OAR 437-002-0109: Explosives and Blasting Agents

(1) Blasting and Use of Explosives: (a) Smoking, firearms, matches, open flame lamps, fires and flame or spark producing devices shall be prohibited in any explosive magazine or within a radius of 100 feet thereof, and with 100 feet of where explosives are being handled, transported, or used; (b) All blasts shall be fired electronically with an electric blasting machine or properly designed electric power sources, except as provided in sections of this rule; (c) All explosives shall be accounted for at all times. Explosives not being used shall be kept in a locked magazine, unavailable to persons not authorized to handle them. The employer shall maintain an inventory and use records of all explosives. Appropriate authorities shall be notified of any loss, theft, or unauthorized entry into a magazine; (d) The preparation of primers shall be done in a safe place, well away from fire, possible sparks, magazines or powder boxes. Where practical to do so, primers should be prepared at the point of use and immediately placed in the bore hole. (2) Recordkeeping and Loading: (a) The blaster shall keep an accurate, up-to-date records of explosives, blasting agents, and blasting supplies used in a blast and shall keep an accurate running inventory of all explosives and blasting agents stored on the operations; (b) No explosives or blasting agents shall be left unattended at the blast site. No loaded holes shall be left unattended or unprotected. All loaded holes shall be fired before leaving the blast site. (3) Electric Firing. Flashlight batteries shall not be used when firing a circuit of electric blasting caps. The electric current delivered to the charge shall meet the manufacturer’s recommended level. (4) Locks. Each door shall be equipped with two mortise locks; with two padlocks fastened in separate hasps and staples; with a combination or mortise lock and padlock; with a mortise lock that requires two keys to open; or a three-point lock. Locks shall be five-tumbler proof. All padlocks shall be protected with 1/4-inch steel caps constructed so as to prevent sawing or lever action on the locks or hasps. (5) Cap Boxes. Storage facilities for blasting caps in quantities of 100 or less shall have sides, bottoms, and covers constructed of No. 12-gauge metal and lined with a nonsparking material. Hinges and hasps shall be attached thereto by welding. A single five-tumbler proof lock shall be sufficient for locking purposes. NOTES: -1- Use the American Table of Distances for Storage of Explosive Materials to determine safe distances from inhabited dwellings, highways, passenger railways, and between explosive materials magazines. -2- Use the appendix, Separation Distances of Ammonium Nitrate and Blasting Agents from Explosives or Blasting Agents, to determine non-propagating distances to ammonium nitrate fuel oil (ANFO) blasting agents and to ammonium nitrate. -3- Use the greater of the distances shown in the American Table of Distances and in the Table of Recommended Separation Distances to determine the required separation between a magazine for storage of explosives and a magazine for storage of blasting agents. (6)(a) Table of Distances. The provisions contained in Table 21 are in lieu of the provisions contained in 29 CFR 1910.109, Table H-21, American Table of Distances for Storage of Explosives. Related Notes are printed following the table for clarity in using Table OR-H-21; (b) Table of Recommended Separation Distances. The provisions contained in Table 22 are in lieu of the provisions contained in 29 CFR 1910.109, Table H-22, Table of Recommended Separation Distances of Ammonium Nitrate and Blasting Agents from Explosives or Blasting Agents. Related notes are printed following the table for clarity in using Table OR-H-22. [Publications: Publications referenced are available from the agency.] [ED. NOTE: Tables referenced are available from the agency.]