Synthetic colours sold in local markets could contain harmful chemicals. For example:
Green – It might contain copper sulphate and can cause problems like eye allergy and temporary blindness.
Red – It might contain mercury sulphide, which can lead to skin cancer, mental retardation, paralysis and impaired vision.
Purple – It might contain chromium iodide leading to health problems like bronchial asthma and allergies.
Silver – It might contain aluminum bromide, which is carcinogenic.
Blue – It might contain Prussian blue, which can cause contract dermatitis.
Black – It might contain lead oxide leading to health problems like renal failure and learning disability