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Liquid Nitrogen Safety Training

Nitrogen in a liquid state at a very low temperature is called liquid nitrogen. Due to the explosive amount of force that can be generated if liquid nitrogen is rapidly vaporized and the severe frostbite that can occur due to any contact, it is essential to know how to safely handle liquid nitrogen.

  1. Identification

    • Liquid Nitrogen in the air looks like white fog.

      Liquid nitrogen is non-toxic, colorless, odorless, non-flammable and an extremely cold liquid and gas when under pressure. Its liquid to gas expansion ratio is 1:694. Cold vapors of liquid nitrogen in the air look similar to white fog.

    Hazard

    • A personal breathing apparatus is necessary when working with liquid nitrogen.

      In addition to possible frostbite due to contact and large volumes of gas production due to vaporization, liquid nitrogen can displace oxygen in the air in confined work areas. If inhaled, liquid nitrogen can cause asphyxiation (suffocation). A self-contained breathing apparatus (SCBA) should always be present in an oxygen-deficient atmosphere.

    Personal Protection

    • Proper clothing should be worn when working with liquid nitrogen.

      When working with liquid nitrogen, the handler must where a full-face shield over safety glasses; all-skin covering clothes (shirts without cuffs); loose-fitting thermal insulated or leather gloves; and safety shoes.

    Handling

    • Liquid nitrogen should not come into contact with skin.

      Liquid nitrogen or containers of liquid nitrogen should not come into contact with any part of the body, as the extreme cold will cause frostbite or the flesh to stick to the container. The flesh will tear if one attempts to withdraw from the container. Frozen areas appear waxy or yellow and are prone to infection. A heathcare professional should be contacted to treat overexposure.

    Storage

    • Liquid nitrogen should be stored in open spaces.

      Liquid nitrogen should not be stored in a confined space and should only be used in spaces with adequate ventilation. Liquid nitrogen is stored in cryogenic containers such as a Dewar flask (containers specialized to hold cold liquids), as they allow for internal pressure control.

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