From Hodgdon's website. Note # 11, and also the Misuse WarningGENERAL WARNINGS
DANGER EXTREMELY FLAMMABLE: Pellets are extremely flammable. Failure to follow warnings and instructions for use, or misuse of this product in any way, may cause personal injury or death to the user or bystander, as well as damage to the firearm and other property. Use Pellets only in strict accordance with loading instructions.
1. Keep Pellets out of reach of children.
2. Do not take Pellets internally.
3. Do not contaminate Pellets with dirt or moisture.
4. Keep Pellets in original, closed box until used. Do not place Pellets loose in clothing.
5. Do not smoke when handling Pellets.
6. Keep Pellets away from heat, sunlight, open flame, sparks from any source, static electricity and moisture. Be sure box is closed while shooting.
7. Do not subject Pellets to impact or friction.
8. Store Pellets in original container in a cool, dry place, away from primers, explosives, solvents, gasoline, or other sources of ignition.
9. Always wear ear and eye protection when handling, loading and firing firearms, and using Pellets.
10. Discharging firearms in poorly ventilated areas, cleaning firearms, or handling ammunition may result in exposure to lead and other substances known to cause birth defects, reproductive harm, and other serious physical injury. Have adequate ventilation at all times. Wash hands thoroughly after exposure.
11. Pellets are intended to be use in place of granular powder. Do not combine Pellets with loose powder. Do not combine Pellets of different caliber sizes.
12. Never mix powders or use nitrocellulose based smokeless powder in muzzleloading firearms.
13. Do not ignite Pellet in hand or outside of firearm.
14. Do not break, cut or modify Pellet by any means.
INTENDED USE
Triple Seven and Pyrodex Pellets are designed for use only in newly manufactured muzzleloading, in-line rifles of 50 caliber, 54 caliber, and 45 caliber. Use Triple Seven only in a 209 primer ignition system. Pyrodex may be used with standard cap, musket cap or 209 primer ignition systems. Use only the correct caliber Pellet designated for the given caliber rifle. They are designed to be used with saboted bullets or conicals together with a fiber wad. Any other use of the Pellets is not recommended. Triple Seven Pellets are not for use in cartridges, or with patched round ball. Pyrodex Pellets may be used in cartridges.
Pistol Pellets are designed and intended for use only in newly manufactured modern replica 44 and 45 caliber cap and ball revolvers. They may also be used in 45 caliber in-line rifles. Any other use of the Pistol Pellet is not recommended.
MISUSE WARNING
Use of Triple Seven Pellets and Pyrodex Pellets in sidelock muzzleloading rifles, in flintlock muzzleloading rifles, using a patched round ball, or the use of conical lead bullets without a fiber wad is NOT recommended. Due to variations in the size and type of flash channels of such rifles, as well as different rifle bore diameters, and conical bullet sizes, hangfires (a delayed ignition of the Pellet) or an improper gas seal of the projectile may occur. These conditions could cause the projectile or a burning Pellet to exit the barrel in a hazardous manner, which could cause personal injury or death to the user or bystander, as well as damage to the firearm.
http://www.hodgdon.com/data/muzzleloading/pellet-warnings.php
