So recently on a trip to find all natural herb henna without any chemical, specifically 2-nitro-p-phenylenediamine (or PPD). If you follow the link you can you see the health effects from the chemical for yourself.
Anyhoo, this is the henna in question: Supreme Dulhan Indian Henna
So for those of you out there, beware!
Hannah Natural Export Quality is quite good and has all the ingredients listed. 100% henna. So maybe this is a good alternative.