Agent Name

Mesityl oxide

CAS Number

141-79-7

Formula

C6-H10-O

Major Category

Other Classes

Synonyms

2,2-Dimethylvinyl methyl ketone; 2-Methyl-2-pentenone-4; 2-Methyl-4-oxo-2-pentene; 3-Isohexen-2-one; 3-Penten-2-one, 4-methyl-; 4-Methyl-3-penten-2-on [Dutch, German]; 4-Methyl-3-penten-2-one; 4-Metil-3-penten-2-one [Italian]; Acetone, isopropylidene-; Isobutenyl methyl ketone; Isopropylidene acetone; Isopropylideneacetone; Mesityl oxide; Mesityloxid [German]; Mesityloxyde [Dutch]; Methyl 2,2-dimethylvinyl ketone; Methyl 2-methyl-1-propenyl ketone; Methyl isobutenyl ketone; Mibk; Ossido di mesitile [Italian]; Oxyde de mesityle [French]; [ChemIDplus] UN1229

Category

Aliphatic Ketones, Other

Description

Oily, colorless to light-yellow liquid with a peppermint- or honey-like odor; [NIOSH]

Sources/Uses

Mesityl oxide has many uses as an industrial solvent. It is used as a paint remover and insect repellent. [ACGIH] Used as a solvent for resins, lacquers, enamels, rubber, inks, and oils; [HSDB]

Comments

Liquid causes first degree burns on short exposure. [CHRIS] Narcosis is induced in acute inhalation studies, and animals develop renal tubular degeneration and hepatic necrosis in subchronic studies. [ACGIH] A lachrymator; [CHEMINFO] A skin irritant and severe eye irritant; [CAMEO]

Exposure Assessment
Skin Designation (ACGIH)

Insufficient data

TLV (ACGIH)

15 ppm

STEL (ACGIH)

25 ppm

PEL (OSHA)

25 ppm

MAK

2 ppm

IDLH (NIOSH)

1400 ppm

Excerpts from Documentation for IDLHs

Human data: The probable response to 100 ppm was predicted to be eye and mucous membrane irritation, difficulty breathing, headache, and vertigo [Shell 1957]. It has been stated that 5,000 ppm might be dangerous to life in 30 to 60 minutes [Smyth et al. 1942].

Vapor Pressure

8.21 mm Hg

Odor Threshold Low

0.01 ppm

Odor Threshold High

12 ppm

Lethal Concentration

LC50 (rat) = 9,000 mg/m3/4H

Explanatory Notes

IDLH = 10% LEL (lower explosive limit); Detection odor threshold from AIHA (mean = 0.017 ppm); Flash point = 31 deg C;

Reference Link

ICSC: Mesityl oxide

Flammability (NFPA)

3: May ignite at ambient temperature

Adverse Effects
Lacrimator

Yes

Neurotoxin

CNS Solvent Syndrome

Hepatotoxin

Hepatotoxin, Secondary

Nephrotoxin

Yes

Dermatotoxin

Skin Burns

Links to Other NLM Databases
Health Studies

Human Health Effects from Hazardous Substances Data Bank:

Toxicity Information

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Chemical Information

Search ChemIDplus

Related Information in HazMap
Diseases

Occupational diseases associated with exposure to this agent:

Processes

Industrial Processes with risk of exposure: