A laboratory’s health and safety hazards can be prevented if personnel take precautions and preventative measures to keep themselves and others safe. Every laboratory will have different chemicals, devices, and layouts. Still, each must ensure safety and best practices are implemented and that adequate training is provided to keep employees updated on safety knowledge and behaviours. This blog post will provide an overview of safety and best practices for laboratory hotplates, one of the most common pieces of lab equipment.
What Are Laboratory Hotplates?
A laboratory hotplate is an essential piece of equipment used to heat samples slowly and safely, eliminating the need for an open flame heat source. These benchtop devices are necessary for various laboratory procedures requiring samples or materials to be heated uniformly and in a controlled manner. A hotplate can be manufactured in several ways to support different scientific needs, but each comprises a plate, an internal heating system, and controls. Some hotplates are designed with an electronic display panel, and additional accessories can be purchased to support the heating application.
Our Top 10 Best Practices for Hotplates
Hotplates in the laboratory pose risks such as burns, electrical shocks, fires, and other hazards. Therefore, we have put together this guide of ten safety tips and best practices for using hotplates in a laboratory.
- Read the Instructions
This is an obvious suggestion. Still, as some devices work in different ways, it is crucial to read any instructions provided, as well as safety labels and other warnings. User manuals will provide details on maximum temperatures and run times, control settings, and user instructions to reduce the risk of harm.
- Use Appropriate Glassware
You should only use heat-resistant, borosilicate glassware, and it must be used with a heat mat. Glassware should not be placed directly onto a hotplate. Before using the glassware, check for any chips, cracks, or contamination, as any damage could significantly weaken them. It’s worth mentioning that plastic and soft glass containers should not be used on a hotplate.
- Removing Items From the Hotplate
When removing items from the hotplate, use gripping devices such as thermal gloves or tongs to prevent burns or scalding even when using a heating block with a heat-resistant handle. When possible, allow containers to cool down before moving them. If items are left to cool, place a ‘hot’ sign in front of them to reduce the risk of harm to others.
- Keep Your Workspace Tidy
A tidy workspace is crucial for the safety and efficiency of a laboratory. When using a hotplate, keep the workspace clear of any items you do not need. This includes chemicals, appliances, notes, and any other objects that could get in your way, be damaged, or be used by accident.
- Check For Damage
Before setting up or using any equipment, every item should be checked for damage. Damage could include corrosion of thermometers and containers, fraying of electrical cords, and cracks or dents to hotplates and beakers, to name a few.
- Use Boiling Stones
When boiling a liquid, boiling stones or sticks should be used to encourage calm and uniform heating. This helps to keep the boiling liquid under control and prevents overflow.
- Choosing the Right Settings
You must choose an appropriate temperature for your application. If heating low boiling solvents, set the temperature 5-10oC above boiling point and 10-20oC above boiling point for high boiling solvents. Asynt’s hotplates offer two temperature settings. PID mode offers the user exceptional temperature control with minimised overshooting albeit with a slower heating rate. Meanwhile, 2P mode provides maximum heating rate but with greater temperature overshooting above the set point.Both options are commonly used and depend on the application.
- On – Off
This is another obvious safety tip, but before using the hotplate, you should check that the on and off buttons work. When the device is switched off, the hotplate should cool down quickly. Both the on and off buttons must work to minimize the risk of burns, fires, and other potential hazards.
- Be aware of the temperature control abilities of your hotplate
Manufactured in Germany, the Asynt hotplate stirrer itself offers two built-in and totally independent temperature control circuits. One is the normal control dial to adjust the temperature of the hotplate or solution temperature but the additional circuit is adjusted by a small screwdriver and works as a limit controller. It is very useful to enable a maximum set temperature and this feature would be especially beneficial in teaching laboratories and alike. This independent limit control ensures in the unlikely event of a failure of the main control circuit that the limit you set cannot be exceeded.
- Ensure colleague safety if leaving unattended
While the hotplate is turned on, ideally it would not be left unattended – however some users require overnight reactions to be carried out meaning it is not practical to remain present throughout the entire duration. Hotplates reach incredibly high temperatures that can cause burns, fires, and shocks if misused. To ensure the safety of yourself and others, inform your colleagues if you need to leave the workstation whilst a hotplate is on. When using Asynt DrySyn® heating blocks, you could use the DrySyn® safety heat sticker. These stickers show when a heating block is cool enough to touch or move without being dangerous. Otherwise, users should ensure that a visual notice is clear to other personnel, advising them that the hotplate is in use and should not be touched.
This list is not exhaustive; many other precautions can be taken to protect laboratory personnel from harm and prevent laboratory product misuse. For more in-depth guidance, we have created our own safety and best practices guide for using laboratory hotplates.
Asynt Laboratory Hotplates
Since 2003, Asynt has been manufacturing innovative and sustainable products for laboratories worldwide. We provide world-class technologies that support scientific research, solve longstanding problems for our clients, and offer a wide range of sustainable products. Our product range includes hotplates such as the Asynt complete hotplate stirrer kit which includes a PT100 digital temperature probe. We have many other options available however to suit your specific requirements.
Further safety & best practice support
Asynt has worked together with renowned Chemists and Safety Advisers, Dr I Smellie* and Dr N Langerman**, to bring you this useful publication; Our “In Best Practice Guide to Safe Laboratory Heating with Heating Blocks” which is a short PDF guide that we are proud to offer with our compliments. Find out more & download your copy here: www.asynt.com/about-us/safety-best-practice/
*Dr Iain Smellie, University of St Andrews www.st-andrews.ac.uk **Dr Neal Langerman, Ph.D. Advanced Chemical Safety, Inc. www.chemical-safety.com