Lab worker, Damian Bowen died where he was working at St Stephens Centre Laboratory, Fulham Road in London on the day of the incident, 23 October 2011.
Southwark Crown Court heard how he had been using the liquid nitrogen to freeze blood samples for transport.
Liquid nitrogen, which rapidly expands as a gas, replaced the oxygen in a room ‘creating a situation where life cannot be sustained’.
Investigating HSE inspector Anne Gloor said: “Mr Bowen was working alone with liquid nitrogen in a small room without any extraction. If the extraction system had been switched on, Mr Bowen would not have died.
“There should have been a system in place to prevent the extraction being switched off, a proper system of maintaining the equipment and clear arrangements for preventing lone working with liquid nitrogen.”
Imperial College London undertook work for the International Aids Vaccine Institute in the rooms it occupied in the same laboratory suite. The famous university rented the room and owned the liquid nitrogen store there.
An investigation by HSE established the local exhaust ventilation provided to extract dangerous substances, such as liquid nitrogen, had been switched off.
Chelsea & Westminster NHS Trust pleaded guilty at the hearing in December 2017 to breaching Section 3 (1) and Section 2(1) of the Health and Safety at Work Act 1974 and was fined £80,000 and ordered to pay costs of £23,069.19.
Imperial College London also pleaded guilty to breaching Section 3 (1) and Section 2 (1) of the Health and Safety at Work Act 1974 and was fined £70,000 and ordered to pay costs of £23,069.19.