Confined Space Characteristics

There are four characteristics of confined spaces that must be taken into consideration before planning a rescue entry: internal configuration, elevation, portal size, and space access.

Internal configuration is either open, meaning there are no obstacles, barriers, or other types of obstructions within the space, or obstructed, meaning there is some type of obstruction present that an entrant would need to maneuver around.

An elevated confined space is defined as a space where the entrance opening is 4 feet or more above ground, requiring the rescuer to have knowledge of high-angle rescue procedures. A non-elevated permit space has an entrance portal located less than 4 feet above ground.

Portal size refers to the confined space entrance opening. A restricted portal is 24 inches or less in dimension, which is too small for a rescuer to enter while using SCBA and too small to remove an injured victim who requires spinal immobilization. An unrestricted space has a portal greater than 24 inches in dimension, which allows for relatively free movement in and out of the confined space.

Space access is characterized as either horizontal, where the use of retrieval lines could be difficult, or vertical, where the portal is located on the top or bottom of the permit space, requiring knowledge of rope techniques.

To learn more about Firefighter Confined Space visit our Firefighter Confined Space Entry & Rescue Online Training web page.