Confined space deaths continue to occur in confined spaces due to a lack of awareness or understanding of the hazards and requirements of entering and working in confined spaces. Bureau of Labor Statistics (BLS) states that fatal injuries in confined spaces have fluctuated from low to high at an average of 92 fatalities per year.
The serious dangers associated with confined spaces, however, are invisible and silent. Entering a tanker, process vessel, boiler, pressure vessel, silo, and storage tank or manhole, for example, can be a hazardous journey for anyone.
A confined space is a fully or partially enclosed space that:
- is not primarily designed or intended for continuous human occupancy
- has limited or restricted entrance or exit, or a configuration that can complicate first aid, rescue, evacuation, or other emergency response activities
There are three major hazards associated with confined spaces.
Oxygen deficiency. Oxygen deficient atmospheres are atmospheres that contain less than 19.5% oxygen.
Flammable atmospheres are those in which oxygen is in the air and flammable gas, vapor or dust is present in the proper proportion of the gas/vapor and oxygen to make it potentially explosive. Different gases have different flammable ranges. If a source of ignition, such as a sparking or electrical tool, is introduced into space with a flammable atmosphere, an explosion may result.
Toxic atmospheres. Most substances, such as liquids, gases, mists, solid materials and dust, can present a hazard in a confined space. Atmospheric concentrations of any substance with an acutely toxic effect above its PEL, and any other atmospheric condition that is immediately dangerous to life or health (IDLH).
A few of the potentially hazardous gases are:
Carbon monoxide. This gas is usually produced by the exhaust of an engine or heater. It is colorless, odorless, tasteless and deadly. If the air you breathe contains carbon monoxide, the gas interferes with your body's ability to utilize the oxygen in your lungs and causes asphyxiation which can be deadly.
Hydrogen sulfide. This is the colorless gas with a rotten egg smell. You may think the smell would give you plenty of warning, but it doesn't. At higher concentrations, the gas can desensitize your sense of smell. In extremely high concentrations, it can immediately kill you. Hydrogen sulfide is released during the decay of organic matter found in muds, sewage and is often present in oil and gas drilling.
Carbon dioxide. Decaying animal or vegetable matter can create this gas. It could also be leaked from a fire suppression system or it may have been used to make inert space. The gas is odorless, colorless and displaces oxygen within a space, which can be fatal.
There are, of course, additional potential hazards such as spaces with high temperatures, excessively noisy areas, chemical piping, steam lines, and others. All potential safety hazards must be evaluated and proper protection provided for each type of hazard to ensure confined space safety.
Employers are responsible for assessing ALL hazards associated with confined space entries with proper training. OSHA program emphasizes planning and training. At a minimum, training must include:
- Recognition of permit space hazards.
- Control of permit space hazards.
- Use of atmospheric monitoring equipment.
- Use and maintenance of PPE such as respirators.
- Use and maintenance of rescue equipment.
- Proficiency in first aid and cardiopulmonary resuscitation (CPR).
- Documentation of training.
0 comments: