MISSISSIPPI STATE -- Homeowners can solve a lot of problems they encounter on their own, but one problem that requires a professional is a smell of gas.

Propane or liquid petroleum is commonly used in homes to fuel such things as heaters, gas logs, grills, water heaters and stoves. It is a very safe energy source, and can be an affordable way to bring these services into the home.

However, like many other household items, it also can be dangerous when used improperly or when equipment is faulty.

Herb Willcutt, safety specialist with Mississippi State University's Extension Service, said propane naturally is an odorless substance that can cause inhalation problems or explode in the presence of a spark or fire.

"LP and natural gas systems have an odorizing agent added so they stink," Willcutt said. "This is done for the safety and protection of individuals. Because of the smell, gas leaks can be detected before they reach an explosive concentration or become a real health risk."

Willcutt cautioned everyone to immediately leave any building where they smell gas. Do not turn on or off lights or appliances, use a cellular phone or a wall telephone, or start a car. These actions could cause a spark to form from either static electricity or the electricity arching in the switch. Do not relight pilot lights or any open flames.

"Immediately leave the building, leaving the door open behind you," Willcutt said. "Call for emergency assistance from a neighbor's house, and do not go back in until help has arrived."

Willcutt recommended calling a service technician in to locate and repair the leak, and safely vent the gas from the building. If such a person is unavailable, call the fire department for assistance.

"We do have some homes and businesses that explode each year in the state because of a gas leak," Willcutt said. "What is more likely to happen is a flash fire will ignite the drapes and furnishings in the home. The initial burst usually causes very little damage, but the fire it starts can be devastating."

Willcutt said gas usually is heavier than air, so it can concentrate in pockets or crawl spaces and be unnoticed for some time. Outdoors, breezes disperse the gas, greatly reducing the danger it presents.

"Never store propane bottles in the home," Willcutt said. "They are most safely stored in outdoor structures away from the home. If you smell gas from one of these tanks, see if the relief valve is letting off some gas or if the valve is turned off fully. In either case, get the bottle outdoors and cool it with a water hose if necessary."