1. News

Borosilicate glass vs Soda Lime glass vs Pyrex – what is the difference?

Q: Lots of lab glassware states the type of glass it is made of – Pyrex, Borosilicate Glass or Soda Lime.

What is the difference between these types of glass?

Lab glassware filled with water
Lab glassware can be soda lime, borosilicate or Pyrex glass – what is the differences between these types?

A: Different types of glass have different chemical compositions, meaning Borosilicate glass and Pyrex are better suited to heating.

Borosilicate glass has a higher porportion of silicone dioxide than Soda Lime glass, as shown on the table below;

Compound Borosilicate Glass – % content Soda Lime Glass – % content
 Silicon Dioxide SiO2  80.6 69
Boron Trioxide B2O3 13 1
Sodium Oxide Na2O 4 13
Aluminium Oxide Al2O3 2.4 4

This difference means that Borosilicate glass does not expand as much on heating, so it is less likely to break when heated.

Pyrex is one particular blend of Borosilicate glass, with a particularly high heating tolerance.

Soda Lime glass is sometimes used for glassware which is not likely to be directly and strongly heated, for example petri dishes or TLC chromatography tanks.

Borosilicate glass or Pyrex is usually used for glassware that may be directly heated, such as beakers or boiling flasks.

if you would like to know about the right type of glassware to use we have Product Guides to help you decide.

To find out more, follow the links above or contact us if you need any help in choosing lab glassware;