Methyl (Methylthio)Acetate (CAS 16630-66-3) — Top Note Fragrance Ingredient
Methyl (Methylthio)Acetate
CAS 16630-66-3
What Is Methyl (Methylthio)Acetate?
Methyl (Methylthio)Acetate (CAS 16630-66-3) is an aroma chemical used as a fragrance and flavour ingredient. Its odour is described as sweet, fruit and fish, placing it within the fruity family as a top note with high volatility. With a molecular weight of 120.2 (formula C4H8O2S), it is handled by perfumers as a building block for compositions where a sweet character is desired. The data below is compiled from public chemical and regulatory sources.
Safety Profile
HANDLE WITH CARE
What Does Methyl (Methylthio)Acetate Smell Like?
The odour profile of Methyl (Methylthio)Acetate is reported as sweet, fruit, fish, garlic, spices, cold, sour, burnt, acid, warm, musky, sweaty, ammonia/urinous, decayed, grass, flower, chemical, edible. The dominant facet is its sweet character, with the remaining notes adding nuance and complexity. As a top note it contributes to the opening of a fragrance. Perceived intensity and exact character depend on concentration, the carrier and the surrounding accord.
Scent Profile
Profile derived from public odour-descriptor data; relative, not absolute.
Chemistry & Properties
The Chemistry
Methyl (Methylthio)Acetate has the molecular formula C4H8O2S and a molecular weight of 120.2 g/mol. Its canonical SMILES representation is COC(=O)CSC. Its reported log P (XLogP) of 0.5224 indicates a moderately polar molecule, which informs how it partitions in a formula. Physical constants below are drawn from PubChem and EPA CompTox public datasets.
Physical & Chemical Properties
| Molecular Weight | 120.2 g/mol |
|---|---|
| Boiling Point | 152.0 °C |
| Melting Point | -30.19 °C |
| Flash Point | 50.38 °C |
| Density | 1.11 g/cm³ |
| Vapor Pressure | 5.75 mmHg |
| Water Solubility | 0.195 g/L |
| XLogP | 0.5224 |
Perfumer Guide
Alternatives & Comparisons
Ingredients occupying a similar odour space — useful as substitutes or companions when Methyl (Methylthio)Acetate is unavailable or restricted.
Shares bakery, sweet, fruit character — a candidate substitute or companion in the same odour space.
Shares sour, sweet, fruit character — a candidate substitute or companion in the same odour space.
Shares bakery, sweet, fruit character — a candidate substitute or companion in the same odour space.
Safety & Regulatory
⚠ Regulatory Disclaimer
General reference only. IFRA, REACH and EU Cosmetics Regulation standards update periodically. Consult the current IFRA Standards Library before formulating. Not legal or regulatory advice.
IFRA Status
No IFRA restriction recorded in the data set. This is not a guarantee of unrestricted status — always confirm against the current IFRA Standards Library.
GHS Classification
Signal word: Danger
Open Methyl (Methylthio)Acetate in Fragrance Studio (Pro) for the calibrated vapour-pressure curve, the modelled odour-threshold estimate, and the substitute-matching engine across 2,900+ aromachemicals.
References & Sources
- PubChem Compound Summary (NIH) — search by InChIKey
- EPA CompTox Chemicals Dashboard — physicochemical & fate data
- IFRA Standards Library (49th / 51st Amendment)
Data: PubChem (NIH), EPA CompTox, IFRA. Last reviewed: Jun 2026.
Related Research
- 1,5-Dimethylhexyl acetate (CAS 67952-57-2) — Citrus Top to Mid Note Fragrance Ingredient
- 1,3-Dimethylbutyl 2-butenoate (CAS 35206-51-0) — Sweet Top to middle Note Fragrance Ingredient
- 2-Cyclopenten-1-one, 2-hydroxy-3,4-dimethyl- (CAS 21835-00-7) — Woody Middle Note Fragrance Ingredient
- 2-sec-Butylcyclohexanone (CAS 14765-30-1) — Woody Base Note Fragrance Ingredient
