A researcher was unplugging an electrical cord when 1/8-inch copper tubing supplying nitrogen to a gas chromatograph came in contact with the energized electrical plug, causing an electrical arc. This caused a hole in the copper tubing. A nearby hydrogen line was unaffected.

The bottled gas supply was shut off. Craftsmen were brought in to reinstall the copper tubing, at a safe distance from the electrical outlet.

Incident Date
Mar 09, 1993
  • Electrical Equipment
  • Piping/Fittings/Valves
  • Flexible Tubing
  • Laboratory Equipment
  • Gas Chromatograph
Damage and Injuries
Probable Cause
Contributing Factors
When Incident Discovered
Lessons Learned

The incident resulted from an inadequate design for the storage location of the copper gas supply tubing (too close to an electrical outlet). The gas supply tubing was too long for its intended purpose and posed a hazard in its coiled state near the outlet. This near miss had the potential for more significant damage/impact to the facility and to the researcher because of a hydrogen gas supply line also in close proximity to the same outlet.

Laboratories should be inspected to ensure that gas supply lines are protected against electrical exposure in the following manner:

Limit the amount of copper tubing to the length that is necessary to reach the intended equipment.
Secure gas supply lines to the wall and/or counter top in a way that will prevent electrical exposure.
Perform visual inspections for loose lines before removing electrical plugs from outlets.
Ensure that there are no exposed energized parts of electrical circuits or equipment near your compressed gas systems.