m-Phenylenediamine (MPD)

m-Phenylenediamine (MPD), also known as meta-phenylenediamine, is an organic compound with the formula C6H8N2. It's one of the isomers of phenylenediamine and is a colorless solid that is used primarily as a precursor to other materials.

m-Phenylenediamine and its salts are used in the formulation of hair dyes, colors, and tints. They serve as a primary intermediate for the synthesis of various pigments and dyes. The compound helps in achieving the desired color and is known for its effectiveness in covering grey hair. It is also used in the creation of certain polymers and in the manufacture of rubber chemicals.

Exposure to m-Phenylenediamine can cause skin sensitization and allergic reactions such as contact dermatitis. It can be particularly irritating to the skin, eyes, and respiratory system. Individuals with sensitive skin or pre-existing allergies may experience more severe reactions.

The use of m-Phenylenediamine and its salts has been associated with an increased risk of certain types of cancer, though the evidence is not conclusive. Additionally, prolonged or repeated exposure may lead to more severe health conditions like organ damage.

In the provided California Assembly Bill No. 496, m-Phenylenediamine and its salts are listed as banned ingredients in cosmetic products effective January 1, 2025. The ban encompasses the manufacturing, selling, delivering, holding, or offering for sale of any cosmetic product that intentionally contains m-Phenylenediamine and its salts among other specified ingredients, due to the associated health risks.

Given the potential health risks and skin sensitivities associated with m-Phenylenediamine and its salts, their use in cosmetics and household products has been regulated in certain regions like California. Consumers, especially those with sensitive skin, are advised to exercise caution and check product labels for the presence of m-Phenylenediamine or its synonyms, to make informed and safe choices.