Because construction projects or industrial establishments are not limited to new buildings, confined spaces may be encountered in a variety of places.

The following table describes typical confined spaces and the most common hazards found there.
Hazards in confined spaces can be divided into two distinct categories: physical hazards and atmospheric hazards.

If control measures (such as continuous mechanical ventilation} are used to ensure that the concentrations of an atmospheric hazard are controlled or maintained at an appropriate level (but not eliminated) then the space would still be considered a confined space. If, however, measures are implemented to eliminate the possibility that any atmospheric hazards may occur in a space, then the confined space provisions no longer need to apply. Eliminating the possibility that an atmospheric hazard will occur is different from controlling the hazard. If workers must enter the confined space to eliminate the hazards (by steam-cleaning or vacuuming, for example) then the confined spaces provisions apply.

Every confined space must be thoroughly assessed and evaluated
by a competent worker to determine whether it is possible to
eliminate the atmospheric hazard completely.
Even if a space is not defined as a confined space under the regulations, the employer must take every precaution reasonable in the circumstances to protect workers entering the space.
Typical Location of Confined Spaces:
 Petrochemical Plants
 Water & Sewage Plants
 Silos & Grain Elevators
 Industrial Sites
 Below Grade Hazards

• Construction Site
  

See attached (under the paperclip at the top, resources)

Chart with Typical Confined Space Locations and their hazards.