Metanil Yellow (Acid Yellow 36) is a dye of the azo class. In analytical chemistry, it is used as a pH indicator and it has a color change from red to yellow between pH 1.2 and 3.2.
Although illegal for food use, Metanil Yellow has been used as an adulterant in turmeric- and pigeon pea-based food products, particularly in India."Common food adulterants in India", India Today, New Delhi, October 19, 2018
Animal studies have suggested that Metanil Yellow is neurotoxic and hepatotoxic.
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