I was searching on the internet and found vermiculite from uline.com. They sell packaging materials (boxes,etc.) and apparently, vermiculite is used for shipping hazardous materials.

Does anyone know if there is a difference in this type of vermiculite and one used for gardening? With shipping, it will run about $30 for a 4 cubic foot bag (minimum of 2 bags). Is that expensive?

If it is the same, it could be a good source. They have warehouses in NJ, Dallas, Chicago, Atlanta, LA and Minneapolis. They do allow you to pick up orders but will ship from the warehouse closest to you to keep shipping costs down.

I've ordered shipping supplies in the past (I sell stuff on ebay) and my orders are always received within two days.