I wouldn't use it! The risks are too great! Even using "body art" quality henna is not sufficient. There are about 3-4 brands which are known not to have toxins (goggle "henna ppd").
I can't recall the names of any others besides Jamila. If you can't find Jamila locally, it's worth the extra $3-$5 to order it online...or not use it at all. Please be careful! Some of these products have mercury salts and LEAD in them...BE WARE when ordering products from countries that don't have the same FDA standards we are accustomed to.
This is so important, I'm going to make a new thread on it as a reminder.