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CAS 1 record

CAS 121-33-5

CAS 121-33-5 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 121-33-5
CAS 121-33-5PubChem CID 1183

Vanillin

Vanillin is a member of the class of benzaldehydes carrying methoxy and hydroxy substituents at positions 3 and 4 respectively. It has a role as an antioxidant, a flavouring agent, an anticonvulsant, an anti-inflammatory agent and a plant metabolite. It is a member of benzaldehydes, a monomethoxybenzene and a member of phenols. — ChEBI

IUPAC name
4-hydroxy-3-methoxybenzaldehyde
Molecular formula
C8H8O3
Molecular weight
152.15 g/mol
Exact mass
152.047344113 Da
XLogP3
1.2
Topological polar surface area
46.5 Ų
Hydrogen-bond donors
1
Hydrogen-bond acceptors
3
Covalent units
1
Defined stereocentres
0

Also known as

Vanillic aldehydeVanillaldehydep-VanillinVanillineLioxin3-Methoxy-4-hydroxybenzaldehyde4-Hydroxy-3-methoxy-benzaldehydeBenzaldehyde, 4-hydroxy-3-methoxy-
16 more reported names
4-Hydroxy-m-anisaldehyde2-Methoxy-4-formylphenolZimcop-Hydroxy-m-methoxybenzaldehyde4-Formyl-2-methoxyphenolMethylprotocatechuic aldehyde4-Hydroxy-5-methoxybenzaldehydem-Anisaldehyde, 4-hydroxy-Protocatechualdehyde, methyl-RhovanilFEMA No. 3107vanilineProtocatechualdehyde 3-methyl etherOleoresin vanillam-Methoxy-p-hydroxybenzaldehydeVanillin Melting Point Standard
Open full PubChem recordPubChem annotations3D structure image
External database identifiers

Evidence from additional scientific databases

NIH PubChem PUG-View
Exact identifier match1183

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. 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
  • Note: This chemical does not meet GHS hazard criteria for 1.8% (42 of 2387) of reports. Source: European Chemicals Agency (ECHA)
  • Signal: Warning Source: European Chemicals Agency (ECHA)
  • GHS Hazard Statements: H317 (14.3%): May cause an allergic skin reaction [Warning Sensitization, Skin]; H319 (83.5%): Causes serious eye irritation [Warning Serious eye damage/eye irritation] Source: European Chemicals Agency (ECHA)
  • 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: European Chemicals Agency (ECHA)
  • ECHA C&L Notifications Summary: Aggregated GHS information provided per 2387 reports by companies from 28 notifications to the ECHA C&L Inventory. Each notification may be associated with multiple companies.; Reported as not meeting GHS hazard criteria per 42 of 2387 reports by companies.; There are 27 notifications provided by 2345 of 2387 reports by companies with hazard statement code(s).; 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: H302 (100%): Harmful if swallowed [Warning Acute toxicity, oral]; H411 (100%): Toxic to aquatic life with long lasting effects [Hazardous to the aquatic environment, long-term hazard] Source: European Chemicals Agency (ECHA)
  • Precautionary Statement Codes: P264, P270, P273, P301+P317, P330, P391, 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)
  • Signal: Warning Source: NITE-CMC
  • GHS Hazard Statements: H320: Causes eye irritation [Warning Serious eye damage/eye irritation]; H402: Harmful to aquatic life [Hazardous to the aquatic environment, acute hazard] Source: NITE-CMC
  • Precautionary Statement Codes: P264+P265, P273, P305+P351+P338, P337+P317, and P501 (click each P-code to see the statement) Source: NITE-CMC
  • Signal: Warning Source: Hazardous Substances Data Bank (HSDB)
  • Toxicity Summary: IDENTIFICATION: Small quantities of vanillin are used in perfumery to round and fix sweet, balsamic fragrances. Vanillin is also used as a brightener in galvanotechnical processes and is an important intermediate in, for example, the production of pharmaceuticals such as l-3,4-dihydroxyphenylalanine (l-DOPA) and methyldopa. For vanillin (USEPA/OPP Pesticide Code: 115801) there are 0 labels match. /Not registered for current use in the U.S., but approved pesticide uses may change periodically and so federal, state and local authorities must be consulted for currently approved uses./ Pharmaceutic aid (flavor). As a flavoring agent in confectionery, beverages, foods and animal feeds. Fragrance and flavor in cosmetics. Reagent for synthesis. HUMAN EXPOSURE AND TOXICITY: In closed-patch tests on human skin vanillin caused no primary irritation when tested at concentrations of 20% on 29 normal subjects, at 2% on 30 normal subjects, and at 0.4% on 35 subjects with dermatoses. Maximization tests were conducted on groups of 25 volunteers. The material was tested at concentrations of 2 and 5% in petrolatum and produced no sensitization reactions. Vanillin was considered to be a secondary all Source: Hazardous Substances Data Bank (HSDB)
  • Environmental Bioconcentration: An estimated BCF of 3 was calculated in fish for vanillin(SRC), using a log Kow of 1.37(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 vanillin is expected to have very high mobility in soil(SRC). The pKa of vanillin is 7.4(3), indicating that this compound will exist partially in the 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 the neutral species from moist soil surfaces is not expected to be an important fate process(SRC) given an estimated Henry's Law constant of 2.2X10-9 atm-cu m/mole(SRC), based upon its vapor pressure, 1.18X10-4 mm Hg(5), and water solubility, 1.102X10+4 mg/L(6). Vanillin is not expected to volatilize from dry soil surfaces(SRC) based upon its estimated vapor pressure(5). A 97% of theoretical BOD using activated sludge in the Japanese MITI test(7) suggests that biodegradation is an important environmental fate process in soil(SRC). 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 vanillin 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 2.2X10-9 atm-cu m/mole(4) derived from its vapor pressure, 1.18X10-4 mm Hg(4), and water solubility, 1.102X10+4 mg/L(5). According to a classification scheme(6), an estimated BCF of 3(SRC), from its log Kow of 1.37(7) and a regression-derived equation(2), suggests the potential for bioconcentration in aquatic organisms is low(SRC). A 97% of theoretical BOD using activated sludge in the Japanese MITI test(8) suggests 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), vanillin, which has a vapor pressure of 1.18X10-4 mm Hg at 25 °C(2), will exist in both the vapor and particulate phases in the ambient atmosphere. Vapor-phase vanillin 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 14 hours(SRC), calculated from its rate constant of 2.7X10-11 cu cm/molecule-sec at 25 °C(SRC) that was derived using a structure estimation method(3). Particulate-phase vanillin may be removed from the air by wet and dry deposition(SRC). Vanillin contains chromophores that absorb at wavelengths >290 nm(4) and, therefore, may be susceptible to direct photolysis by sunlight(SRC). Source: Hazardous Substances Data Bank (HSDB)
  • Sources/Uses: Found in foods and plants; Used as a flavoring agent and fragrance; [Merck Index] Used as a chemical intermediate, fuel additive, odor agent, and anti-UV agent; [IUCLID] In the group of essential oils with active product registrations in the US for uses as insect feeding depressants, insecticides, and repellants; Used to control clothes moths and fleas; [EPA REDs] Used in attractants for the control of flies, roaches, and crickets; [HSDB] Source: Haz-Map, Information on Hazardous Chemicals and Occupational Diseases
  • Industrial Processes with risk of exposure: Farming (Pesticides) [Category: Industry] Source: Haz-Map, Information on Hazardous Chemicals and Occupational Diseases
  • Uses: For vanillin (USEPA/OPP Pesticide Code: 115801) there are 0 labels match. /SRP: Not registered for current use in the U.S., but approved pesticide uses may change periodically and so federal, state and local authorities must be consulted for currently approved uses./ Source: Hazardous Substances Data Bank (HSDB)
  • Uses: Pharmaceutic aid (flavor). As a flavoring agent in confectionery, beverages, foods and animal feeds. Fragrance and flavor in cosmetics. Reagent for synthesis. Source: Hazardous Substances Data Bank (HSDB)
  • Uses: Source of L-dopa. Source: Hazardous Substances Data Bank (HSDB)
  • Uses: The single largest use for vanillin is as a starting material for the manufacture of an antihypertensive drug having the chemical name of methyldopa or L-3-(3,4-dihydroxyphenyl)-2-methylalanine. Source: Hazardous Substances Data Bank (HSDB)
  • Uses: For more Uses (Complete) data for VANILLIN (8 total), please visit the HSDB record page. 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 2026-09-02 by checksum-valid CAS matching. Chemical properties do not replace the regulatory decision on this page.

Records for CAS 121-33-5

1 total
Annex
III
Entry
346

Vanillin

4-Hydroxy- 3-methoxybenz- aldehyde

The presence of the substance shall be indicated in the list of ingredients referred to in Article 19(1), point (g), when its concentration exceeds: — 0,001 % in leave-on products — 0,01 % in rinse-off products.

EC
204-465-2

How CAS 121-33-5 is used on this site

CAS 121-33-5 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 121-33-5 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 121-33-5 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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