From the guidance doc (emphasis mine):
http://www.hse.gov.u.../books/l151.htm
pyrotechnic articles articles that contain explosives substances or an explosive mixture of substances designed to produce heat, light, sound, gas or smoke or a combination of such effects through self-sustained exothermic chemical reactions. They include fireworks plus other items such as flares, smoke signals and flash cartridges. Pyrotechnic articles will also include all such articles that have been characterised as such by a notified body under the provisions of Directive 2007/23/EC, pyrotechnic articles that are equipment falling within the scope of Directive 96/98/EC and percussion caps intended specifically for toys falling within the scope of Council Directive 88/378/EEC. Pyrotechnic articles will also include those articles that have identified as such by Directive 2004/57/EC.