Borosilicate glass is well known for its durability and resistance to thermal shock.  Unique constituents including silica and boron oxide result in a glass that has very low coefficients of thermal expansion and a melting point much higher than ordinary glass (over 1500 degrees!).  With its superior durability, chemical and heat resistance, Borosilicate glass is often used for scientific laboratory equipment, optical and lighting applications, as well as in glass cookware such as Pyrex.

While Borosilicate is far more durable and resistant to thermal shock than other types of glass, it is glass so breakage is still a possibility.  However, when broken, borosilicate glass tends to crack into larger pieces rather than shattering (it will snap rather than splinter), making clean up less hazardous than a typical glass.

Borosilicate glass is hypoallergenic, lead-free and unlike a plastic straw, it is BPA-free.  Have peace of mind knowing that no toxins are being leached into your beverages as you consume them!