Acetyl cyclohexanesulfonyl peroxide (CAS 3179-56-4)

CAS Number

3179-56-4

Molecular Formula

C8H14O5S

Molecular Weight

222.26

EINECS Number

221-658-7

MDL Number

MFCD00143110

BRN Number

2333795

Last Updated

6/1/2026

Appearance

White needle-like crystals (pure state), commercially supplied as a water-wetted paste (containing >=12% water) or clear liquid solution in high-flash-point solvents

Appearance State

Solid or liquid depending on formulation and diluent. Insoluble in water, readily soluble in most aromatic, ester, and dimethyl phthalate organic solvents.

Color

Colorless to White

Odor

Sharp, strongly acrid, and characteristic pungent odor

Form

Water-wetted paste, crystalline solid or dilute solution (e.g. Trigonox ACS-M 28, Lupersol 228Z)

Melting Point

42 °C (decomp)

Boiling Point

307.8 °C @ 760 mmHg (Calculated. Prone to rapid self-accelerating decomposition and explosion under heat, normal pressure boiling point has no safety guiding significance)

Flash Point

139.9 °C

Density

1.28 g/cm³

Vapor Density

7.67 (air=1)

Vapor Pressure

4.15E-04 mmHg @ 25 °C

Refractive Index

1.484

LogP Value

1.85 (predicted)

Merck Index

Not Specified

Solubility

Insoluble in water, soluble in dimethyl phthalate, toluene, and dichloromethane

Water Solubility

Insoluble (Pure substance insoluble, but must be kept wet with >=12% water to prevent mechanical sensitivity spike; trace acid/base in water will accelerate hydrolysis/decomposition)

Solubility Detail

Insoluble in water. NOAA CAMEO records specify that the commercial formulation must be restricted to a purity of <=82%, phlegmatized and wetted with >=12% water to mitigate extreme mechanical and shock sensitivity. Storing or transporting this high-efficiency low-temperature initiator (used in coatings, rubber, and plastics manufacturing) in its dry, pure state is strictly prohibited.

Storage Conditions

Must be handled under stringent temperature-controlled organic peroxide standards. Ambient storage/transportation is entirely forbidden; it must be force-frozen (typically between -15°C and -10°C, strictly below the prescribed Control Temperature). Possessing an exceptionally low SADT (ca. 15°C to 20°C), it will rapidly undergo violent exothermic thermal runaway and explosion at ambient temperatures. Storage must be limited to isolated, explosion-proof hazard warehouses equipped with redundant refrigeration, emergency pressure relief, and dedicated ventilation. Avoid moisture loss, light, friction, and shock. Keep strictly isolated from reducing agents, acids, bases, and metal compounds.

InChI Key

BSVQJWUUZCXSOL-UHFFFAOYSA-N

Signal Word

Danger

Hazard Symbols

E, O, C

Risk Codes

R2, R3, R5, R8, R34

UN Number

UN 3112 (Organic peroxide solid, Type B, temperature controlled) or UN 3115 (Organic peroxide liquid, Type D, temperature controlled)

IARC Classification

Not Classified

WGK Germany

2

RTECS Number

Not Specified

Auto-ignition Temperature

ca. 15-20 °C (自加速分解温度 SADT，视配方活性稀释程度而定)

TSCA Listed

Listed (Active)

Packing Group

II

Customs Code

2915900090

Occupational Exposure Band (OEB)

Not Specified

Occupational Exposure Limit (OEL)

Not established (NJ DHSS etc. haven't established definitive exposure limits)

Immediately Dangerous to Life or Health (IDLH)

Not Specified