Potassium perchlorate is toxic, and breathing protection should be worn when handling fine powder.
Potassium Perchlorate can be absorbed through the skin!!!!.
$7.00 per lb - 2lb minimum
Potassium perchlorate is a very common oxidizer in pyrotechnics. Composition based on perchlorates tend to be less sensitive than those based on chlorates, and perchlorates can be used with sulfur and sulfides. For these reasons potassium perchlorate is much preferred above chlorates
UPDATE: We have started getting a new Potassium Perchlorate for a new supplier. This stuff has no anti-cake in it but had been super-dried to help avoid clumping. In a soon to be published article this Potassium Perchlorate has outperformed all others that have been available. This new supply is very high purity and should outperform anything you have used it the past