halon and other human-made chemicals that can deplete ozone (e.g., chlorofluorocarbons, or CFCs) enable them to reach the stratosphere, where they break down and the Cl and Br from them can destroy ozone. Halon is a major source of bromine in the stratosphere. 

Stratospheric Ozone Destruction is a Health Risk

Ozone in the earth's stratosphere protects the earth from the penetration of harmful ultraviolet (primarily UV-B) solar radiation by absorbing most of this harmful UV-B, allowing only a small amount to reach the earth's surface. Without the filtering action of the ozone layer, more of the Sun's UV-B radiation would penetrate the atmosphere and reach the earth's surface. Increased UV-B radiation can lead to increased incidence of certain skin cancers and cataracts, as well as other human health and environmental consequences. 

Can Halon Be Recycled?

If Halon is contained in cylinders retired from service or if a container is leaking, the Halon can (and should) be recovered for recycling and reclamation.

Why Recycle?

Conservation of Halon is necessary to preserve existing supplies until alternative products and systems can be implemented. Actual use should be restricted to real incidents requiring fire suppression. Routine testing of systems for proper operation with the Halon product is unlawful.

How is "Recycling" Distinguished from Recovery and Reclamation?

The term, "recycling" is used in a variety of ways concerning the processing of clean agents. In its broadest usage, it refers to a process that involves recovery, recycling and reclamation. These terms are defined as follows.

Recovery: The collection and storage of controlled substances (such as Halon) from machinery, equipment, containment vessels, etc., during servicing or prior to disposal.

Recycling: The process of removing contaminants (oils, nitrogen, particulates, moisture) by refrigeration and filtration so that the Halon can again be used in a fire suppression system.

Reclamation: The reprocessing and upgrading of a recovered controlled substance through such mechanisms as filtering, drying, distillation and chemical treatment, in order to restore the substance to a specified standard of performance.

Recycling and reclamation, as defined above, are sometimes together referred to as "recycling."

A key objective of H3R Clean Agents is to facilitate the redeployment of clean agents that we have recovered and recycled to customers who require them for critical uses, and who commit to using this finite resource responsibly.