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Blasting mats and drilling near charged holes

Summary An OSHA region asked about construction blasting distances. OSHA said equipment such as a backhoe placing blasting mats was not covered by the cited 50-foot equipment restriction. It distinguished the ban on drilling near a misfired loaded hole from drilling near a hole initially loaded with explosives.
Document
Federal opinion letter
Agency
Occupational Safety and Health Administration (OSHA)
Document number
1981-08-26
Date issued
August 26, 1981
Status
Active
Status last verified October 10, 2026
Topics
Workplace Safety OSHA 1926 Blasting
Source
View the official document

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About this page: The full text below is the official document from Occupational Safety and Health Administration (OSHA). Ezel adds the plain-English summary and tracks the document's status. The official source linked on this page is authoritative for any reliance.

August 26, 1981

MEMORANDUM FOR: DAVID H. RHONE
REGIONAL ADMINISTRATOR

THRU: JOHN B. MILES FIELD COORDINATOR

FROM: BRUCE HILLENBRAND
DEPUTY DIRECTOR,
FEDERAL COMPLIANCE AND STATE PROGRAMS

SUBJECT: Blasting and Use of Explosives Relative to 29 CFR 1926.905(h) and (k)

REFERENCE: Your memorandum dated July 22, 1981.

The requirement in 29 CFR 1926.905(h) "that equipment shall not be operated within 50 feet of loaded holes" does not include equipment such as a backhoe used in the placement of blasting mats. 29 CFR 1926.905(k) requires that no drilling be performed within 50 feet of a loaded hole where the explosives have failed to detonate. The regulations do not apply to holes which have been filled with explosive in the initial loading.

Because 29 CFR 1926.905 does not regulate the distance between a loaded hole and the drilling of the next hole, CSHO's will have to cite as a recognized hazard section 5(a)(1) of the Act for drilling performed too close to a loaded hole. For guidance in this matter, the Mine Safety and Health Administration requires in Subchapter N-55.6-107 "Mandatory. Holes shall not be drilled where there is danger of intersecting a charged or misfired hole".

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