What Is Confined Space? Exploring the Dangers and Regulations of Confined Space

Confined space safety isn’t just important for compliance. It’s about protecting lives and ensuring workers can return home after their shifts.

To put the gravity of implementing safety measures into perspective, it’s estimated that more than 100 confined space fatalities occur across Canada on an annual basis, according to WorkSafeBC.

In this blog, we’ll explore what defines a confined space, identify the hazards that make these environments so dangerous, and provide effective ways to keep employees safe.

What Is Confined Space?

A confined space is a fully or partially enclosed area above or below ground in a workplace. Although these environments are not designed for continuous human occupancy, they are large enough for a person to enter and perform work tasks. They also always have a limited or restricted means of entry and exit, such as a narrow opening.

Generally speaking, these areas are more dangerous than other work environments because their limited space makes it challenging for workers to maneuver around and escape quickly in an emergency. Additionally, confined spaces often isolate workers from immediate help, meaning rescue procedures may be delayed.

Some of the most common types of confined spaces include:

• Bins
• Boilers
• Bunkers
• Culverts
• Hoppers
• Manholes
• Open ditches
• Pipelines
• Sewers
• Ship holds
• Silos
• Subcellars
• Tanks
• Vaults
• Vessels
• Water supply towers
• Wells

What Are the Hazards in a Confined Space?

When employees are working in confined spaces, they are exposed to a wide range of hazards. While some are easy to identify, such as poor visibility due to a lack of lighting, other hazards, such as invisible toxins, can be well hidden.

To ensure occupational safety, it is critical that anyone entering a confined space is aware of the hazards and understands the risks associated with them.

Toxic Gases

Due to poor ventilation, confined spaces often experience a buildup of toxic gases, including hydrogen sulfide (H2S), methane (CH4), sulphur dioxide (SO2), and carbon monoxide (CO). Depending on which toxic gas is present, an explosion or fire could occur, or the worker could develop eye irritation, lose consciousness, or asphyxiate.

Typically, ventilation equipment, such as a blower or fan, is used to maintain the quality of the air in a confined space, but because conditions may change quickly, it is essential to continuously monitor air quality.

Oxygen Deficiency

Unfortunately, poor ventilation in confined spaces can also lead to an oxygen-deficient atmosphere, which is when the oxygen volume is less than 18%. The safe oxygen level in a confined space, however, is a minimum oxygen concentration of 19.5%, according to the Government of Canada. This is because of the risks associated with evacuating a person from a confined space and the potential for a rapid decrease in oxygen content.

Oxygen deficiency can be caused by:

• Oxygen being used up when metals rust
• Oxygen being consumed during combustion (ex: welding)
• Oxygen being replaced by other gases (ex: carbon monoxide)
• Oxygen being used by micro-organisms (ex: in sewer lines)

It is paramount that pure oxygen is never used to ventilate a confined space, as an atmosphere with an oxygen volume higher than 23% is a fire and explosion hazard.

Physical Hazards

Confined spaces may also have physical hazards that could cause a worker to fall, drown, or be crushed or buried.

Some of these possible hazards include:

• Ladders
• Falling objects
• Moving equipment
• Electrical cables
• Temperature extremes
• Noise
• Liquid
• Poor lighting

If the physical hazard cannot be eliminated, protocols must be in place to protect the health and safety of all workers on site.

How Can You Prepare When Entering a Confined Space?

Thorough preparation is necessary to ensure safety when entering a confined space because these environments are always considered hazardous.

For occupational health and safety, it is essential to perform a risk assessment of the area, determine which personal protective equipment (PPE) is required, and adhere to any permits and regulations for the confined space.

Perform Risk Assessments

Before anyone enters a confined space, it is crucial that a qualified person conducts a comprehensive risk assessment. These assessments identify which hazards are present, as well as evaluate the potential severity and likelihood of the risks associated with them. By identifying and understanding these factors, the appropriate protocols can be implemented to mitigate health risks and protect workers. A risk assessment also allows employers to determine the appropriate emergency procedures and rescue plans for workers, ensuring an effective safety response.

Use Personal Protective Equipment

PPE is known to be a worker’s first line of defence against hazardous conditions, and it is a critical component of confined space safety. A risk assessment is the best way to determine which PPE is needed for a specific confined space.

The most common PPE that is used in confined spaces includes respirators to protect against toxic gases, helmets to prevent head injuries, and harnesses for safe entry and exit. Workers also often require full-body suits, gloves, and eye protection.

It is important that all PPE is properly fitted and in good condition, as this will help ensure the highest level of protection for the worker.

Adhere to Permits and Regulations

Most jurisdictions require an entry permit for confined spaces. These permits outline the necessary precautions, including atmospheric testing, ventilation requirements, and emergency procedures.

In addition to maintaining legal compliance, adhering to these regulations enhances worker safety by providing a structured approach to jobs in confined spaces.

How Can Danger Be Prevented in Confined Spaces?

There are dangers in any confined space, however, many hazards can be effectively managed and emergency situations can often be avoided with the proper prevention methods.

Fires and Explosions

In confined spaces, there is a significant risk of fires and explosions due to the possible presence of flammable gases. To lower the risks in a flammable atmosphere, it is essential to control ignition sources, continuously monitor gas levels, and ensure that all safety protocols are strictly followed.

Before any work is done in a confined space, it’s important to eliminate all ignition sources, or at least as many as possible.

Some ignition sources may include:

• Arcing of electrical motors
• Chemical reactions
• Discharge of static electricity
• Hot surfaces
• Lighting
• Open flames
• Sparks from metal impact
• Welding arcs

Additionally, it’s crucial to use spark-resistant tools when the type of work allows for it.

Energy Sources

If they are not properly managed, energy sources can pose significant risks in confined spaces. These energy sources include electrical, mechanical, hydraulic, pneumatic, chemical, and thermal systems, which can lead to shocks, burns, crushing, or entrapment.

To prevent these dangers, it is important to perform:

• Lock-out tag-out: This involves shutting down and locking out machinery, electrical circuits, and other energy systems to prevent accidental activation.
• De-energization: This includes disconnecting power supplies, draining hydraulic and pneumatic systems, and securing any moving parts.

How Can Safety Be Maintained in Workplaces With Confined Spaces?

One of the most effective ways to maintain safety in workplaces with confined spaces is to provide the proper training.

All workers who may need to enter a confined space should receive safety training, and it is the employer’s responsibility to ensure this training is completed.

Most commonly, the industries that require this confined space safety training include:

• Construction
• Manufacturing
• Oil and gas
• Mining
• Agriculture
• Utilities
• Transportation

At Trojan Safety, we have over 30 years of experience providing comprehensive health and safety training programs that empower employees to recognize potential hazards, understand their probability and impact, and implement safety measures to mitigate identified risks.

We proudly offer a Confined Space Entry and Rescue course, which provides three years of valid certification. Some of the training covered in this program includes:

• Hazard assessments, due diligence, and documentation for safe work practices
• Hands-on practice in controlling confined space health hazards, lock-out tag-out procedures, ventilation, and atmospheric testing
• Permits, roles, and responsibilities of supervisors, safety monitors, and entrants
• Practical confined space rescue using the simulator

Reach out to us today to improve safety in your workplace.