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1,2-propanediol

chemical oxygenated compound

Found in 16 ingredients across the CompKitchen flavor graph.

Look up another compound — search by name, CAS number, PubChem CID, or FEMA #.

2D Lewis structure of 1,2-propanediol
2D Lewis Structure
Formula
C3H8O2
Molecular weight
76.09 g/mol
PubChem CID
1030 — full record on PubChem

Properties

Odor description
odorless, faint, alcoholic
Odor threshold — in a food matrix
117 ppb – 1594 ppb median 856 ppb · 2 published values · see all 2 with sources
Volatility
high
Retention index
758
Not in FEMA GRAS publications 1-33. Of 3,367 listed flavoring substances, none match this compound name. May still be food-safe under other regulatory routes (FDA 21 CFR 172, EFSA, JECFA) — check femaflavor.org for the authoritative current list.

How this molecule is described

Sources disagree about odour more often than they disagree about chemistry. Rather than show one answer, here is every description on file with how many ingredient records carry it.

Also filed as
propylene glycol

Same molecule, unified here — previously counted and displayed as separate compounds.

Descriptions on file

Ordered by how many independent descriptor streams give each wording, then by how often it appears. The bar is still replication — one source copied onto many ingredients scores high there — so the two can disagree.

chemical FlavorDB 2.0, Flavordb Odor Column 2 sources agree
1
alcoholic, odorless, very slight FlavorDB 2.0
7
solvent, chemical, fruity, burnt FlavorDB 2.0
4
chemical, fatty, fruity, burnt FlavorDB 2.0
1
odorless, faint, alcoholic shown above Llm Adjudicated
—
fruity, burnt Flavordb Odor Column
—

Bars are the share of ingredient records carrying each description. High agreement means the sources replicate each other — not necessarily that they are right.

Published thresholds

2 measured values from the literature. Grouped by what was actually measured — a threshold smelled in clean water, tasted in the mouth, or measured in a real food are three different quantities and are not pooled.

In a food matrix

117 ppb – 1594 ppb

Measured in a real food, where the matrix shifts detection — not a clean-water value.

Threshold Matrix Source Paper
117 ppb SIDA water (food: unknown) Literature corpus 40401362, 25829605, 26283896 +1
1594 ppb SIDA water (food: olive oil) Literature corpus 40401362, 25829605, 26283896 +1

Only values we can attribute are listed. Where a compendium's licence does not permit public attribution its figures are omitted here, so every number on this page traces to a citable source.

Where you'd actually smell it

Odor Activity Value = measured concentration ÷ odor threshold (60.0 ppb, the engine's canonical value — see the 2 published values). OAV ≥ 1 = perceptible.

Food Concentration (ppb) OAV Source
olive oil 1586.0 26.4 ⚡ —
bread 1200.0 20.0 ⚡ —

Concentrations from PubMed Central Open Access papers (free literature corpus, MIT-style licensed). Copper = OAV ≥ 10 (strongly perceptible). Green = OAV ≥ 1 (perceptible).

These OAVs depend on which threshold you divide by. Published values for this molecule span 60–3.36e+06 ppb and the column above uses the lowest, which makes every OAV as large as it can be. At the high end each figure would be 56000× smaller, and rows near the line would cross it. Read the colours as “worth a look”, not as a measurement.

Found in

Measured impact first, then profile share

Every ingredient known to contain 1,2-propanediol. Ingredients with a measured concentration come first, ranked by odour activity; the rest follow by how large a share of that ingredient's profile this molecule is. The figure beside each is how many different compounds that ingredient has in total — not the concentration of 1,2-propanediol in it. Full concentrations are in the OAV table above.

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