Oct. 30, 2009 -- Carbon monoxide is an invisible, odorless gas that can be deadly if left undetected. National Grid reminds its customers of the following safety information to help identify and prevent carbon monoxide poisoning.

Carbon monoxide is the byproduct of the incomplete burning of fuels such as natural gas, butane, propane, wood, coal, heating oil, kerosene and gasoline. Common sources include malfunctioning forced-air furnaces, kerosene space heaters and natural gas ranges. Other sources include wood stoves, charcoal grills, motor vehicle engines, and fireplaces. During the heating season when windows and doors are tightly shut, fresh air is sealed out, allowing any carbon monoxide that may be present to build up over time.

The symptoms of carbon monoxide poisoning are similar to those of the flu. Depending upon the amount of carbon monoxide in the air and length of exposure, symptoms may include headaches, weakness, confusion, chest tightness, skin redness, dizziness, nausea, sleepiness, fluttering of the heart or loss of muscle control.

If you suspect carbon monoxide is present in your home, go outside immediately and breathe deeply. If symptoms are severe, get medical attention right away.

Carbon Monoxide Prevention Tips:

• Arrange for an annual check of your heating system by a licensed professional heating contractor. If you haven’t had your heating system inspected yet, call now.

Check chimneys or flues for debris, bird nests or other blockages, and have them cleaned periodically.

• Be sure space heaters and wood stoves are in good condition, have adequate ventilation and are used in strict compliance with manufacturer’s instructions.

• NEVER use a gas range for heating, burn coal or charcoal in an enclosed space, or leave a car idling in a closed garage.

• Consider installing a government-approved home carbon monoxide detector on every floor.

• Install back-up electricity generators outside. Open windows do not provide sufficient ventilation to safely operate a generator indoors.

For additional safety information, go to National Grid’s web site at www.nationalgridus.com

National Grid is an international energy delivery company. In the U.S., National Grid delivers electricity to approximately 3.3 million customers in Massachusetts, New Hampshire, New York and Rhode Island, and manages the electricity network on Long Island under an agreement with the Long Island Power Authority (LIPA). It is the largest distributor of natural gas in the northeastern U.S., serving approximately 3.4 million customers in Massachusetts, New Hampshire, New York and Rhode Island. National Grid also owns over 4,000 megawatts of contracted electricity generation that provides power to over one million LIPA customers.