methyl 3-(methyl thio) propionate

Methyl 3-(methyl thio) propionate is a sulfur-containing organic ester with the molecular formula C₅H₁₀O₂S. This compound appears as a clear liquid and exhibits a distinctive sulfurous odor profile characterized by vegetative, garlic, onion, and tomato notes, often described as alliaceous and sweet. It is also associated with tropical and fruity facets reminiscent of mango, papaya, and pineapple. Known under synonyms including methyl 3-(methylthiopropionate) and methyl 3-(methylmercapto)propionate, it is naturally found in tropical fruits such as naranjilla and pineapple, as well as in white wines. This volatile ester is referenced in controlled-vocabulary databases like PubChem. Industrially, it is synthesized or extracted for use primarily in flavor and fragrance formulations to impart sulfurous and fruity complexity.

Methyl 3-(methyl thio) propionate occurs naturally in various tropical fruits including naranjilla and pineapple, as well as in fermented products like white wine. Its biological presence contributes to the characteristic aroma and flavor profiles of these sources. Owing to its unique sulfurous and vegetative sensory qualities, this compound is utilized as a flavoring and fragrance agent. It is valued for enhancing notes of garlic, onion, horseradish, tropical fruits, and tomato in diverse applications. Regulatory bodies such as FEMA (US) recognize it as a generally recognized as safe (GRAS) flavoring substance, with usage levels specified to ensure consumer safety. Its inclusion in flavor and fragrance formulations is carefully controlled to maintain desired sensory effects without overpowering other components.

Methyl 3-(methyl thio) propionate is an ester with moderate volatility, demonstrated by a vapor pressure of 0.735 mmHg at 25 °C and a boiling point range of 180 to 182 °C at atmospheric pressure. It has a specific gravity near 1.07 at 25 °C and a refractive index between 1.46 and 1.468 at 20 °C, indicating a clear liquid state under ambient conditions. The compound exhibits a slightly positive log P value (~0.84 estimated), indicating moderate lipophilicity, which favors solubility in organic solvents like alcohol and dipropylene glycol while being very slightly soluble in water. Its flash point is 162 °F (approximately 72 °C), suggesting it is stable under typical handling conditions. The presence of sulfur influences its characteristic odor and potential reactivity, but it remains stable in most media commonly used in flavor and fragrance formulations.

(IUPAC):	Atomic Weights of the Elements 2011 (pdf)
Videos:	The Periodic Table of Videos
tgsc:	Atomic Weights use for this web site
(IUPAC):	Periodic Table of the Elements
FDA Substances Added to Food (formerly EAFUS):	View
CHEMBL:	View
HMDB (The Human Metabolome Database):	HMDB34377
FooDB:	FDB012754
YMDB (Yeast Metabolome Database):	YMDB01750
Export Tariff Code:	2930.90.9190
VCF-Online:	VCF Volatile Compounds in Food
ChemSpider:	View
FAO:	Methyl 3-methylthiopropionate

Safety information

Preferred SDS: View
European information :
Most important hazard(s):
Xi - Irritant
R 36/37/38 - Irritating to eyes, respiratory system, and skin. S 02 - Keep out of the reach of children. S 24/25 - Avoid contact with skin and eyes. S 26 - In case of contact with eyes, rinse immediately with plenty of water and seek medical advice. S 36 - Wear suitable protective clothing.
Hazards identification
Classification of the substance or mixture
GHS Classification in accordance with 29 CFR 1910 (OSHA HCS)
None found.
GHS Label elements, including precautionary statements
Pictogram
Hazard statement(s)
None found.
Precautionary statement(s)
None found.
Oral/Parenteral Toxicity:
Not determined
Dermal Toxicity:
Not determined
Inhalation Toxicity:
Not determined

Safety in use information

Category:
flavor and fragrance agents
RIFM Fragrance Material Safety Assessment: Search
IFRA Code of Practice Notification of the 49th Amendment to the IFRA Code of Practice
Recommendation for methyl 3-(methyl thio) propionate usage levels up to:
	0.2000 % in the fragrance concentrate.
Maximised Survey-derived Daily Intakes (MSDI-EU):		94.00 (μg/capita/day)
Structure Class:		I
Use levels for FEMA GRAS flavoring substances on which the FEMA Expert Panel based its judgments that the substances are generally recognized as safe (GRAS).
The Expert Panel also publishes separate extensive reviews of scientific information on all FEMA GRAS flavoring substances and can be found at FEMA Flavor Ingredient Library
publication number: 3
Click here to view publication 3
		average usual ppm	average maximum ppm
baked goods:		-	1.00000
beverages(nonalcoholic):		-	0.35000
beverages(alcoholic):		-	-
breakfast cereal:		-	-
cheese:		-	-
chewing gum:		-	-
condiments / relishes:		-	-
confectionery froastings:		-	-
egg products:		-	-
fats / oils:		-	-
fish products:		-	-
frozen dairy:		-	0.37000
fruit ices:		-	0.37000
gelatins / puddings:		-	-
granulated sugar:		-	-
gravies:		-	-
hard candy:		-	0.74000
imitation dairy:		-	-
instant coffee / tea:		-	-
jams / jellies:		-	-
meat products:		-	-
milk products:		-	-
nut products:		-	-
other grains:		-	-
poultry:		-	-
processed fruits:		-	-
processed vegetables:		-	-
reconstituted vegetables:		-	-
seasonings / flavors:		-	-
snack foods:		-	-
soft candy:		-	-
soups:		-	-
sugar substitutes:		-	-
sweet sauces:		-	-

Safety references

European Food Safety Athority(EFSA):Flavor usage levels; Subacute, Subchronic, Chronic and Carcinogenicity Studies; Developmental / Reproductive Toxicity Studies; Genotoxicity Studies...

European Food Safety Authority (EFSA) reference(s):

Flavouring Group Evaluation 8 (FGE.08)[1]: Aliphatic and alicyclic mono-, di-, tri-, and polysulphides with or without additional oxygenated functional groups from chemical group 20 View page or View pdf

Flavouring Group Evaluation 8, Revision 1 (FGE.08Rev1): Aliphatic and alicyclic mono-, di-, tri-, and polysulphides with or without additional oxygenated functional groups from chemical groups 20 and 30 View page or View pdf

Scientific Opinion on Flavouring Group Evaluation 8, Revision 3 (FGE.08Rev3): Aliphatic and alicyclic mono-, di-, tri-, and polysulphides with or without additional oxygenated functional groups from chemical groups 20 and 30 View page or View pdf

Scientific Opinion on Flavouring Group Evaluation 08, Revision 4 (FGE.08Rev4): Aliphatic and alicyclic mono-, di-, tri-, and polysulphides with or without additional oxygenated functional groups from chemical groups 20 and 30 View page or View pdf

Scientific Opinion on the safety and efficacy of aliphatic and aromatic mono- and di-thiols and mono-, di-, tri-, and polysulphides with or without additional oxygenated functional groups (chemical group 20) when used as flavourings for all animal species View page or View pdf

EPI System: View

AIDS Citations:Search

Cancer Citations:Search

Toxicology Citations:Search

EPA Substance Registry Services (TSCA):13532-18-8

EPA ACToR:Toxicology Data

EPA Substance Registry Services (SRS):Registry

Laboratory Chemical Safety Summary :61641

National Institute of Allergy and Infectious Diseases:Data

WGK Germany:3

methyl 3-methylsulfanylpropanoate

Chemidplus:0013532188