With the introduction of Confined Spaces in Construction standard (1926 Subpart AA) in 2015, OSHA increased protection for workers by placing more stringent requirements on a project’s owner and general contractor. OSHA also took the opportunity to clarify and update some rules from the original confined space standard for general industry (1910.146).

There are five important differences between the two that employers need to understand.

1. New obligations for project stakeholders

“OSHA has new requirements for coordination among the people who own the confined space and the people who will make entry into and work in the space, regardless of whether they are controlling the confined space during the project or are a subcontractor,” said Bruce Magee, Region Product Development Manager, United Rentals Trench Safety.

Under OSHA 1926 AA, the owner must inform the general contractor about any known hazardous conditions in that space before work begins. The GC, in turn, must tell the subcontractor about these hazards. The communications must run both ways. If the subcontractors’ crews find any new problems in the confined space, they must tell the GC, who alerts the owner. This helps ensure that the owner has the latest information to pass down to any other workers who may be entering the confined space.

2. The competent person requirement

The confined space construction standard requires any employer that will instruct any employee to enter the space to have a competent person on site. This person must identify the space and has the responsibility to evaluate all of the confined spaces in which people will work to determine if they contain any hazards that would require the contractor to get a permit for the project. The competent person also has to understand the specific air monitoring operations and appropriate testing for the confined spaces.

“The onus is on each employer that will have workers entering or working in proximity to make sure that they have a competent person on the site,” said Magee.

Previously, there was no requirement for an onsite competent person in the general industry confined space standard.

3. The continuous atmospheric monitoring requirement

In the confined space standard for general industry, OSHA allowed intermittent atmospheric testing. In contrast, OSHA 1926 AA requires continuous monitoring for dangerous conditions such as air that’s deficient in oxygen or contains flammable gas in excess of 10 percent of its lower flammable limit.

OSHA will exclude the continuous atmospheric testing requirement if there’s no commercially available equipment to handle it, but Magee said that’s very rare in North America.

4. The continuous monitoring of engulfment hazards requirement

Crews working in storm drains and sewers can be injured by a sudden rush of water or sludge if there’s a significant rainstorm that sends water down these lines. Under the 1926 AA standard, OSHA requires contractors to have either some kind of electronic or electro-mechanic sensor upstream that will warn of an engulfment or a person posted upstream to watch for any problems. These warning systems give workers time to evacuate the confined space before they are engulfed.

The systems might not be required if the contractor uses some kind of mechanical block to keep the water or sludge from moving down the line, Magee added.

5. When permits are suspended vs. canceled

Entry employers following 1926 AA do get one break.

“Under 1910.146, OSHA said if you’re working in a permit-required confined space and a prohibited condition should arise within the space, the permit is canceled,” Magee explained. “Work would have to stop, and the permit would have to be rebuilt from the ground up.”

With 1926 AA, OSHA allows for the permit to be suspended, not canceled, if a prohibited condition arises. The employer would have to get the crew out while it dealt with the hazardous situation (which could be anything from a gas leak to a poisonous snake or insect in the space). Once the hazard has been removed, work can resume.

It’s important to note that the 1926 AA standard applies only to construction activities, not maintenance work. OSHA has added that any employer that engages in either construction or maintenance work will be deemed to be in compliance with both if the employer meets the requirements of 1926 AA.

Regulatory clarifications to understand

When OSHA introduced the new confined space construction standard, it also clarified and enlarged on some of the ambiguous language in the general industry regulation. These amplifications also apply to the new standard. Below are three important points to understand.

Permit requirements

In the general industry standard, OSHA allowed workers to enter a confined space with potential engulfment hazards only if the contractor had obtained a permit, making it a permit required confined space (PRSC) entry. Under the clarifications released with 1926 AA, employers would not have to get that permit if they had eliminated all engulfment hazards by isolating them or using blocking methods such as lock out/tag out.

Rescue authority

When a contractor chooses an agency to serve as its rescue authority, that agency must notify the contractor if it’s not going to be able to provide that service. Suppose a local fire company is the agency for a contractor and that fire company has to travel to the next town to help put out a big blaze. The company would have to be willing to notify the contractor that they aren’t available to fulfill the rescue function —and then actually do so. The contractor would have to stop work in the confined space until the company was back in town. “Without that piece of your rescue plan in place, you can’t continue to work,” said Magee

Confined space training

OSHA has always required that the person working in a confined space be trained. It has further explained that requirement by emphasizing that the training has to be given in a language and vocabulary that the worker can understand. It’s up to the trainers to find ways to get the safety message across by using basic words and analogies to explain the important concepts.

Have questions about the Confined Spaces in Construction standard? Contact the trench safety team at United Rentals or check out the Confined Spaces in Construction courses at United Academy.

Freelance writer Mary Lou Jay writes about business and technical developments in a variety of industries. She has been covering residential and commercial construction for more than 25 years.