Key Terms

Access is a means of entering a space.

An attendant is an employee posted outside of, and near the entrance to, a confined space. Attendants must monitor the other workers and may assist with tasks they are performing, but giving assistance cannot impede the attendants' duties. Attendants should be in constant contact with workers in the confined space.

A competent person is a person with adequate knowledge, training, and experience who is able to organize the work being done and carry out the tasks at hand. Tasks may be as simple as moving materials or as complicated as developing a confined space plan.

A confined space is a fully or partially enclosed space that is not both designed and constructed for continuous human occupancy. Atmospheric hazards may occur in a confined space because of its construction, location, or contents, or because of work that is performed in it.

Egress is a means of exiting a space.

Entry is the action by which a person passes through an opening into a confined space.

An entry permit is a document that must be created before work can begin in a confined space. Entry permits should include specific information about the tasks being performed, the employees completing the tasks, entry and exit times, hazards, the preventive measures taken against the hazards, and so forth. A competent person must review and confirm the information on the entry permit at the start of each shift.

Hot work comprises activities, such as welding, that may produce a spark, flame, or heat.

Inerting is the act of countering flammable gases by decreasing the oxygen content in the air below combustible levels. When a space is being inerted, workers should wear appropriate respiration equipment because the atmosphere becomes unsafe.

Oxygen content is the percentage of pure oxygen in the air. Oxygen content must be kept between roughly 19.5 percent and 23 percent to be safe and breathable.

Purging involves displacing gases and replacing them with fresh air, ensuring acceptable oxygen content and air quality for human occupancy. The act of purging is usually a preparation for ventilation.

Ventilation is the act of continuously providing fresh air by mechanical means in order to maintain acceptable oxygen content and air quality.

To learn more about Confined Spaces visit our Canada Confined Space Online Training web page.