North Carolina State University is a landGrant university and a constituent institution Department of Forest Biomaterials
of The University of North Carolina
NC STATE UNIVERSITY
College of Natural Resources
Campus Box 8005
Raleigh, NC 27695-8005
919.515.5807
919.515.6302 (fax)
Paper Science & Engineering
Wood Products
WP Extension
919.515.2888
919.515.3181
919.515.5637
STANDARD OPERATING PROCEDURE (SOP)
FOR HANDLING LIQUID NITROGEN
Location:
3225A Pulp and Paper Labs; 1235 & 1235A Pulp and Paper Labs
Contact:
Barbara White, Research Operations Manager
Telephone: 919-513-0298 or 919-753-8523
CAUTIONS
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FROSTBITE HAZARD. Liquid nitrogen boils at -196° C. During operation,
components of this equipment become very cold. Contact with unprotected skin can
result in severe burns. DO NOT begin this procedure without wearing appropriate
personal protective equipment (PPE).
ASPHYXIATION HAZARD. Operation of this equipment liberates large quantities
of nitrogen gas. There is an asphyxiation hazard due to displacement of oxygen.
Take appropriate measures to ventilate the space and stand away from the unit
during liquid nitrogen transfer.
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Standard Operating Procedure
1. Review the MSDS information before handling liquid nitrogen.
2. When handling liquid nitrogen, observe the following safe procedures:
i. Wear safety goggles.
ii. Wear gloves which are designed to protect the hands from
extreme cold.
iii. Perform any task with adequate ventilation.
When transferring liquid nitrogen from a commercial tank to dewars, observe
the following safe procedures:
i. Attach the appropriate cryogenic delivery tube to the liquid
connection of the commercial tank.
ii. Open the liquid valve slowly.
iii. DO NOT overfill the Dewar.
iv. Close the liquid valve when finished.
v. Remove the cryogenic delivery tube from the dewar and
disconnect it from the commercial tank, avoiding contact with
the skin.
vi. Insert the liquid withdrawal device into the Lab 50 Dewar slowly
to avoid spattering liquid nitrogen.
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