When firing with safety fuse ignited individually using handheld lighters,
the safety fuse shall be of lengths which provide at least the minimum burning
time for a particular size round, as specified in the following table.
TABLE E-1--SAFETY FUSE--MINIMUM BURNING TIME
----------------------+----------------------
Number of holes | Minimum burning time
in a round |
----------------------+----------------------
1.....................| 2 minutes.1
2-5...................| 2 minutes 40 seconds.
6-10..................| 3 minutes 20 seconds.
11-15.................| 5 minutes.
----------------------+----------------------
1 For example, at least a 36-inch length of 40-second-per-foot safety fuse
or at least a 48-inch length of 30-second-per-foot safety fuse would have to
be used to allow sufficient time to evacuate the area.
(c) Where flyrock might damage exposed safety fuse, the blast shall be timed
so that all safety fuses are burning within the blastholes before any
blasthole detonates.
(d) Fuse shall be cut and capped in dry locations.
(e) Blasting caps shall be crimped to fuse only with implements designed for
that purpose.
(f) Safety fuse shall be ignited only after the primer and the explosive
material are securely in place.
(g) Safety fuse shall be ignited only with devices designed for that purpose.
Carbide lights, liquefied petroleum gas torches, and cigarette lighters shall
not be used to light safety fuse.
(h) At least two persons shall be present when lighting safety fuse, and no
one shall light more than 15 individual fuses. If more than 15 holes per
person are to be fired, electric initiation systems, igniter cord and
connectors, or other nonelectric initiation systems shall be used.
[58 FR 69596, Dec. 30, 1993]
