OSHA requirements are set by statute, standards and regulations. Our interpretation letters explain these requirements and how they apply to particular circumstances, but they cannot create additional employer obligations. This letter constitutes OSHA's interpretation of the requirements discussed. Note that our enforcement guidance may be affected by changes to OSHA rules. Also, from time to time we update our guidance in response to new information. To keep apprised of such developments, you can consult OSHA's website at https://www.osha.gov.

July 14, 1983

Mr. Richard F. Tallini
Controlled Energy Specialist, Inc.
P.O. Box 2846
Allentown, Pennsylvania 16001

Dear Mr. Tallini:

This is in response to your letter of June 15, 1983, requesting a clarification of 29 CFR 1910.109 as it applies to two kinds of explosive devices used in steel mills. The two devices are (1) the "Jet Tapper Assembly", which you say creates a new explosive category called Explosive Actuated Power Device with firing Train Interrupter, and (2) the plain jet tappers and electric blasting caps which require assembly by plant personnel and do not contain a firing train interrupter.

The "Jet Tapper Assembly" does not comply with the intent of 29 CFR 1910.109(c)(l)(ii) and 29 CFR 1910.109(d)(l)(iv). 29 CFR 1910.109(c)(l)(ii) intended that blasting case, electric blasting caps, detonating primers, and primed cartridges net be stored in the same magazine with other explosives. 29 CFR 1910.109(c)(l)(iv) intended that blasting caps or electric blasting caps not be transported over the highways on the same vehicles with other explosives.

The plain jet tappers and electric blasting caps which require assembly by plant personnel, and which do not contain a firing train interrupter, may meet the intent of the standard if used in accordance with the applicable requirements in 29 CFR 1910.109. Plain jet tappers assemble to electric blasting caps in the steel mills, plant personnel, and then stored up to three days or more with primed charges on the open hearth floors in cabinets, would be in violation of 29 CFR 1910.109(e)(4)(iii). As you acknowledge in your letter, the above-mentioned standard requires primers to be made up only as required for each round of blasting. It appears that our standard does present a practical problem in open hearth steel mills as job described.

Because there are problem areas in 29 CFR 1910.109, OSHA is preparing to review this standard. This process would incorporate the relevant revision of this NFBA Codes; resolve, where possible, major conflicts with the regulations of other Federal agencies; and modify the "use of explosives" paragraph. In the interim, OSHA Instruction STD 1-5.12 (Formerly OSHA Program Directive 100-90) will be used for information and guidance in the enforcement of 29 CFR 1910.109 (copy enclosed).

Also enclosed is a portion of OSHA instruction CPL 2.45A, which defines a deminimis violation. Citations are not issued for deminimis violations, penalties are not proposed, and statement of the violation is not required of the employer.

Steel mill employers may apply for a variance from the provisions of 29 CFR 1910.109 concerning explosive and blasting agents. If you or your customers desire additional information concerning a variance application, please call or write the Director of the Office of Variance Determination:

James T. Concannon, Director
Office of Variance Determination
U. S. Department of Labor - OSHA
Room N3662
200 Constitution Avenue, N. W.
Washington, D.C. 20210
Telephone: 202-523-7144

I hope this information is helpful to you. If I may be of further assistance, please feel free to contact me.


John K. Barto
Chief, Division of Occupational
Safety Programming