10 Confined Space Examples You Need to Know

Characteristics

Understanding the concept of confined spaces is vital to keeping workers safe from their hazards. The specifics may vary depending on the industry or region; but in its basic sense, an area must meet all these three specific criteria to be called a confined space:

1. Has limited openings for entry and exit – It can be difficult to enter a confined space and perform general maintenance or other work activities. This makes rescue or escape challenging in case something goes wrong while a worker is inside the space.
2. Is just enough space for a worker to enter and conduct work – If a worker cannot comfortably fit his or her body in the space, there is a high possibility that the worker will be trapped inside. Ensure first that the confined space can fit a person before commencing work in said area.
3. Not intended for continuous occupancy – Confined spaces are not designed to hold a person, especially for extended periods. It can also mean that an area is intended to contain something else other than people—examples of this are spaces such as vessels, furnaces, and tanks.

Types of Confined Spaces

The term “confined space” is a broad term that covers a variety of spaces. There may be several confined spaces in your workplaces, depending on the type of business. They can fall under either of these two categories:

Permit Confined Spaces

Dangerous confined spaces are known as permit confined spaces because they require appropriate permits, which can only be obtained after a qualified person has completed a confined space risk assessment of the specific area.

A permit confined space meets one or more of the following characteristics:

• It contains or could contain a hazardous atmosphere, such as those from toxic fumes or gases.
• It contains material that could engulf the person inside, such as grains in a silo or water in a tank.
• It has an inwardly converging wall or a floor that slopes downward and tapers to a small cross-section.
• It has any other recognized safety hazard that can cause serious, immediate harm.

Non Permit Confined Spaces

A non-permit confined space doesn’t or couldn’t contain hazards that could cause serious harm or death. Entering a non-permit space doesn’t require a confined space risk assessment. Common non-permit spaces include equipment closets, drop ceilings, ventilated tunnels, and machinery cabinets.

10 Confined Space Examples

Confined spaces can be found in various places inside your workplace. They often include partially and fully enclosed areas such as but not limited to:

1. Pipes – They serve as channels for transporting materials across various industries, such as sewer pipes for water treatment. While these spaces may be large enough to perform work, they can put workers in hazardous conditions due to exposure to harmful substances and poor ventilation.
2. Manholes – These spaces are entry and exit points to underground utility systems, allowing access for inspection and maintenance checks of underground utilities. Because of their design, they may expose workers to toxic gases, slippery surfaces, and potential engulfment by loose materials.
3. Access Tunnels – These passageways, whether built underground or underwater, play a crucial role in construction, utilities, and transportation systems. However, given the inherent risks associated with these spaces, working in certain tunnels may require permits as mandated by OSHA.
4. Pits – These enclosed spaces are often found in wastewater treatment plants (e.g., valve pits), building facilities (e.g., elevator pits), and more. Permits are required for those working in pits that run deeper than four feet, contain hazardous atmospheres, and pose serious health and safety risks.
5. Crawl Spaces – These shallow, unfinished areas, located beneath the first floor of a building, act as a barrier between the ground and the structure, providing space for plumbing, electrical wiring, and HVAC systems. Due to their limited height and access points, they can present hazards such as poor air quality, potential engulfment of materials, and risks of asphyxiation.
6. Boilers – These pressurized vessels are used to produce steam and hot water for heating systems, industrial processes, and power generation. They’re often installed in spaces with restricted access or movement, thus requiring strict guidelines to ensure worker safety in those confined spaces.
7. Storage Tanks – These containers are used for holding large volumes of liquids and gases in industries like oil and gas and chemical manufacturing. They often have limited access points and aren’t designed for human occupancy.
8. Silos – These large cylindrical structures are used as storage for bulk materials like grain, sand, flour, and fertilizers. Without proper protocols for inspection and maintenance, they can cause harm to the worker’s health and safety due to their enclosed nature.
9. Utility Vaults – These underground storage areas keep utility equipment such as pumps and backflow preventers, accessible via a maintenance hole. Since workers can get trapped inside and inhale harmful gases, the Occupational Safety and Health Administration (OSHA) requires permits for operating in these spaces.
10. Cold Storage Areas – These specialized facilities, such as walk-in freezers and cold rooms, help preserve perishable goods and materials by maintaining specific temperature ranges that inhibit decay and spoilage. By design, these spaces can put workers at risk of cold stress, hypothermia, and oxygen deficiency.