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BSEE: Confined space entry – tank cleaning

The United States’ Bureau of Safety and Environmental Enforcement (BSEE) has published Safety Alert 477 relating to working in Confined Spaces. In recent months, BSEE has observed a trend of safety incidents that occurred while personnel conducted tank cleaning operations in confined spaces. 

Incident 1: What happened – worker required CPR

A worker was vacuuming, and the nozzle became stuck inside the tank. To free the nozzle, the worker – who was wearing a respirator with organic filters specifically used for working outside the tank – fully entered the tank, where he fell ill. Coworkers found the worker inside the tank. Cardiopulmonary Resuscitation (CPR) was administered to revive the worker.

What went wrong

  • The crew could and ought to have stopped the job;
  • The company’s existing confined space entry policies were not complied with.
  • Human factors: it was noted that an employee felt compelled to rush, leading to hasty and ill-informed decisions. This haste ultimately led to unauthorized and unplanned entry into the tank, further exacerbating the situation.

Actions included

  • Additional refresher training for confined space rescue;
  • Invoking safety stand downs – stop and think!
  • Installing appropriate personnel barriers;
  • Ensuring management meets with supervisors to go over policies and procedures before every job.  

Incident 2: What happened: worker almost passed out

A worker began to feel ill while conducting tank cleaning operations and attempted to exit the tank. While exiting, the worker nearly passed out. The worker initially appeared alert but was slow to answer questions, was sweating profusely, and then collapsed. A coworker revived the worker using CPR. The worker was flown ashore, and medical evaluation showed the worker had nonstress-induced cardiac arrythmia that may have contributed to the episode. 


The BSEE recommends that operators and their contractors, where appropriate, consider:  

  • Ensuring all personnel understand what constitutes a confined space and confined space entry. Ensuring personnel are aware that confined spaces may be hazardous even if part of the body remains outside of the space;
  • Ensuring a Job Safety Analysis (JSA) is in place and is discussed before starting work;
  • Completing, if required, a confined space entry Permit to Work, which should explain the hazards and mitigations common to confined space work;
  • Stopping the job and discussing/analyzing any potential safety and environmental hazards;
  • Renewing approval before proceeding when deviating from the JSA and/or permit – ensuring proper Management of Change;
  • Ensuring proper personal protective equipment (PPE) is worn;
  • Ensuring others know of your planned activities and the duration of the planned activities prior to entering a confined space;
  • Ensuring personnel inside the confined space have means to communicate with personnel outside. Regular communication can be used to detect if the personnel inside have become impaired;
  • Ensuring proper ventilation prior to entering a confined space. If proper ventilation cannot be achieved, utilizing the necessary breathing apparatus;
  • Developing a rescue plan for extracting personnel who are unable to exit a confined space due to injury or incapacitation. Identifying the personnel who will execute the rescue plan and the equipment that will be used;
  • Ensuring employees and/or contractors have the proper training to operate in an enclosed space. Also ensuring the training is current and up to date; 
  • Clear marking of storage tanks regarding the substance contained and any associated hazards (flammability, reactivity, health hazards, etc.) – keep Material Safety Data Sheets (MSDS) for all substances found on location in an easily accessible area, including chemicals in the storage tanks.  

Members may wish to refer to:

Safety Event

Published: 19 February 2024
Download: IMCA SF 04/24

Relevant life-saving rules:
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