Agent Name

Methyl ethyl ketoxime

Alternative Name

2-Butanone oxime

CAS Number

96-29-7

Formula

C4-H9-N-O

Major Category

Nitrogen Compounds

Synonyms

2-Butanone oxime; Butanone oxime; Ethyl methyl ketone oxime; Ethyl methyl ketoxime; Ethyl-methylketonoxim [Czech]; MEK-oxime; Methyl ethyl ketone oxime; Skino #2; Troykyd anti-skin B; [ChemIDplus] MEKO; [AIHA] UN1993

Category

Oximes

Description

Colorless liquid with a musty odor; [CAMEO]

Sources/Uses

Used as an anti-skinning agent in alkyd paints; Also used as a blocking agent (urethane polymers) and a corrosion inhibitor (boilers); [AIHA]

Comments

A skin sensitizer; [Quick CPC] Dermal sensitization, hemolytic anemia, and CNS depression reported in animal studies; Hemolytic effects were seen in a 4-week inhalation study at 533 ppm, but not at 283 ppm; MEKO has been produced since 1958, and no adverse effects in workers have been reported; Painters using alkyd paints containing MEKO were exposed at levels <1-2 ppm; [AIHA] 8-hour exposure of 12 rats to saturated atmosphere caused no mortalities; Hematological changes (increased methemoglobin and reticulocytes and decreased hemoglobin) observed in 4-week inhalation study of rats at 400 ppm; In a 13-week oral neurotoxicity study of rats, transient neurobehavioral changes were observed immediately following administration, but reversed by the next day; No progressive long term neurotoxicity observed; [IUCLID]

Exposure Assessment
WEEL

10 ppm

Vapor Pressure

0.9 mm Hg

Lethal Concentration

LC50 (rat) > 1350 ppm/4hr

Explanatory Notes

LC50 (rat) > 50,000 mg/m3/4hr; [ChemIDplus] The Guide in the Emergency Response Guidebook is for "Flammable liquid, n.o.s."

Flammability (NFPA)

2: High ambient temperature required

Adverse Effects
Skin Sensitizer

Yes

Anemia

Anemia, Hemolytic

Neurotoxin

Other CNS Neurotoxin

Methemoglobinemia

Methemoglobinemia, Secondary

Links to Other NLM Databases
Toxicity Information

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Chemical Information

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Related Information in HazMap
Diseases

Occupational diseases associated with exposure to this agent:

Processes

Industrial Processes with risk of exposure: