Borosilicate glass is being used by a variety of industries for all kinds of uses. You probably have heard of it, but do you know what it is?
If you don’t, read on…
What Is Borosilicate Glass?
To understand borosilicate glass, we first need to understand what glass is.
What Is Glass?
Now, you might say everyone knows what glass is. It’s that strong but brittle material that is used to make the eponymous glasses—both the drinking and the vision correction kinds. It’s also transparent, which makes it ideal for windows.
Those who are ecologically minded use bottles made out of this material instead of plastic. Food manufacturers might use it to make jars for sauces or bottles for drinks. It’s a very versatile material.
What you might not know is that glass is made of liquified sand—which is mostly silicon dioxide. Sand can withstand a lot of heat, so you’d need to heat it to 1700° C (or 3090° F) to turn it into liquid. However, once it melts, it doesn’t revert to its original grainy structure once cooled. It doesn’t even solidify.
Glass is what’s called an amorphous solid. It’s not liquid, but it’s not quite solid either. And, the way the molecules crystallise, they allow light to pass through, making it transparent.
Commercially, it’s made by adding recycled waste glass, sodium carbonate (commonly known as soda ash), and calcium carbonate (limestone) to sand. Soda ash helps bring down its melting point but would result in a type of glass that would dissolve in water. The limestone is what stops that from happening.
The result is what we call glass—ordinary, easily-shattered, cracks-when-heated-too-quickly-transparent glass. It’s also called soda-lime glass.
So, What’s Borosilicate Glass?
This type of glass is made almost the same way, but it has an additional ingredient in the mix—boric acid. The boron in boric acid makes borosilicate glass much more heat-resistant and shock-resistant than soda-lime glass. This glass is also quite resistant to most chemicals.
History of Borosilicate Glass
In 1882, Otto Schott, a German chemist, decided to experiment with ways of creating glass that could withstand heat. He discovered the fact that boron could lower the coefficient of thermal expansion in glass. In simple terms, it meant the glass could be heated without it breaking.
The process of making this type of glass was further refined by chemists, W.C. Taylor and Eugene Sullivan, who worked at Corning Glass. The company continued testing the properties and uses of borosilicate glass, leading to customised formulations that resulted in glass with specific properties for a variety of tasks.
Then, in 1914, a physicist, Jesse Littleton, joined the company. He was tasked with testing and evaluating the properties of borosilicate glass. The story goes that his wife, annoyed when her ceramic baking casserole broke, suggested using the new type of glass for baking cookware.
She used a sample glass container he had brought home to bake a cake. With this proof of concept, Corning brought out a new line of glass baking dishes under the name of Pyrex®. The rest, as they say, is history.
Where Can We Use Borosilicate Glass?
The robust nature of borosilicate glass lends itself quite well to several uses.
Scientific Lenses and Hot Mirrors
High-precision optical devices like telescopes require lenses that don’t change shape with temperature changes.
Bakeware and Cookware
As mentioned before, baking and cooking often expose the utensils to high temperatures.
Thermal Insulation
When space shuttles reenter the Earth’s atmosphere, they have to be insulated from the extreme heat generated due to friction. Borosilicate tiles are resilient enough to be used for this purpose.
High-Intensity Lights
The lights used in theatre and film productions need to work for a long time and can generate very high temperatures. Regular glass cannot endure these conditions.
Solar Panels
Borosilicate glass is ideal for solar panels because it is both more heat-resistant and clearer than soda-lime glass. This leads to more efficient energy production. And, of course, it’s also more durable.
Sight Glass
Industrial tanks are often made of borosilicate glass. That’s because visual monitoring may be necessary to oversee the contents and processes. However, it might not be feasible to have to open the container, potentially interrupting the process.
Aircraft Exterior Lenses
High-altitude flights have to go through extreme temperatures. For these, borosilicate glass is the preferred material for exterior lamps.
Aquarium Heaters
Electricity and water are not a good combination. So, aquarium heaters need a non-conductive material to form a barrier between the heating element and the wet environment. Borosilicate glass not only fulfils that function but can also survive the hot temperatures inside with the cold water outside.
Electronics
Borosilicate glass is used in the semiconductor industry, where silicon wafers may be bonded to it.
Rapid Prototyping
Some types of 3D printers “print” by extruding heated plastic onto a surface. Borosilicate glass makes a brilliant platform on which this heated material can be deposited.
Laboratory Glassware
In a laboratory, containers and equipment are put to the test. They have to deal with chemicals that might be corrosive, heat, temperature, and pressure. That’s why borosilicate has been the preferred choice of material for Petri dishes, microscope slides, bottles, beakers, flasks, test tubes, and more.
Of course, this is a field where precision is extremely important. That’s why borosilicate glass, which is non-reactive and sturdy, finds acceptance. Equally important is finding the right manufacturer. GlasKeller, for example, is known for its Swiss excellence and wide range of products.
So, as you can see, borosilicate glass, whilst looking just as ordinary and transparent as regular glass, can offer so much more in terms of durability and use cases.

Parul Mathur has been writing since 2009. That’s when she discovered her love for SEO and how it works. She developed an interest in learning HTML and CSS a couple of years later, and React in 2020. When she’s not writing, she’s either reading, walking her dog, messing up her garden, or doodling.