The mechanisms and rates by which hydrogen gas is generated and subsequently accumulated in the holding tank need to be fully understood by vendors and employees alike. Active venting, warning signs, and local alarms designed to activate when…

The investigative report noted that the explosion could have been prevented by (among other things) a continuous gas analyzer test of oxygen and hydrogen product purity. The continuous analyzer should be interlocked to shut the electrolyzer down…

1. Management must ensure that operating decisions are not based primarily on cost and production. Performance goals and operating risks must be effectively communicated to all employees. Facility management must set safe, achievable operating…

1. Increase physical protection, shielding, and securing of transported hydrogen tube valves, piping, and fittings from multi-directional forces that are likely to occur during accidents, including rollovers. Reference: 49 Code of Federal…

• Battery power supplies require adequate ventilation for all operations, or the battery box should be designed to:
  • Eliminate all sparking devices
  • Ventilate during charging operations
  • Provide inert gas…

Routine maintenance activities on pressurized hydrogen systems should be conducted per written design specifications. The procedures should provide detailed oversight regarding bolt, nut and fitting replacements or repairs. A formal review…

This incident emphasizes the need for proper gas detection and ventilation systems, as well as fire suppression systems, in laboratories using and storing hydrogen. This is especially true when open flame burners are in close proximity.…

• Verify that all PRDs contain fuse-backed adapters.
• Explore elimination of rupture disk PRDs and substitution of spring-style relief valves.
• Develop new hydrogen unloading procedure using a written checklist. * Add…

Several recommendations were outlined by the investigating committee to govern future operations of the hydrogen compressor in the synthetic liquid fuels laboratory:

1. Install a cutoff that will shut down the compressor when the…

Many accidents reported from paper mills have much in common with this incident. Microorganisms in the process water with pulp produce hydrogen gas that mixes with air to form an explosive atmosphere. The ignition source is typically sparks…

The investigation team concluded that hydrogen gas was released through a failed 19-inch diameter gasket and ignited under the roof of the compressor shed where it was partially confined. Some gas escaped from the shed prior to the explosion, but…

The investigation determined that hydrogen was formed by the reaction of hot aluminum and water, air was admitted via the inspection door, and the mixture was ignited by the hot clinker or sparks from the chisel. Aluminum should have been…

• Carefully revise the risk assessment process to evaluate any confined areas where hydrogen is handled.
• Separate the fire and gas detection alarm system from the process information to provide easy and clear identification.…

In addition to the probable causes listed above, the lack of a standard operating procedure for hydrogen leak detection was one of the probable causes of this incident. Additional contributing factors included the following:
- Severe pipe…

1. Carbon steel Nelson curve methodology cannot be depended on to prevent HTHA equipment failures and cannot be reliably used to predict the occurrence of HTHA equipment damage. Revisions to recommended practices should be considered…