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Student Sustains Cold Burns When Touching Liquid Nitrogen

What Happened?

While loading metal racks into a liquid nitrogen storage tank, a researcher's right hand was submerged in the liquid nitrogen, resulting in cold burns to three of their fingers. They notified her PI immediately and were evaluated in the emergency room. The researcher was wearing cryogenic gloves with latex gloves underneath at the time of the incident; liquid nitrogen penetrated the cryogenic gloves during submersion.

What Was The Cause?

  • Direct cause: Liquid nitrogen penetrated the researcher's cryogenic gloves when their hand was submerged in the tank while loading metal racks, causing cold burns to fingers.
  • Indirect causes: 
    • PPE not rated for the actual hazard: Cryogenic gloves are designed for brief, incidental contact with cryogenic liquids and cold surfaces and not for submersion. Manufacturers explicitly state that the gloves are not waterproof and will allow liquid nitrogen to enter if the hand is immersed. Once inside, the insulation traps the cryogen against the skin and worsens the injury.
    • Inner glove likely worsened the injury: The latex glove worn underneath would have held any liquid nitrogen that penetrated against the skin, rather than allowing it to evaporate or drain. 
    • Task design required hand proximity to the liquid surface: Loading racks into a liquid-phase tank is inherently prone to submersion, i.e., the rack often submerges in the liquid phase, and the hand follows unless long-handled tools or lifters are used.
    • Hazard-model gap: Cryogenic gloves feel substantial and insulated, which creates a common misperception that they provide submersion protection. The distinction between incidental-contact PPE and immersion protection (which effectively doesn't exist for liquid nitrogen in routine lab use) is often not made explicit during training.
    • Possible engineering/equipment gap: If long-handled rack lifters, tongs, or vapor-phase storage were unavailable or unnecessary for this task, the researcher had no practical way to avoid having their hands near the liquid surface.
  • Root cause: A submersion-prone task was performed with PPE rated only for incidental contact. The hazard was built into the workflow, and the controls in place — cryogenic gloves plus a latex inner glove — were not matched to the actual exposure potential. The PPE was used as directed; it simply was not the right control for this task.

How Can Incidents Like This Be Prevented?

  • Install long-handled rack lifters, tongs, or hooks for rack insertions and retrievals, so the hand never approaches the liquid surface.
  • If possible, use vapor-phase storage rather than liquid-phase.
  • Alternatively, implement tank fill-level limits with a visible marker, so the liquid surface stays well below the tank opening.
  • Design or revise the written SOP to distinguish incidental-contact tasks from submersion-prone tasks, specifying the required tools and PPE for each.
  • Avoid close-fitting inner gloves (nitrile) for submersion-prone tasks — they trap penetrated liquid against the skin. 
  • Reinforce in training that appropriate PPE, including cryogenic gloves, protects against splashes and brief contact, not submersion. No glove on the market is rated for hand immersion in liquid nitrogen. Wear a face shield and lab coat for any open-tank work, to address splash and boil-off hazards.
  • Reinforce in training a glove-failure response: remove the glove immediately, begin rewarming with tepid water, seek medical evaluation.

Resources

 

QUICK ACTION TIPS 

Contact with cryogenic materials can rapidly freeze and destroy skin tissues. If exposed:

  1. Contact a physician immediately
  2. Remove all clothing that may restrict circulation to the frozen area
  3. Flush affected area with tepid, not hot, water. The water temperature should be barely above body temperature; do not use dry heat
  4. Do not rub frozen body parts, before or after warming
  5. Keep person warm and rested
  6. Cover thawed body part with dry sterile gauze and large, bulky protective clothing
  7. Report the incident to your supervisor

Liquid Nitrogen

  • A jet of cryogen vapors can freeze the skin or eyes faster than liquid contact
  • Liquid-to-gas expansion ratio of nitrogen is ~700:1 at 20 °C (68 °F), which can generate great force
  • Liquid Nitrogen acts as an asphyxiant in confined spaces