To say "black henna" products are a blatant not to mention disgusting example of henna at its most adulterated is a vast understatement. Originally used because women were unable to buy natural henna for body art (black henna hair color was only at hand at times due to the import markets created in Europe, Australia, etc., which depleted domestic supply), denatured black henna created its unhealthy niche amoung some. This inturn led to numerous, well known, adverse health conditions to be reported amoung women in the Old World. Due to a lack of understanding concerning the dangers of using these products and an illigal neglect of providing proper ingredient labels, many people in the US now have become injured or effected by black henna.
A number of products now sport the claim that their is no PPD in their product. Since many of these products are imported "as is" with no spot checking, such claims must be taken with a grain of salt. What if the claim is true however? Does this mean the black henna product is safe, non-toxic and legal (in the US)? The answer is of course a resounding no. People have reportedly suffered the exact same skin reactions from black powders later tested and found not to have traces of PPD. Why? The reason is there are a whole host of other synthetic dyes and oxidizing chemicals which are not safe and not disclosed in these black henna products. In addition, many of these products are comprised of only 50% henna, with chemicals and fillers being the other half. Some of these include silver nitrate, carmine, titanium dioxide, ethyl cellulose, barium peroxide, tartaric acid, pyrogallol, etc. Carmine is extremly hazardous and can cause swelling and other PPD mimicking symptoms. The silver nitrate also causes chemical burns which may not show for days. The FDA states products called henna or that use henna on the lable may not have such adulterations. Thus they are not to be sold in the US.
The reason henna has so many problems today is complicated. Greed is of course at the root of the problem but there are many other contributing factors. In the US, the main problem comes with the companies selling henna for body art. Many do not take into consideration the henna they are buying in bulk has not been tested for Lawsone levels or simple things like lead and/or bacteria which can cause people to become extremly ill. This is because henna purchased by the ton is extremly cheap and many times does not catch the eye of the FDA in bulk. Questions to ask youself and/or anyone selling henna is, what kind of quality control is done? Is each batch of henna received lab tested for adulterants? Are whole leaves ground here in the US or where they were exported from? What are the product standards in the country where it is exported from? India and Pakistan are major exporters but also frequently have contamination problems. Does the box and company conform to FDA standards? Does the company understand how the FDA views henna and its uses? Has the company had complaints lodged against them?
The reason why it is important not to buy adulterated henna products is because of the time most Mehndi designs are left on the skin or color on the hair. This can span from 1 hour to overnight. Many of the advser chemicals used to adulterate henna are ones traditionally used in hair color. These chemicals are never intended to be left on the skin but instead the dead shaft of the hair. Unlike safer bodypaints and non-toxic pen ink, these chemicals can enter the blood and be circulated about your body causing all sorts of health problems. This is likely one of the main reasons the FDA states henna should only be sold in a pure state, if henna is mentioned on the label..