This Safety Alert on the Safe Transport of Liquid Nitrogen in Elevators outlines the required safe method of delivering portable liquid nitrogen containers in commercial or other buildings when an elevator must be used.
Liquid Nitrogen has the potential to displace oxygen in the event of a leak, or in the event of vent-gassing in confined and poorly ventilated areas Elevators are confined spaces and a leak from a portable liquid nitrogen container could quickly displace oxygen in the enclosed lift cabin.