Lab Product Links & Literature

How to Use Lab Hot Plates and Stirrers

(+Tips to Avoid Starting a Fire)

Using lab hot plates and stirrers safely can help prevent fires and other accidents. No one wants to join the “I started a fire in the lab” club. Take a look at the tips and suggestions below and make a mental note to read your institution’s guidelines for working with hot plates and stirrers afterwards.

We have included three tips to achieve better, safer results with your stirrers and five safety tips for using a lab hot plate.

Troubleshooting Common Issues with Your Stirrer 

It all boils down to basic physics (pun intended) and a little trial and error. Although magnets are not a new concept, sometimes the laws of physics work against each other. If you are having issues with your stirrer, try these steps:

  1. Check Your Speed

    Sometimes the magnet in the unit gets off kilter from the magnet in the stir bar. By slowly speeding up or down, you can reengage the magnets.
  2. Size Matters

    Most stir bar kits come with a variety of sizes. If the magnet in your unit is not working with the stir bar, and speed is not helping, try using a different size.
  3. Use the Right Tool for the Job

    You may need to use something with more power if the material you are mixing is too thick. The vessel cannot be smaller than the path of the stir magnet, and you may also have issues with round or beveled vessels. Matching the vessel, equipment and stir bar to the job is important. Sometimes, it takes a bit of trial and error to find the right combination! 

Safety Tips for Using a Lab Hot Plate

  1. Turn the Right Dial.

    Make sure there are clear labels on your combination Hotplate-Stirrer and try not to rush yourself into working quickly. One too many accidents can be caused by heating flammable liquids when they were meant to be stirred.    
  2. Keep It Clean.

    Spills can increase potential for erosion, fires and electrical malfunctions — not to mention ruining your lab notes. Do not let any accidental spills sit around.
  3. Don’t Turn Your Back on Me.

    There is some wisdom in the saying: “Don’t get too comfortable.” For example, you may think you are heating to “X” only to find out you are heating to “2X.” The chemical you are using may also have a flash point you are unaware of. Familiarity breeds contempt. Do not let your guard down!
  4. Major Incompatibility.

    File these combinations under the label “Doesn’t play well with others.” When working in the lab, you should ALWAYS avoid:
    • Using a hot plate and fume hood with any combustible/flammable materials.
    • Putting a hot plate on a lab soaker.
    • Placing a hot plate on the lab bench with a roll of nitrocellulose on the shelf above it.
  1. When in Doubt, Throw it Out.

    Hot plates are now under $500. This is far cheaper than a fire! 

MIDSCI Carries Only the Best in Laboratory Equipment

MIDSCI is invested in your safety and the quality of your research. While we aim for this article to be personable and relatable, accidents are not funny. Please be safe and follow the recommendations of your institution and safety director.   

Whether you are interested in hot plates, stirrers, or combination hotplate-stirrers for your research facility, MIDSCI has a solution. We carry the industry leading PR1MA product line, with equipment that is built to last and backed by warranty to offer total peace of mind. MIDSCI is also committed to providing quality customer service. Our phones are answered by real people who provide answers to all of your questions in real time. So, what are you waiting for? Give us a call!

If you are interested in a new lab hot plate or stirrer, or other scientific research equipment, submit a contact form, call us toll-free at 1 (800) 227-9997 or send an email to

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