Standard Operating Procedures
Please post the liquid nitrogen safety procedure in all laboratories and areas that use liquid nitrogen.
A. REFILLING DEWARS IN LABORATORIES
- Never refill dewars or transfer liquid nitrogen alone!
- Make sure that there is good ventilation. Open a door if you are in a small room.
- Use Dewars rated for liquid nitrogen
- Never use a dewar that does not have a pressure relief valve or pressure venting lid/stopper.
- Never use dewars with makeshift or homemade lids/stoppers.
- Use pressure venting lids/stoppers supplied by the dewar manufacturer
- Dewars larger than 20 Liters will be lifted and poured by two people
- Do not use a funnel
- Wear required personal protective equipment:
- Cryogenic gloves
- Lab coat with sleeves pulled over cuffs of cryogenic gloves
- Liquid proof shoe covers/spats
- Chemical splash goggles or laboratory face shield
B. DISPENSING LIQUID NITROGEN FROM STORAGE TANKS
- Dispense only into dewars that are rated for liquid nitrogen. (See A.3 above)
- Dispense only into dewars that are:
- Equipped with carrying handles or wheels
- Stable/not in danger of tipping over easily
- Persons filling dewar(s) will be in constant attendance during filling
- Prevent splashing. Place filling hose at or below the mouth of the receiving dewar
- Wear required personal protective equipment (see A.6-10 above)
C. TRANSPORTING LIQUID NITROGEN BETWEEN BUILDINGS
- Use dewars rated for liquid nitrogen. (See A.3 above)
- Never transport liquid nitrogen in a open container
- Wear or carry required personal protective equipment (see A. 6-10 above)
- Do not use unstable wheeled carts or dewars
- Avoid grates, large cracks in sidewalks/pavement, or other hazards that could cause
D. TRANSPORTING LIQUID NITROGEN WITHIN LABORATORIES AND BETWEEN LABORATORIES IN THE
- Use dewars rated for liquid nitrogen (see A. 3 above).
- Do not transport liquid nitrogen in open containers
- Wear required personal protective equipment (see A. 6-10 above)
- If you are carrying a dewar containing liquid nitrogen:
- Make sure the dewar is your ONLY load (no books, coffee, other items)
- Carry transport dewar as far away from your face and body as possible
- Watch for other people who may run into or bump you