Navigating the Hidden Dangers of Confined Spaces

Navigating the Hidden Dangers of Confined Spaces

Understanding the invisible dangers and the critical importance of preparedness in confined work environments.

Your workmate enters a confined space and collapses. What do you do? Most would follow their instinct and try to immediately rescue him. The problem is, would-be rescuers account for 60 percent of fatalities in confined spaces. The Bureau of Labor Statistics reports that 1,030 workers died in confined space incidents from 2011 to 2018.

According to Certified Safety Professional Mark Cangemi, Senior Technical Training Specialist at Honeywell, an overall lack of training and hazard recognition contributes to these risks. He adds, “The No. 1 cause of fatalities in confined spaces is preventable atmospheric hazards.” When a person collapses due to invisible hazards, the same dangers are present for those attempting a rescue, putting them at risk of succumbing to the same hazard as the initial victim.

The Occupational Safety & Health Administration (OSHA) defines confined space as any space that:

  1. Has limited or restricted means of entry or exit
  2. Is large enough for a person to enter to perform tasks
  3. Is not designed or configured for continuous occupancy

OSHA mandates testing the confined space atmosphere in this order:

  • For oxygen
  • For combustible gases
  • For toxic gases and vapors

Examples of confined spaces include wind turbines, sewers, manholes, storm drains, crawl spaces, septic tanks, silos, vats, boilers, pumping/lifting stations, ducts, pipelines and more. They are located across numerous industries and may be encountered in virtually any occupation. The main reason workers enter confined spaces is to perform their work functions of routine maintenance, repairs, and inspections of the confined space.

Permit Spaces 

If confined spaces are present on a worksite, the employer must have a competent person determine whether the confined spaces are “permit spaces.” A permit space has one or more of the following characteristics: (1) contains or has the potential to contain a hazardous atmosphere; (2) contains a material that has the potential for engulfing an entrant; (3) has an internal configuration such that an entrant could be trapped or asphyxiated by inwardly converging walls or by a floor which slopes downward and tapers to a smaller cross-section; or (4) contains any other recognized serious safety or health hazard. 

If employees are expected to enter permit spaces, the employer must develop a written permit space program and make it available to employees or their representatives. They must meet the guidelines established by either Federal or State safety standards and regulations. This may include issuing entry permits, assigning attendant(s), designating entrants, and ensuring a means of rescue.

Gaining a permit also requires testing the confined space atmosphere using equipment designed to detect chemicals and gases that may be present. Even once given the all-clear to enter, if a worker exits the space and later needs to re-enter, the atmosphere needs to be tested again.

Top Confined Space Hazards: Lack of Oxygen, Hydrogen Sulfide, Carbon Monoxide

If a workplace contains a permit space, the entry employer must protect its workers against the hazards present. Potential risks include explosions, loss of consciousness, drowning, asphyxiation, low oxygen levels and more. The protection that is required depends on the type and severity of the hazards present in the permit space.

Since many serious and fatal hazards are invisible, confined space testing can mean the difference between life and death for workers. For example, a space that lacks oxygen is not readily apparent. In a rusty tank, the oxidation process, which creates rust reduces the level of oxygen in the air. Entering a rusty, confined space can be as deadly as entering a fuel tank. 

According to OSHA and the National Fire Protection Association (NFPA), the atmosphere of a confined space is only safe for workers when:

  • Oxygen concentration is 19.5 to 22 percent by volume.
  • The concentration of a flammable vapor in the atmosphere is less than 10 percent by volume of its lower explosive limit.
  • Any toxic materials in the atmosphere are within permissible concentrations at the time of inspection.
  • The residues and chemicals remaining in the confined space are not capable of producing toxic material concentrations above that permissible level.

The effects of exposure to an oxygen-deficient atmosphere are swift and can be irreversible, even fatal. From the moment a person enters that space, they’re effectively impaired. The oxygen content within the blood starts to drop. This affects the brain, causing a loss of coordination and impairing judgment. The person likely will not be able to find his or her way out of the space, or could lose strength, fall and lose consciousness.

This process can occur in less than six minutes, so there’s little time for rescue. 

While it’s not as common as low oxygen, too much oxygen (over 21 percent) is also dangerous to the occupants of a confined space. It increases the risk of fire or explosion and can be detected only by using a properly calibrated oxygen monitor. 

Even if oxygen levels are normal, there may be hazardous contaminants in the air, like hydrogen sulfide (rotten egg smell) and carbon monoxide, which is odorless and colorless. 

OSHA requires that all employees who enter and work in confined spaces be trained by their employer to perform all required duties safely. These spaces can present physical and atmospheric hazards that can be prevented if addressed prior to entering the space to perform work. The bottom line is that no confined space is safe to enter until it has been tested and determined to be safe by a competent person. An untested space is immediately dangerous to life and health (IDLH).

Hazard Recognition

The causes of most confined space entry incidents are simple: employers and workers fail to recognize and control the hazards associated with confined spaces, and they conduct inadequate or incorrect emergency responses, resulting in the death or injury of the initial entrant, the would-be rescuer, or both. 

Pre-planning for confined space entry should include all pertinent parties and involve reviewing entry procedures as well as covering specific hazards inherent to the spaces being entered. Cangemi adds, “It’s important for employers to recognize if their confined spaces require vertical or horizontal entry and access in order to determine the correct PPE for the application.” 

Individuals who work in confined spaces must be aware of the risks involved and how to prevent them. Hazards in confined spaces can be deadly because of the potential for engulfment, oxygen deficiency, oxygen enrichment, flammable gases or vapors, combustible dusts, toxic substances and other physical hazards. Other health hazards that could impact employee safety include electrical equipment, mechanical equipment, poor visibility, biohazards, claustrophobia, noise, radiation, and temperature.

Safety Training

Senior Technical Training Specialist Mark Cangemi points out, “In my opinion, the biggest problem is employers not fully understanding the risks associated with their specific confined spaces.” He recommends companies invest the time and money to educate themselves on the particular hazards and proper solutions for their confined space workers. 

Learning about and understanding confined spaces is crucial. Cangemi continues, “People die because of a lack of information; because there are no safety plans in place for rescue. Awareness is everything.” 

He also adds that employers should provide the most effective safety equipment and invest in the training to use that equipment properly to control the hazards. “And remember, a well-designed and properly executed rescue plan is a must.”

Confined space rescue and descent operations require top-level safety solutions to help keep workers safe. Enclosed spaces or working at height expose workers to high risks of fire, explosion, loss of consciousness, asphyxiation, or falling. Fall protection PPE and portable gas detectors are valuable tools in the effort to prevent serious (and fatal) injuries. Possessing the appropriate safety products, tools, space rescue systems, descent devices and rope descenders are essential for helping to save lives in confined spaces.  

Safety training also helps companies avoid penalties and injuries by ensuring the highest quality training to meet requirements for OSHA 29 CFR § 1910.146 Permit-required and Non-permit Confined Spaces Standard. 

Who is required to take this training? 1.) People supervising confined space entry and 2.) Anyone entering and working within a confined space, along with attendants (those who are tasked with assisting with the entry, but not actually entering themselves). 

Approximately 5,000 people attend safety training sessions hosted by my company each year. The sessions are conducted on-site, at various locations, and online, offering practical training to suit customer needs.

Circling back to the opening scenario, what should a person do if a workmate collapses in a confined space? Senior Technical Training Specialist Mark Cangemi concludes: “What you should do is follow the hierarchy of rescue, the steps of your company’s exact rescue plan and procedures established for this specific confined space and work scenario. This plan needs to be developed, practiced, and reviewed for effectiveness.” 

His final advice for confined space employers and workers is simple: “Be safe. Be compliant.”

This article originally appeared in the October 2023 issue of Occupational Health & Safety.

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