OSHA’s Confined Space Construction Rule

There could soon be a new rule to protect employees from the hazards resulting from exposure to confined spaces in the construction industry.  The Office of Information and Regulatory Affairs (OIRA) started reviewing OSHA’s final rule on confined spaces in construction on November 14th, 2014. The review is one of the final steps required before OSHA can formally publish the rule.  OIRA, which is a branch of the White House’s Office of Management and Budget,  is limited to a 90-day review, but can request an extension.

OSHA does not believe the general industry confined space standard addresses the unique characteristics of confined spaces in construction. Compared to general industry, the construction industry experiences higher employee turnover rates, with construction employees more often working at multiple worksites performing short-term tasks. Unlike most general industry worksites, construction worksites are continually evolving, with the number and characteristics of confined spaces changing as work progresses. Multiple contractors and controlling contractors are found more often at construction worksites than at general industry worksites. Also, in contrast to general industry, OSHA believes that many contractors who perform construction work in sewer systems are unfamiliar with the hazards associated with these worksites. Therefore, OSHA placed more emphasis in this proposed standard on assessing hazards at sewer worksites than it did in the general industry confined-spaces standard.

Under the proposed rule, employers would first determine whether there is a confined space at a job site. If there is a confined space, the employer would determine if there are existing or potential hazards in the space. If there are such hazards, the employer then would classify the space according to the physical and atmospheric hazards found in it.

The four classifications are:

  • Isolated-Hazard Confined Space
  • Controlled-Atmosphere Confined Space
  • Permit-Required Confined Space
  • Continuous System-Permit-Required Confined Space

The proposed requirements for each type of confined space are tailored to control the different types of hazards.

OSHA issued the general industry confined space rule (29 CFR 1910.146) on January 1993.   The general industry standard requires employers to classify hazardous confined spaces as “permit-required confined spaces,” and to implement specific procedures to ensure the safety of employees who enter them.   However, the general industry standard does not apply to construction employers and does not specify the appropriate level of employee protection based on the hazards created by construction activities performed in confined spaces.

The table below shows the key differences between the general industry standard and the proposed standard for confined spaces in construction.

General Industry Standard Proposed Construction Standard
Organization of the Standard
The standard begins with requirements for entering permit-required confined spaces.  (PRCSs) The proposed standard takes a step-by-step approach, explaining how to assess hazards, determine the classification of the space, and how to safely enter it.
Information Exchange
The standard requires a host employer to coordinate entry operations with a contractor when the host employer and the contractor both have employees working in or near a permit space. The proposed standard requires the controlling contractor to coordinate entry operations among contractors who have employees in a confined space, regardless of whether or not the controlling contractor has employees in the confined space.
Confined Space with Hazards Isolated
Does not address working in confined spaces in which the hazard has been isolated. Allows employers to establish an Isolated-Hazard Confined Space by isolating or eliminating all physical and atmospheric hazards in a confined space.
Controlled-Atmosphere Permit-Required Confined Space
Monitoring required as necessary. Continuous monitoring required unless employer demonstrates that periodic monitoring is sufficient.
Permit-Required Confined Spaces (PRCS)
No explicit requirement for entry supervisor to monitor PRCS conditions during entry. Explicit requirement for entry supervisor to monitor PRCS conditions during entry.
Requires a written PRCS plan No written plan required when employer maintains copy of the standard at the worksite.
No specific early-warning requirements for up-stream hazards. Early-warning requirements for up-stream hazards in sewer-type spaces.


OSHA has preliminarily determined employees in the construction industry who perform work in confined spaces face a significant risk of death or serious injury, and this proposed rule would substantially reduce the risk. Currently, approximately 20,000 establishments have employees entering at least one confined space as defined by the proposed rule. There are an estimated annual total of 641,000 confined spaces; about half of these confined spaces would be considered permit-required confined spaces under this proposal .   OSHA  determined this proposed rule, when implemented properly by employers, would reduce the average number of fatalities and injuries in confined spaces covered by the proposed standard by about 90% (6 fatalities prevented annually and 880 injuries prevented annually).