Metanil Yellow

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Metanil Yellow
Metanil Yellow Structural Formula V1.svg
IUPAC name
Sodium 3-[(4-anilinophenyl)diazenyl]benzenesulfonate
Other names
Acid Yellow 36; Acid Metanil Yellow; Monoazo
3D model (JSmol)
ECHA InfoCard 100.008.736 Edit this at Wikidata
  • InChI=1S/C18H15N3O3S.Na/c22-25(23,24)18-8-4-7-17(13-18)21-20-16-11-9-15(10-12-16)19-14-5-2-1-3-6-14;/h1-13,19H,(H,22,23,24);/q;+1/p-1
  • C1=CC=C(C=C1)NC2=CC=C(C=C2)N=NC3=CC(=CC=C3)S(=O)(=O)[O-].[Na+]
Molar mass 376.39 g·mol−1
Melting point > 250 °C[1]
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

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.[1]

Although it is an unpermitted food dye, because of its bright yellow color, Metanil Yellow has been used as an adulterant in turmeric powder and arhar dal, particularly in India.[2][3][4][5]

Animal studies have suggested that Metanil Yellow is neurotoxic[3] and hepatotoxic.[6]


  1. ^ a b R. W. Sabnis (2007). Handbook of Acid-Base Indicators. Boca Raton: CRC Press. p. 219. ISBN 978-0-8493-8219-2.
  2. ^ Dhakal, S; Chao, K; Schmidt, W; Qin, J; Kim, M; Chan, D (2016). "Evaluation of Turmeric Powder Adulterated with Metanil Yellow Using FT-Raman and FT-IR Spectroscopy". Foods. 5 (2): 36. doi:10.3390/foods5020036. PMC 5302347. PMID 28231130.
  3. ^ a b Nagaraja, T. N; Desiraju, T (1993). "Effects of chronic consumption of metanil yellow by developing and adult rats on brain regional levels of noradrenaline, dopamine and serotonin, on acetylcholine esterase activity and on operant conditioning". Food and Chemical Toxicology. 31 (1): 41–4. doi:10.1016/0278-6915(93)90177-z. PMID 8095244.
  4. ^ Nath, P. P., Sarkar, K., Tarafder, P., Mondal, M., Das, K. and Paul, G (2015). "Practice of using metanil yellow as food colour to process food in unorganized sector of West Bengal" (PDF). International Food Research Journal. 22 (4): 1424–1428.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  5. ^ "Common food adulterants in India", India Today, New Delhi, October 19, 2018
  6. ^ Saxena, B; Sharma, S (2015). "Food Color Induced Hepatotoxicity in Swiss Albino Rats, Rattus norvegicus". Toxicology International. 22 (1): 152–157. doi:10.4103/0971-6580.172286. PMC 4721164. PMID 26862277.