Summary: 1. Never refill Dewars or transfer cryogenic liquids alone!
2. Make sure that there is good ventilation. Open a door and/or a window!
3. Remove watches, rings and other metal jewelry on hands and wrists
4. Wear required Personal Protective Equipment (PPE). In general the following PPE is the
a. Cryogenic gloves.
b. Lab coat with sleeves pulled over cuffs of cryogenic gloves.
c. Full length cuffless pants that extend over shoes tops.
d. Closed-toed shoes that are impervious to liquids, such as leather, or covered with
liquid proof shoe covers/spats.
e. Safety Glasses or Chemical Splash Goggles and a Full Face Shield.
5. Use Dewars rated for the cryogen being transferred.
6. Dewars larger than 20 Liters will be lifted and poured by two people.
7. Never use a funnel as during overfill cryogenic liquid may be propelled upward.
8. Ensure the receiving vessel is dry.
9. The receiving vessel must be raised so the delivery tube is immediately above the
mouth of the vessel (i.e., the cryogenic liquid should never be allowed to fall through
air to reach the receiving vessel). Use a table, cart or other mechanical means to
position the vessel in the proper location. Never hold the vessel with unprotected
hands while filling.