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This website publishes administrative rules on their effective dates, as designated by the adopting state agencies, colleges, and universities.

Rule 4123:1-5-29 | Explosives and blasting.


(A) Specifications for all blasting operations.

(1) No explosives will be abandoned.

(2) Smoking, firearms, (except firearms carried by guards), matches, open flame lamps, and other fire, flame, heat or spark-producing devices are not permitted in or within fifty feet of explosive magazines or while explosives are being handled, transported or used.

(3) Persons authorized to prepare explosive charges or conduct blasting operations will use every reasonable precaution, including, but not limited to, warning signals, flags, barricades, or woven wire mats to protect employees.

(4) Before a charge is detonated, employees will be instructed to leave the blasting area.

(5) Blasting operations in the proximity of overhead power lines, communications lines, utility services, or other services and structures, the blaster will notify the appropriate representatives of such utilities at least twenty-four hours in advance of blasting, specifying the location and intended time of such blasting. Verbal notice will be confirmed with written notice.

(6) Signs will be posted warning against the use of mobile radio transmitters on all roads within one thousand feet of blasting operations where electric blasting caps are used.

(7) All blasting operations will be suspended and employees removed from the blasting area during the approach and progress of an electrical storm.

(8) Empty boxes, paper, and fiber packing materials which have previously contained explosive materials will be disposed of in a safe manner, or reused in accordance with the department of transportation's hazardous materials regulations (49 CFR parts 177-180).

(9) Containers of explosives will not be opened in any magazine or within fifty feet of any magazine. In opening kegs or wooden cases, no sparking metal tools will be used; wooden wedges and either wood, fiber or rubber mallets will be used. Nonsparking metallic slitters may be used for opening fiberboard cases.

(10) Explosive materials that are obviously deteriorated or damaged will not be used and will be disposed of in accordance with the manufacturer's recommendation.

(B) Transportation of explosives.

Any vehicle used to transport explosives on the job site will have a nonsparking floor and side members and will be equipped with a fully charged fire extinguisher of not less than ten-ABC rating. Blasting caps or electric blasting caps will not be transported over the highways on the same vehicles with other explosives, unless packaged, segregated, and transported in accordance with the department of transportation's hazardous materials regulations (49 CFR parts 177-180).

(C) Storage of explosives and blasting agents.

(1) Blasting caps, electric blasting caps, or other detonating devices will not be stored in the same magazine with other explosives or blasting agents.

(2) Primed cartridges will not be stored.

(3) All explosives stored on the job site will be stored in approved storage facilities. All brush and combustible materials will be kept clear of the magazine to a distance of no less than twenty-five feet.

(D) Loading of explosives or blasting agents.

(1) All drill holes will be sufficiently large to admit freely the insertion of the packages of explosive materials.

(2) Tamping will be done only with wooden rods or plastic tamping poles without exposed metal parts, except that nonsparking metal connectors may be used for jointed poles. Violent tamping is not permitted. Primed cartridges will not be tamped.

(3) No holes will be loaded except those to be fired in the next round of blasting. After loading, all remaining explosives shall be immediately returned to the magazine.

(4) Drilling will not be started until all remaining butts of old holes are examined with a wooden rod for unexploded charges, and, if any are found, they will be refired before work proceeds.

(5) Drill holes which have contained explosives or blasting agents will not be made deeper.

(6) No loaded holes will be left unattended.

(E) Initiation of explosive charges.

(1) General.

(a) When fuse is used, the blasting cap will be securely attached to it with a standard ring type cap crimper. All primers shall be assembled no less than fifty feet from any magazine.

(b) Primers for use in blasting will be made up only as needed for each round of blasting.

(c) No blasting cap will be inserted in the explosive materials without first making a hole in the cartridge for the cap with a wooden punch of proper size or standard cap crimper.

(d) If there are any misfires while using cap and fuse, all employees will be required to remain away from the charge for at least an hour. If electric blasting caps are used and a misfire occurs, this waiting period may be reduced to thirty minutes.

(2) Electric blasting caps.

(a) Blasters, when testing circuits to loaded holes, will use only blasting galvanometers or other instruments which have been designed and approved for the purpose.

(b) Only the employee making the final check on the wire connections will fire the shot. All connections will be made from bore hole back to the source of firing current, and the leading wires will remain shorted and not be connected to the blasting machine or other source of current until the charge is to be fired.

Last updated October 19, 2023 at 2:49 PM

Supplemental Information

Authorized By: 4121.12, 4121.121, 4121.13
Amplifies: 4121.47
Five Year Review Date: 11/1/2026
Prior Effective Dates: 1/1/1986, 4/10/2011, 6/1/2016