Safety fuse means a flexible cord containing an internal burning medium by which fire is conveyed at a continuous and uniform rate for the purpose of firing blasting caps or a black powder charge.
30 CFR § 56.2
The following definitions apply in this part. In addition definitions contained in any subpart of part 56 apply in that subpart. If inconsistent with the general definitions in this section, the definition in the subpart will apply in that subpart: