1926.903: Underground Transportation of Explosives
Explosives underground must go straight to use or storage, in amounts not over what the blast needs, and never be left unattended. Notify the hoist operator before using a shaft conveyance. Trucks need weekly electrical checks with a certification record and no truck-powered auxiliary bed lights. Explosives travel alone in a powder car, only the operator, helper and powderman may ride, and at least two car lengths must separate the locomotive and powder car.
Key takeaways
- 1926.903 is part of OSHA's construction standards (29 CFR Part 1926, Subpart U).
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In this article
What this rule covers
29 CFR 1926.903, "Underground transportation of explosives", is an OSHA construction standard (Part 1926, Subpart U). It has 18 numbered paragraphs. The official text below is copied word for word from the Electronic Code of Federal Regulations (eCFR). The numbers, injury cases and training on this page show how OSHA enforces it on real job sites.
Official text
Show the full text of 1926.903 (18 paragraphs)
(a) All explosives or blasting agents in transit underground shall be taken to the place of use or storage without delay.
(b) The quantity of explosives or blasting agents taken to an underground loading area shall not exceed the amount estimated to be necessary for the blast.
(c) Explosives in transit shall not be left unattended.
(d) The hoist operator shall be notified before explosives or blasting agents are transported in a shaft conveyance.
(e) Trucks used for the transportation of explosives underground shall have the electrical system checked weekly to detect any failures which may constitute an electrical hazard. A certification record which includes the date of the inspection; the signature of the person who performed the inspection; and a serial number, or other identifier, of the truck inspected shall be prepared and the most recent certification record shall be maintained on file.
(f) The installation of auxiliary lights on truck beds, which are powered by the truck's electrical system, shall be prohibited.
(g) Explosives and blasting agents shall be hoisted, lowered, or conveyed in a powder car. No other materials, supplies, or equipment shall be transported in the same conveyance at the same time.
(h) No one, except the operator, his helper, and the powderman, shall be permitted to ride on a conveyance transporting explosives and blasting agents.
(i) No person shall ride in any shaft conveyance transporting explosives and blasting agents.
(j) No explosives or blasting agents shall be transported on any locomotive. At least two car lengths shall separate the locomotive from the powder car.
(k) No explosives or blasting agents shall be transported on a man haul trip.
(l) The car or conveyance containing explosives or blasting agents shall be pulled, not pushed, whenever possible.
(m) The powder car or conveyance especially built for the purpose of transporting explosives or blasting agents shall bear a reflectorized sign on each side with the word “Explosives” in letters, not less than 4 inches in height; upon a background of sharply contrasting color.
(n) Compartments for transporting detonators and explosives in the same car or conveyance shall be physically separated by a distance of 24 inches or by a solid partition at least 6 inches thick.
(o) Detonators and other explosives shall not be transported at the same time in any shaft conveyance.
(p) Explosives, blasting agents, or blasting supplies shall not be transported with other materials.
(q) Explosives or blasting agents, not in original containers, shall be placed in a suitable container when transported manually.
(r) Detonators, primers, and other explosives shall be carried in separate containers when transported manually.
[44 FR 8577, Feb. 9, 1979; 44 FR 20940, Apr. 6, 1979, as amended at 52 FR 36382, Sept. 28, 1987]
Source: eCFR, text current as of 2026-10-15.
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OSHA interpretation letters
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Frequently asked questions
How often must underground explosive trucks have their electrical system checked?
Weekly, with a certification record showing the date, the inspector's signature and the truck's serial number or other identifier.
Who may ride on a conveyance carrying explosives underground?
Only the operator, his helper and the powderman; no one may ride in a shaft conveyance carrying explosives.
How far must the locomotive be from the powder car?
At least two car lengths.
About this page
Sources
- 29 CFR 1926.903 (eCFR), text current as of 2026-10-15
- U.S. Department of Labor enforcement data: OSHA inspections, citations and accident records, copied nightly
3-year window. Federal OSHA only; state-plan rules are not counted. Plain-language text is a summary, not legal advice; the official text controls. Black Belt Safety is not part of OSHA or the Department of Labor.