PPD in hair dye: India's limits and the caution label

p-Phenylenediamine, PPD, is the molecule that makes permanent black and brown hair dyes work. In India it is a restricted ingredient: IS 8481:2005, the Indian standard for oxidation hair dyes, allows 2.5 to 4.0 per cent in black shades and 1.0 to 3.0 per cent in brown, and Rule 37 of the Cosmetics Rules 2020 requires every PPD dye to carry a specific caution legend, warning that the product may cause skin irritation, must be patch-tested 48 hours before use and must not be used on eyelashes or eyebrows because it may cause blindness.

Outside hair dye, PPD has no permitted use. That is the legal problem with 'black mehandi' or 'instant henna' cones: natural henna stains orange to brown over hours, and a cone that gives a black stain in minutes almost always contains PPD at dye strength, applied to skin where it is not allowed. The blistering reactions and permanent sensitisation that dermatologists see each wedding season come from these cones.

The standard also catches substitutions. In late 2024 and early 2025 the Chennai laboratory found m-phenylenediamine, the meta isomer, in VIP Hair Colour Shampoo and a Chinese hair colour conditioner; that isomer is on the prohibited list outright. And for people already sensitised, dyes sold as PPD-free deserve a careful look, since the usual substitute, toluene-2,5-diamine, cross-reacts in many of them.