The use of flame-based heating elements (e.g. oil, propane, gasoline, natural gas) or gas-fired electricity generators can cause CO to build up in a home, garage, or camper. Even if a generator is outdoors but near an open window, door, or other opening where exhaust can enter the building, dangerous exposure can occur. Generators should always be placed at least 25 feet from any home. Sources of CO include: 

• Furnaces, fireplaces, and wood stoves
• Pressure washers and gas-powered tools
• Certain swimming pool heaters (gas/propane)
• Portable heaters (kerosene/gas/propane)
• Hot water heaters (gas)
• Paint stripping chemicals
• Dryers (gas)
• Stoves/grills (kerosene/gas/propane/charcoal)
• Anything with an internal combustion engine (cars, chainsaws, snowblowers, etc)

In the setting of disaster events such as hurricanes, earthquakes, and snowstorms, CO poisoning is a predictable public health hazard. Insufficient planning for disaster events may lead to increased use of portable devices.