Confined space safety

The term "confined space" is intimidating in itself. It brings up thoughts such as closets and elevators and small, tight areas. We have all had those times in our lives when we felt uncomfortable because we were in a small space.

When we look at the term "confined space" as it applies to safety and industry it takes on an even more serious tone. When I think of confined spaces in an industrial setting, I think of entering storage tanks and underground pits, places a person wouldn't normally enter.

Following procedure

Here is a scenario of a typical confined space entry: The chemical unit has been shut down for repairs, and maintenance welders will be entering a distillation column to weld in new trays. To make sure this task is done safely they will follow the confined space procedure:

When the distillation column was being shutdown it was washed as thoroughly as possible to remove the chemicals that had been present.

The column was then isolated by placing blinds in all piping connected to the column, and valves were locked and tagged along with any equipment such as agitators that would present a hazard.

The column was then ventilated by opening all manways, and an air mover was placed in the manway to promote air circulation.

The supervisor of the area begins to fill out the permit by checking all the blinds and lockouts to ensure that the column is isolated.

The supervisor then monitors the column by placing the hose of an analyzer into the column at several areas to check for oxygen content, combustibles and toxic chemicals. He then completes the permit.

The welders enter the column after signing in with the attendant who is in charge of keeping track of who enters the column by having them sign in and out. The attendant never enters the column and is always ready to summon help if needed.

After the repairs are made and everyone exits the column, the permit is completed and closed out. The column can then be readied for service.

Because confined spaces are so hazardous, companies need to be sure that they have a confined space procedure in place. Let's look at such a program in four steps:

Step 1: Identify confined spaces

There are more confined spaces at your workplace than you may realize. A confined space is defined as:

(1) Large enough and so configured that an employee can bodily enter and perform assigned work. This means that if there is enough room for a person to enter it could be a confined space. One that comes to mind is a pit or drainage area under a production line, areas where the oil and liquids from a manufacturing line drain to an accumulation point. Years ago we would have never considered this a confined space. Employees would enter these areas never thinking twice about a hazard.

(2) Has limited or restricted means for entry or exit. If there is not a door and the person has to enter the space by some other means such as a ladder or a manway, the area is a confined space. A large trash dumpster is a good example. Large dumpsters usually have a door on one end that lies down and makes one end of the container completely open. If this door is open then entry and exit is easy, but if this door is closed and a person has to use a ladder placed inside of the container it can become a confined space.

(3) Is not designed for continuous employee occupancy. The dumpster would meet this requirement, as would the oil accumulation pit. "Not designed for continuous occupancy" broadens the scope of what is considered a confined space. This item is probably the most frustrating for management as they try to identify confined spaces because it broadens the scope of the program.

With these criteria in mind you can tour your facility and identify the confined spaces. As you identify the confined spaces you will have to determine if they are permit required or non-permit required confined spaces. (See "Non-permit or permit required?" sidebar.) Additionally, be sure and label each confined space.

Step 2: Procedure in writing

Similar to all safety procedures, the confined space program must be in writing. Using the OSHA permit required confined space regulation 1910.146 as an outline, you can write your program. There are also plenty of confined space procedures available on the Internet that can be used as additional resources. Although your procedure has to meet certain criteria, make sure it is usable and that it can actually be performed as written.

The procedure should cover:

The scope of the program.
Definitions of terms and the roles of the key people playing a part in the program. For example, define what the entrant's role is and what the attendant's duties are.
How a confined space will be prepared for entry. This section will address the blinding of lines, the lock and tag of equipment and ventilation of the confined space.
The monitoring of the space for oxygen, combustibles and toxic atmospheres.
Personal protective equipment that will be required.
Rescue procedures that will detail what to do if a person needs to be removed from the space and how help will be alerted.
The permit and how it should be filled out.
How to close out the permit and return the equipment to service.

Step 3: Training/implementation

After you have the procedure in writing along with the development of a permit, it will be time to do the training.

Different roles can be trained at different levels. Those preparing the confined space for entry, the entrants and the attendants will need the most detailed training. It is recommended that all personnel at a minimum have awareness training of the program.

With the program in writing, the confined spaces identified and the personnel trained, the program can be implemented.

Step 4: Audits

The confined space procedure should be audited on a regular basis. Auditing is as simple as going to a confined space that is being entered and identifying if the procedure is being followed. A simple check sheet developed from the procedure would be a handy tool for this activity.

Confined spaces are hazards, but implementing a good program can reduce those hazards.

SIDEBAR: Non-permit or permit required?

A non-permit confined space is a confined space that does not contain or, with respect to atmospheric hazards, have the potential to contain any hazard capable of causing death or serious physical harm.

A permit required confined space is a confined space that has one or more of the following characteristics:

Contains or has the potential to contain a hazardous atmosphere.
Contains a material that has the potential for engulfing an entrant.
Ready removal of a suddenly disabled employee is difficult due to the location and/or size of access openings.
Contains any other recognized serious safety or health hazard.