Devices that supply heat for reactions or separations include the following:
- Open flame burners
- Hot plates
- Heating mantles
- Oil and air baths
- Hot air guns
- Ashing systems
Some laboratory heating procedures involve an open flame. Common hazards associated with laboratory heating devices include electrical hazards, fire hazards, and hot surfaces. Follow these guidelines when using heating devices:
- Before using any electrical heating device, follow these guidelines: Ensure that heating units have an automatic shutoff to protect against overheating. Ensure that heating devices and all connecting components are in good working condition.
- Heated chemicals can cause more damage and more quickly than would the same chemicals at a lower temperature. RULE OF THUMB: Reaction rates double for each 10° C increase in temperature.
- Heating baths should be equipped with timers to ensure that they turn on and off at appropriate times.
- Use a chemical fume hood when heating flammable or combustible solvents. Arrange the equipment so that escaping vapors do not contact heated or sparking surfaces.
- Use non-asbestos thermal-heat resistant gloves to handle heated materials and equipment.
- Perchloric acid digestions must be conducted in a perchloric fume hood.
- Minimize the use of open flames.
IMPORTANT: Never leave an open flame unattended.