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Flavor ingredients

Methional

Also known as 3-(Methylthio)propionaldehyde, Propanal, 3-(methylthio)-, 4-Thiapentanal

CAS 3268-49-3Formula C4H8OSMolar mass 104.17 g/molEC 221-882-5
GHS signal word: Danger. Pictograms: Flammable, Corrosive, Acute toxicity (severe), Harmful or irritant 27 suppliers listed
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Methional chemical structure, C4H8OS, CAS 3268-49-3
2D chemical structure

Key facts

What buyers check first

All properties
Appearance
Colorless to pale yellow liquid
Melting point
-75 °C
Boiling point
165 °C
Density
Relative density (water = 1): 1.03
Flash point
61 °C
HS code
293090
Category
Flavor ingredients
UN number
UN 2785
Illustrative photo, clear colourless liquid in a glass reagent bottle on a laboratory bench
Typical packagingIllustrative packaging image, not the actual product

What is Methional?

Plain description, key identifiers and synonyms

3-methylthiopropanal is an aliphatic sulfide. It has a role as a prostaglandin antagonist. It is functionally related to a propanal.

Identifiers

Registry numbers, names and line notations, tap to copy

IUPAC name
3-methylsulfanylpropanal
CAS number
3268-49-3 CAS number cross-checked
EC number
221-882-5
Molecular formula
C4H8OS
UNII
0AAO8V0F1R
MDL number
MFCD00007022
InChIKey
CLUWOWRTHNNBBU-UHFFFAOYSA-N
InChI
InChI=1S/C4H8OS/c1-6-4-2-3-5/h3H,2,4H2,1H3
SMILES (canonical and isomeric)
CSCCC=O

Synonyms

  • 3-(Methylthio)propionaldehyde
  • Propanal, 3-(methylthio)-
  • 4-Thiapentanal
  • Propionaldehyde, 3-(methylthio)-
  • 3-Methylmercaptopropyl aldehyde
  • Methylmercaptopropionic aldehyde
  • methylmercaptopropionaldehyde
  • 3-[Methylthio]propionaldehyde
  • Thiapentanal
  • Methyl mercaptopropionaldehyde
  • 3-(Methylthio)propanal
  • 3-methylsulfanylpropanal
  • 3-(Methylsulfanyl)propanal
  • 3-methylthiopropanal
  • 3-(Methylmercapto)propionaldehyde
  • beta-(Methylthio)propionaldehyde
  • 3-Methylthiopropional
  • beta-(Methylmercapto)propionaldehyde
  • 3-methylthiopropionaldehyde
  • 3-Methyl-thiopropanal
  • 3-(Methythio)-propanal
  • 3-(methylthio)-propanal
  • 3-methylsulfanyl-propanal
  • 3-methylthio-propionaldehyde
  • 3-methylmercapto-propionaldehyde
Show all 35 synonyms
  • Methional (natural)
  • Methylmercaptoaldehyde
  • 3-methylthio propanal
  • 3-(Methylthiol)propanal
  • 3-methylthio-1-propanal
  • 3-(Methylthio)-1-propanal
  • 3-(methythio)propionaldehyde
  • 3-(methylthio)propan-1-one
  • Methional, >=97%, FG
  • 3-(Methylsulfanyl)propanal #

Physical and chemical properties

Measured values and descriptors computed from the structure

Physical and chemical properties

Measured values, check the supplier specification for your grade

Appearance
Colorless to pale yellow liquidexp.
Odour
Powerful, onion, meat-like odorexp.
Taste
Pleasant, warm, meat and soup-like flavor at low levelsexp.
Melting point
-75 °Cexp.
Boiling point
165 °Cexp.
Density
Relative density (water = 1): 1.03exp.
Flash point
61 °Cexp.
Autoignition temperature
255 °Cexp.
Solubility
In water, 16.3% vol at 25 °C, pH 7exp.
Vapour pressure
0.397 mm Hg at 25 °Cexp.

Values vary by grade. Ask suppliers for the COA or TDS of the batch you buy.

Computed descriptors

Calculated from the structure, useful for screening and formulation

Molecular weight
104.17 g/molcalc.
Exact mass
104.0296 Dacalc.
LogP (octanol/water)
0.94calc.
Topological polar surface area
17.07 Ųcalc.
Hydrogen bond donors
0calc.
Hydrogen bond acceptors
2calc.
Rotatable bonds
3calc.
Heavy atoms
6calc.
Rings
0calc.
Aromatic rings
0calc.
Fraction sp3 carbons
0.75calc.
Formal charge
0calc.
Stereocentres
0calc.
Lipinski rule of five
Passes (0 violations)calc.

Calculated for screening. Confirm critical figures with the supplier.

Safety and hazards

GHS classification summary, not a safety data sheet

GHS signal word
Danger
GHS02: Flammable
Flammable
GHS05: Corrosive
Corrosive
GHS06: Acute toxicity (severe)
Acute toxicity (severe)
GHS07: Harmful or irritant
Harmful or irritant
200NFPA 704 rating

Hazard statements

  • H226Flammable liquid and vapour.
  • H302Harmful if swallowed.
  • H311Toxic in contact with skin.
  • H315Causes skin irritation.
  • H317May cause an allergic skin reaction.
  • H318Causes serious eye damage.
  • H332Harmful if inhaled.
  • H412Harmful to aquatic life with long lasting effects.
Precautionary statements (32)
  • P210Keep away from heat, hot surfaces, sparks, open flames and other ignition sources. No smoking.
  • P233Keep container tightly closed.
  • P240Ground and bond container and receiving equipment.
  • P241Use explosion-proof electrical, ventilating and lighting equipment.
  • P242Use non-sparking tools.
  • P243Take action to prevent static discharges.
  • P261Avoid breathing dust, fume, gas, mist, vapours or spray.
  • P262Do not get in eyes, on skin, or on clothing.
  • P264Wash skin thoroughly after handling.
  • P264 + P265Wash skin thoroughly after handling. Do not touch eyes.
  • P270Do not eat, drink or smoke when using this product.
  • P271Use only outdoors or in a well-ventilated area.
  • P272Contaminated work clothing should not be allowed out of the workplace.
  • P273Avoid release to the environment.
  • P280Wear protective gloves, protective clothing, eye protection and face protection.
  • P301 + P317If swallowed: Get medical help.
  • P302 + P352If on skin: Wash with plenty of water.
  • P303 + P361 + P353If on skin (or hair): Take off immediately all contaminated clothing. Rinse skin with water or shower.
  • P304 + P340If inhaled: Remove person to fresh air and keep comfortable for breathing.
  • P305 + P354 + P338If in eyes: Immediately rinse with water for several minutes. Remove contact lenses, if present and easy to do. Continue rinsing.
  • P316Get emergency medical help immediately.
  • P317Get medical help.
  • P321Specific treatment (see supplemental first aid instructions on the label).
  • P330Rinse mouth.
  • P332 + P317If skin irritation occurs: Get medical help.
  • P333 + P317If skin irritation or rash occurs: Get medical help.
  • P361 + P364Take off immediately all contaminated clothing. And wash it before reuse.
  • P362 + P364Take off contaminated clothing. And wash it before reuse.
  • P370 + P378In case of fire: Use appropriate media to extinguish.
  • P403 + P235Store in a well-ventilated place. Keep cool.
  • P405Store locked up.
  • P501Dispose of contents and container in accordance with local regulations.
UN number
UN 2785
Transport hazard class
6.1
Packing group
III

GHS classification summary, not a safety data sheet (SDS). Classifications can differ by supplier, grade and concentration. Always check the supplier's SDS.

Full safety data and first aid

Methional suppliers

Sponsored listings first, then the documented ranking: membership, verification, replies, completeness, freshness and ratings

All 27 suppliers
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Where suppliers are based

27 suppliers in 5 countries

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Methional price

Indicative price range per kg from live supplier offers

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Uses and applications

What the substance is used for, by industry and function

Reported uses (ppm):

Table: Reported uses (ppm): (Flavor and Extract Manufacturers' Association, 1994) [Table#8611].

The vast majority of 3-(methylthio) propionaldehyde is used as intermediate in chemical industry for the production of the amino acid methionine and methionine-hydroxyl analoge. A minor use of 3-(methylthio) propionaldehyde as a food flavoring agent has been identified.

Industrial uses: Intermediate.

Pharmacological actions

  • Prostaglandin Antagonists

Roles

  • antagonist
  • hormone antagonist
  • hormone receptor modulator
  • pharmaceutical
  • prostaglandin antagonist
  • receptor modulator

Functional uses

  • Flavouring and nutrient
  • Fragrance

How it is made

The production of 3-(methylthio) propionaldehyde by reaction of acrolein with methylmercaptan is conducted in a closed reaction vessel followed by a distillative purification. The separated light and high boiler products are fed into a thermal oxidizer.

By transamination and decarboxylation of various amino acids, by oxidation of alcohol.

Regulatory status

Inventories, regulations and trade controls that list this substance

United States

  • TSCA inventory (USA)
    Status: Active in US commerce

HS code and trade data

Customs classification and reported world trade statistics

Global trade

World import and export statistics for the HS code Methional is traded under.

HS 2930.90Indicative HS code

Organo-sulphur compounds, other

World exports in 2024
$5.83B
+0.1% vs 2023, imports $5.93B
2019 to 2024
Top exporters
  1. China40.7%
  2. United States10.9%
  3. Japan9.3%
Top importers
  1. United States13.3%
  2. Brazil12.6%
  3. China6.6%
Reported customs values in USD, not prices.Full trade data

The HS code shown for Methional is indicative (it was assigned by structure rules). Confirm the classification with your customs broker before shipping.

Frequently asked questions

Quick answers about Methional, based on the data on this page

What is Methional?

3-methylthiopropanal is an aliphatic sulfide. It has a role as a prostaglandin antagonist. It is functionally related to a propanal.

What is the CAS number of Methional?

The CAS registry number of Methional is 3268-49-3.

What is the molecular formula and weight of Methional?

The molecular formula of Methional is C4H8OS and its molar mass is 104.17 g/mol.

What is Methional used for?

Reported uses (ppm): Table: Reported uses (ppm): (Flavor and Extract Manufacturers' Association, 1994) [Table#8611]. The vast majority of 3-(methylthio) propionaldehyde is used as intermediate in chemical industry for the production of the amino acid methionine and methionine-hydroxyl analoge.

Is Methional hazardous?

Methional carries the GHS signal word "Danger". Main hazards: flammable liquid and vapour, harmful if swallowed, toxic in contact with skin. This summary is not an SDS, always read the supplier safety data sheet.

What is the HS code of Methional?

Methional is usually classified under HS code 293090 (Organo-sulphur compounds, other). This is indicative, confirm it with your customs broker before shipping.

Where can I buy Methional?

CompoundList lists 27 suppliers of Methional in China, United States, Germany, Egypt and 1 more. Send one free request to get and compare quotes. Your contact details stay private until you accept a quote.

What is the price of Methional?

Suppliers quote Methional on request because prices depend on grade, purity, quantity and destination. A free request on CompoundList gets you several quotes to compare.

Guides for buyers

Practical guides that help when you source, ship or handle Methional

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Data last updated 7 Oct 2026. Details may have changed, please confirm them with the supplier. Report an error on this page
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