Agent Name

Tropaeolin O

CAS Number




Major Category



4-((2,4-Dihydroxyphenyl)azo)benzenesulfonic acid, monosodium salt; Benzenesulfonic acid, 4-((2,4-dihydroxyphenyl)azo)-, monosodium salt; CI 14270; Benzenesulfonic acid, 4-(2-(2,4-dihydroxyphenyl)diazenyl)-, sodium salt (1:1); C.I. Acid Orange 6, monosodium salt (8CI); Sodium 4-(2,4-dihydroxyphenylazo)benzenesulphonate; 2,4-Dihydroxyazobenzene-4'-sulfonate sodium salt; Acid Leather Yellow PGW; Acid Orange 6; Acid Phosphine G New; Acme Yellow Acid Yellow RS; Benzenesulfonic acid, p-((2,4-dihydroxyphenyl)azo)-, sodium salt; C Yellow 12; C.I. 14270; C.I. Acid Orange 6; C.I. Food Yellow 8; Cetil Chromine Yellow GR; Chrysoin G; Chrysoin S (6CI); Chrysoin S Specially Pure; Chrysoine; Chrysoine Extra; Chrysoine Extra Pure A; Chrysoine N; Chrysoine S; Chrysoine S Extra Pure; Chrysonine S; Chrysonis S; Curol Orange G; Dermina Yellow G; E 103; E 103 (dye); Eniacid Yellow RS; Eurocert Chrysoine S; Gold Yellow; Hispacid Yellow CG; Monosodium 4-((2,4-dihydroxyphenyl)azo)benzenesulfonate; Naphthazine Yellow RP; Neklacid Yellow G; Orange Acid G; p-((2,4-Dihydroxyphenyl)azo)benzenesulfonic acid, sodium salt; p-(2,4-Dihydroxyphenylazo)benzenesulfonic acid, sodium salt; Resorcin Yellow; Resorcine Yellow; Resorcine Yellow O Extra; Resorcinol Yellow; Resorcinol Yellow A; Sodium azoresorcinolsulfanilate; Tertracid Yellow TRO; Tropaelin-O; Tropaeolene (Biological Stain); Tropaeolin R; Tropaeoline; Tropaeoline O; Tropeolin O; UNII-NF91VMI73L; Yellow T; [ChemIDplus] 4-[2-(2,4-Dihydroxyphenyl)diazenyl]benzenesulfonic acid sodium salt (1:1); Sodium p-(2,4-dihydroxyphenylazo)benzenesulfonate; [Merck Index]


Azo Dyes


Brown solid; [Merck Index] Brown powder; [Acros Organics MSDS]


Used as a pH indicator and occasionally as a plasma stain; [Merck Index] Used as a food color; [JECFA]


Intravenous LD50 (rat) > 1,000 mg/kg; [RTECS] No evidence of skin sensitization in guinea pigs; [JECFA] May cause irritation; [Acros Organics MSDS]

Exposure Assessment
Vapor Pressure

1.3E-12 mm Hg

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Toxicity Information


Chemical Information

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