Permanent Hair Dye Ingredient Poses Significant Health Risks Friday, November 21, 2025 ppd hairdye allergies carcinogenic poisoning dermatology safety chemicals toxicity haircare Permanent hair dyes widely used in the US and Europe commonly contain the aromatic amine p-phenylenediamine (PPD). This chemical is essential for ensuring long-lasting color by making it resistant to washing and drying. … Read More