2-Butanone peroxide (CAS 1338-23-4)
2-Butanone peroxide (CAS 1338-23-4) is an organic peroxide compound with molecular formula C8H18O6 and molecular weight 210.22. Also known as 2-BUTANONE PEROXIDE, METHYL ETHYL KETONE PEROXIDE, Methyl methyl ketone peroxide. It typically appears in oily liquid form.
Methyl Ethyl Ketone Peroxide (MEKP) is one of the most critical room-temperature curing agents in the fiberglass reinforced plastics (FRP) and unsaturated polyester resin (UPR) industries. Typically used in conjunction with a cobalt accelerator, it can rapidly initiate the crosslinking and curing of resins at room temperature. It is widely applied in yacht manufacturing, anti-corrosion pipes, wind turbine blades, automotive parts, and crafts casting. Its low viscosity and ease of handling make it the preferred choice for hand lay-up and spray-up molding processes.
Below you can find its complete physical and chemical properties, safety data, GHS hazard classifications, and a catalog of 226 products from 12 manufacturers.
CAS 1338-23-4 is also known as:
- 2-BUTANONE PEROXIDE
- METHYL ETHYL KETONE PEROXIDE
- Methyl methyl ketone peroxide
CAS Number
1338-23-4
Molecular Formula
C8H18O6
Molecular Weight
210.22
EINECS Number
215-661-2
MDL Number
MFCD00042641
BRN Number
1799831
Chemical Name
2-Butanone peroxide
Last Updated
7/28/2025
Aliases
Appearance
Colorless oily liquid with a strong, pungent odor
Appearance State
Oily liquid. Slightly soluble in water, miscible with many organic solvents.
Color
Colorless
Odor
Pungent odor
Form
Oily Liquid
Melting Point
110
Boiling Point
110 (dec.)
Flash Point
ca. 87.8
Density
1.053 @ 20 °C
Vapor Density
3.9 (air=1)
Vapor Pressure
0.644-73.6 Pa @ 25°C
Refractive Index
1.455 (20°C D)
LogP Value
0.3 @ 25 °C
Merck Index
6173
Solubility
Insoluble in water, soluble in alcohol, ether, benzene.
Water Solubility
0.1-0.5 g/100 mL @ 22°C
Solubility Detail
Insoluble in water, soluble in alcohol, ether, benzene.
Storage Conditions
Store at 2-8°C.
InChI Key
WFUGQJXVXHBTEM-UHFFFAOYSA-N
GHS Hazard Symbols
Hazard Class
Signal Word
Danger
Hazard Symbols
O
Risk Codes
R7, R8, R9, R22, R23, R34, R35, R41, R43
UN Number
UN 3105
IARC Classification
Group 3
WGK Germany
1
RTECS Number
-
Auto-ignition Temperature
249
TSCA Listed
Listed (Active)
Packing Group
II
Customs Code
29096000
Occupational Exposure Band (OEB)
Not Specified
Occupational Exposure Limit (OEL)
ACGIH C: 0.2 ppm
Immediately Dangerous to Life or Health (IDLH)
75 ppm
Hazard Statements
H226,H242,H302,H314Precautionary Statements
P220,P280,P305+P351+P338,P310,P403+P235,P410Safety Statements
S3/7, S14, S17, S26, S36/37/39, S45, S47, S53
12 suppliers offering 226 products for 2-Butanone peroxide (CAS 1338-23-4). Compare equivalent grades across brands (e.g., Trigonox vs Luperox) by assay, physical form, and availability from trusted manufacturers and distributors worldwide.
Are you a Manufacturer or Distributor?
List your company and organic peroxide products for free to reach thousands of global buyers and engineers.