You can’t see it, taste it or smell it, and that’s what makes the deadly carbon monoxide gas so dangerous.

“Carbon monoxide causes more poisoning deaths each year than all others combined,” said Tom Greiner, associate professor of agricultural and biosystems engineering. “You don’t even know that it is there.”

Greiner, who was alerted to the dangers of carbon monoxide intoxication in the early 1980s after one of his close friends nearly died from carbon monoxide poisoning, got a chance to show his knowledge of the subject when he was featured Wednesday night in a segment on the ABC newsmagazine “20/20.” The report focused on carbon monoxide in the home, which leads to its effects on the human body.

Other than the “20/20” segment, Greiner also recently published an article that stemmed from research he did on the dangers of carbon monoxide poisoning from Liquefied Petroleum Gas (LPG) powered forklifts and other appliances. This research was published in the Center for Disease Control’s Morbidity and Mortality Weekly Report in December.

Tom Carson, toxicologist and professor of veterinary diagnostic and production animal medicine, also did research on LPG-powered machines.

“We are concerned with animal health,” he said. “There were several cases of late-term abortion in pigs that had been reported, but no infectious cause was found. We discovered that LP gas-fixed heaters were causing high carbon monoxide levels in the sows.”

Greiner said carbon monoxide is deadly for people and animals because it deprives red blood cells of necessary oxygen.

“Inside the body, carbon monoxide ties itself to hemoglobin, or red blood cells,” he said. “The cells then are not oxygenated. It is like reverse asphyxiation because your body is deprived of oxygen from the inside.”

As an example, Greiner said it is easier to understand the process by thinking of red blood cells as buckets carrying oxygen within the body.

“Think of the hemoglobin as a bucket that travels through the body,” he said. “When the bucket reaches the lungs, it is filled with oxygen. That oxygen flows wherever the bucket goes. Carbon monoxide sticks to the hemoglobin 240 times stronger than oxygen, and it gets carried throughout the body in the same fashion.”

Some carbon monoxide in the bloodstream is normal and is exhaled without problem but too much can be deadly, Greiner said.

“[A concentration of] 400 ppm [parts per million] of carbon monoxide in the air can cause a headache in 45 minutes,” he said. “If a person remains in that environment long enough, it could even cause death.”

Higher amounts take much less time to cause serious damage. Greiner said exposure to air with a concentration of 10,000 ppm of carbon monoxide, as is often the case in fires, can cause death after only one minute.

Greiner said no one is immune to the effects of carbon monoxide, but “the ill, children, especially the unborn, and the elderly are the most at risk.”

“Carbon monoxide can make people do crazy things. If there is enough in the [body], a person can appear to be ‘drunk on carbon monoxide,'” he said. “That is very serious, leading to brain damage, blackouts, coma, convulsions and, finally, death.”

Many people who have been seriously affected by carbon monoxide intoxication experience long-term effects, Greiner said.

“Between 15 and 40 percent of individuals, possibly as high as 75 percent, experience neurological problems,” he said.

New technologies such as hyperbaric chambers may be able to combat these side effects, though. Greiner said the chamber has proven in some cases that it “performs miracles” by administering pure oxygen to the victim.

Carbon monoxide detectors and a regular “tune-up” of home appliances are the best defenses against the gas, Greiner said. Avoiding common and possibly deadly mistakes is also important.

“Don’t ever warm up your car in an attached garage,” he said. “The carbon monoxide will remain there and could seep into the home.”