October 03

Safety Tips: Melting Hard Glass

Hard glass, also known as borosilicate glass, is a type of glass that is designed to withstand much greater amounts of heat without cracking or shattering. It is most commonly used by chemists in the form of reagent bottles. When mixing chemicals, great amounts of heat can be generated, making the hard glass optimal for their work. More commonly known uses of hard glass are for cooking, the most popular brand of kitchenware being called Pyrex.

The borosilicate glass comes in very handy in its ability to handle large amounts of heat without breaking. However, come time to recycle the glass, the very feature that made it so useful becomes a danger to the workers who need to melt it down.

Hard glass is specifically designed to endure heat that’s much greater than normal glass; hence why it’s used in cooking. It isn’t supposed to melt until the temperature reaches roughly 1,000 degrees, which under normal conditions won’t be reached without some heavy duty equipment. Creating that heat, even under the best circumstances, is a risk that can lead to major injuries and horrifying burns if proper safety procedures aren’t followed at all times.

When glass is heated up as a whole, it can explode. Cracks form in it, and the form that the glass is in is torn apart. However, if the hard glass is already broken down into shards and pieces that are too small to fracture or really do more than pop when the heat gets too much, this danger may be avoided.

Safety Equipment
Exposure to potential problems is always a danger when melting glass of any variety. The best counter to this is to wear proper safety equipment. A protective apron or jacket, along with safety glasses or a full face mask is a good start. You also want to have safety gauntlets to protect your hands from heat and burns which could result from exposure.

When melting hard glass, you need to ensure that your instruments and tools are up to the increased heat and the hard glass material. Normal instruments like glass blowing tubes and handling rods may not be meant to work with Pyrex. Check the temperatures and materials the tools are meant to be used at to make sure that the hard glass is the only thing that melts during your work.


Hard glass represents a unique exposure compared to normal glass during the meltdown phase of glass recycling. The extra risks come mainly from the need of a 1000 degree melting point inside the furnace and the risk of explosion which could send shards of glass flying. Utilizing the proper safety practices is extremely important in ensuring worker safety.

Even with the use of proper safety equipment, however, accidents can happen. Should an accident occur, it benefits a glass working business to have a glass insurance program in place that was built from the ground up with glass installers and manufacturers in mind.

For more information on glass insurance, visit GlassPro.

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