First aid injury: Thermos cup exploded after being in hyperbaric environment

  • Safety Flash
  • Published on 13 May 2014
  • Generated on 12 December 2025
  • IMCA SF 07/14
  • 2 minute read

A Member has reported an incident in which a brushed aluminium ‘Thermos’ style cup exploded after being taken out of a hyperbaric environment. 

What happened?

The incident occurred when the cup – which had been in Sat at -256 fsw with the diver – was placed in the medical airlock and brought to the surface. Once at surface pressure the Assistant Life Support Technician (ALST) removed the cup and placed it under his arm, whereupon a violent separation of the cup from its plastic base occurred. The ALST suffered minor bruising and the cup was destroyed. Immediate medical attention was given, and a proper and timely notification to the appropriate authorities was made. The remains of the cup were retained for investigation.

Our member’s investigation noted the following:

The diver had considered that there was no risk of a pressure differential as the interface between the metal and the plastic base on the cup was of insufficient strength to allow a pressure differential to form.

Our member took the following actions:

  • Advised divers in saturation what had happened.
  • Asked them to check carefully for additional objects of a potentially hazardous nature.

Our member made the following recommendations:

  • Allow this style of cup or vessel in the saturation chambers only if drilled to prevent pressure build up.
  • Add non-venting thermal vessels to the list of items forbidden for use in saturation chambers.
Thermos cup after explosion – bottom of cup blew out
Thermos cup after explosion – top view
Thermos cup after explosion – plastic base of the cup blew out due to trapper pressure
Thermos cup after explosion – bottom end minus the plastic that blew out

Latest Safety Flashes:

Vessel ran aground

A vessel on a short voyage ran aground while navigating through a narrow channel at low tide.

Read more
Fire in the engine room – fuel spray fire

A fire broke out on the starboard main engine due to a leak from the fuel pipe connection.

Read more
Fire hazard: missing splash tapes on fuel hose connections

It was observed that several engine fuel hose connections were not fitted with splash tapes.

Read more
Dropped pallet during cargo transfer

A plastic pallet loaded with plastic lube oil drums fell while being hoisted.

Read more
Positive – Enhancing safety communication through digital monitors

All crew and office personnel have 24/7 access to essential safety and operational updates.

Read more

IMCA Safety Flashes summarise key safety matters and incidents, allowing lessons to be more easily learnt for the benefit of the entire offshore industry.

The effectiveness of the IMCA Safety Flash system depends on the industry sharing information and so avoiding repeat incidents. Incidents are classified according to IOGP's Life Saving Rules.

All information is anonymised or sanitised, as appropriate, and warnings for graphic content included where possible.

IMCA makes every effort to ensure both the accuracy and reliability of the information shared, but is not be liable for any guidance and/or recommendation and/or statement herein contained.

The information contained in this document does not fulfil or replace any individual's or Member's legal, regulatory or other duties or obligations in respect of their operations. Individuals and Members remain solely responsible for the safe, lawful and proper conduct of their operations.

Share your safety incidents with IMCA online. Sign-up to receive Safety Flashes straight to your email.