Skip to Main Content

(a) Loading shall not commence until all drilling is completed and drill holes are cleaned or blown out, unless this procedure is impracticable under conditions encountered. When conditions justify simultaneous loading and drilling in the same area, such operations shall be separated as widely as practicable and in no case shall a drilling operation be closer than 50 feet to a hole being loaded. All drill holes shall be sufficiently large to freely admit the insertion of the explosive materials.

(b) At least 5 foot candles illumination shall be provided to safely perform loading operations. Only approved lights shall be used within 50 feet of the loading area.

(c) No vehicle traffic shall be permitted over loaded holes.

(d) Loading operations shall be carried on with the smallest practical number of persons and explosive materials loading equipment present and no one but the loading crew, inspection personnel, and authorized supervisory personnel shall be allowed within 50 feet of the loading area.

(1) At locations where 50 foot minimum distance cannot be maintained, an alternative plan shall be submitted to the Division for approval 30 days prior to anticipated start of work. The Division shall give written notice of receipt to the applicant within 7 days. Notice of approval/disapproval, shall be given within 15 days of receipt of the application. The Division may shorten the 30-day notification requirement where construction has commenced and unexpected site and/or emergency conditions requiring blasting occur.

(2) The Division shall approve the alternative plan if the following elements are satisfied:

(A) All blasting operations will be conducted using low sensitivity explosive materials.

(B) All blasting operations will be conducted using initiation systems which cannot be affected by stray current or radio frequency energy.

(C) A lightning and electric storm-detection system and written plan of action is provided to the Division. The plan shall include provisions for a detection system capable of warning the loading crew when a storm is 100 miles away. When a storm is detected 50 miles from the loading operation, the storm's movement is to be monitored. When a storm is detected at 25 miles from the loading operation, loading operations will be discontinued and all persons in the blast area withdrawn to a safe location.

(D) K-rails, barriers, traffic control systems or natural terrain shall be used to prevent entry by vehicular traffic into the loading site.

(e) The amount of explosive materials delivered into a loading area shall not exceed the amount estimated by the licensed blaster as necessary for the blasting. No holes shall be loaded except those to be fired in the next round of blasting.

(f) Detonators shall not be less strength than No. 8.

(g) The detonator, if used, shall be properly encased in explosives when inserted into the drill hole.

(h) Tamping shall be by pressured or light blows only, and never by excessive ramming. The primer shall not be tamped.

(i) All blast holes in open work shall be stemmed to a point that will sufficiently confine the charge.

(j) Stacks of explosive materials shall be spaced and distributed in the loading area to prevent propagation of an explosion between any two piles or loaded holes in the event of a premature explosion in any portion of the blast area.

(k) Springing holes:

(1) Boreholes shall not be sprung within 100 feet of any hole containing explosive materials for primary blasting.

(2) A hole that has been sprung shall not be loaded until sufficient time has elapsed for the hole to cool. Artificial means may be used to cool the hole.

(l) Except for avalanche blasting, drop fuses or any other method that calls for ignition of the fuse prior to placement of the charge in its final position shall not be used.

(m) Drill holes or any part of such holes which have been charged with explosive materials shall not be deepened.

(n) Drilling shall not be started until all remaining butts of old holes are examined for unexploded charges and if any are found, they shall be detonated or properly disposed of before other work proceeds. (See Section 5293).

(o) Except as provided in Section 5278(w), holes to be blasted shall be charged as near to blasting time as practical and such holes shall be blasted as soon as possible after charging has been completed.

(1) No explosive materials shall be left unattended at the blast site.

(2) Loaded holes shall not be left unattended except as permitted in Section 5278(w).

(3) No one but the attendant(s) (see CCR, Title 8, Section 3207 for the definition of Qualified Person, Attendant or Operator), the loading/detonation crew, inspection personnel, and authorized supervisory personnel shall be allowed within 50 feet of the loaded holes.

(A) At locations where 50 foot minimum distance cannot be maintained, an approved alternative plan pursuant to the requirements in subsection (d) shall be implemented.

(p) Explosive materials shall be kept separated from detonators until charging is started.

(q) Capped primers shall be made up at the time of charging and as close to the blasting site as conditions allow.

(r) Only wooden or other nonsparking implements shall be used to punch holes in an explosive cartridge.

(s) Areas in which charged holes are awaiting firing shall be guarded or barricaded and posted or flagged against unauthorized entry.

(t) The double-trunkline or loop system shall be used in detonating-cord blasting.

(u) Trunklines, in multiple-row blasts, shall make 1 or more complete loops, with crossties between loops at intervals of not over 200 feet.

(v) All detonating cord knots shall be tight and all connections shall be kept at right angles to the trunklines.

(w) Loaded holes intended for geophysical operations:

(1) Shall be attended; or

(2) May be left unattended, but only where the loaded explosives, if detonated, will not cause injuries and where the loaded explosives are:

(A) Anchored, tamped or stemmed so that the charge cannot be removed; or

(B) Left so that the detonator leads are inaccessible to or concealed from unauthorized persons.

(3) No one but the attendant(s), the loading/detonation crew, inspection personnel, and authorized supervisory personnel shall be allowed within 50 feet of the loaded holes.

(A) At locations where 50 foot minimum distance cannot be maintained, an approved alternative plan pursuant to the requirements in subsection (d) shall be implemented.

Note: Authority cited: Section 142.3, Labor Code. Reference: Section 142.3, Labor Code.

HISTORY

1. Amendment of subsections (a) and (c) filed 3-28-75; effective thirtieth day thereafter (Register 75, No. 13). 2. Amendment of subsection (d) and new subsection (l) filed 10-17-75; effective thirtieth day thereafter (Register 75, No. 42).

2. Amendment of section heading and section filed 9-24-97; operative 10-24-97 (Register 97, No. 39).

3. Amendment filed 7-11-2003; operative 8-10-2003 (Register 2003, No. 28).

4. New subsections (o)(3)-(o)(3)(A), amendment of subsection (w)(2) and new subsections (w)(3)-(w)(3)(A) filed 7-22-2010; operative 8-21-2010 (Register 2010, No. 30).