Confined Spaces

What Are Confined Spaces?

Many workplaces contain areas that are considered "confined spaces" because while they are not necessarily designed for people, they are large enough for workers to enter and perform certain jobs. A confined space also has limited or restricted means for entry or exit and is not designed for continuous occupancy.

People working in confined spaces face life-threatening physical and atmospheric hazards including toxic substances, electrocutions, explosions, asphyxiation, and faulty structures - hazards that can be avoided if they are recognized and addressed prior to entering these spaces to perform work.

Hazards of Confined Spaces

- Oxygen Deficient Atmospheres
- Oxygen Enriched Atmospheres
- Flammable Atmospheres
- Toxic Atmospheres
- Collapse of Faulty Structures
- Mechanical and Electrical Hazards
- Temperature Extremes
- Engulfment Hazards
- Noise, Slick/Wet Surfaces, Falling Objects, rats and snakes.

Monitoring Confined Spaces for Atmospheric Hazards

Prior to entering a confined space the air must be monitored. What you’re looking for includes:

The proper levels of oxygen - Too much oxygen presents the risk of fire, while too little oxygen will result in impaired co-ordination, respiratory impairments, and even death
No combustible gases are present
Toxic gases are below the permissible working limits

When monitoring you need to take samples of the air at the top, middle and bottom of the confined space as the gases and vapours will vary in concentration. Depending on the density of the gas, you may find highly concentrated levels at the top or very bottom of the work space. And you must sample the air at a distance from the opening to the confined space. That’s because air from outside will give you a false sense of adequate oxygen presence.

To carry out these atmospheric tests requires the equipment that’s properly calibrated for the job.

Once a pre-entry check has been completed and it’s established the confined space is safe to work in, the air within it must be monitored continuously. Conditions in a confined space can change without warning due to toxic vapour release, leakage or by disturbing the air within the space.

Preparation & People: Competent person

Standards and safety equipment are only as good as the people who follow and use them. Before activity can even begin at a worksite, employers are tasked with ensuring a “competent person” conducts an evaluation and identifies confined spaces, including permit spaces. In the process, the competent person may also perform testing procedures, which could identify risks from the start and prevent life-threatening situations from arising.

People & Practice: Attendant

One of the most important personnel roles as it relates to confined space is the attendant. This mandated person will stay stationed outside one or more permit spaces. Not only is this individual tasked with summoning rescue and emergency services if he or she determines that entrants require assistance to escape, but in order to make that call, he or she must first be aware of the potential hazards that workers can face, including the behavioral effects of any exposure.

OSHA Standards

In 2015, OSHA replaced a training-only requirement for confined space work in construction with a more comprehensive standard that includes a permit program and training requirements.

OSHA uses the term "permit-required confined space" (permit space) to describe a confined space that has one or more of the following characteristics: contains or has the potential to contain a hazardous atmosphere; contains material that has the potential to engulf an entrant; has walls that converge inward or floors that slope downward and taper into a smaller area which could trap or asphyxiate an entrant; or contains any other recognized safety or health hazard, such as unguarded machinery, exposed live wires, or heat stress.

Key compliance requirements:

Before work at a site begins, a competent person must identify all confined spaces and permit-required spaces.
Employees must be informed about the permit spaces through signage or other means.
The internal atmosphere must be tested.
Workers must be provided personal protective equipment when engineering and work practice controls do not adequately control hazards.
Workers must be trained about the hazards.
Employers must ensure that properly trained rescue and emergency services are available before entry into permit-required confined spaces.

NEVER WORK IN A CONFINED SPACE WITHOUT PROPER TRAINING!

NEVER WORK IN A CONFINED SPACE WITHOUT FULLY UNDERSTANDING AND EVALUATING THE HAZARDS!

NEVER WORK IN A CONFINED SPACE WITHOUT AN ATTENDANT STATIONED AT THE ENTRY POINT!

Links to Further Information:

Osha - Confined Spaces in Construction

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