30 CFR § 56.6602
Static electricity dissipation during loading.
When explosive material is loaded pneumatically into a blasthole in
a manner that generates a static electricity hazard--
(a) An evaluation of the potential static electricity hazard shall
be made and any hazard shall be eliminated before loading begins;
(b) The loading hose shall be of a semiconductive type, have a
total of not more than 2 megohms of resistance over its entire length
and not less than 1000 ohms of resistance per foot;
(c) Wire-countered hoses shall not be used;
(d) Conductive parts of the loading equipment shall be bonded and
grounded and grounds shall not be made to other potential sources of
extraneous electricity; and
(e) Plastic tubes shall not be used as hole liners if the hole
contains an electric detonator.