Using a Co2 Fire Extinguisher

There are a number of different types of fire extinguisher. CO2 extinguishers are among the most common. You'll be able to identify them by their red casing, with a black band indicating that the contents are carbon dioxide. Contents of a fire extinguisher are also written on the extinguisher, usually in white letters. It's a good idea to make sure you know whether your extinguisher is a CO2 model, or some other type. That way, you'll know how to use it properly.

The first thing to do when you see a fire, before you even grab the carbon dioxide fire extinguisher, is to let others know there's a problem. If there's an alarm, use that to alert the other people in the building. If no alarm is available, tell someone and have him or her spread the word. Call the fire department before you attempt to put out a fire, and don't try to deal with one unless you know what to do.

Then, be sure that the CO2 fire extinguisher is really the right tool for the job. It works on most fires, including flammable liquids, gases, and electrical fires. However, the pressure at which the extinguisher operates can damage items, and small pieces of ice may fly out of it. CO2 fire extinguishers are not commonly used around computers because of the possibility of damage. Instead, another type of "clean" fire extinguisher may be used. For most applications where a grease or electrical fire is a danger, however, carbon dioxide fire extinguishers are a good choice, because they leave behind no powdery or harmful residues. Some dry chemical extinguishers contain dangerous chemicals, and all of them leave behind a mess to clean up.

Carbon dioxide fire extinguishers are also not ideal for some paper, cardboard, or plastic fires, since they can't displace enough oxygen to make sure that the fire is out. Because these extinguishers don't always cool the fire enough, there may be enough heat to cause a problem. When the carbon dioxide dissipates, and the oxygen returns, the fire may re-ignite. For oil fires and electrical fires, however, they are quite effective. Never use a carbon dioxide fire extinguisher on a fire containing flammable metals - it can actually increase the chemical reaction!

Once you're certain that what you need is a CO2 fire extinguisher, release its trigger mechanism by pulling out the plastic tag. Move the discharge horn up to a right angle with your body, and use your body to support it. Never hold this discharge horn with your hand while using it. Metal discharge horns will become so cold on a CO2 fire extinguisher that your hand could freeze to them. You should only deal with a fire when it's in the very earliest stages. Never try to put out a fire that's gotten established in a building, or try to deal with a fire if you're not sure what you're doing. Remember - you're not obligated to try to put a fire out. Call the fire department as soon as possible if you're not confident you can deal with the fire.

Carbon dioxide fire extinguishers make a lot of noise when used, so don't be surprised. Aim at the base of the flame, whether the burning material is located, not at the tips. If you have any worries about whether you're doing things right, or you empty the extinguisher without putting out the fire, leave the area immediately. It's better to be safe than sorry. Your fire extinguisher isn't the only thing that's useful in an emergency, either. A fire blanket is an excellent solution for any fire that's smaller than the blanket. Always be sure to hold the blanket in such a way that it protects your hands, and leave it on the fire for at least thirty minutes.

Never walk on an area where a fire has been, even if you've used an extinguisher on it. It may reignite, or you could find that your extinguisher's CO2 supplies are exhausted unexpectedly. Recharge all extinguishers as soon as possible after you use them, to make sure they're ready for the next possible accident. Not having a working fire extinguisher on hand could be a big problem. Remember to inspect your CO2 fire extinguisher monthly to be certain it's ready for use.

It's Official! Pluto Is Not A Planet!

Astronomers at the International Astronomical Union (IAU) General Assembly in Prague, decided on Aug. 24, 2006 that the Solar System has eight planets, not nine, and Pluto is not one of them. Instead, Pluto has been designated a "dwarf planet."

424 astronomers were involved in the vote.

"I'm embarrassed for astronomy. Less than 5 percent of the world's astronomers voted," said Alan Stern, leader of NASA's New Horizons mission to Pluto and a scientist at the Southwest Research Institute. He expects the decision to be overtuurned by the astronomy community. Other astronomers have criticized the definition as ambiguous.

The assembly ruled has ruled, in order to qualify as a planet, a world must meet three criteria:

It must have enough mass and gravity to gather itself into a ball. It must orbit the sun. It must reign supreme in its own orbit, having "cleared the neighborhood" of other competing bodies.

So Jupiter, for example, which circles the sun supreme in its own orbit, is a planet - no adjective required. Pluto, on the other hand, shares the outer solar system with thousands of Pluto-like objects, some bigger, some smaller. Because it has not "cleared its own neighborhood," it is now to be called a dwarf planet.

There is one flaw in that argument, though; Earth, Mars, Jupiter and Neptune all have asteroids as neighbors and can hardly be said to have cleared their neighborhoods. True, those asteroids are a sparse population, but research in recent years has discovered over 1,000 Near Earth Objects, bodies that could potentially impact our planet in the future. Not so much a case of Earth serenely sailing a pristine path as occasionally getting a bug-splat on its windscreen as it orbits through space.

"It's patently clear that Earth's zone is not cleared," Stern said. "Jupiter has 50,000 Trojan asteroids," which orbit in lockstep with the planet. "It won't stand," he said. "It's a farce."

The historian and astronomer emeritus at Harvard, Owen Gingerich, who led the committee that proposed the initial definition, has called the new definition "confusing and unfortunate" and said he was "not at all pleased" with the language about clearing the neighborhood. Gingerich also did not like the term "dwarf" planet.

Mike Brown, of Caltech, recently found an object with the snappy moniker of 2003 UB313, which is larger than Pluto.

"As of today I have no longer discovered a planet," he said. But Brown called the result scientifically a good decision.

"The public is not going to be excited by the fact that Pluto has been kicked out," Brown said. "But it's the right thing to do."

This decision clarifies the vocabulary of planetary astronomy while simultaneously upturning 76 years of "Pluto is a planet" pop-culture. Will non-specialists heed Pluto's demotion? That remains to be seen. Meanwhile, according to the IAU, the Solar System has eight planets: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune; and three dwarf planets: Ceres, Pluto and 2003 UB313.

Quite a number of textbooks and classroom charts will now have to be updated to take account of Pluto's change in status.

Named after the god of the underworld in Roman mythology (and not a cartoon dog), Pluto orbits the Sun at an average distance of 5.9 billion kilometres (3.7 billion miles) taking 247.9 Earth years to complete a single circuit of the Sun.

The New Horizons spacecraft is due to fly by Pluto and the Kuiper Belt in 2015.