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 many contractors who perform construction work in sewer systems are unfamiliar with the hazards associated with these worksites. Therefore, OSHA's new construction confined space standard places more emphasis in this standard on assessing hazards at sewer worksites than it did in the general industry confined-spaces standard.
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The new standard, Subpart AA of 29 CFR 1926 will help prevent construction workers from being hurt or killed by eliminating and isolating hazards in confined spaces at construction sites similar to the way workers in other industries are already protected.
The standard applies to both new construction within an existing sewer and alterations and/or upgrades. For example:
The new construction rule requires employers to determine:
If there is a confined space, the employer should determine existing or potential hazards in the space. If there are such hazards, the employer should classify the space according to the physical and atmospheric hazards found in it.
The four classifications are:
Each type of confined space is tailored to control the different types of hazards. You can learn more about the different types of construction confined spaces in 29 CFR 1926.1203–Definitions.
The host employer owns or manages the property on which construction is taking place.
The controlling contractor is the employer that has overall responsibility for construction at the worksite.
If a host employer has overall responsibility for construction at the worksite, then they are both a host employer and a controlling contractor.
The subcontractor is the junior or secondary contractor who contracts with the controlling or "prime" contractor to perform some or all contractual-obligations under the prime contract.
The entry employer is usually a subcontractor who directs workers to enter a confined space for work or rescue.
The rule makes the controlling contractor, rather than the host employer, the primary point of contact for information about permit spaces at the worksite. The host employer must provide information about permit spaces at the worksite to the controlling contractor, who then passes it on to the employers whose employees will enter the spaces (entry employers).
Likewise, entry employers must give the controlling contractor information about their entry program and the hazards they encounter in the space. The controlling contractor then passes that information on to other entry employers and back to the host. As mentioned above, the controlling contractor is also responsible for making sure employers outside a space know not to create hazards in the space, and that entry employers working in a space at the same time do not create hazards for one another’s workers.
There are five key requirements in the new construction rule, and several areas where OSHA has clarified existing requirements. The five new requirements include:
In addition, OSHA has added provisions to the construction rule that clarifies existing requirements in the General Industry standard. These include:
Crawl spaces and attics can be both confined spaces and permit-required confined spaces under the new standard. For instance, working in an attic and applying a large amount of spray foam (or another chemical) in a short period of time can expose a worker to low oxygen levels or a hazardous atmosphere.
Also, changes to the entry/exit, the ease of exit, and airflow could create a confined space or cause the space to become permit-required.
Crawl spaces can present many confined space hazards, including:
Working in attics can present confined space hazards, such as:
Even though a pit is typically open on top and over 4 feet deep, it can still be a confined space or permit-required confined space. Pits can be completely underground or below grade, such as a utility vault within a sewer system or a pit within a pit in a wastewater treatment plant.
Pits are found in many environments. Examples include:
Many of these spaces qualify as permit-required confined spaces.
Employers must take all necessary steps to keep workers safe in confined spaces, including following the OSHA Construction Confined Spaces standard. This standard applies to both new construction in a pit and alterations and/or upgrades. Among the pit-related tasks covered by the standard are:
Construction work can create confined spaces, even if there are none at the start of a project. Changes to the entry/exit, the ease of exit, and airflow could produce a confined space or cause one to become permit-required.
Types of sewer systems include sanitary (domestic sewage), storm (runoff), and combined (domestic sewage and runoff). Sewer systems are extensive and have different components that are considered confined spaces, including pipelines, manholes, wet wells, dry well vaults, and lift/pump stations. Therefore, employers conducting work in sewer systems will likely have workers who will encounter confined spaces.
Sewer systems also consist of wastewater treatment plants, where confined spaces include digestion and sedimentation tanks, floating covers over tanks, sodium hypochlorite tanks, and wastewater holding tanks, among others. Many of these components may also qualify as permit-required confined spaces.
Sewer systems can present a host of confined space hazards, including:
For more information about hazards in the construction industry, read OSHA’s Anatomy of Confined Spaces in Construction.
For a complete discussion of confined space safety, be sure to take OSHAcademy Course 713, Confined Space Program.
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In this video, Pennsylvania OSHA, in cooperation with Indiana University of Pennsylvania, PA OSHA director Sam Gualardo, discusses confined space safety in construction as part of their Focal Point Series.