Deaths of workers in confined spaces are a recurring occupational tragedy. According to NIOSH (National Institute for Occupational Safety and Health), approximately 60% of deaths involve would-be rescuers. With the proper equipment and training, the vast majority of these fatalities can be prevented.
The danger of toxic gas hazards is a very real and daily threat that people face in numerous occupations. In the state of Kentucky, one police officer and two sewer workers died in an attempt to rescue a third sewer worker who had been overcome by H2S gas at the bottom of an underground pumping station. All four were pronounced dead upon their removal from the station.
In the state of Georgia, a plumbing contractor and two co-workers were laying out a new sewer line for an industrial building under construction when a fatal accident occurred. The contractor entered the manhole and descended 15 feet into the sewer to measure a stub out location for the new line. Co-workers were unsuccessful in their rescue attempts and the contractor was removed by the fire rescue squad. He was pronounced dead on arrival at a local hospital. Atmospheric tests revealed the oxygen level in the sewer to be six percent.
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In all tragic events any gas monitoring equipment is seized and the investigation begins. How prepared are you for the questions that will follow? Accurate record keeping provides evidence of the event as well as the proper testing and maintenance of the gas monitor. The due diligence of data collection and retention may help avoid a long and costly litigation. Even when gas monitoring prevents a tragic event, loss of time, money and productivity may have to be justified.
While this paper will focus on multi-gas monitors used primarily in confined space entry, the principles as it pertains to documentation can be used for all applications of gas detection. This includes event and data logging retrieved from the gas monitor as well as data retrieved form bump testing and calibration devises.
Generally speaking, a confined space is any space that is large enough for an employee to enter and perform work. The space has limited means of entry or exit, and is not designed for continuous occupancy. A permit-required confined space has one or more of the following characteristics:
A hazardous atmosphere (oxygen deficiency, toxic gases or explosive gases) is present or has the potential to be present.
Material with the potential for engulfment is present.
The space has inwardly sloping walls or dangerously sloping floors.
The space contains any other serious safety hazard.
Many occupations such as sewer workers are typically very knowledgeable when entering and working in confined spaces. Unlike other occupations where confined space entry is an infrequent event, sewer workers' typical work environment is a permit required space. They must understand that the atmosphere may suddenly become lethally hazardous from causes beyond their control.