Every day – in labs around the globe – scientists pick up, put down (and sometimes drop!) lab glassware. But
what they are really thinking about is what’s inside the glassware – not the properties of glass.
Scientists know their lab glassware, from reagent bottles and funnels to beakers, Erlenmeyer flasks and beyond.
Glass – a heat-resistant, easy to form, transparent and nearly inert material – lines the shelves of almost every
biology and chemistry lab worldwide.
Reactivity & pH stability of 3 Key Types of Glass
Most lab managers and scientists choose glass types based on their respective reactivity, pH stability and heat
resistance. How often have you thought about what glass is made from? Did you know there are three main
types of glass that are found in laboratory instruments and glassware?
They are fused quartz glass, soda-lime glass, and borosilicate glass. Each has slightly different glass properties
for scientific applications. You need to choose according to your specific lab or application needs.
- Fused quartz (fused silica) contains no ingredients other than the silica. This non-crystalline amorphous
glass has very high melting temperatures (about 2000°C). Fused quartz is used in the manufacturing of
semiconductors and laboratory equipment. Its optical purity and low thermal expansion are excellent,
and fused quartz is often used to make lenses. Other optics that require accurate transmission of
ultraviolet light are usually made of fused quartz.
- Soda-lime silica glass is the most common type of glass. Bottles and other containers made of soda-lime silica glass
often hold food, beverages, and other similar items. Some bakeware is made from tempered soda-lime silica
glass. It has high chemical durability. However, vaccines packaged in soda-lime silica glass have been
found to be less stable (less than 30 months) due to alkalinity leached from the glass.
- Borosilicate glass is made mostly from silica and boron trioxide. Borosilicate glass is resistant to thermal
stress (rapid thermal changes) and to most chemicals. Reagent bottles, beakers, graduated cylinders,
flasks, kettles, and test tubes are often made from borosilicate glass. However, borosilicate glass is not
resistant to hydrofluoric acid or heated caustic substances. Common brands include Refmex, Kimax,
Borocam, WHEATON, Borosil, Endural, Schott, and Simax. Vaccines packaged in US Pharmacopeia
borosilicate glass and stored at 0° to 4° C retained potency for 30 months, giving you an idea of the inert
nature of borosilicate glass.
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