Natural gas is completely safe when it's sealed inside pipes and used in the right way. The dangers occur when gas leaks out or doesn't combust properly in an appliances.

Natural gas is flammable - if there's a flame or even a spark in the area of a leak, it could cause an explosion. Fortunately, natural gas leaks are very rare.

And explosions are even more uncommon - the mixture of natural gas and oxygen in the air must be at a precise proportion for a spark to set it off.

When it's pumped from deep under the earth, natural gas is colorless, tasteless and odorless. Utility companies like Alliant Energy add a chemical that gives the gas a distinct aroma: rotten eggs. This makes even a tiny gas leak easier to detect.

The other danger of natural gas is carbon monoxide. This invisible, odorless gas is produced when natural gas appliances aren't working right.

Ideally, natural gas burns in an appliance completely and efficiently, mixing with the oxygen in the air to produce harmless carbon dioxide (CO2) and water vapor. But if conditions aren't right, the natural gas won't combust completely, giving off deadly fumes of carbon monoxide (CO).

When humans breathe in carbon monoxide, it enters the bloodstream and depletes oxygen from the blood cells. Exposure is harmful at high levels over a short period of time, or at lower levels over a longer period - overnight, for example.

Carbon monoxide can be especially dangerous during the winter, when our homes are sealed up tight. That's why it's so important to have a carbon monoxide detector in your home.