Hazard Control and Ventilation in Confined Spaces: Best Practices and Techniques

confined space safety

Confined spaces are inherently risky. They are typically spaces that are not intended for continuous human occupancy and present significant hazards to workers, including entrapment, poor ventilation, asphyxiation and explosion. To mitigate these risks, effective confined space safety measures must be put in place prior to any entry.

Best practices for confined space safety

Regular risk assessments

Every confined space on a site must undergo a regular risk assessment to identify and characterize the risks that any person entering the space would be exposed to and the measures that could be taken to mitigate them. Before any entry occurs, the risk assessment must be revisited to ensure that the necessary mitigation actions are in place and all workers understand and accept the risk that they are taking when entering the confined space.

Entry control procedures

Entry control procedures must exist for every confined space on site, limiting access to only those personnel who are authorized, trained and equipped with appropriate PPE to enter the space. This may include implementing permit-to-work systems, a strict routine of pre-entry checks, and extensive training for operators.

Ventilation systems and practices

If regular access into a confined space is needed, consideration must be given to installing ventilation ducts and exhaust systems to improve the air quality in the space. If access is not routinely required, mechanical ventilation or the use of breathing apparatus may be acceptable as long as personnel are trained and able to use the equipment safely and effectively.

Emergency preparedness

Despite taking every possible confined space safety precaution, an emergency can still occur, and workers must know how to respond when this happens. Organizations with confined spaces on their site must put robust emergency response plans in place that include rescue procedures and communication protocols. They must also train their staff on rescue techniques to support the safe evacuation of any workers who are inside the confined space.

Continuous contact

Any time an individual is deployed in a confined space, they must remain in continuous contact with a dedicated point of contact situated outside the confined space. Communication protocols must be established so that any failure to check in alerts support staff to a possible emergency situation and allows an early response to be implemented.

Monitoring equipment

The person working in the space must be equipped with equipment that will continuously monitor the atmospheric conditions in the space and alert them and their point of contact to the presence of toxic gasses, combustible atmospheres or low oxygen levels, allowing for an expedient evacuation.


Personnel must be trained for the specific confined spaces that they will enter and the particular risks they are likely to encounter. They must know how to alert others to dangerous conditions and be empowered to abort any entry attempt that they feel is unsafe. They must be skilled in the use of PPE and safety equipment and provided with regular refresher training.

Effective hazard control and ventilation are vital for keeping workers safe in confined spaces. Adhering to best practices and techniques will minimize risks and empower workers.