Air Quality Testing

Before any workers are allowed to enter a confined space, employers must take certain safety measures. One of the most important safety measures is air quality testing. To conduct the tests, a trained employee must use detection equipment with remote probes and sampling lines that he or she can operate from outside the space. The tester should take samples throughout the space, not just in the center, because air conditions may change from top to bottom or side to side, especially where gases of different densities are present. For conditions to be acceptable, the air quality tests must demonstrate the following:

• The oxygen content is within a safe range.
• The atmosphere is not hazardous and does not contain flammable or toxic gases.
• Any ventilation equipment in use in the space is working properly and consistently.

Keep in mind that air quality testing may need to be ongoing, depending on the nature of the work. If conditions may change, or the work being performed may change the atmospheric conditions in the confined space, continuous monitoring is required. The tester should list conditions recorded during air quality testing on the entry permit.

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