Smokeless powders are classified as, typically, division 1.3 explosives under international, regional and national regulations, however they are used as solid propellants, so in normal use they undergo Deflagration, rather than detonation.
Smokeless powders are classified as, typically, division 1.3 explosives under the UN "Recommendations on the transportation of Dangerous goods-Model Regulations", region regulations such as ADR and national regulations, such the United Statess ATF. However they are used as solid propellants, so the undergo Deflagration rather than detonation.