...ON PURPOSE!
Fireworks are cool, but for your legal flameshooting needs please search altavista for flash paper, which will open up the whole world of stage effects, and products that shoot flames. People bitch about That annoying country to the south of Canada, but when it comes right down to it we lead the whole world in PRODUCTS THAT SHOOT FLAMES!

From the fireworksfx.com site:

    Flame Projector - Practically no smoke. Available in Medium (12') and Large (16'). (Small (6') Flame Projector listed previously as "Phantom Flame" in LeMaitre Standard Cartridges section - used with Pod.) The Large Flame Projector displays a spectacular effect that will truly startle the audience. This flame was used exclusively on the "Urban Jungle" Rolling Stones tour in Europe. Flame Projectors for professional use only. LMP810 - $80.50, LMP815 - $89.75
    Large Gerbs - Made in England by LeMaitre. Very little smoke. 4oz. Gerb shoots approximately 12 feet high for about 25 seconds. 8 oz. Gerb shoots approximately 25 feet high for about 25 seconds. For gerb holders, see Mounting Hardware listed earlier in this section. Both sizes are available in Silver, Gold, Color Changing (gold to silver), Flitter and Shimmer. LM1602-1608 - $29.50-$54.00