A colorless, tasteless household substance kills thousands every year.

Its name is dihydrogen monoxide, and it causes death when accidentally inhaled and produces chemical dependency in humans. In solid form, it can cause severe tissue damage and burns.Oh, and by the way - dihydrogen monoxide is also known as tap water.

John Paling, faculty member of the Center for Human and Environmental Toxicology at the University of Florida, uses this example to demonstrate that context, hype and misinformation often confuse the public about the difference between perceived and real risks.

Paling, a former wildlife filmmaker for the National Geographic Society, "Nova" and the BBC, was in Salt Lake City Thursday presenting his ideas to local professionals who either work with risk daily or have to communicate risk to the public. Paling's visit was sponsored by the state Division of Comprehensive Emergency Management.

For years, Paling said, there was no dialogue between technical people and the public for communicating what comprised real risk. That's why he developed a "Richter scale for risks," The Paling Perspective Scale.

"The scale enables people to have a yardstick and view risks in the context of their own lives," Paling said.

With his measurements, Paling said the average person can determine what needs to be worried about - and what really doesn't.

The scale is dependent on statistical information about risks from community experts, local media or government agencies, and it's up to concerned individuals to do the research, said Paling.

The key question, said Paling, to keep asking the experts is: "What is your estimate of the odds in a million on an annual basis of (the concern) affecting me or my community?"

The "riskometer" can then be used to plot risks from -6 - the most minuscule with a one in 1 trillion chance of happening - to +6 - the most massive, with a one in one chance of happening.

In the middle of the scale is what Paling calls a "Home Base Zone." Activities that fall here represent possible risks most people feel comfortable with and don't alter their lifestyles to avoid, including taking baths, childbirth and eating peanut butter sandwiches. These things have about a one in 1 million chance of presenting risk.

So, what are the rapidly increasing risks in Utah, according to Paling's scale? Death from traffic accidents, being diagnosed with AIDS and workers dying in transportation incidents.

Burning weapons at the U.S. Army's chemical weapons incinerator in Tooele County presents risks that fall in the "Home Base" range, according to Paling's scale, with a one in 1 million risk of death for those living near the fence line.

Storage of chemical weapons in the same place was a bit more risky - but still in the middle range - with a one in 500,000 chance of death, according to the scale.

Examples of general risks in any one year approaching the "massive" designation include being robbed in Newark, N.J., criminal child abuse or neglect, dying from smoking and being raped in Cleveland.