Confined Space vs. Restricted Space 

Workers may be required to conduct tasks that require them to enter a space with specific hazards that can make these spaces dangerous. Whether the space in question is classified as a confined or restricted space depends on several factors, which are discussed below.  

What is the Difference?

A space can be either a confined or a restricted space depending on the hazards present. Each space requires its own set of controls after it is classified as either confined or restricted.  

A restricted space is a space that is difficult to enter and exit from and not intended for continuous occupancy. Examples of a restricted space may include attic spaces, below-ground vaults, trenches and crawl spaces.  

A confined space is a space that can become hazardous to a worker entering it because of: 

1. An atmosphere that is or may be injurious by reason of oxygen deficiency or enrichment, flammability, explosivity or toxicity, 

2. A condition or changing set of circumstances within the space that presents a potential for injury or illness, or 

3. The potential or inherent characteristics of an activity which can produce adverse or harmful consequences within the space. 

Confined spaces can be tanks, crawl spaces, trenches, mechanical rooms and plumbing or electrical vaults. These spaces are not considered sites for ongoing or regular work, often having restricted means of entry and exit and poor ventilation.  

It is important to note that the work being done in the restricted space can turn it into confined.

Requirements for Entry 

Each space is different, dependent on the industry and tasks being completed within the space. It is the responsibility of the employer to evaluate every hazard and identify the controls needed to protect workers. 

An effective training program is required to ensure that workers are aware of the hazards and safe work procedures for confined and restricted space work. A code of practice is required to outline all the confined and/or restricted spaces, the practices and procedures to be followed for each space, and all requirements from the Alberta OHS Code Part 5 for Confined Spaces.