Ionization smoke alarms are devices designed to detect smoke and alert occupants of a potential fire. They work by using a small amount of radioactive material to ionize the air in a sensing chamber. When smoke enters this chamber, it disrupts the ionization process, triggering the alarm. These alarms are particularly effective at detecting fast-burning fires, such as those caused by paper or flammable liquids. However, they may be less sensitive to smoldering fires, which produce more smoke before bursting into flames. For comprehensive protection, it's often recommended to use both ionization smoke alarms and photoelectric smoke alarms.