Fire at a fertiliser plant

A hydrogen leak occurred at the connection between a temperature measuring sleeve and a flange on the cleaning tower of a fertilizers plant (approximately 70% hydrogen, 21% nitrogen and the rest carbon monoxide and other impurities).
Workers reported to the factory leaders, who issued the order to block the leak. Workers tried to use iron cards and rubber sheets to plug the leak, but failed. They were sent again to block the leak with tire. While doing so, the leaking hydrogen ignited, probably due to static sparks produced by the friction of the hydrogen flow against the tire rubber. The fire caused two fatalities. The accident caused direct economic losses of more than 340,000 yuan.

The INITIATING CAUSE was a leak. The cause of the leak is unknown. The INGITION CAUSE was triggered by the attempt to stop the leak.

The ROOT CAUSE was ill management:
(i) the plant operator violated rules and regulations, issuing orders which disregarded basic health and safety principles;
(ii) the worker were not provided with effective personal protection;
(iii) there was a complete lack of emergency procedures, probably hinting at a lack of risk assessment.

flange, cleaning tower

The fire caused two fatalities. The accident caused direct economic losses of more than 340,000 yuan.

The plant did not have in place effective emergency plan and probably was lacking as well of preventive and mitigating measures, such as the capacity to isolate that part of the facility where the leak occurred, to depressurise and purge it before starting any type of repair work. Even the materials provided to the workers to stop the leak was not respecting the minimal safety considerations for this type of emergency: rubber is an electrically isolator; its handling can easily generate electrostatic sparks able to ignite hydrogen.
The incident reveals a complete absence or neglection of a proper risk assessment of operations.

In order to ensure safety when fighting leaks, the following fundamental safety measures should be strictly adopted:
(1) Strictly implement safety technical measures and safety technical specifications such as fire prevention, explosion prevention, poison prevention, corrosion prevention, and radiation prevention.
(2) The emergency team should be in charge of the action. The number of personnel should be small and chosen among those experienced and familiar with the working conditions of the equipment.
(3) The emergency team has to wear personal protective equipment matching the working conditions met during the emergency. Safety tools and equipment have to be available at any time.
(4) Before intervening on the leaking components, the area should be cleared taking measures such as evacuation, drainage, ventilation.
(5) The intervention must avoid sparks and use the correct tools (for example pneumatic and not electric stools).
(6) Before acting, the emergency team has to prepare an emergency fighting plan. This execution of the plan has to be reported to supervisors, including any abnormal phenomena and deviation.