Underground Construction

Underground construction refers to the construction of underground tunnels, shafts, chambers and passageways. It does not include trenching and excavation operations that are not physically connected to the underground construction nor underground electrical transmission and distribution lines.

Underground Construction

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What are the hazards associated with underground construction?

Hazards associated with underground construction include, but are not limited to, engulfment, noise, fire and explosion, potential overexposure to silica, and toxic and oxygen deficient atmospheres.

What can I do to protect myself?

Your employer must provide training in the recognition and avoidance of hazards associated with underground construction. Don the required personal protective equipment before entering the work space.

What resources are available to assist employers?

Safety and Health Programs

Example programs on confined spaces, hearing conservation, hazard communication, respiratory protection, and personal protective equipment hazard assessment can assist the employer with their hazard communication program and identifying the appropriate personal protective equipment required in the workplace.

Training and Outreach Services

Presentations on confined spaces, occupational noise exposure, silica, personal protective equipment, respiratory protection and hazard communication are available for workplaces in construction and can assist employers in training their staff.  The presentations should be modified to address site-specific conditions and hazards.

In addition, the education, training and technical assistance bureau provides free online safety and health training and outreach services (i.e., speaker's bureau requests, safety booths) upon request. 

Lastly, the NCDOL Library offers free safety and health videos (including streaming video services) and related research assistance on consensus standards (i.e., ANSI, NFPA, NEC). The

Safety and Health Topics

Safety and health topic pages on confined spaces, noise, personal protective equipment (PPE), respiratory protection, silica and hazard communication can provide more resource information. 

Consultation Services

The consultative services bureau provides free and confidential onsite consultation regarding worksite safety and health hazards.

Which standards apply?

OSH has adopted the following standards which apply to underground construction in North Carolina. Note: Please also check the standards information and activity webpage to see if there has been any recent or upcoming regulatory activity on this topic. 


Mine Safety and Health Act (MSHA) - Other non-OSH regulatory requirements referenced:

  • 30 CFR Part 36 - approval requirements for permissible mobile diesel-powered transportation equipment (MSHA)

  • 30 CFR Part 7 Subpart E (formerly 30 CFR Part 32) - diesel engines intended for use in underground coal mines (MSHA)

Other Applicable Standards

The Which OSHA Standards Apply webpage can help identify other standards that may be applicable to your worksite.

Where can I learn more?

Industry Guides

Fact Sheets

Compliance Documents

Technical Assistance

Inquiries about workplace safety and health requirements can be submitted to Ask OSH through the online form, by email to ask.osh@labor.nc.gov, or by phone at 919-707-7876.