Label abbreviations descriptions

MESITYL OXIDE†

Chemical Identification
CAS # 141-79-7
Formula

C₆H₁₀O
Synonyms

isobutenyl methyl ketone; isopropylideneacetone; methyl isobutenyl ketone; 4-methyl-3-penten-2-one

Physical Properties
Physical description Oily, colorless to light-yellow liquid with a peppermint- or honey-like odor.
Boiling point 266°F Molecular weight 98.2
Freezing point/melting point -52°F Vapor pressure 9 mmHg
Flash point 87°F Vapor density
Specific gravity 0.853 at 68°F Ionization potential 9.08 eV
Lower explosive limit (LEL) 1.4% Upper explosive limit (UEL) 7.2%
NFPA health rating 3 NFPA fire rating 3
NFPA reactivity rating 1 NFPA special instruction
Vapor hazard ratio (VHR)
Historical exceedance percentage
Target organs

Monitoring Methods Used by OSHA
Analyte code (IMIS no.) 1635
Sampling group
Sampler/Sampling media CSC tube (100/50 mg) [SKC 226-01]
Sampling time*
Sampling volume (TWA)*

1-25 L
Sampling flow rate (TWA)*

0.01-0.2 L/min
Sampling volume (STEL/Peak/C)*
 

 
Sampling flow rate (STEL/Peak/C)*
 

 
Analytical method instruments GC-FID
Method reference NIOSH 1301 (fully validated)
Notes
 

 
Special requirements
 

 

* All sampling instructions above are recommended guidelines for OSHA Compliance Safety and Health Officers (CSHOs), please see the corresponding OSHA method reference for complete details.

Bulk/Wipe Method
Wipe Sampler/Sampling media
 

 
Bulk Method
 

 

On-Site Screening Techniques
Device Detector tube Infrared spectrophotometer
Model/Type Matheson-Kitagawa 8014-190U Miran 1A & 1B
Sampling information
(see manufacturer instructions) 		5-100 ppm range 0.8 ppm@8.2 µm

Exposure Limits
OSHA PEL
8-hour TWA
(ST) STEL
(C) Ceiling
Peak
NIOSH REL
Up to 10-hour TWA
(ST) STEL
(C) Ceiling
ACGIH TLV©
8-hour TWA
(ST) STEL
(C) Ceiling
CAL/OSHA PEL
8-hour TWA
(ST) STEL
(C) Ceiling
Peak
PEL-TWA
 

25 ppm (100 mg/m³)

 REL-TWA
 

10 ppm (40 mg/m³)

 TLV-TWA
 

15 ppm [1992]

 PEL-TWA
 

15 ppm (60 mg/m³)
PEL-STEL
 

 

 REL-STEL
 

 

 TLV-STEL
 

25 ppm [1992]

 PEL-STEL
 

25 ppm (100 mg/m³)
PEL-C
 

 

 REL-C
 

 

 TLV-C
 

 

 PEL-C
 

 
Skin notation
 

N

 Skin notation
 

N

 Skin notation
 

N

 Skin notation
 

N
Notes:
 

See 29 CFR 1910.1000 Table Z-1.

 Notes:
 

 

 Notes:
 

 

 Notes:
 

 
Health factors:  See NIH-NLM PubChem. IDLH
 

1400 ppm
Carcinogenic classifications: Not listed Notes:
 

10 % of LEL
AIHA emergency response planning guidelines - ERPG-1/ERPG-2/ERPG-3:
 

 

Additional Resources and Literature References

Last Updated Date : 01/04/2021