Confined Space Entry and Monitor - Online Training

Hazard Identification in Confined Spaces

According to the CCOSH, any of the hazards found in regular workplaces can be present in a confined space. However, the risks are higher because confined spaces do not allow an easy escape. The list of hazards that may be found in confined spaces includes:

• Low air quality, due to the lack of natural ventilation.
• Asphyxiant gases, which can make breathing impossible by displacing oxygen.
• Hazardous chemicals that can enter the body through the skin.
• Flammable or explosive atmospheres, due to gases, liquids or dusts that can be ignited.
• Dangerous residues and other process-related hazards.
• Extreme physical conditions: noise, temperature, vibration, radiation, voltage, etc.
• Lack of visibility, which can be caused by factors like poor lighting or smoke.
• Vehicle traffic, in the case of tunnels.
• Material collapse or flooding.
• Biological hazards like viruses, bacteria and fungi.

While these hazards are not exclusive to confined spaces, they are more dangerous in these areas. Workers cannot distance themselves from hazards easily, and rescuing trapped workers is more difficult. Also, conditions can change quickly in confined spaces, sometimes as a consequence of the work being conducted.

Importance of Hazard Monitoring in Confined Spaces

As previously mentioned, conditions can change very quickly in confined spaces, and there are also some hazards that cannot be detected with human senses. For example, carbon monoxide is a colorless and odorless gas that is highly toxic to humans. Workers can only protect themselves from these hazards if they have adequate monitoring devices.

According to the CCOSH, many airborne hazards can be detected with air quality testing before entering a confined space. Some aspects to consider include oxygen levels, flammable gases, toxic gases, and adequate ventilation.

Even if no hazards are present when entering a confined space, these may emerge as the consequence of some work activities. With monitoring, workers can keep track of hazards continuously while working in a confined space. Oxygen and combustible gases should be monitored continuously, to ensure that the atmosphere has not become flammable or explosive during work activities.
Hazard Control Methods for Confined Spaces

The hazard control methods used in regular worksites are also effective in confined spaces:

• Engineering controls, which have the goal of eliminating hazards.
• Administrative controls, which have the goal of minimizing contact with hazards.
• Personal protective equipment (PPE).

Installing temporary mechanical ventilation is an example of engineering control, while an Entry Permit is an example of administrative control. The ventilation system should be monitored and workers should leave in case of a malfunction – air quality can deteriorate very quickly in a confined space without ventilation.

Also, personal protective equipment should be selected carefully for each confined space, since some PPE has negative effects like reduced mobility and increased heat.