Furfural

from source

C5H4O2 · 96.08 g/mol

Furaldehyde · Furol · a-Furole · Furyl-methanal

What is Furfural?

The almond-and-bread smell that forms when bran, corn cobs, or oat hulls are heated with acid. It also builds up in stale coffee and old wine. Found in coffee and spirits. from source

CategoryFood & flavor

Chemical familyAldehydes

LeaderboardsBiggest Deadliest

Fig. 1 · 2D structure RDKit

SMILESC1=COC(=C1)C=O

Where you'll find it

Coffeewhat else is in it →Spiritswhat else is in it →

Curated by MoleculeFinder from source

The dose makes the poison inferred

A reported rat oral LD50 for Furfural is 127 mg/kg, the dose lethal to half the animals tested. Scaled by body mass alone:

your weight154 lb

8.9 g

a median lethal dose scaled to 154 lb (8,890 mg)

“The dose makes the poison” is a cross-species estimate shown as neutral science, not a threshold anyone should act on. Real toxicity depends on the person, not body mass alone.

Toxicity & hazards

Toxicity · LD50

127 mg/kg · moderately toxic · LD50 rat oral from source

The dose lens above scales this to a body weight.

1 more reported value

950 mg/kgLD50 · oral · dog

DangerFlammableToxicIrritantHealth hazardH226, H301, H311, H312, H315, H319, H330, H331, H335, H351, H370, H372, H373, H402, H412from source

Sources & methodology

PubChem CID: 7362
Wikidata: Q412429
Structure: PubChem → RDKit
LD50: PubChem
Everyday relationships: MoleculeFinder editorial curation
Data refreshed: October 19, 2026

How MoleculeFinder sources and labels its data