Scratched, cracked, or otherwise damaged glassware can lead to unexpected breakage or explosions under heat. Discard damaged glassware.

Moving glass between extreme temperatures can lead to shattering and explosions, examples include: 

• Boiling liquid rapidly with high temperatures or open flames.
• Placing hot liquids into refrigerators or freezers.
• Placing cold liquids in rapid heated conditions.
• Placing hot glass on a cold bench-top.

Always bring very hot or very cold glass to room temperature first — slowly — before moving to another extreme temp (ie. allow boiling liquids to cool to room temp before storing in freezer).

Do not use “makeshift” glassware such as drinking glasses, mason jars, ball jars, and misc containers.  These are A) sometimes not tempered leading to shards B) not made to be repeatedly heated, handled with instruments/chemicals, and/or C) not made uniform in volume.

• Best for mixing: beakers allow for accurate pours, and are designed for this purpose.
• Best for heating: beakers and bottle allow for short term (beakers) and long term heating (bottles).
• Best for volatile liquids (terpenes / light hydrocarbon): flask slant inward reduces aeration.
• Best for measuring small amounts: small vials — allow for capping and heating cooling.
• Best for measuring / mixing large amounts: beakers, large jars.

Glassware Cleaning For Extracts

For “Liquid” Material 

• Use a sonic cleaning bath. Sonic cleaners remove extracts very quickly and with a cleaning agent like industrial purple—a far cheaper alternative to solvents.
• Use industrial dishwashers: Industrial dishwashers with high-temperature jets are also cheaper solvents; however, they are usually $15K+.
• If using solvents: Isopropyl alcohol is a lower cost substitute vs ethanol.

For “Solid” and Caked Material 

• Use a sonic cleaning bath: sonic cleaners given enough time will remove extracts.
• Use oven cleaner: fairly easy way to remove hard material leftover from distillations or ovens.
• Use methylene chloride: can remove almost any organic stain or layer.  Take precautions — while this material is not flammable, and to be used in a fume hood, or C1D1 environment due to its asphyxiant properties.