Agent Name


CAS Number




Major Category

Other Classes


2,3-Pentadione; Acetyl propionyl; Acetyl propionyl (natural); Acetylpropionyl; [ChemIDplus] UN1224


Aliphatic Ketones, Other


Colorless to dark yellow liquid with a pleasant buttery odor; [Reference #1] Yellow liquid; [Alfa Aesar MSDS]


Used as flavoring agent or adjuvant; [FDA] Used as a substitute for diacetyl in food flavoring and food production; [Reference #1]


A moderate skin irritant; [RTECS] Safe when used as a flavoring agent in food; [JECFA] Due to structural similarities with diacetyl, there are concerns that occupational exposure may lead to a decline in pulmonary function; Airway epithelial damage demonstrated in rats is similar to that caused by diacetyl; [Reference #1] A skin and strong eye irritant; [Alfa Aesar MSDS] See "Diacetyl." See "2,4-Pentanedione."

Reference Link

CDC/NIOSH: Criteria for a Recommended Standard: Occupational Exposure to Diacetyl and 2,3-Pentanedione - 2011

Exposure Assessment
Vapor Pressure

21.4 mm Hg

Odor Threshold Low

0.00002 ppm

Explanatory Notes

Odor threshold from Reference #1; The Guide in the Emergency Response Guidebook is for "Ketones, liquid, n.o.s."

Links to Other NLM Databases
Toxicity Information

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