Know your definitions
For starters, there must be a consistent definition of terms so everyone understands where special precautions are needed. A simple “confined space†must meet three criteria:1) limited means of egress (one way in, same way back out);
2) not designed for continuous occupancy (no HVAC, lighting, and such); and,
3) space large enough for a body to fit in it to perform work.
Once a “confined space†is identified through these criteria, an employer must determine whether the space meets the criteria for being “permit-required.†A “permit-required confined space†must:
- meet the definition of a confined space, then
- contain or have potential to contain a hazardous atmosphere, OR
- contain or have potential to contain an engulfment or entrapment hazard, OR
- contain physical hazards, OR
- other serious safety and/or health hazard not in any of the three above.
A confined space, then, becomes a permit-required space when a serious or life-threatening hazard exists in addition to the “confined†space itself. This requires special precautions and additional attention to ensure entrants are aware of and protected from the increased hazard(s).
Bottom line: If your space has either real or potential hazardous atmospheres (oxygen deficient, oxygen enriched, presence of toxic vapors/fumes, presence of explosive vapors/fumes), being engulfed by material, physical hazards (unguarded moving machinery, narrowing passages in ductwork, excessive heat, excessive noise, to name a few), or other hazards that pose a serious threat, you must take additional steps to ensure no one is injured or killed.
Test before entering
The most important step is testing the atmosphere — the air quality in the space where work will be performed. Many air monitors now test up to four gases simultaneously. If your monitor does not, then the first check is the oxygen level. Don’t forget — this check is done BEFORE you enter the space. Be sure to check all levels where work is to be done for various hazards. For example, many flammable gases are lighter than air and will be near the top or ceiling of the space. Carbon monoxide will remain close to the area where it is released, and hydrogen sulfide is heavier than air and will sink to the low places. Any of these can be deadly, so check each area prior to going in.Training requirements
Entrants, those that will actually have direct exposure to the hazards identified in the permit-required space, must have additional training and knowledge to perform work in that space. Entrants must know the hazards to be encountered and what type of personal protective equipment will be necessary for the task. They certainly must have knowledge of the task to be performed and the amount of time expected for the task to take. And, the entrants must know what special precautions, if any, must be taken to reduce or eliminate their exposure to the life-threatening hazards.
For example, does the space require purging or ventilating prior to entry? Is lockout required of electrical, pneumatic, hydraulic, chemical, or other forms of energy? Are there physical hazards that can be addressed, such as high heat, high-level noise, or unguarded moving machinery? And, once these special precautions are taken, can the permit-required space be re-classified? In other words, by performing the special precautions, has the entrant eliminated the life-threatening hazard that made it a permit-required space in the first place?
Ensuring precautions
The authorizing supervisor has a special responsibility. Too often, a supervisor simply looks at the permit application and signs off on the work to be done without actually doing anything. This is dangerous for the supervisor as well as to the entrants!
The supervisor must ensure all precautions are actually taken by walking back through with the entrants and double-checking what has been done. This is not to question good employees on the job they have (or have not) done, but provides the last line of protection for the employees to ensure everything is correct prior to entering the space.
Communication lifeline
The supervisor also assigns the attendant — the person responsible for no other task than ensuring those in the permit-required space stay alive while they are in there. The attendant cannot be involved in other tasks or, for that matter, be assigned to the entry point of the space and curl up with a good book. The attendant is the communication link to the outside world for those in the space. The attendant ensures all entrants are accounted for and may also be responsible for recording those “periodic†air monitor readings if entrants are inside for prolonged times.As a result, the attendant must also be knowledgeable of the hazards in the space, know the emergency procedures for getting help, if needed, and calls for help if the situation mandates it.
The attendant does NOT enter the space or perform any function of rescue for those in the space. The attendant maintains communication and calls for help, if needed. While rescuers are on the way, the attendant can continue talking to the entrants if communication lines are working to reassure them that help is coming. The attendant can also find out more of the situation for the rescuers if a communication line remains open with the entrants. And depending on the space and the procedures, the attendant may also function as a retriever with a retrieval system as long as the entry point plane is not broken.
