Agent Name

Acid Orange 7

CAS Number




Major Category



4-((2-Hydroxy-1-naphthalenyl)azo)benzenesulfonic acid, monosodium salt; Benzenesulfonic acid, 4-((2-hydroxy-1-naphthalenyl)azo)-, monosodium salt; 1-p-Sulfophenylazo-2-naphthol, monosodium salt; 11550 Orange; 2-Naphthol Orange II; 4-((2-Hydroxy-1-naphthyl)azo)benzenesulfonic acid, sodium salt; Acid Leather Orange Extra; Acid Leather Orange Extra G; Acid Leather Orange Extra PRW; Acid Leather Orange G; Acid Leather Orange PRW; Acid Orange; Acid Orange A; Acid Orange II; Acilan Orange II; Airedale Orange II; Amacid Orange Y; Atul Acid Orange II; Betanaphthol Orange; Brasilan Orange A; Bucacid Orange A; C.I. 15510; C.I. Acid Orange 7; C.I. Acid Orange 7, monosodium salt; CI 15510; Calcocid Orange Y; Certiqual Orange II; Colacid Orange; Curol Orange; D and C Orange No. 4; D&C Orange 4; D&C Orange No. 4; Diacid Orange II; Erio Orange II; Fenazo Orange; Hidacid Orange II; Hispacid Orange AF; Java Orange II; Kayaku Acid Orange II; Kiton Orange II; Kromon Lake Orange Toner; Lake Orange A; Lake Orange II YS; Leather Orange Extra; Lurazol Orange E; Lutetia Orange 3JR; Mandarin G; Mitsui Acid Orange II; Naphthalene Lake Orange G; Naphthalene Orange G; Naphthol Orange; Naphtocard Orange II; Neklacid Orange II; Nitto Acid Orange II; No. 177 Orange Lake; Nubilon Orange R; Orange 2 sodium salt; Orange Extra N; Orange Extra P; Orange II; Orange II For Lakes; Orange II Special For Lacquer; Orange IIC; Orange IIP; Orange IIS; Orange IISM; Orange No. 205; Orange Toner GRT; Orange Y; Orange YA; Orange YZ; Oranz kysela 7; Oranz kysela 7 [Czech]; Peeracid Orange II; Perca Orange GR; Persian Orange; Persian Orange Lake; Persian Orange X; Pure Orange II S; Rifa Acid Orange II; Sanyo Gum Orange A; Solar Orange; Special Orange GR; Special Orange H; Symuler Orange Lake 43; Symulon Acid Orange II; Takaoka Acid Orange II; Tangarine Lake X-917; Tertracid Orange II; Tropaeolin OOO No. 2; Tropaeolin OOO; Tropaeolin OOO 2; Tropoclin OOO2 (Indicator); Vondacid Orange II; Wool Orange A; beta-Naphthyl Orange; p-((2-Hydroxy-1-naphthyl)azo)benzenesulfonic acid sodium salt; Benzenesulfonic acid, 4-(2-(2-hydroxy-1-naphthalenyl)diazenyl)-, sodium salt (1:1); Sodium 4-((2-hydroxy-1-naphthyl)azo)benzenesulphonate; [ChemIDplus] Sodium 4-[(2-hydroxy-1-naphthyl)azo]benzene sulfonate; Orange 205; Acid Orange 7 monosodium salt; COLIPA C015; [ToxPlanet: EC: SCCS (Scientific Committee on Consumer Safety), Opinion on Acid Orange 7, 22 March 2011]


Azo Dyes


Orange-brown solid; [Merck Index] Dark red powder; [Sigma-Aldrich MSDS]


Used as a dye, biological stain, and limited use as an indicator; [Merck Index] Used as a non-reactive dye in non-oxidative and oxidative hair dyes; [ToxPlanet: EC: SCCS (Scientific Committee on Consumer Safety), Opinion on Acid Orange 7, 22 March 2011] Permitted for use as an inert ingredient in non-food pesticide products; [EPA]


Not a skin or eye irritant in rabbits; No evidence of skin sensitization; Hematological changes observed in 90-day oral study of rats; No adverse effects observed in 90-day dermal study of rabbits; No evidence of teratogenicity; [ToxPlanet: EC: SCCS (Scientific Committee on Consumer Safety), Opinion on Acid Orange 7, 22 March 2011] A skin and strong eye irritant; May cause allergic reactions in sensitive individuals; [Sigma-Aldrich MSDS]

Links to Other NLM Databases
Toxicity Information


Chemical Information

Search ChemIDplus

Related Information in HazMap

Industrial Processes with risk of exposure: