2-butanol

floral alcohol

Found in 51 ingredients across the CompKitchen flavor graph.

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

2D Lewis Structure

Formula: C4H10O
Molecular weight: 74.12 g/mol
PubChem CID: 6568 — full record on PubChem

Properties

Odor description: fruity, winey, sweet, oily
Odor threshold — in a food matrix: 18.5 ppb – 405 ppb median 212 ppb · 2 published values · see all 4 with sources
Volatility: high
CAS number: 78-92-2
Retention index: 1027

Regulatory · United States

FEMA GRAS — Generally Recognized As Safe for flavoring use

? Partial match

FEMA number: 4698
GRAS publication: GRAS 25
FEMA primary name: 4-MERCAPTO-3-METHYL-2-BUTANOL

Reported use levels (ppm by food category)

Typical vs maximum reported addition levels in finished food. Use as a regulatory ceiling reference — verify against the current GRAS publication for your product category.

Food category	Typical (ppm)	Maximum (ppm)
baked goods	0.2	0.5
condiments/ relishes	0.2	0.5
gravies	0.2	0.5
meat products	0.2	0.5
poultry	0.2	0.5
processed vegetables	0.2	0.5
seasonings/ flavors	0.2	0.5
snack foods	0.2	0.5
soups	0.2	0.5

Source: FEMA GRAS publications 1-33. 4 related FEMA records for this name — verify the exact substance for regulatory use.

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.

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.

wine Flavornet Cas

—

pine FlavorDB 2.0, Flavordb Odor Column 2 sources agree

sweet FlavorDB 2.0, Flavordb Odor Column 2 sources agree

camphor FlavorDB 2.0, Flavordb Odor Column 2 sources agree

apricot, oily, sweet, wine FlavorDB 2.0

apple, fermented, butter, camphor FlavorDB 2.0

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

4 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

18.5 ppb – 405 ppb

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

Threshold	Matrix	Source	Paper
18.5 ppb	water (food: unknown)	Literature corpus	—
405 ppb	water (food: goat milk)	Literature corpus	—

In air

38.0 ppb – 95499 ppb

Airborne detection — not comparable to a water threshold.

Threshold	Matrix	Source	Paper
38.0 ppb	air	Nagata 2003	—
95499 ppb	air (C2_cometto_muniz_abraham)	Cometto-Muñiz (PMC)	—

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 (211.75 ppb, the engine's canonical value — see the 4 published values). OAV ≥ 1 = perceptible.

Food	Concentration (ppb)	OAV	Source
lime	200000.0	945 ⚡	PMID 41267287
baijiu	8090.0	38.2 ⚡	PMID 36960200
bread	1200.0	5.67	PMID 38840722
cheese	79.0	0.37	—
rice	0.1	0.00	—

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

Found in

Measured impact first, then profile share

Every ingredient known to contain 2-butanol. 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 2-butanol in it. Full concentrations are in the OAV table above.

201 cmpds

295 cmpds

54 cmpds

85 cmpds