SHEET /m/coumarin · PubChem CID 323 · CAS 91-64-5 · REV 2026.07
Coumarin
from sourceC9H6O2 · 146.14 g/mol
Benzo-alpha-pyrone · O-Hydroxyzimtsaure-lacton · O-Hydroxycinnamic lactone · Rattex
What is Coumarin?
The smell of fresh-cut hay, sweet clover, and tonka bean. It is banned as a food additive in the US because high doses damage the liver in animals. from source
Fig. 1 · 2D structure RDKit
C1=CC=C2C(=C1)C=CC(=O)O2The dose makes the poison inferred
A reported rat oral LD50 for Coumarin is 293 mg/kg, the dose lethal to half the animals tested. Scaled by body mass alone:
“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
293 mg/kg · moderately toxic · LD50 rat oral from source
The dose lens above scales this to a body weight.
4 more reported values
- 196 mg/kgLD50 · oral · mouse
- 202 mg/kgLD50 · oral · guinea pig
- 220 mg/kgLD50 · other · mouse
- 242 mg/kgLD50 · other · mouse