Tannerite Brand targets are specifically designed to be safe and only initiated by a centerfire rifle. Tannerite is non-hazardous and can be shipped without expensive hazmat fees, it is safe and legal. The catalyst mixes easily into each 1/2 pound target. Contains 24- 1/2 lb targets, premeasured packets of catalyst, mixing container and instructions. Tannerite brand targets were specifically designed to be safe whether its sitting on a shelf, being mixed or used. When shot with a high-power rifle it produces a water vapor and a thunderous boom resembling an explosion. BUT sparks from the bullet hitting hard objects such as rocks, metal (as would be the case in any shooting environment) MUST be considered when using Tannerite targets. Follow all of the safety instructions. Elevate the target on a cardboard box and make sure the area is free of debris, dry grasses. Do not use target in locations where a general fire order is in effect and do not use target near combustible materials Never place these targets inside, on top of, or under any metal, rock, or other surfaces that could produce flying debris or sparks, or within another object. This is dangerous and constitutes improper use of the product. Use Tannerite brand targets only as directed and in full compliance with all applicable federal, state, and local laws; improper use may result in serious injury, death, fire, or property damage. By purchasing and using this product, you assume all risks and liabilities, and are responsible for verifying local legality and land-use restrictions before shooting.