Halon® —the name is still almost synonymous with clean agent fire suppression. Developed by Dupont® in the 1950s, Halon became the go-to agent where clean agents were needed. Its adoption worldwide garnered Halon the lion’s share of the market. Then why, in the early 1990s, when Halon was seemingly at the top of its game, did Dupont phase out production?

Before discussing Halon’s demise, it is important to understand its history. Halon 1211 and 1301 emerged as the product of a joint venture between the U.S. Army and Dupont. It was its use throughout the Department of Defense which led to its meteoric rise in the marketplace. Halon was highly effective, non-toxic to personnel, and left no residue after discharge. It was the agent of choice for data centers, call centers, art galleries, aircraft, and oceangoing vessels.

Halons are a group of chemicals that contain carbon, fluorine, and bromine. They have long been recognized for their firefighting capabilities, but early compounds had the unfortunate side effect of being toxic to humans. The Halon developed by Dupont in the 1950s was thought to be a panacea because it was nontoxic, non-conductive, left no residue, and was relatively affordable.

Everything was bright for Halon until the mid-1980s. Research by scientists earlier in the decade revealed a large hole in the ozone layer above Antarctica, as well as measurable thinning. The ozone layer is critical to human existence because it filters out harmful ultraviolet (UV) rays. Increased UV exposure can lead to increased instances of skin cancer and permanent eye damage.

It was discovered that certain manmade chemicals were contributing to the ozone depletion. In response, the 1985 Vienna Convention represented a worldwide effort aimed at protecting the ozone layer. This spelled serious trouble for the manufacturers of chlorofluorocarbons (CFCs) and bromofluorocarbons (BFCs). Refrigerants in the CFC category and Halon in the BFC category were seen as major offenders because of their discovery in the stratosphere. Halon is a particularly bad actor because of bromine’s (Br) affinity to ozone (O3).

Further research validated CFCs’ and BFCs’ damage to the ozone, and in 1987 the Montreal Protocol was signed by thirty-nine countries and the EU. Halon production was to be held at 1986 levels and other CFC production was severely restricted. However, in 1988, NASA reported that ozone depletion was still occurring much faster than expected. And the main culprits? Chlorine and bromine.

In 1988 Dupont announced they would phase out CFC and BFC production in the year 2000. But after continued research revealed that their products were significantly responsible for ozone depletion, they eventually stepped this up to 1993. Congress later passed bills in 1989 calling for a total ban on production by late 1997 and adding a hefty tax to Halon.

Halon is still talked about today because so much of it is still in existence, whether in systems or available through recycling banks. Revisions to National Fire Protection (NFPA) standards now eliminate the discharge of Halon during testing. But no matter what, Halon is on its way to extinction.

The demise of Halon has led to several positive improvements. First and most importantly, the ozone layer is recovering. Secondly, the market demand for Halon alternatives has led to the creation of fire suppression products that are every bit as effective, while possessing none of the ozone depletion or global warming potential. In many ways, some products offer several advantages over legacy gas systems, such as not requiring installation of piping and being essentially maintenance-free.

There is no question that Halon, as a fire suppression agent, served us well. However, the cost of its efficiency was serious environmental damage. It is fortunate that the world agreed that it needed to go, and it is fortunate for us that the ozone layer is replenishing.

Ensure that you always use fire protection agents that are safe for personnel and the environment alike. And don’t cry over Halon; there are far better choices available now.

Sources: http://web.cjcu.edu.tw/~yrpu/Pro_English/Halon%20Systems.pdf

Show all