Tips to prevent a carbon monoxide tragedy

Replace your carbon monoxide alarm every five to seven years for older models and every 10 years for newer ones. AP

Carbon monoxide is invisible to the senses, and every year, the poison endangers thousands statewide. The chance of exposure increases in the winter, so we turned to state and local experts for advice on how to stay safe.

The leading cause of carbon monoxide emissions in the home is heating systems, according to Jennifer Mieth, public information officer at the Massachusetts Department of Fire Services. According to the agency, many carbon monoxide emergencies occur when homeowners turn on the heat between 5 p.m. and 10 a.m. from November through February. In 2015, 44 percent of all carbon monoxide emergency calls to Massachusetts fire departments were made during the winter, said Mieth, who suggests checking your heating system at the beginning of the season.

Other common appliances can emit the toxic gas as well, including hot water heaters, gas stoves, gas dryers, barbecue grills, lawn mowers, snow blowers, and fireplaces.

On Jan. 13, a carbon monoxide leak killed a Roslindale man and hospitalized two others. A faulty stove and heating system in the man’s condominium were to blame, according to the Boston Globe report.

In 2015 — the latest year in which data from the Massachusetts Fire Incident Reporting System were available — 304 fire departments responded to a total of 16,015 carbon monoxide incidents, including 4,860 confirmed cases where the gas was detected, according to Mieth. Prolonged exposure to carbon monoxide can lead to headaches, nausea, dizziness, unconsciousness, or even death.

Give your heating system a tuneup

Pay attention to vents and chimney flues, said Ryan Williams, general manager of 128 Plumbing, Heating, Cooling & Electric in Wakefield. Tree limbs, or even animals, can block chimneys.

After a storm, residents should clear all ventilation pipes of snow and ice. Mieth also warned against using ovens as a heat source. In addition to being a fire hazard, gas ovens can emit carbon monoxide, she said.

If you need to use a generator, make sure it is 10 feet away from the house to keep the exhaust outside, Mieth added.

Install carbon monoxide detectors

In 2006, a year after the death of 7-year-old Nicole Garofalo of Plymouth from carbon monoxide poisoning, the state enacted Nicole’s Law, which makes the detectors a requirement in most housing. A snowdrift had blocked the furnace vent at her family’s home.

“Most homes you go to don’t have one at all, or if they have one, it’s been disconnected or removed,’’ Williams said. “It’s one of those things that’s easy to forget.’’

Mieth said homeowners should install at least one carbon monoxide detector on every floor and within 10 feet of bedrooms to avoid the risk of sleeping through an alarm.

A detector must also be installed in the same room as the gas or oil-fired heating appliance, Williams said.

Under the law, landlords must install carbon monoxide detectors, the Department of Fire Services says on its website.

Having them won’t matter if your detectors are not in good working order. “Change your batteries when you change your clocks [for daylight saving time],’’ Mieth recommended. The benefit of hard-wired detectors is that they are always powered and resort to a battery backup only during an outage.

Replace the alarms themselves every five to seven years for older models and every 10 years for newer ones, Mieth said. When in doubt, check with the manufacturer.

Be mindful of car emissions

Carbon monoxide can build up when a car runs in a garage. “You should never do that; back your car out and let it run outside,’’ Mieth advised.

A 91-year-old woman died in December after she was found unconscious in her Chatham home, where high levels of carbon monoxide were present. A car that was left running in the garage was the likely source, a fire official told the Cape Cod Times.

Another danger is forgetting to clear snow away from tailpipes. Mieth said parents are sometimes tempted to tuck their children in the car to stay warm while they shovel out. A blocked tailpipe, however, can cause the buildup of deadly emissions inside the vehicle.

Assume there are no false alarms

The most important step is taking your alarm seriously, Mieth emphasized. “When your carbon monoxide detector goes off, assume it’s true, trust it, [and] call the fire department,’’ she said.

And always wait outside for help to arrive.

Nicole DeFeudis can be reached at Subscribe to our newsletter at