Save our gas

时间:2019-03-07 09:02:04166网络整理admin

By Fred Pearce THE space shuttle could be grounded and aircraft banished from the skies when the manufacture of firefighting chemicals ceases in 2006 to protect the ozone layer. Firefighters have called on the world’s users of halons not to destroy the ozone-depleting chemicals—or worse, release them into the air—as old fire-extinguishing systems are junked. Instead, users should recycle and store the precious gas in banks around the world to support essential uses for which there are as yet no substitutes. Gary Taylor, Canadian fire consultant and co-chair of the Protocol’s Halon Technical Options Committee, says there are problems with supplies of halon-1301, one of the two most widely used forms. In confined spaces where firefighting chemicals have to be swift-acting but non-toxic, halon-1301 will continue to be needed for a long time. “There is as yet no safe alternative,” says Taylor. At any time, commercial airlines carry 700 tonnes of the chemical—more than current annual global production. “The world’s entire commercial aircraft fleet is protected by halon-1301,” says Taylor. “They need it to get an air-worthiness certificate.” NASA’s space shuttle fleet and its launch facilities are protected by 40 000 pieces of firefighting equipment containing halon-1301. NASA is conserving stocks by cutting unnecessary emissions, according to Michelle Collins, who manages the space agency’s halon bank. The policy has cut emissions by 95 per cent since 1987 to just 250 kilos a year. Some industrialised countries have built up large stockpiles of recycled halons, as none has manufactured the chemicals since 1994. Australia has a store of 2000 tonnes to meet essential needs until 2030. Nine-tenths of the world’s current halon production is in China. But according to Taylor’s committee, most of it is wasted on uses for which alternatives are freely available. The concern is that these halons will eventually be released into the air rather than being recycled. A recent UN deal should see Western governments funding the closure of the world’s last manufacturing plants in China in 2006. “It would be a tragedy for the world to gather up and destroy all the halons and then have to come back a couple of years later and restart production to supply airlines and the military,” says Taylor. More on these topics: