There are 3 classes of explosive materials:

(a) High explosives (for example, dynamite, flash powders, and bulk salutes);

(b) Low explosives (for example, black powder, safety fuses, igniters, igniter cords, fuse lighters, and “display fireworks”, except for bulk salutes); and

(c) Blasting agents (for example, ammonium nitrate-fuel oil and certain water gels).

[27 CFR 555.202]