Donna Roser’s four young kids climbed the stairs to tell her they heard a noise coming from the basement. She went to listen and heard three distinct beeps. The carbon monoxide detector was going off, and she immediately got her family outside. She called 911 and waited outside until the Easton Volunteer Fire Department and Talbot County EMS arrived.

Average carbon monoxide or CO levels in homes range from 0.5 to 15 parts per million (ppm). Anything more than 35 ppm is considered unacceptable and dangerous. The levels in the Roser home were above 35 ppm. EMS tested Roser, her children ages 3, 4, 7 and 8, and her helper Faith Clark. None of them experienced any CO poisoning symptoms and none had elevated CO levels. The gas to the house was shut off and the family stayed out of the house until a representative from Sharp Energy could investigate the source of the contamination. CO is a byproduct of combustion and is found in fumes from cars, gasoline engines, stoves, lanterns, burning charcoal and wood, gas ranges and heating systems. Normally leaks occur with gas-fired appliances and that was the cause of the contamination in this case, said a Sharp Energy spokesman. The water heater was disconnected and the family will have to replace it.

Each year, carbon monoxide poisoning claims an estimated 500 lives in America and sends another 15,000 people to the hospital, according to the U.S. Centers for Disease Control. CO is a poisonous, colorless, odorless and tasteless gas. Although it has no detectable odor, CO is often mixed with other gases that do have an odor. Carbon monoxide is harmful when breathed because it displaces oxygen in the blood and deprives organs of oxygen. Lightheadedness and dizziness are the most obvious signs someone has carbon monoxide poisoning. During prolonged or high exposures, symptoms can worsen and include vomiting, confusion, and loss of consciousness. Symptoms vary from person to person and can occur sooner in people who are more susceptible, such as children, the elderly, people with lung or heart disease and people with elevated CO blood levels like smokers. CO poisoning poses a special risk to fetuses, according to the U.S. Centers for Disease Control.

To prevent CO leaks, gas appliances should be inspected annually by a trained technician. Furnaces can collect dirt and should be cleaned regularly. Propane gas water heaters must be properly vented. Draining the tank periodically of two to three gallons of water helps to eliminate sediment build up. With gas stoves, check the color of the flame; if it is not blue, have the unit serviced. In addition, do not cover the bottom of the oven; it restricts air circulation.

One of the most important prevention steps is getting a carbon monoxide detector. CO alarms are designed to sound before the CO reaches potentially life-threatening levels. Consumers should follow the manufacturer’s instructions for installation, testing and replacement. The Consumer Product Safety Commission recommends that one CO alarm be installed in the hallway outside the bedrooms in each separate sleeping area of the home. Alarms can be plugged into an outlet or installed high on the wall and should be backed up with a battery.