Laboratory hot plates present obvious dangers, such as the potential for people to burn themselves or even start a fire. While newer hot plates are manufactured to avoid sparks, older hot plates are more of a spark risk due to the position of the “on-off” switch on the unit itself as well as the bimetallic thermostat, which can become corroded.
Below are 10 Safety Tips to keep in mind when using a hot plate:
1. When heating material in a bath, make sure the glassware’s heat resistant. Also, you should inspect the glassware for cracks visible to the naked eye. Never place a glass flask, soft glass, or jars directly on a hot plate, and make sure the surface of the hot plate is larger than the object being heated.
2. When you are bringing liquids to a boil, adding boiling stones will help facilitate the process.
3. Be careful when condensing the material in a vessel until it’s completely dry. If there is too little moisture and the vessel remains exposed to heat, it will eventually crack.
4. For liquids, including water, it’s a good idea to use either the medium or medium high setting. Low boiling liquids should not be heated at the high setting, which can produce surface temperatures as high as 540 C (1004 F).
5. It’s advisable not to heat a metal pan on a hot plate, which can damage the hot plate and maybe even pose a shock risk.
6. When removing objects from a hot plate, use tongs or rubber coated, heat resistant gripping devices. The same holds when true when pouring hot liquids.
7. Do not store volatile or flammable materials in the vicinity of a hot plate.
8. Limit the use of older hot plates for flammable materials.
9. Check for corrosion of thermostats, which can create a spark hazard.
10. Perhaps the most important thing of all is to remember to turn the hot plate off. Hot plates that have been left on are the source of most hot plate related injuries.