What is confined space?
There are so many definitions of Confined space, but the OSHA defined Confined space as a space that:
- It is large enough and so configured that an employee can bodily enter and perform assigned work.
- Has limited means for exit and entry (e.g., tanks, vessels, silos, storage bins, hoppers, vaults and pits).
- It is not designed for continuous employee occupancy.
What are the hazards associated with confined space?
There are a number of hazards associated with confined spaces. They include the below:
- Flammable gases.
- Toxic gases.
- Electrical risks.
- Structural issues.
- Engulfment.
What are the various ways to mitigate hazards associated with confined space?
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The first way to address the hazards is to get the services of a qualified person to conduct the initial survey of the operations to be carried out in the confined space before the start of any work. The qualified person will be able to identify the hazards and develop strategies to mitigate the risks using the hierarchy of controls. The qualified person should document the number of employees working in the space and determine the magnitude and likelihood of the hazards and their potential consequences of each of the hazards.
What tests should be carried out in a confined space?
Before entry, the competent person has to conduct a test for atmospheric oxygen, flammable or explosive substances, and other airborne chemical substances. The competent person should also determine if the activity will result in a change to the atmosphere.
What does engulfment mean?
Engulfment means to be swallowed up in or immersed in material, which may result in asphyxiation. When someone is in a tank that contains liquid, and the tank is filled with that liquid, someone can actually get drowned and asphyxiated from that liquid, and it can be termed that the person was engulfed in the liquid. There are a number of materials that can lead to engulfment. These materials include plastics, sand, liquids, fertilizer, grain, coal, coal products, fly ash, animal feed and sewage.
What is an unsafe level of oxygen in a confined space?
The air that we breathe contains 21% oxygen. However, 19.5% — 23.5% oxygen levels are safe for humans. Some situations can deplete the oxygen in the confined space, and some situations include oxygen being displaced by a biological process, for example, by methane produced in a sewer. When the confined space is purged with an inert gas to remove a toxic fume, it can lead to oxygen depletion. Nitrogen is mainly used in this activity. The oxidation of the metal tanks can result in oxygen depletion. Combustion of flammable substances can lead to oxygen depletion in a confined space.
Even in a confined space, when there is too much oxygen, it is still a big problem because too much oxygen can increase the risk of fire or explosion. Some situations can give rise to an oxygen-enriched atmosphere caused by specific chemical reactions, such as a chemical reaction with hydrogen peroxide. A leak from an oxygen tank can also increase the oxygen levels in the space.
Is there any need for signs and barricades around a confined space activity?
Before starting any work activity in that area, signs and proper barricades should be available to prevent entry of persons not involved in the work process. The signs should be visible to everyone .Signpost alone will not do the work completely and this is where barriers should come in for proper protection around the confined space area.
Do I need a confined space entry permit before entering a confined space?
Not all confined spaces require a permit to access them; however, permit-required confined space needs a permit before entry. The permit is a formal document that will authorize the workers to enter the confined space when all hazards in the confined space have been appropriately managed. The permit also provides communication between site management and the workers, showing that the workers are authorized to enter the confined space and that it is safe to use.
What must a worker do before entering a confined space?
Before entering a confined space, that worker must have been trained in the job.
- There should have been a rescue plan in place in case of emergency.
- Ensure there is an entry permit and it is filled.
- Wear the necessary PPE for the task.
- Ensure that the activity’s risk assessment is available and appropriately communicated to them.
- Have a standby watch for the work in the environment.
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Onyeka Emma is a QHSE Professional with more than 10 years of experience in occupational health and safety, which spans many industries such as construction, beverage, oil and gas, etc. He has many health and safety certifications, including NEBOSH IGC, ISO 9001:2015, ISO 14001:2015, and ISO 45001:2018 Lead auditor certificate. A member of IOSH, ISPON, and Nigeria Red Cross Society. He is interested in business, entrepreneurship, Speaking, and motivating people to do better for themselves. He enjoys leisure with a good motivational book.
