DURING the majority of inspections and maintenance performed on aircraft fuel tanks, personnel must enter the interior of the tanks. This type of entry is defined as confined space entry and is regulated by the Occupational Safety and Health Administration. In these spaces, personnel can be potentially exposed to dangers such as oxygen deficiency and enrichment, explosive gases, and toxic effects from fuels and maintenance chemicals.
FRANCIS Bacon, a philosopher, once said that "knowledge is power." While this saying can be applied to many different situations throughout life, it has added value when talking about confined spaces in the work area. It's important to have a knowledge and understanding of confined spaces because the lack of same could result in serious injury, including death.
WHEN monitoring the atmosphere in a confined space, there are several important issues that need to be considered, reviewed, and managed. One of the major issues centers on air quality and what you are breathing, both prior to entry and during occupation of a confined space. You need to know what the oxygen content of the atmosphere is and whether there are explosive or toxic gases that could threaten the safety of the environment or, perhaps more importantly, your life.
"IT showed something bad. . . . Come check this thing out, it showed something!" were the gasping utterances of a dirty, sweat-streaked, very excited (and obviously frightened) maintenance fellow. The multi-gas monitor, after months of use, had sounded an alarm that startled the crew while working in a tunnel.
MULTI-GAS detectors designed for use in confined space entry (CSE) are often not enough to protect against all chemical vapor hazards in the workplace. In their standard configuration, these meters have sensors for oxygen depletion, combustible gases (lower explosive limit or LEL), carbon monoxide (CO), and hydrogen sulfide (H2S). Such sensors cover the most common hazards--such as fires from natural gas, propane, or gasoline leaks, and asphyxiation in confined spaces due to lack of oxygen.
CONFINED spaces can have many characteristics with numerous types of hazards. Escape from the roof of a burning building! Rescue from a swimming pool! Entrapment in a coal mine! Engulfment in an avalanche! Oxygen deficiency in a fuel tank! These are situations that are all too real to rescue personnel who conduct emergency rescue operations.
THE most critical element in ensuring that work inside confined spaces is completed safely is the ability to anticipate safety problems before they become life threatening. Hazard evaluation can be as simple as evaluating changes in work attitude or as complex as evaluating environmental conditions.
MANY decisions to enter confined spaces are made without recognition of the expected danger. Lack of knowledge, carelessness, and simple acceptance of the hazard are the main reasons. The decisions to enter are made in spite of all efforts to provide hazard awareness and safety training.
CONSTRUCTION workers make up only 6 percent of the total workforce, but they are involved in more than 20 percent of all work-related fatalities. Trenching accidents that are directly related to excavation work account for almost 200 deaths annually.
THE attendant is the last individual external to the confined space who can monitor working conditions that will ensure the safety of the workers inside the work space. Attention to specific details outlined on the work permit, the ability to adequately oversee "permitted operations," and the authority to "stop work" when rules are violated are the critical elements of the responsibility.
SAD but true: In spite of all safety regulations and precautions, almost 500 deaths occurred in confined spaces during the past five years. Seventy-five percent of these deaths involved skilled workers who were cleaning, repairing, or performing routine maintenance.
TOXIC VOC exposure is one of the most overlooked hazards in confined space entry. Volatile organic compounds (VOCs) are organic compounds characterized by their tendency to evaporate easily at room temperature.
A worker is about to enter a confined space. Prior to entry, he reaches down to his belt and pulls out his gas monitoring device. He points the device into the confined space and initiates a scan of the entire area. Beams of light emit out of the instrument in all directions and cover the entire interior of the confined space.
OXYGEN deficiency is one of the most common of all categories of atmospheric hazards. It stands to reason that the sensors used to measure oxygen concentration are one of the most widely used types of sensors included in portable atmospheric monitors, especially those used in confined space monitoring procedures.
JUST about every industrial facility and parking lot with a manhole has the potential to contain an Occupational Safety and Health Administration-defined "confined space."
I started (and continue) my professional career, for better or worse, in the Golden State of California. As a result, much of my early understanding of health and safety management practices was framed around the early requirements of California's Occupational Safety and Health Division (Cal/OSHA).
OF all the dangers inherent to confined space work, it's the invisible threat of atmospheric hazards that poses the greatest risks to employees.
PERMIT-required confined spaces are death traps if entry teams don't take proper precautions.
THE North American multi-sensor gas detector market is very large. Most of these instruments are purchased, at least in part, for use in confined space entry programs.