StacksVerified U.S. regulatory reference

30 CFR §7.69

Verified against eCFR.gov as of June 20, 2026View official text on eCFR.gov ↗
Each approved blasting unit shall be identified as permissible by a legible and permanent marking securely attached, stamped, or molded to the outside of the unit. This marking shall include the following:
  1. (a)The assigned MSHA approval number.
  2. (b)The maximum blasting circuit resistance.
  3. (c)A warning that the unit's components must not be disassembled or removed.
  4. (d)The replacement battery types if the unit has replaceable batteries.
  5. (e)A warning placed next to the charging connector that the battery only be charged in a fresh air location if rechargeable batteries are used.
  6. (f)A warning that the unit is compatible only with detonators that will—
    1. (1)Fire when an average of 1.5 amperes is applied for 5 milliseconds;
    2. (2)Not misfire when up to an average 100 amperes is applied for 10 milliseconds; and
    3. (3)Not fire when a current of 250 milliamperes or less is applied.