Construction Injury prevention

Close quarters

The hazards of confined spaces


Key points

  • Confined spaces have limited exits and entrances, and can force employees to work in positions that are hard on the body.
  • Confined space hazards include ergonomics, heat and struck-by.
  • Experts recommend always having a second worker outside the confined space to communicate with the worker.

The roll of duct tape was only 5 feet away, resting inside a reactor chamber at a refinery. The chamber was being purged with nitrogen, and cleanliness criteria dictated that the roll of tape could not be there. In an attempt to retrieve it, one worker either fell or intentionally went inside and – due to the near-zero oxygen concentration within the reactor – was dead within minutes, according to a Chemical Safety Board report on the incident.

The situation, already horrific, then got worse.

An onsite foreman quickly descended the reactor’s ladder in an apparent rescue attempt. He never returned.

“All too often, and as this case illustrates, would-be rescuers become victims,” the CSB report states.

CSB went on to say that the double-fatality case, which occurred in Delaware in 2006, offers important lessons: Confined spaces can be dangerous even if they do not appear to be, and proper safety and rescue precautions must be taken when working in them.

According to OSHA, about 90 deaths involving confined spaces occur every year. Guy Colonna, division manager for industrial and chemical engineering at the National Fire Protection Association in Quincy, MA, said such incidents may occur because workers and employers do not know what confined spaces actually are or what dangers may lurk inside. One study concluded 40 percent of confined space fatalities involve attempted rescuers.

“They’re still failing to recognize a space as having the attributes of a confined space, and they’re making assumptions about the space and going in without the proper safeguards,” Colonna said.

Defining confined spaces

Generally, a confined space is large enough for a person to enter, has limited or restricted means of exit, and is not designed for continuous human occupancy, according to Gary Flores, EHS regional director for Strike USA, a pipeline manufacturer and service provider based in The Woodlands, TX. Everything from tanks and tunnels to manholes and silos can be considered confined spaces.

Colonna stressed that confined spaces do not always have to be an area with only one opening. An area may have several openings but would still be considered a confined space if those openings are 15 feet off the ground. Likewise, a space with multiple openings can be considered a confined space if a worker has to crawl under and over various obstructions to get to the opening.

A “permit-required” confined space contains one or more of the following characteristics:

  • A hazardous atmosphere or the potential for one
  • Material, such as grain, that could potentially engulf an individual
  • Walls converging inward or floors sloping downward and tapering into a smaller area that could trap or asphyxiate an individual
  • Any other recognized safety or health hazards, including unguarded machinery and heat stress

Employers are required to alert workers of the location and the dangers of permit-required confined spaces. This can be done with signs or by other methods, the Washington-based American Federation of State, County and Municipal Employees states.


The buddy system

To help protect a worker inside a confined space, many stakeholders consider it a best practice to have a second worker on the outside. OSHA advises these workers to always maintain contact through either visual, phone or radio means. This monitoring allows the attendant to order the worker in the confined space to evacuate, and to contact emergency personnel to help with rescue if necessary.

Although not all types of work require an outside individual, David LeGrande, health and safety director for the Washington-based Communication Workers of America, stressed that it is a best practice for that worker to monitor the situation, and said some states have enacted provisions requiring the second worker regardless of the type of work.

A confined space may have been tested to be clear for entrance, but an airborne contaminant may be at ground level in the confined space and not noticeable until the employee begins to work at the lower level. That individual could then be overcome by the substance and pass out.

“And that’s why it’s so important to have a second person above ground,” LeGrande said.

This outside worker should be trained in first aid and CPR, he said, and should be able to perform emergency procedures that could include helping the worker get out of the confined space.


LeGrande worries that employers are failing to adequately train employees about working in confined spaces. Instead of going through proper procedures, warning employees of all possible hazards and explaining precautions to take, he said, employers are focusing on completing the work.

“It’s all spurred by this drive to increase performance and productivity,” he said.

Denise Bowles, health and safety specialist with the American Federation of State, County and Municipal Employees, said AFSCME wants workers who are trained to think about their confined workplaces and ask whether they can get in and out safely.

Bowles has learned of situations in which new workers learn from colleagues who have been on the job for years, but who have not had formal training on confined space hazards and are entering the areas incorrectly.

Workers should be trained on the dangers they could face in a confined space, procedures for safe entry and exit, and what protective gear they should have, AFSCME states. Employers also should train workers on the company’s written confined space program, Flores suggested, including air monitoring, safe work practices, lockout/tagout and an emergency action plan.

Confined space incidents

Read a list of NIOSH Fatality Assessment and Control Evaluation Reports.

Proper equipment

Bowles suggested going through confined space equipment to make sure it is still in good shape. If damaged, it may not operate effectively, putting workers at risk.

“Take a look at the equipment you have and make an honest assessment of the useful life of it,” said Dianne Matthew Brown, AFSCME health and safety specialist. “A lot of stuff gets thrown around and it takes abuse it was never meant to take.”

Bowles knows of a municipality that, to help ensure its gear stays in good condition, places all confined space equipment in a single trailer. When employees must perform confined space work, they hook the trailer up to their truck and tow it to the site, use the equipment, and return it to its proper location before towing it back to the main facility.

“It makes it easy, and you don’t have to worry about the equipment being thrown in the back of the truck,” Bowles said.

Emergency response

Workers in confined spaces should be hooked up to equipment that can retrieve them if they are overcome. Unfortunately, this is not always possible.

“They have to crawl over and under pipes that are in that space,” Bowles said. In those situations, workers may have to unhook from retrieval equipment. If something goes wrong, that individual will not be quickly pulled out – the attendant on the outside no longer has visual contact, and cannot safely go into the confined space without proper protection against whatever incapacitated the victim.

Some worksites have emergency response teams on standby, and Brown suggested establishing a relationship with local emergency services. All personnel should be trained on emergency procedures, a written plan and the emergency retrieval systems, according to Flores. Employees should know all potential hazards, and none should attempt a rescue without being trained, he added.

Rescue scenarios could be avoided if proper safety procedures are followed beforehand – even with pressures to get the job done quickly, Bowles said.

“Your job is to get services back online, but we want to make sure we do it safely,” she said.

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