Introduction
When designing seals, gaskets, or protective coatings for chemical, outdoor, or high-temperature environments, engineers often narrow their choices to three proven elastomers:
CSM (Chlorosulfonated Polyethylene, known historically as Hypalon®)
EPDM (Ethylene Propylene Diene Monomer)
FKM (Fluoroelastomer, often known by the trade name Viton®)
Each offers unique benefits. Below is a technical side-by-side to help you select the best material for your application.
Need a detailed chemical chart?
See the CSM Chemical Compatibility Chart

Quick Comparison Table
Property / Feature CSM (Hypalon®) EPDM FKM (Viton®)
Operating Temp. Range –40 °C to +130 °C (short peaks to 150 °C) –50 °C to +150 °C (some up to 170 °C) –20 °C to +200 °C (special grades to 250 °C)
Ozone / UV / Weathering Excellent – retains properties for decades outdoors Excellent Good – can chalk slightly under continuous UV
Chemical Resistance Excellent vs. acids, alkalis, oxidizers; fair vs. oils Good vs. water, steam, mild chemicals; poor vs. oils/fuels Outstanding – resists fuels, oils, strong chemicals
Fuel & Oil Resistance Fair to Poor Poor Excellent
Cost (relative) $$ (moderate) $ (economical) $$$ (premium)
Typical Applications Roofing membranes, marine coatings, tank linings, chemical gaskets Automotive cooling systems, water seals, steam hoses Aerospace fuel seals, chemical plant O-rings, automotive under-hood

Key Insights for Material Selection
1. Chemical Exposure
Strong Acids / Oxidizers → CSM excels.
Automotive fuels / Hydrocarbons → FKM is best.
Hot water / Steam → EPDM leads.
2. Outdoor & UV Stability
Both CSM and EPDM outperform FKM for continuous sunlight and ozone.
CSM offers superior color retention, valuable for architectural and marine applications.
3. Temperature Range
FKM covers the widest high-temperature range.
EPDM performs well at low temperatures (down to –50 °C).
CSM is a balanced choice when UV + chemical exposure is critical.

Typical Industry Applications
CSM: Roofing membranes, inflatable boats, chemical tank linings, expansion joints.
EPDM: Automotive weatherstripping, steam hoses, potable water seals.
FKM: Aerospace fuel systems, chemical processing gaskets, high-temperature O-rings.
Explore YQXPOLYMER CSM Grades → CSM Product Overview

Cost vs. Lifecycle Value
EPDM: Lowest material cost; ideal for water/steam but not for oil or aggressive chemicals.
CSM: Mid-range price; offers the best balance of chemical and weathering resistance for long-term outdoor use.
FKM: Highest cost but unmatched for chemical and high-temperature resistance—worth it for critical aerospace or chemical plant applications.

Why Choose YQXPOLYMER CSM
YQXPOLYMER supplies high-purity, spray-grade CSM designed for demanding marine, infrastructure, and chemical markets:
Consistent viscosity and particle size for predictable compounding
Compliance with REACH, RoHS, and ISO 9001
Technical support for custom formulations and blends
Request a sample or consultation → Contact YQXPOLYMER

More Suggestions
CSM Chemical Compatibility Chart
YQXPOLYMER Technical Data
Applications in Marine & Offshore