Henna itself does not cause contact allergies. Henna powder is sourced from the leaves of the henna tree and mixed with water, tea, lemon juice and oils to form a paste to dye the skin an orange-brown colour. These are all organic ingredients with a shelf-life of a few days before it goes off. Therefore readymade cones that have been lying around in a shop or via the internet cannot possibly be natural henna. Everyone wants a dark stain nowadays – but the only way you can achieve this quickly is with chemicals.
Be natural – be patient – be safe
In India, Morocco and Egypt, brides traditionally have their hands and feet decorated with filigree designs using henna (called ‘mehndi in India). But the paste has to be kept on for several hours (or better still, overnight) in order for the stain to remain dark and visible for several days or more.
It works by soaking through the layers of your skin and therefore needs to be in contact with the skin for the longest time (at least 4-5 hours) but longer is best.
Most holiday tourists do not want to wait for hours to obtain a good colour result. So street artists often use henna powder containing the additive para-phenylenediamine (PPD), which shortens the setting time and gives a dark stain in minutes. So PPD creates a black dye that sets quickly. The disadvantage is that it has a strong sensitising effect. This means that if the immune system was previously exposed to PPD and considered it a harmful substance (although there was no initial reaction), a visible allergic reaction occurs upon re-exposure (having another tattoo).
After a delay of 24 to 72 hours after the dye is applied, the skin swells and becomes red and itchy. Blisters often appear, which burst and weep. Scars may remain after they have healed. I have been shown henna tattoos that are still scarred into the skin YEARS later.
IF YOU EXPERIENCE ITCHING OF ANY KIND – WASH IT OFF. This is the chemicals burning your skin. Natural henna never itches.
Even if there is no skin reaction, the tattoo can trigger a PPD allergy, which can have serious consequences. Once an individual has been sensitised to PPD, he or she must avoid products containing this substance in the future. This can be difficult because PPD is widely used. It is found in dark leather and textile dyes and also in printing dyes and box hair dyes.
It is best to steer clear of any ready-made henna tattoos in order to avoid this health risk. Although the use of PPD in cosmetic skin dyes has been banned in the European Union, it is difficult to know whether regulations are properly observed in all countries. And the ban does not apply to countries outside of Europe.
IF IT SAYS ‘NATURAL’ ON THE CONE – REMEMBER IT CANNOT BE SO!
Henna paste is made from ground leaves, sugar, lemon juice and oils – all organic ingredients with a shelf life of a few days, unless kept in a fridge or freezer.
AVOID ANYTHING THAT SAYS INSTANT OR BLACK HENNA (there is no such thing). The only way to ensure a dark stain is freshly made henna paste that is kept on for more than 5 hours or overnight.
Blog Post on Black Henna here
This blog post explains it better than me
Research Article on Black Henna effects HERE
The Henna Lady Bristol 