Lawsonia inermis L. (Henna) and Safety Issues
Mohammad KamilAbstract
Background:
Henna, a coloring made from a plant, is approved by the Food and Drug Administration only for use as a hair dye. It is not approved for direct application to the skin, as in the body-decorating process known as mehndi. This unapproved use of a color additive makes these products adulterated. It is unlawful, for example, to introduce an adulterated cosmetic into interstate commerce. Because henna typically produces a brown, orange-brown, or reddish-brown tint, other ingredients must be added to produce other colors, such as those marketed as “black henna” and “blue henna.” Even brown shades of products marketed as henna may contain other ingredients intended to make them darker or make the stain last longer on the skin.
Methods:
Different samples of Henna powder and cones are collected from the market to know their chemical constituents. TLC and GCMS analysis of various henna extracts was carried out. Sensitivity tests were conducted on animals. Further, allergic reactions to henna observed in few patients are described.
Results:
The standard henna powder is comparable to the sample shows additional spots, the major one seems to be PPD, The sample is re-checked using GC/MS and was found to contain PPD. The other chemical constituents present in the sample are lawsone (2-hydroxy, 4-naphthoquinone and tannins. Blisters and erythematous plaques due to acute vesicular contact dermatitis following PPD contaminated the temporary henna were observed in patients.
Conclusion:
The extra ingredient used to blacken henna is often a coal-tar hair dye containing p-phenylenediamine (PPD), an ingredient that can cause dangerous skin reactions in some people. That’s the reason hair dyes have a caution statement and instructions to do a “patch test” on a small area of the skin before using them. Sometimes, the artist may use a PPD-containing hair dye alone. Either way, there is no telling who will be affected. By law, PPD is not permitted in cosmetics intended to be applied to the skin.