First, henna is never black. It is a plant that is native to the tropical regions of Africa, South Asia and Australasia, and its leaves produce a dye called Lawone, which is an orange-red color, which adheres well to proteins and is therefore used to dye skin, hair, nails and silk. Pure henna should not irritate the skin, although some people may develop allergies, henna can actually be a good skin conditioner. Traditional henna tattoos are caramel or reddish brown, but not black.

To make real henna tattoos, the leaves are dried and ground into a powder that is mixed with lemon juice, strong tea, or other slightly acidic liquids to form a paste. This is allowed to “sit” for 6-12 hours so that the cellulose in the leaves can dissolve and release the law. Once on the skin, the Lawone molecules migrate from the henna paste to the outer layers of the skin. The pasta will crack and fall off, but smearing the sugar or lemon mixture on the dried pasta can seal it in. When you remove the paste, the stain will be orange but darken to a reddish brown. It can be darkened even more by steaming, heating, or using alkaline solutions, but chlorinated water and soap can spoil the stain. The stain should fade as the skin exfoliates and sheds the outer layer of stained skin cells.

The concept of “black henna” may have its origins in tribal peoples who are seen with black tattoos that can be from alkalized henna or other sources. Indigo plants can be fermented and partially dried, then mixed with henna and used to dye hair black, but they cannot dye the skin.

In the US, henna is only approved for use in hair dyes and is not allowed to be imported for other uses, such as tattoos, which is why people offering black henna tattoos do so illegally and from all modes do not use real henna. “Black henna” generally contains dyes that are not listed, the main one being 1,4-phenylenediamine or paraphenylenediamine (PPD). This chemical is used in hair dyes but can only make up 6% or less, cannot come into direct contact with the scalp, and must be rinsed off immediately. However, in “black” henna tattoos it usually constitutes 10% -60% and is left on the skin for half an hour.

PPD is used because it is a cheap substitute for henna and stains the skin in half an hour, whereas henna can take up to 8 hours before the staining is complete. PPD can be mixed with peroxide or peroxide can be wiped over the tattoo to bring out the color and dries quickly. However, PPD is much more abrasive than henna and has several adverse effects:

• Severe allergic reactions can cause permanent sensitivity, making the use of PPD-based hair dyes life-threatening.
• Permanent scars
• Intense itching
• Eruptions
• Blistered skin
• Chemical burns
• It is toxic, either by inhalation or in contact with the skin.
• Irritating to eyes, respiratory system and skin.
• It is a possible mutagen (it can cause the genetic information or DNA in your cells to change, so either the wrong proteins are made or no proteins are made depending on the change, both of which can be extremely harmful).

Black henna is often used by street performers and in resorts or attractions. The countries known to have tattooists using black henna are:

• Thailand
• The philippines
• Australia
• Mexico
• Greece
• Turkey
• Egypt
• South Africa
• Goa (in India)
• Bali (in Indonesia)
• Key West (in Hawaii, USA)

These places or rather tattooists can get away with it because there is often a delayed reaction to PPD as the ink sinks into the skin. This can take anywhere from 3 to 12 days and by then many tourists have left, so the tattoo artists are not charged.