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CAS 1 record

CAS 120-80-9

CAS 120-80-9 matches 1 EU annex record across Annex II–VI of Regulation 1223/2009.

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Chemical identity and properties

PubChem 2D chemical structure for CAS 120-80-9
CAS 120-80-9PubChem CID 289

Catechol

Catechol is a benzenediol comprising of a benzene core carrying two hydroxy substituents ortho to each other. It has a role as a genotoxin, an allelochemical and a plant metabolite. It is a conjugate acid of a catecholate(1-). — ChEBI

IUPAC name
benzene-1,2-diol
Molecular formula
C6H6O2
Molecular weight
110.11 g/mol
Exact mass
110.036779430 Da
XLogP3
0.9
Topological polar surface area
40.5 Ų
Hydrogen-bond donors
2
Hydrogen-bond acceptors
2
Covalent units
1
Defined stereocentres
0

Also known as

pyrocatechol1,2-dihydroxybenzene1,2-benzenediolpyrocatechin2-hydroxyphenolo-Dihydroxybenzeneo-Hydroxyphenolo-Benzenediol
16 more reported names
o-Dioxybenzeneo-HydroquinonePhthalhydroquinonePyrocatechineo-PhenylenediolOxyphenic acidFouramine PCHPelagol Grey CDurafur developer CCatechin (phenol)Fourrine 68Benzene, o-dihydroxy-Catechol (phenol)o-DiphenolC.I. Oxidation Base 26ortho-Hydroxyphenol
Open full PubChem recordPubChem annotations3D structure image
External database identifiers

Evidence from additional scientific databases

NIH PubChem PUG-View
Exact identifier match289

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

  • 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. IMMEDIATELY call a hospital or poison control center even if no symptoms (such as redness or irritation) develop. IMMEDIATELY transport the victim to a hospital for treatment after washing the affected areas.; 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. Whene Source: CAMEO Chemicals
  • First Aid: (General first aid procedures); Eye: Irrigate immediately - If this chemical contacts the eyes, immediately wash (irrigate) the eyes with large amounts of water, occasionally lifting the lower and upper lids. Get medical attention immediately.; Skin: Water wash immediately - If this chemical contacts the skin, immediately wash the contaminated skin with water. If this chemical penetrates the clothing, immediately remove the clothing and wash the skin with water. If symptoms occur after washing, get medical attention immediately.; Breathing: Respiratory support; Swallow: Medical attention immediately - If this chemical has been swallowed, get medical attention immediately. Source: The National Institute for Occupational Safety and Health (NIOSH)
  • Signal: Danger Source: Regulation (EC) No 1272/2008 of the European Parliament and of the Council
  • GHS Hazard Statements: H301: Toxic if swallowed [Danger Acute toxicity, oral]; H311: Toxic in contact with skin [Danger Acute toxicity, dermal]; H315: Causes skin irritation [Warning Skin corrosion/irritation]; H319: Causes serious eye irritation [Warning Serious eye damage/eye irritation]; H341: Suspected of causing genetic defects [Warning Germ cell mutagenicity]; H350: May cause cancer [Danger Carcinogenicity] Source: Regulation (EC) No 1272/2008 of the European Parliament and of the Council
  • Precautionary Statement Codes: P203, P262, P264, P264+P265, P270, P280, P301+P316, P302+P352, P305+P351+P338, P316, P318, P321, P330, P332+P317, P337+P317, P361+P364, P362+P364, P405, 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: Danger Source: European Chemicals Agency (ECHA)
  • GHS Hazard Statements: H301 (16.4%): Toxic if swallowed [Danger Acute toxicity, oral]; H302 (83.6%): Harmful if swallowed [Warning Acute toxicity, oral]; H311 (16.4%): Toxic in contact with skin [Danger Acute toxicity, dermal]; H312 (83.6%): Harmful in contact with skin [Warning Acute toxicity, dermal]; H315 (> 99.9%): Causes skin irritation [Warning Skin corrosion/irritation]; H317 (12.6%): May cause an allergic skin reaction [Warning Sensitization, Skin]; H319 (94.6%): Causes serious eye irritation [Warning Serious eye damage/eye irritation]; H341 (16.4%): Suspected of causing genetic defects [Warning Germ cell mutagenicity]; H350 (11.4%): May cause cancer [Danger Carcinogenicity] Source: European Chemicals Agency (ECHA)
  • Precautionary Statement Codes: P203, P261, P262, P264, P264+P265, P270, P272, P280, P301+P316, P301+P317, P302+P352, P305+P351+P338, P316, P317, P318, P321, P330, P332+P317, P333+P317, P337+P317, P361+P364, P362+P364, P405, 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 2962 reports by companies from 34 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)
  • Signal: Warning Source: European Chemicals Agency (ECHA)
  • GHS Hazard Statements: H317 (100%): May cause an allergic skin reaction [Warning Sensitization, Skin]; H412 (100%): Harmful to aquatic life with long lasting effects [Hazardous to the aquatic environment, long-term hazard] Source: European Chemicals Agency (ECHA)
  • Precautionary Statement Codes: P261, P272, P273, P280, P302+P352, P321, P333+P317, P362+P364, and P501 (click each P-code to see the statement) Source: European Chemicals Agency (ECHA)
  • ECHA C&L Notifications Summary: The GHS information provided by 1 company from 1 notification to the ECHA C&L Inventory. Source: European Chemicals Agency (ECHA)
  • GHS Hazard Statements: H315 (100%): Causes skin irritation [Warning Skin corrosion/irritation]; H319 (100%): Causes serious eye irritation [Warning Serious eye damage/eye irritation]; H412 (100%): Harmful to aquatic life with long lasting effects [Hazardous to the aquatic environment, long-term hazard] Source: European Chemicals Agency (ECHA)
  • NFPA Health Rating: 3 - Materials that, under emergency conditions, can cause serious or permanent injury. Source: Hazardous Substances Data Bank (HSDB)
  • NFPA Fire Rating: 1 - Materials that must be preheated before ignition can occur. Materials require considerable preheating, under all ambient temperature conditions, before ignition and combustion can occur. Source: Hazardous Substances Data Bank (HSDB)
  • NFPA Instability Rating: 0 - Materials that in themselves are normally stable, even under fire conditions. Source: Hazardous Substances Data Bank (HSDB)
  • Cosmetic Ingredient Review Conclusion: The CIR Expert Panel concludes that Pyrocatechol is unsafe for use in leave-on products, and that the available data are insufficient to support the safety of Pyrocatechol as used in hair dyes. Source: Cosmetic Ingredient Review (CIR)
  • Cosmetic Ingredient Review Finding(s): The ingredient is unsafe for use in cosmetics; Ingredients for which the data are insufficient and their use in cosmetics is not supported Source: Cosmetic Ingredient Review (CIR)
  • Toxicity Summary: IDENTIFICATION AND USE: Catechol is a tablet or colorless crystal, prism or aqueous solution, which discolors to brown on exposure to air and light. It has a faint characteristic odor. It is used as antioxidant in the rubber, chemical, photographic, dye, fat, and oil industries. It was formerly used as an antiseptic. Catechol was found unsafe for use in cosmetics. HUMAN EXPOSURE AND TOXICITY: Catechol contact with the skin has been known to cause an eczematous dermatitis. It is highly irritating upon direct contact; severe eye and deep skin burns result. Well absorbed by skin. Systemic toxicity similar to that of phenol however, catechol may be more likely to cause convulsions and hypertension. At high doses, renal and liver injury may occur. Absorption through the skin, in a few instances, has resulted in symptoms of illness resembling closely those induced by phenol, except for certain central effects (convulsions) that were more marked. Death apparently is initiated by respiratory failure. Catechol was found to be a more harmful toxin than phenol in human blood cells in vitro, since it provokes statistically significant changes in the function of erythrocytes even at low doses. Source: Hazardous Substances Data Bank (HSDB)
  • Environmental Bioconcentration: An estimated BCF of 3 was calculated for catechol(SRC), using a log Kow of 0.88(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), a Koc value of 118(2), indicates that catechol is expected to have high mobility in soil(SRC). Volatilization of catechol from moist soil surfaces is not expected to be an important fate process(SRC) given an estimated Henry's Law constant of 1.2X10-9 atm-cu m/mole(SRC), based upon its vapor pressure, 3.66X10-3 mm Hg(3), and water solubility, 4.61X10+5 mg/L(4). Catechol is not expected to volatilize from dry soil surfaces(SRC) based upon its vapor pressure(3). The percent biodegradation after 6 months in various loam soils ranged from 24 to 50%(5), indicating that biodegradation is a moderate environmental fate process in soil(SRC). Source: Hazardous Substances Data Bank (HSDB)
  • Environmental Fate: AQUATIC FATE: Based on a classification scheme(1), a Koc value of 118(2), indicates that catechol 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 1.20X10-9 atm-cu m/mole(SRC), derived from its vapor pressure, 3.66X10-3 mm Hg(4), and water solubility, 4.61X10+5 mg/L(5). According to a classification scheme(6), an estimated BCF of 3(SRC), from its log Kow of 0.88(7) and a regression-derived equation(8), suggests the potential for bioconcentration in aquatic organisms is low(SRC). Utilizing the Japanese MITI test, 83% of the Theoretical BOD was reached in 2 weeks(9) indicating that biodegradation is an important environmental fate process in water(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), catechol, which has a vapor pressure of 3.66X10-3 mm Hg at 25 °C(2), is expected to exist solely as a vapor in the ambient atmosphere. Vapor-phase catechol is degraded in the atmosphere by reaction with photochemically-produced hydroxyl radicals(SRC); the half-life for this reaction in air is estimated to be 2.8 hrs(SRC), calculated from its rate constant of 1.04X10-10 cu cm/molecule-sec at 25 °C(3). Catechol in its nonionized form will not be subject to direct photolysis since this form does not absorb light above 300 nm in methanol solution(4). Reaction of catechol with nitrate radicals during nighttime may be an important removal process based on a rate constant of 3.8X10-12 cu cm/molecule sec for the reaction of phenol with nitrate radicals(2) which corresponds to a half-life of 15 minutes at an atmospheric concentration of 2X10+8 nitrate radicals per cu cm(SRC). The ionized form of catechol may photolyze based on an absorption maximum at 313 nm in basic aqueous solution(6) and at 289 nm in basic methanol solution(4). Therefore, catechol may be susceptible Source: Hazardous Substances Data Bank (HSDB)

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
SourceResultChecked
NIH PubChem PUG-ViewExact match2026-08-31

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.

Records for CAS 120-80-9

1 total

How CAS 120-80-9 is used on this site

CAS 120-80-9 is the Chemical Abstracts Service identifier used to pin this page to a specific substance. In the current dataset, 1 EU annex record shares this identifier, which helps you cross-check whether the same substance appears under one regulatory context or several.

Use this page when a supplier specification, SDS or raw-material dossier gives you CAS 120-80-9 and you need to see every linked Annex II–VI record in one place. The entry cards above are the quickest route to concentration limits, warnings, annex placement and product-type conditions.

Frequently asked questions

A substance identified by CAS 120-80-9 may appear in multiple EU cosmetic regulation annexes when it is subject to different conditions in different contexts. For example, a substance might be restricted under Annex III with specific conditions, and the same CAS might also appear in Annex IV as an approved colorant under separate entry conditions. Each entry must be reviewed individually.

Cross-reference the CAS number against your raw material specification sheets and CoA documents. When a CAS appears in Annex II, verify absence. When it appears in Annex III, verify that concentration limits and product type conditions are met in your formulation. All annex entries sharing this CAS number are listed above.

A CAS number is assigned by the Chemical Abstracts Service (USA) and is globally recognised. An EC number is a European Commission identifier from inventories such as EINECS, ELINCS or the NLP list. Both identifiers may appear in EU cosmetic annex entries. Some substances have both, some have only one, and some older entries may have neither.

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