Annex II Entry 1257 21/10/2010

4-Aminobenzenesulfonic acid (Sulfanilic acid) and its salts, when used as a substance in hair dye products

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4-Aminobenzenesulfonic acid (Sulfanilic acid) and its salts, when used as a substance in hair dye products is listed in Annex II as a prohibited substance for cosmetic products placed on the EU market.

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Prohibited substance— Annex II, EU Regulation 1223/2009

Entry: 1257

Chemical identity and properties

PubChem 2D chemical structure for CAS 121-57-3

CAS 121-57-3PubChem CID 8479

Sulfanilic acid

4-aminobenzenesulfonic acid is an aminobenzenesulfonic acid that is aniline sulfonated at the para-position. It has a role as a xenobiotic, an allergen, a xenobiotic metabolite and an environmental contaminant. It is a conjugate acid of a 4-aminobenzenesulfonate. — ChEBI

IUPAC name: 4-aminobenzenesulfonic acid

Molecular formula: C6H7NO3S
Molecular weight: 173.19 g/mol
Exact mass: 173.01466426 Da
XLogP3: -0.6
Topological polar surface area: 88.8 Å²
Hydrogen-bond donors: 2
Hydrogen-bond acceptors: 4
Covalent units: 1
Defined stereocentres: 0

Also known as

Sulphanilic acidp-Aminobenzenesulfonic acidAniline-4-sulfonic acidAniline-p-sulfonic acidSulfanilsaeureAniline-p-sulphonic acidp-Aminophenylsulfonic acidp-Anilinesulfonic acid

16 more reported names

Kyselina sulfanilovap-sulfoaniline4-Sulfoaniline4-Sulfanilic acidNSC 7170CCRIS 4576CHEBI:27500HSDB 5590EINECS 204-482-51-aminobenzene-4-sulfonic acidAI3-15414UNII-434Z8C2635NSC-71704-aminophenylsulfonic acidp-aminobenzene sulfonic acid434Z8C2635

Open full PubChem record PubChem annotations 3D structure image

External database identifiers

ChEBI:CHEBI:27500
ChEMBL:CHEMBL1566888
EPA DTXSID:DTXSID6024464
PubMed:22798828
PubMed:22750687
PubMed:22719384
PubMed:22706451
PubMed:22701692
PubMed:22666289
PubMed:22609751
PubMed:22586486
PubMed:22579405
PubMed:22574013
PubMed:22567567
PubMed:22558436

Evidence from additional scientific databases

NIH PubChem PUG-View

Exact identifier match8479

Attributed physical-property, hazard, environmental and use annotations.

Color/Form: Orthorhombic plates or monoclinic from water Source: Hazardous Substances Data Bank (HSDB)

Density: 1.485 at 77 °F (NTP, 1992) - Denser than water; will sink Source: CAMEO Chemicals
Density: 1.485 at 25 °C/4 °C Source: Hazardous Substances Data Bank (HSDB)
Density: 1.49 g/cm³ Source: ILO-WHO International Chemical Safety Cards (ICSCs)
Density: 1.485 @25 °C Source: PAC Chemical Database, U.S. Department of Energy

Dissociation Constants: pKa = 3.25 at 25 °C; pKa = 3.34 at 15 °C Source: Hazardous Substances Data Bank (HSDB)

LogP: log Kow = -2.16 Source: Hazardous Substances Data Bank (HSDB)
LogP: -0.9 Source: ILO-WHO International Chemical Safety Cards (ICSCs)

Melting Point: Decomposes without melting at 550 °F (NTP, 1992) Source: CAMEO Chemicals
Melting Point: 288 °C decomposes without melting Source: Hazardous Substances Data Bank (HSDB)

Physical Description: 4-aminobenzene sulfonic acid appears as white powder with faint purple tinge. Grayish-white flat crystals. Becomes anhydrous at around 212 °F. Low toxicity (used medicinally). Source: CAMEO Chemicals
Physical Description: Dry Powder Source: EPA Chemical Data Reporting (CDR)
Physical Description: Greyish-white solid; [Hawley] White to grey solid; [ICSC] Light grey fine crystals and fragments; [MSDSonline] Source: Haz-Map, Information on Hazardous Chemicals and Occupational Diseases
Physical Description: WHITE POWDER OR WHITE-TO-GREY CRYSTALS. Source: ILO-WHO International Chemical Safety Cards (ICSCs)

Solubility: less than 1 mg/mL at 68 °F (NTP, 1992) Source: CAMEO Chemicals
Solubility: Insoluble in ethanol and ether Source: Hazardous Substances Data Bank (HSDB)
Solubility: Soluble in fuming hydrochloric acid Source: Hazardous Substances Data Bank (HSDB)
Solubility: Slowly sol in water: about 1% at 20 °C, about 1.45% at 30 °C, about 1.94% at 40 °C Source: Hazardous Substances Data Bank (HSDB)
Solubility: In water, 10.68 g/L at 20 °C; 14.68 g/L at 30 °C Source: Hazardous Substances Data Bank (HSDB)
Solubility: Solubility in water: poor Source: ILO-WHO International Chemical Safety Cards (ICSCs)

Vapor Pressure: 0.0000002 [mmHg] Source: Haz-Map, Information on Hazardous Chemicals and Occupational Diseases

First Aid: EYES: First check the victim for contact lenses and remove if present. Flush victim's eyes with water or normal saline solution for 20 to 30 minutes while simultaneously calling a hospital or poison control center. Do not put any ointments, oils, or medication in the victim's eyes without specific instructions from a physician. IMMEDIATELY transport the victim after flushing eyes to a hospital even if no symptoms (such as redness or irritation) develop.; SKIN: IMMEDIATELY flood affected skin with water while removing and isolating all contaminated clothing. Gently wash all affected skin areas thoroughly with soap and water. If symptoms such as redness or irritation develop, IMMEDIATELY call a physician and be prepared to transport the victim to a hospital for treatment.; INHALATION: IMMEDIATELY leave the contaminated area; take deep breaths of fresh air. If symptoms (such as wheezing, coughing, shortness of breath, or burning in the mouth, throat, or chest) develop, call a physician and be prepared to transport the victim to a hospital. Provide proper respiratory protection to rescuers entering an unknown atmosphere. Whenever possible, Self-Contained Breathing Apparatus (SCBA) shou Source: CAMEO Chemicals

Signal: Warning Source: Regulation (EC) No 1272/2008 of the European Parliament and of the Council
GHS Hazard Statements: H315: Causes skin irritation [Warning Skin corrosion/irritation]; H317: May cause an allergic skin reaction [Warning Sensitization, Skin]; H319: Causes serious eye irritation [Warning Serious eye damage/eye irritation] Source: Regulation (EC) No 1272/2008 of the European Parliament and of the Council
Precautionary Statement Codes: P261, P264, P264+P265, P272, P280, P302+P352, P305+P351+P338, P321, P332+P317, P333+P317, P337+P317, P362+P364, and P501 (click each P-code to see the statement) Source: Regulation (EC) No 1272/2008 of the European Parliament and of the Council
Signal: Warning Source: European Chemicals Agency (ECHA)
GHS Hazard Statements: H315 (98.6%): Causes skin irritation [Warning Skin corrosion/irritation]; H317 (98.6%): May cause an allergic skin reaction [Warning Sensitization, Skin]; H319 (99.8%): Causes serious eye irritation [Warning Serious eye damage/eye irritation] Source: European Chemicals Agency (ECHA)
Precautionary Statement Codes: P261, P264, P264+P265, P272, P280, P302+P352, P305+P351+P338, P321, P332+P317, P333+P317, P337+P317, P362+P364, and P501 (click each P-code to see the statement) Source: European Chemicals Agency (ECHA)
ECHA C&L Notifications Summary: Aggregated GHS information provided per 442 reports by companies from 9 notifications to the ECHA C&L Inventory. Each notification may be associated with multiple companies.; Information may vary between notifications depending on impurities, additives, and other factors. The percentage value in parenthesis indicates the notified classification ratio from companies that provide hazard codes. Only hazard codes with percentage values above 10% are shown. For more detailed information, please visit ECHA C&L website. Source: European Chemicals Agency (ECHA)
GHS Hazard Statements: Not Classified Source: NITE-CMC
Signal: Warning Source: NITE-CMC
GHS Hazard Statements: H317: May cause an allergic skin reaction [Warning Sensitization, Skin]; H319: Causes serious eye irritation [Warning Serious eye damage/eye irritation] Source: NITE-CMC
Precautionary Statement Codes: P261, P264+P265, P272, P280, P302+P352, P305+P351+P338, P321, P333+P317, P337+P317, P362+P364, and P501 (click each P-code to see the statement) Source: NITE-CMC
Signal: Warning Source: Hazardous Chemical Information System (HCIS), Safe Work Australia

Environmental Bioconcentration: An estimated BCF of 3 was calculated in fish for sulfanilic acid(SRC), using a log Kow of -2.16(1) and a regression-derived equation(2). According to a classification scheme(3), this BCF suggests the potential for bioconcentration in aquatic organisms is low(SRC). Source: Hazardous Substances Data Bank (HSDB)

Environmental Fate: TERRESTRIAL FATE: Based on a classification scheme(1), an estimated Koc value of 10(SRC), determined from a structure estimation method(2), indicates that sulfanilic acid is expected to have very high mobility in soil(SRC). The pKa of sulfanilic acid is 3.25 at 25 °C(3), indicating that this compound will partially exist in anion form in the environment and anions generally do not adsorb more strongly to soils containing organic carbon and clay than their neutral counterparts(4). Volatilization of sulfanilic acid from moist soil surfaces is not expected to be an important fate process(SRC) given an estimated Henry's Law constant of 8.9X10-13 atm-cu m/mole(SRC), using a fragment constant estimation method(2). Sulfanilic acid is not expected to volatilize from dry soil surfaces(SRC) based upon an estimated vapor pressure of 1X10-9 mm Hg at 25 °C(SRC), determined from a fragment constant method(2). Based on results of the majority of eight separate laboratory determinations, it can be concluded that sulfanilic acid is not readily biodegradable(5). Sulfanilic acid, present at 100 mg/L, reached 8% of its theoretical BOD in 2 weeks using an activated sludge inoculum at 30 mg/L in the Jap Source: Hazardous Substances Data Bank (HSDB)
Environmental Fate: AQUATIC FATE: Based on a classification scheme(1), an estimated Koc value of 10(SRC), determined from a structure estimation method(2), indicates that sulfanilic acid is not expected to adsorb to suspended solids and sediment(SRC). Volatilization from water surfaces is not expected(3) based upon an estimated Henry's Law constant of 8.9X10-13 atm-cu m/mole(SRC), developed using a fragment constant estimation method(2). According to a classification scheme(4), an estimated BCF of 3(SRC), from a log Kow of -2.16(5) and a regression-derived equation(2), suggests the potential for bioconcentration in aquatic organisms is low(SRC). Sulfanilic acid absorbs UV light at wavelengths >290 nm(6) and may be susceptible to direct photolysis in sunlit water(SRC). Based on results of the majority of eight separate laboratory determinations, it can be concluded that sulfanilic acid is not readily biodegradable(7). Sulfanilic acid, present at 100 mg/L, reached 8% of its theoretical BOD in 2 weeks using an activated sludge inoculum at 30 mg/L in the Japanese MITI test(8) which also indicates the compound is not readily biodegradable(SRC). Source: Hazardous Substances Data Bank (HSDB)
Environmental Fate: ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), sulfanilic acid, which has an estimated vapor pressure of 1X10-9 mm Hg at 25 °C(SRC), determined from a fragment constant method(2), is expected to exist solely in the particulate phase in the ambient atmosphere. Particulate-phase sulfanilic acid may be removed from the air by wet or dry deposition(SRC). Sulfanilic acid absorbs UV light at wavelengths >290 nm(3), and therefore may be susceptible to direct photolysis by sunlight(SRC). Source: Hazardous Substances Data Bank (HSDB)

Industry Uses: Intermediate; Plasticizer; Brightener Source: EPA Chemical Data Reporting (CDR)

Sources/Uses: Used to make dyes and other organic chemicals; Also used as an analytical reagent (Ehrlich's reagent and determination of nitrites) and antibacterial; [Merck Index] Used in the paper, pulp, board, and polymer industries; Used as an additive to construction materials and foodstuffs; [IUCLID] Source: Haz-Map, Information on Hazardous Chemicals and Occupational Diseases
Industrial Processes with risk of exposure: Pulp and Paper Processing [Category: Industry] Source: Haz-Map, Information on Hazardous Chemicals and Occupational Diseases
Uses: Manufacture of various dyes and organic chemicals; as reagent in analytical chemistry (Ehrlich's reagent, determination of nitrites) Source: Hazardous Substances Data Bank (HSDB)
Uses: Intermediate in the production of dyes, pesticides, pharmaceuticals. Source: Hazardous Substances Data Bank (HSDB)
Uses: CHEM INT FOR DYES (ESP AZO DYES), EG, C.I. ACID ORANGE 24 Source: Hazardous Substances Data Bank (HSDB)
Uses: CHEM INT FOR ANALGESICS AND OTHER ORG CHEMS Source: Hazardous Substances Data Bank (HSDB)
Uses: For more Uses (Complete) data for SULFANILIC ACID (6 total), please visit the HSDB record page. Source: Hazardous Substances Data Bank (HSDB)
Uses: Substance listed with specific concentration in tattoo ink and/or permanent make up according to EU Commission Regulation 2020/2081. The concentration limit (by weight) is 0.0005%. Source: NORMAN Suspect List Exchange

Mapped by: Existing checksum-valid CAS to unique PubChem CID match. Retrieved: 2026-08-31. Open source record

Scientific classifications and hazard annotations provide context and do not replace the market-specific regulatory decision shown above.

Additional source coverage and match status

Source	Result	Checked
NIH PubChem PUG-View	Exact match	2026-08-31

A recorded no-match is useful evidence that the source was checked; it is not a claim that the substance does not exist elsewhere.

Retrieved from NIH PubChem on 2026-08-31 by checksum-valid CAS matching. Chemical properties do not replace the regulatory decision on this page.

PubChem 2D chemical structure for CAS 515-74-2

CAS 515-74-2PubChem CID 23664644

Sodium sulfanilate

IUPAC name: sodium 4-aminobenzenesulfonate

Molecular formula: C6H6NNaO3S
Molecular weight: 195.17 g/mol
Exact mass: 194.99660851 Da
Topological polar surface area: 91.6 Å²
Hydrogen-bond donors: 1
Hydrogen-bond acceptors: 4
Covalent units: 2
Defined stereocentres: 0

Also known as

Sodium sulphanilate4-Amino-benzenesulfonic acid monosodium saltBenzenesulfonic acid, 4-amino-, monosodium saltEINECS 208-208-5Sulfanilic acid monosodium saltCCRIS 7446Sulfanilic Acid Sodium Salt4-Aminobenzenesulfonic acid, sodium salt

16 more reported names

4-Aminobenzenesulfonic acid, monosodium salt9YJ2Q81720EC 208-208-5Benzenesulfonic acid, 4-amino-, sodium salt (1:1)4SulfoanilinNapSulfanilsaeure NaSulfanilsaure Na SalzRefChem:8878944Aminobenzol1sulfonsaeureNaSodium 4aminobenzenesulfonate4AminobenzolsulfonsaeureNaSalzAnilin4sulfonsaure NatriumsalzSODIUM SULFANILATE [INCI]4Aminobenzolsulfonsaure Natriumsalz4Aminobenzenesulfonic acid, sodium salt4Aminobenzenesulfonic acid, monosodium salt

Open full PubChem record PubChem annotations 3D structure image

External database identifiers

ChEMBL:CHEMBL3183582
EPA DTXSID:DTXSID5029184

Retrieved from NIH PubChem on 2026-09-02 by checksum-valid CAS matching. Chemical properties do not replace the regulatory decision on this page.

Record details

Chemical name

4-Aminobenzenesulfonic acid (Sulfanilic acid) and its salts, when used as a substance in hair dye products

Regulatory information

Regulation

(EC) 2009/1223

See every entry this act set

SCCS opinions

Identified ingredients

SODIUM SULFANILATE

Key data

CAS

121-57-3 / 515-74-2

204-482-5 / 208-208-5

Annex

Entry number

1257

Inventory links for 4-Aminobenzenesulfonic acid (Sulfanilic acid) and its salts, when used as a substance in hair dye products

Inventory Restriction reference

Ref 38092

SODIUM SULFANILATE

CAS: 515-74-2

EC: 208-208-5

Direct matches are limited for this record, so nearby entries from Annex II are shown as well.

Annex II 1256