Cryogenic Liquid Safety

7. Transporting by hand or cart through a building or between buildings.
  • Large mobile Dewars used for transport:
    • If a dewar cart similar to the one shown to the right is used, be sure to adjust it properly before attaching it to the dewar.  Follow the manufacturers instructions where possible.  In many cases, the instructions are printed on the side of the cart.  Instructions for several different types of carts from several manufacturers are also available by clicking on the picture of the cart to the right.
    • If the dewar needs to be lifted by a crane, it must be done so safely.  Information on correctly lifting a dewar with a crane is also available by clicking on the dewar picture to the right.  Dewars should not be lifted by the top ring.
    • should be equipped with a braking mechanism.  Do not use feet to brake.
    • steel toed boots are recommended.  
    • take care to avoid crushing hands or fingers between the vessel or cart and walls or door frames.
    • if there is any risk of tipping a hand carried dewar, a cart should be used.
    • Wheeled trolleys may not be used if the vessel must pass over elevator thresholds or other slots/crevasses wider than 25% of the wheel width.
  • For transport of large Dewars outside -- over pavement, sidewalks, wheelchair curb-cuts... -- a 4-wheel tipcart should be used.  The casters welded to the tank, and/or the casters on the trolleys in common use, are not meant for transport over pavement and concrete.  While en route exercise great care stay completely clear of sewer grates, large cracks, and/or uneven portions of the pavement, and any other hazards which could catch a cart wheel and cause tipping.
  • Inside buildings, from room to room, the best transport is by Dewars which either have carrying handles (4 L and less) or are on wheels (larger Dewars), and which have pressure relief valves or pressure venting lids.  (A wide-base Dewar which is stable on a wheeled cart qualifies as "on wheels.")
  • For short distances in hallways it is acceptable to hand-carry a pint (~ 500 mL) or smaller Dewar of cryogen which has no handles, if and only if
    • the Dewar is your only load (no books, no coffee, no other items), and
    • the vessel has a venting lid (a cork or loose stopper is fine), and
    • you are carefully watching for people who will run into you, and
    • the vessel is carried with both hands and as far away from your face as comfortably possible.