There is no such thing as “black henna” – As henna is a plant, it is only brown in tone and NEVER black. Products that are sold and used as “black henna” are chemically created dyes contained paraphenylenediamine (PPD). PPD is widely used for hair dyes and is not approved for direct use on skin. It is a known and prevalent allergen with sensitising qualities such that while some people may use it and have immediate and horrific permanent scarring, others may use it for years with no obvious external reaction while the body slowly develops a sensitivity to it. It is proven to affect internal organs through external use. Regular users of PPD can find over the years that they develop skin conditions or other more serious and sudden reaction, causing them to be hospitalised*. Despite this, many cones claiming to be “black henna” are still imported/exported and sold.
See also: ‘The Risks of PPD are Real and Life Threatening‘