Halon Frequently Asked Questions
What Are Halons And How Do They Work?
They are low-toxicity, chemically stable compounds that have been used for fire and explosion protection throughout this century. Today, Halon 1211 (a liquid streaming agent) is used mainly in hand-held fire extinguishers and Halon 1301 (a gaseous agent) is used mainly in total flooding systems. These Halons have proven to be extremely effective fire suppressants, which are clean (leave no residue) and remarkably safe for human exposure.
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. Many people believe that Halon displaces the air out of the area it is dispensed in. Wrong! Even for the toughest hazards, less than an 8% concentration by volume is required. There is still plenty of air to use in the evacuation process.
|Who Uses Halons?|
Historically, the largest single user of Halon has been the electronics industry. The protection of vital electronics facilities, such as computer rooms and communications rooms, is estimated to account for 65% of Halon 1301 use. The U.S. Government uses Halon for military applications (in ships, aircraft and tanks), for protecting fragile historical documents such as the Bill of Rights, and even protection of the President's limousine. Halons are also used extensively in oil production, electric power generation, and are required on all commercial passenger aircraft. Manufacturers who make everything from dolls to cars use Halon to protect their personnel and products.
|How Long Has Halon Been Used For Fire Protection?|
Carbon tetrachloride (Halon 104) was used prior to 1900, even though its combustion by-products were lethal. Due to a number of deaths, a search for something safer began. Several other Halons were tried, but it was not until 1947 that research by the Purdue Research Foundation and the U.S. Army resulted in the discovery of two effective low toxicity Halons: 1211 and 1301. When used properly, these Halons have an excellent fire fighting record with little, if any, risk.
|What Alternatives Are There?|
There are a number of traditional fire extinguishing agents, such as water, carbon dioxide, dry chemicals, and foam that are good alternatives to Halons for many applications. In addition, recent research has led to the commercialization of new agents and technologies. These fall into four basic categories: halocarbon compounds; inert gas mixtures; water-mist or fogging systems; and powdered aerosols. The growing list of alternatives to Halon, in conjunction with advanced detection and fire resistant materials, provides protection from a broad spectrum of potential hazards. For more information on Halon replacement agents, see the March 1996 report (revision 12) of the EPA Questions and Answers on Halon and their Substitutes, or contact H3R, Inc.
|Can Halon Be Recycled?|
Unlike aluminum cans or newspapers, once Halon is released it is virtually impossible to recover. If Halon is still contained in cylinders retired from service or if a container is leaking, the Halon can be recovered for reuse. In fact, some Halon distributors and users have been doing this for many years, long before Halon emissions were identified as an environmental problem. Current legislation prohibits the production or importation of new Halon 1211, 1301, or 2402 into the U.S.. Recycled Halon is now the only source of supply.
It can be obtained from a number of sources, including fire equipment distributors, and H3R, Inc a recycler of 1211 and 1301 Halon.
|What Is Industry Doing About Halon Use?|
When the environmental effects of Halon became known, industrial users of Halon and fire protection professionals worked together to limit Halon use and emissions. Through changes in standards and specifications, industry has virtually eliminated its use of Halon for testing and training purposes. Historically, testing and training has been responsible for the majority of Halon emissions. Many companies have also implemented programs to reduce false discharges due to human error and equipment failure. Safety training and awareness programs in conjunction with advances in detection and control systems have contributed greatly to reduction in emissions. Many organizations that continue to rely on Halon systems for fire protection have instituted programs to identify their most critical needs. Halons that can be removed from non-critical or obsolete facilities are then recovered for use in more critical applications.
|Is Halon Use Restricted?|
Although some states are banning the sale of certain hand-held extinguishers for non-commercial uses, the answer is generally no. However, effective January 1, 1994, the production and importation of new Halon was banned in the developed world by international agreement. Careful use and conservation of Halon is, therefore, important so that existing supplies will be sufficient to meet all future needs.