Confined space hazards in cargo truck tanks are an afterthought for many employers. 

A new peer-reviewed article by Daniel J. O’Connell, CSP, ASP, CET (SAFETRAN LLC), titled “Cargo Truck Tanks: An Often-Unrecognized Confined Space Hazard,” outlines the unique risks presented by these environments. It also provides guidance to help safety professionals take precautions, improve production and prevent serious incidents. Since workers interact with cargo truck tanks in several different ways, O’Connell begins by describing how these tanks are used and why employers should prioritize training and communication around these safety concerns. 

Tank trucks, commonly called “cargo tanks” or “tankers,” are motor vehicles with completely enclosed storage vessels. Those storage vessels can be either permanent or detachable, and the commodities they carry come in direct contact with the tank interior. They many have one or more storage compartments, and are regularly used to transport liquid, solid or gaseous materials. Tank truck inspectors, technicians, welders and clean-out specialists frequently enter the interior of these storage vessels to perform routine maintenance and must be instructed on the types of hazards they will encounter on the job, O’Connell says.

Cargo tank trucks are confined spaces, and the Occupational Safety and Health Administration (OSHA) regulates them accordingly. According to federal standard 29 CFR 1910.146(g)(1), employees are required to demonstrate specific skills related to their duties in confined spaces. These skills include facilitating a confined space rescue using emergency retrieval equipment and operating a gas tester to determine whether a tank has safe entry conditions. To comply with OSHA requirements, employees working with cargo tank trucks must also demonstrate their knowledge of personal protective equipment (PPE) per 29 CFR 1910.132(f)(2) and respiratory protection per 29 CFR 1910.134(k)(1).

An Often-Unrecognized Threat

O’Connell cites three OSHA case studies from 2011 to 2014 in which an employer’s failure to help workers identify or respond to a cargo truck tank hazard ended in a fatality. The first, which features the story of a tank wash lead worker, took place in the manway opening of a cargo tank trailer previously containing Styrofoam, polyol and a mixture of nine other chemicals. Residual nitrogen, present in the tank as a result of the offloading process, has oxygen-displacing characteristics and created on oxygen-deficient atmosphere. The worker lost consciousness and fell into the tank.

The second involved a truck driver who was working in a service bay near a cargo tank truck. The tanker, which was initially set to transport about 18,000 pounds of liquid egg, contained a nitrogen conditioner intended to preserve the load by removing the oxidation potential. This process, which O’Connell says is commonly used in the industry, is called “blanketing.” Blanketing creates a slightly positive air pressure within storage containers and keeps out the air, which in this instance caused the driver to asphyxiate.  

In the third case study, a worker was cleaning the interior of a 6,000-gallon tanker truck full of wastewater. Despite the fact that this process is usually accomplished with water jets from the top of the tank, which allows people to work outside confined spaces, this worker entered the tank without cleaning tools or PPE. Emergency responders found the employee unresponsive due to low oxygen levels, and the employee later died of asphyxiation at the hospital.    

The Problem With Current Safety Practices

Productivity in the service industry means balancing personal safety, health and performance, O’Connell says. Quick turnarounds, traffic congestion and aggressive demands at service facilities frequently put worker safety and health at risk. Additionally, many employers and workers are unaware of the hazards of oxygen deficiency. The article references a 2003 safety bulletin from the Chemical Safety and Hazard Investigation Board (CSB), which states that “because 78 percent of the air we breathe is nitrogen gas, many people assume that nitrogen is not harmful.”  

Too often, employers ignore not only the moral obligation they have to protect their teams, but also the quantifiable benefits that responsible companies enjoy. According to O’Connell, these benefits include improved production and increased employee morale. A successful safety culture and training program can also help mitigate the costs of losing workers due to injury or illness, a poor reputation or damaged workforce stability.

How to Improve Going Forward

O’Connell calls for a new paradigm in occupational safety and health (OSH) regarding truck tanks. His recommendations center around providing workers with the correct equipment, training and methodologies they need to perform safely and effectively. He lists eight primary tank confined space practices, which include:

• Affixing warning signs or labels near cargo vessel openings
• Properly training cargo tank workers and crewmembers to recognize the hazards presented by blanketed or inerted environments (where inert gasses are used to purge or ventilate cargo tanks)
• Instructing and drilling workers in safe entry and rescue procedures
• Maintaining a zero tolerance policy for unplanned entries into confined spaces and violating company safety rules

Prior to entering a vessel, O’Connell says workers should also complete a pre-entry confined space evaluation to determine the specific hazards of each tank. Using a checklist for this evaluation helps ensure that workers will be less likely to forget or omit important safety steps during the process. Paired with what employees learn during comprehensive safety training, this tool can help employers take immediate action to control or eliminate hazards prior to allowing workers inside a confined space.

When company managers exemplify the safety culture they would like to create, O’Connell says it can have a significant, positive impact on profits and worker well-being.

Read the complete version of “Cargo Truck Tanks: An Often-Unrecognized Confined Space Hazard,” which originally appeared in the June 2018 issue of Professional Safety.

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