(Note: Have a look at the training program below for Confined Space Entry Training)

The CSB also released a 15-minute safety video entitled “No Escape: Dangers of Confined Spaces,” which includes a detailed animation depicting the horrible tragedy that unfolded inside the mountain tunnel at Xcel’s Cabin Creek plant on October 2, 2007.

Here’s the video. Very graphic!

The accident occurred in the water tunnel, or penstock, of the hydroelectric plant, located 45 miles west of Denver. The penstock carries water from an upper reservoir to a lower one, driving power turbines. The painting contractors, from RPI Coating, Inc., were recoating a 1,530-foot steel portion of the 4,300-foot penstock when a flash fire suddenly erupted as the vapor from flammable solvent, used to clean the epoxy spraying wands, ignited, probably from a static spark in the vicinity of the spraying machine. The initial fire quickly grew, igniting additional buckets of the solvent, methyl ethyl ketone (MEK), and other combustible epoxy materials stored nearby.

The CSB concluded the causes of the accident included (1) a lack of planning and training for hazardous work by Xcel and its contractor, RPI Coating, Inc., (2) Xcel’s selection of RPI despite its h aving the lowest possible safety rating (zero) among competing contractors, and (3) allowing volatile flammable liquids to be introduced into a permit-required confined space without necessary special precautions.

The CSB report found that the permit-required confined space rule set by the U.S. Occupational Health and Safety Administration (OSHA) does not prohibit entry or work in confined spaces where the concentration of flammable vapor exceeds ten percent of the chemical’s lower explosive limit, or LEL. (The LEL is the concentration of vapor in air below which ignition will not occur.)

OSHA’s rule does state that an atmosphere exceeding ten percent of the LEL creates an atmosphere “immediately dangerous to life and health” and that steps should be taken to define safe entry conditions; however, the rule does not define what those safe entry conditions should be or specifically prohibit entry into such hazardous atmospheres, the report notes. The CSB recommended OSHA establish a fixed maximum percentage of the LEL for entry so that work in potentially flammable atmospheres would be prohibited.

(Note: For an excellent training program on how to select and use LEL gas monitors, for combustible gas detection, please see this)

Additionally, the Board made recommendations to the company, the governor of Colorado, the Colorado Public Utilities Commission, trade groups, and other organizations.

CSB Board Member William B. Wark said, “This tragedy should never have happened. The companies did not effectively plan for the dangers of bringing significant amounts of flammable liquids into the tunnel, which was a hazardous confined space. Doing so was an unacceptable deviation from good safety practices.”

There were ten workers in the tunnel and one at the entrance at the time of the fire. Five were unable to get around the fire on the painting platform to get to the only available exit – the improvised tunnel entrance. Five workers on the other side of the platform made it to safety, although three of those workers sustained injuries.

The CSB found that Xcel and RPI failed to have technically-qualified confined space rescue crews immediately standing by at the penstock in case of emergency, as required by regulations. Workers called 911 for help but responders entering the penstock had to retreat in the thick smoke, as did workers who had approached the fire with extinguishers.

The closest confined space technical rescue unit – equipped and trained to enter the smoke-filled tunnel – was approximately one hour and 15 minutes away. The trapped workers died about one hour before this response unit arrived, their escape blocked by a steep vertical section of the tunnel deep inside the mountain.

CSB Investigations Supervisor Don Holmstrom, who led the investigation, said, “The five trapped workers communicated with co-workers and emergency responders using handheld radios for approximately 45 minutes, desperately calling for help, before succumbing to smoke inhalation. Their lives likely could have been saved had qualified, company-provided rescuers been in a position to respond immediately to a fire or other emergency.”

Board Member Mark Griffon, joining Mr. Wark and Mr. Holmstrom at the news conference, said, “Even before the operation began, the stage was set for disaster. Xcel not only did not adequately plan for the operation, but it selected the painting contractor with the lowest possible safety rating among the bidders, and it did so mostly on the basis of cost – it was the lowest bid.”

The investigation found that Xcel hoped to compensate for RPI’s safety record by closely supervising the contract work, but did not do so even when the company learned of safety issues during the initial penstock work.

The CSB investigation found Xcel and RPI managers were aware of the plan to operate the epoxy sprayer in the tunnel and to use flammable solvent to clean the sprayer and other equipment.

Mr. Holmstrom said, “As a result of not performing a hazard evaluation of the work to be done, the companies failed to identify serious safety hazards involving use of flammable liquids within the confined space. Use of safer, nonflammable solvents was not evaluated, continuous air monitoring was not required, and key policies and permit forms did not establish a percentage limit for flammable vapor in the tunnel atmosphere.”

Board Member Wark noted the lack of planning for escape in an emergency. “The penstock had only one egress point – the tunnel entrance,” he said. “Xcel and RPI did actually identify this as a major concern in their planning. But despite this, no plans were made for prompt rescue in an emergency, and no rescuers qualified to enter this confined-space environment were standing by.”

The CSB investigation determined that while companies are required to perform a hazard analysis prior to issuing permits for work in confined spaces, regulatory standards pertaining to the use of flammables within confined spaces are inadequate.

Board Member Griffon stated, “Other OSHA regulations on confined and enclosed spaces – for example in the maritime industry and other sectors – prohibit work in such confined spaces above a specific percentage of the LEL, often ten percent. We are recommending that OSHA adopt such enforceable limits for all industry.”

The CSB recommended that OSHA amend its confined space rule to establish a maximum percentage substantially below the lower explosive limit for any given flammable for safe entry and occupancy while working.

The CSB made recommendations to nine other entities. These included that the governor implement an accredited firefighter certification program for technical rescue with specialty areas including confined space rescue; that the Colorado Public Utilities Commission (PUC) require regulated utilities to adopt provisions for selecting contractors based on safety performance measures and qualifications; and that the PUC require utilities to investigate all incidents resulting in death, serious injury or significant property damage and submit and make public written findings and recommendations within one year of the accident.

Numerous recommendations were made to RPI Coating, particularly aimed at revising its confined space entry program and guidance.

CSB investigators and board members cited difficulties encountered in the investigation resulting from efforts by Xcel Energy and RPI Coating to impede the investigation and prevent the release of the investigation report.

Citing a formal Letter of Admonishment sent to the Xcel chief executive officer earlier in the week, Board Member Wark said, “The lack of cooperation and efforts by Xcel to impede our investigation are unprecedented. Mr. Griffon and I join our chairman in criticizing these actions in the strongest terms.”

The letter, signed by CSB Chairperson Rafael Moure-Eraso, states Xcel Energy did not fully comply with CSB requests for documents or answers to questions in formal interrogatories. This required the CSB to seek assistance from the U.S. Attorney’s office in Denver, resulting in delays to the investigation and additional costs to taxpayers. In May, Xcel took the extraordinary and unprecedented step of going to federal court seeking to block release of the CSB report and the safety video. The court sided with the CSB in favor of release.

Xcel was given an advanced draft copy of the report last April for review for accuracy and for confidential business information in accordance with CSB review protocols. Xcel never responded, but in August 2010, contrary to the conditions of confidentiality attached to their receiving this preliminary copy, released it to a news organization.

The letter from Chairperson Moure to Xcel’s CEO concludes, “In light of this disappointing pattern of corporate conduct, I am writing you directly to ensure that you are personally aware of the actions taken by Xcel to delay the CSB investigation, block publication of the CSB final report, and distort the conclusions of the investigation by releasing an unauthorized draft copy of the CSB report. The CSB will issue a formal recommendation that Xcel shareholders be directly notified by management of the significant findings and recommendations of the CSB report, and of the actions Xcel management intends to take to implement needed safety improvements. In the wake of the corporate responsibility concerns raised by the Big Branch Mine accident in West Virginia and the disaster in the Gulf of Mexico, I strongly urge Xcel to renew its focus on safety and to swiftly implement the CSB’s recommendations.”

So what are confined spaces? A confined space is defined in most labor or safety regulations, as an area that is enclosed from almost all sides,  has limited access from outside, is not usually manned and  which could become dangerous for humans who work inside. Examples of confined spaces are typically oil storage tanks, process reactors in chemical plants,  the inside of a boiler or furnace or even a city sewer.

What dangers do workers face when they enter confined spaces? Well, they may face a danger of asphyxiation, danger due to lack of breathing air, toxic or hazardous chemicals and even drowning due to water (say in case of an entry into a water storage tank that is being cleaned before refilled with water). Due to these dangers, there are systematic procedures that must be followed in case of a confined space entry. Not following these, is not just illegal, it may endanger human lives. The first requirement in such a procedure, is for an entry permit that is to be issued to any worker who enters a confined space.

According to OSHA (Occupational Health and Safety Administration), a permit required confined space as having the following characteristics

1. Contains or has the potential to contain a hazardous atmosphere
2. Contains a material that has the potential for engulfing the entrant
3. Has an internal configuration that might cause an entrant to be trapped or asphyxiated by inwardly converging walls or by a floor that slopes downward and tapers to a smaller cross section
4. Contains any other recognized serious safety or health hazards.

Despite these guidelines, annually, there are several accidents and fatalities that occur every year, as a result of workers entering confined spaces. The only way to prevent such accidents is by ensuring that all workers (and their supervisors), who work or are likely to work (even once a year) in a confined space are adequately trained to work in such spaces.
The permit to enter a confined space has to be issued by the worker’s supervisor, who is well aware of the dangers of the confined space. There should also be a provision for a person who will remain standby outside, ready to rescue the person inside, in case of a problem.
All hazardous sources of energy must be locked out and tagged, inlet lines must be blocked and oxygen inside must be measured to ensure that the entrant (worker actually entering the confined space) is safe. Note that in case of activities that consume oxygen (think of a welder who is welding something inside a storage tank), there must be a continuous supply of breathing air. Nitrogen blanketing systems must be shut off and ensured that they are not activated before the person comes out.
The worker must wear personal protective equipment. If entering an area that has a presence of toxic gas (like Hydrogen Sulfide) in normal operation, the entrant must also carry a personal gas monitor that will warn in case the contamination level of the toxic gas is above the safe limit.
Of course, there are many other precautions that must be taken, the ones given here are the most basic ones. To ensure that your workers are not subjected to undue dangers, you must ensure training in confined spaces to all concerned. A very cost effective way of doing this is by having an e-learning course that covers everything and can be viewed again and again by multiple workmen.
Check out the one given here, its recommended by Industrial Plant Safety.