ISSUE NO. 21-2025

FatalFacts U.S. DEPARTMENT OF LABOR OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION OSHA.GOV • 1-800-321-OSHA (6742)

Enclosed Tank Cleaning DESCRIPTION OF INCIDENT

Maintenance workers were fatally injured while cleaning the inside of a tank car used to transport natural gasoline. A worker entered the tank car and became unresponsive. His co-worker, wearing a full-face air purifying respirator, went in to help and was also overcome. Two other workers, each wearing a purifying respirator, tried to assist, but could not breathe and both exited the tank. The workers fatally injured were removed from the tank car by emergency professionals.

FINDINGS The atmosphere in the tank did not contain enough oxygen. Vapors from leftover gasoline in the tank car displaced oxygen resulting in a hazardous atmosphere (note: oxygen concentrations below 19.5% create a hazardous atmosphere). The employer did not test the air inside the tank before letting workers enter. Employees entered a hazardous, oxygen deficient space, resulting in their fatalities. Figure 1: A maintenance worker was fatally injured after being overcome by a low oxygen atmosphere inside a tank car he was cleaning. A second worker died trying to rescue the first worker. HOW TO PREVENT THESE INCIDENTS Employers performing permit-required confined y Create an emergency response plan. space operations in enclosed tanks must develop and à Develop and implement procedures for calling implement a written program for safe entry operations rescue and emergency services, for rescuing with the following requirements: entrants from permit spaces, for providing y Prevent employees from entering the tank car necessary emergency services to rescued without a permit. employees, and for preventing unauthorized personnel from attempting a rescue. y Identify and evaluate hazards inside the tank before permitting employees to enter. à Assign at least one trained attendant outside the permit space into which entry is authorized à Test and monitor the air before and during entry for the duration of entry operations. Ensure that first for oxygen, then for flammable and toxic the workers entering the tank communicate with gases and vapors. the attendant to enable the attendant to monitor à Ensure that other activities near the tank entrant status and to enable the attendant to alert cleaning, such as exhaust or sparking, do not entrants of the need to evacuate the space. make the tank cleaning more dangerous. End the confined space entry when a hazard or condition y Provide proper PPE and other equipment. not previously stated on the permit is introduced à Insofar as feasible engineering and work practice in or near the space. controls do not adequately protect employees, à Ensure workers involved in the confined space use appropriate PPE, including respirators entry are capable of completing their task safely. following 1910.134.

à Provide workers with personal air monitoring equipment and appropriate training. KNOW YOUR RIGHTS y Provide proper training for workers, attendants, Workers have the right to: entry supervisors, and employees providing first aid. à Ensure that the employees have the y Safe working conditions. Training and understanding, knowledge, and skills necessary information about workplace hazards, how to to safely perform their duties. Emergency prevent them, and the OSHA standards that responders must be trained in CPR and first aid. apply to their workplace. à Ensure each worker involved in the y Review records of work-related injuries and permit‑required confined space entry illnesses. understands the established permit entry y File a complaint with OSHA if they believe their and emergency procedures. workplace is unsafe or their employer is not à Ensure workers involved in observation and following OSHA’s rules. potential rescue operations are attentive, informed, y Report an injury or speak up about health and and capable of completing their assignment. safety concerns without retaliation. If a worker Emergency responders should understand their has been retaliated against, they must file a duties and have necessary training. complaint with OSHA as soon as possible, but à Ensure workers are trained in the operation of no later than 30 days. atmospheric monitoring equipment, the use of For additional information, see osha.gov/workers. PPE, and all other necessary equipment. y Review entry procedures when there is reason to believe that the current program may not protect employees, and correct deficiencies. OSHA Standards and Regulations: osha.gov/laws-regs ADDITIONAL RESOURCES OSHA Publications: osha.gov/publications y OSHA’s Safety and Health Topics: Confined Spaces OSHA-Approved State Plans: y 29 CFR 1910.146 Permit-required confined spaces osha.gov/stateplans y 29 CFR 1910.134 Personal Protective Equipment y 1926 Subpart AA - Confined Spaces in Construction No Cost On-Site Consultation Services: y Refer to the consensus standard on permit-required osha.gov/consultation confined space: American National Standard ANSI/ Training Resources: osha.gov/training ASSE Z117.1: Safety Requirements for Entering Confined Spaces Compliance Assistance Services: osha.gov/employers

Note: The described case was selected as an example of improper work practices that likely contributed to a workplace fatality. The incident prevention recommendations do not necessarily reflect the outcome of any legal aspects of this case. OSHA encourages your company or organization to duplicate and share this information. This Fatal Facts is not an OSHA standard or regulation, and it creates no new legal obligations. The recommendations contained herein are advisory in nature and are intended to assist employers in providing safe and healthful workplaces. The Occupational Safety and Health Act of 1970 (OSH Act) requires employers to comply with safety and health standards promulgated by OSHA or by an OSHA-approved state plan. The requirements of OSHA-approved state plans can be reviewed by selecting the state’s website at: osha.gov/stateplans. The OSH Act’s General Duty Clause, Section 5(a)(1), requires employers to provide employees with a workplace free from recognized hazards likely to cause death or serious physical harm.

DTSEM FF-4490 09/2025