This section provides an overview on how to select the right levels to rate your confined spaces within your workplace and apply the correct procedures, plans and equipment. 

Introduction

Confined spaces, due to their different types and levels of hazards found in the area, will require them to be classified through a rating system. The following are the four levels that can be used to rate the confined spaces and assist in selecting a correct entry procedure, equipment and rescue plan.

High Risk    

An area that meets the definition above; however, there is a great potential of immediate danger (death or critical injury) due to an airborne contaminant or other hazards which the workers inside are exposed to. A High Risk Confined Space may only be entered under the following conditions: 1) Perform the same procedures as for Low Risk. 2) The worker uses suitable breathing apparatus; safety harness attached to lanyard and is securely attached, and the free end is held by an outside attendant equipped with an alarm and keeping watch outside the space. 3) A person trained in First Aid and Cardiopulmonary Resuscitation is immediately to perform the necessary techniques in an emergency.

Medium Risk 

An area that meets the confined space definition; however, there is only a remote chance of the hazard present causing an immediately life threatening or critical injury. A Medium Risk Confined Space in which there exists, or is likely to exist, a hazardous gas, vapour, dust, fumes or have an oxygen-deficient or enriched atmosphere may only be entered under the following conditions: 1) Perform the same procedures as for Low Risk. 2) The space is purged or ventilated to provide and maintain a safe atmosphere. 3) Suitable arrangements have been made to extricate worker from the confined space if he requires assistance. 4) A person trained in First Aid and Cardiopulmonary Resuscitation is immediately to perform the necessary techniques in an emergency.

Low Risk

An area that meets the confined spaced definition and that the hazards in the confined space are not present and the space remains free from hazards while the workers are in the area. Example: Liquid Storage Tanks. A Low Risk Confined Space may only be entered under the following conditions: 1) There is an easy egress from all accessible parts of the space. 2) Mechanical equipment is de-energized and locked out. 3) An attendant is stationed outside the space. 4) All pipes and other supply lines that may cause a hazard are blanked off. 5) A competent person will test the confined space and state that the space is free from hazards and will remain free from hazards while a worker is inside and record the test on a permanent record. 

An Isolated Work Area 

An area where the hazard present may cause an injury; however, the area does not have all the criteria listed in the definition. The primary problem is recognizing that the individual is in distress and needs retrieval. Example: Elevator Pits, Culverts.