For example, if a low-acid food, such as green beans, is canned improperly (not canned under pressure or improperly canned using a pressure canner), C. botulinum bacteria and other bacteria present will be destroyed by the boiling of water and food, but the C. botulinum spores will not be destroyed. The canning process will remove the oxygen from the jar, creating a low-oxygen environment that is will allow the spores to grow into active bacteria. When the jars are stored at room temperature, the spores can germinate and produce the toxin. However, the toxin is sensitive to heat and can be destroyed if the food in question is boiled for 10 minutes (longer at high altitudes).