Summary:The risks associated with the use of laboratory chemicals must be well understood prior to their use in an experiment. As many chemicals have multiple hazards, ensure to review the safety guidance for all hazard classes that may apply.

Definition:
Cryogenic liquids are materials with extremely low boiling points (i.e. less than – 150 °F).

Characteristics:

• One special property of both cryogenic liquids and dry ice is that they undergo substantial volume expansion when converted to a gas phase, which can potentially lead to an oxygen deficient atmosphere where ventilation is limited.

• Few cryogenic liquids can also pose additional hazards including toxicity and flammability (i.e. liquid carbon monoxide).

Examples:
Cryogenic liquids used in Stanford University laboratories include: Liquid nitrogen, helium, and argon. Dry ice is the common term for frozen carbon dioxide.