Depends on which kind..I used to work for a Japanese Incense company..
So here's what I know:
*Nag Champa: It has a bamboo core-which is dipped in something to make it light..and it's rolled in cow poo! So not only are you burning the supposed scent of Nag, also cow poo!!

*alot of incense has animal parts used to bind the incense!
* The Bamboo core is coated w/funky stuff IMO...
* Most incense uses weird perfumes etc....
*I worked for a company that does not use a bamboo core and no animal ingred..The incense is made purely from plants, even the "binder" that is made up of plants and fruit based to hold the incense together...It's soo amazing once you start burning pure, clean incense vs. cheap crapp that smokes like mad!
