"Sting in the tail: 'henna' tattoo of a scorpion causes eczema", BUPA medical team - 21 December 2000 http://www.bupa.co.uk/health_news/211200henna.html states:
"Dermatologists know that henna - a vegetable dye commonly used in Muslim and Hindu body art - causes minor skin irritation at worst. In these more severe cases it was unlikely to be the culprit. Suspicions turned instead to other possible ingredients of the body paint. Four patients were tested with other common dye chemicals, by placing them on small patches of skin and checking for reactions. All of the results were positive for an allergy to chemicals used in hair dye, especially p-phenylenediamine."

Natural henna is characterized as "a rare and weak skin sensitizer" in "Allergic contact dermatitis caused by skin painting (pseudotattooing) with black henna, a mixture of henna and p-phenylenediamine and its derivatives." by Le Coz CJ, Lefebvre C, Keller F, Grosshans E.. The article also states that the contact dermatitis associated with "black henna" is due to inappropriate use of p-phenylenediamine. See:

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=11115163&dopt=Abstract

Therefore the "black henna" temporary tattoos injuries should not impact the import of pure henna (Lawsonia Inermis).

Adulterants such as para-phenylenediamine have been introduced into henna, or used in place of henna by greedy, ignorant and unscrupulous people. Adulterated henna is illegal, and FDA regulations regarding use of para-phenylenediamine should be upheld! Pure henna (Lawsonia Inermis) should remain exempt from certification. The European Union has issued a statement declaring PPD and similar chemicals should not be used in skin stains (temporary tattoos). See: "Position Statement concerning para-Phenylenediamine and similar Substances and their use in Skin Stains (Temporary Tattoos) adopted by the SCCNFP during the 16th Plenary Meeting of 13 March 2001"
http://europa.eu.int/comm/food/fs/sc/sccp/out140_en.html

Para-phenylenediamine should NEVER be used in, or in place of henna (Lawsonia Inermis) for temporary body art, as per FDA regulation.

The FDA is correct to insist that henna (Lawsonia Inermis) NOT be adulterated with unlisted and/or unsafe ingredients. These products should be seized in the interest of public safety. However, 100% pure henna has such a high level of safety that it should remain exempt from certification, and its import should be permitted.

Henna is only the only safe hair dye for people who have become sensitized to para-Phenylenediamine. The import of 100% pure henna should be permitted for these people, as using commercial synthetic hair dye would imperil their health.

100% pure henna is the ONLY hair dye permitted to Orthodox Jews and Conservative Muslims. Henna should be a permitted import for these people, who, by their religious conscience, cannot use any commercial hair dye.