For most businesses, installing epoxy resin flooring is just the beginning of achieving optimal performance from every square foot. To maximize its value, you need to understand what’s beneath the glossy surface and how it behaves. That knowledge helps you set clear expectations and avoid costly issues over your floor’s lifespan.
In this guide, we’ll break down epoxy resin from the ground up by asking, “What is epoxy resin?” We’ll explore what epoxy resin is made of, how epoxy resin is manufactured, and the different types available. Finally, we’ll address whether epoxy resin is toxic to humans so you can plan safer, long-lasting commercial installations.
Epoxy Resin: What Is It Made Of?
Epoxy resin may appear simple once the curing process is complete, but its performance stems from a carefully balanced chemical recipe. Understanding what goes into that formula helps you choose systems that match your project’s demands, environment, and safety requirements.
Below are the components that manufacturers combine to create epoxy flooring and coating materials:
Epoxy Resin Base (Epoxide Monomers)
The epoxy resin base is the primary liquid component containing reactive epoxide groups. These groups open and link together during curing, building the crosslinked structure that gives epoxy its strength and hardness. Common base resins include Bisphenol A and Bisphenol F epoxies, chosen for specific viscosity, chemical resistance, and performance targets.
Curing Agents (Hardeners)
Curing agents, often called hardeners, react with the epoxy resin to transform it from a liquid into a solid polymer. Different chemistries, such as amines or anhydrides, control working time, cure speed, and final mechanical properties. By selecting specific hardeners, manufacturers tailor systems for temperature conditions, chemical exposure, and application methods like trowel or roller.
Reactive Diluents
Reactive diluents are low-viscosity liquids added to reduce thickness and improve workability without weakening the cured epoxy network. Unlike solvents, they chemically react within the system during curing, becoming part of the final polymer structure. They help installers achieve better penetration into concrete, smoother leveling, and easier application in cooler or tighter conditions.
Fillers and Reinforcement
Fillers are solid particles added to adjust viscosity, build thickness, and enhance properties like compressive strength or impact resistance. Common fillers include silica, quartz, calcium carbonate, and various specialty minerals selected for specific performance benefits. In flooring, these fillers also help control shrinkage, reduce cost per square foot, and improve wear resistance under traffic.
Pigments and Colorants
Pigments and colorants provide color, opacity, and design flexibility for branding, zoning, or decorative flooring systems. They are finely ground solids dispersed in the resin, chosen for lightfastness, chemical resistance, and compatibility. Consistent pigmentation ensures uniform color coverage, predictable mixing ratios, and professional-looking results across large commercial areas.
Additives and Modifiers
Additives and modifiers are specialty ingredients that fine-tune handling, appearance, and performance under specific service conditions. Examples include defoamers, UV stabilizers, flow agents, thixotropes, and adhesion promoters tailored to targeted applications. These small-dose components can significantly improve clarity, leveling, edge coverage, and long-term durability of epoxy flooring systems.
Solvents and VOC-Control Components
Some epoxy formulations include solvents to adjust viscosity and open time, especially in primers or specialty coatings. These evaporate during curing, which is why many modern systems emphasize low-VOC, high-solids, or solvent-free designs. Choosing lower-VOC systems can support indoor air quality goals and help meet tighter regulatory or project specifications.
How Epoxy Resin Is Manufactured
Behind every high-performance epoxy floor is a carefully controlled manufacturing process, not just a single product. Here’s how epoxy resin is created step by step before it ever reaches your job site:
1. Selecting and Preparing Raw Materials
Manufacturing begins with choosing key raw materials like epichlorohydrin and bisphenols or other chosen backbone molecules. These ingredients are weighed precisely to achieve the target molecular weight and performance. Consistent raw material quality ensures each production batch behaves predictably during curing and in real-world service.
2. Reacting Epichlorohydrin With the Resin Backbone
The core chemical reaction combines epichlorohydrin with bisphenol A, bisphenol F, or another chosen backbone under controlled conditions. Heat, catalysts, and mixing speed are carefully managed to form epoxide groups. This step builds the fundamental epoxy resin chains that later crosslink with curing agents.
3. Controlling Molecular Weight and Viscosity
The reaction is monitored to reach specific molecular weights, which directly influence viscosity and handling. Operators measure parameters like temperature, epoxide value, and flow characteristics during processing. Once targets are met, they stop the reaction to lock in the desired balance between flow and strength.
4. Removing Byproducts and Purifying the Resin
After reaction, byproducts such as salts or residual chemicals are separated through washing, filtration, or other purification steps. This cleaning process reduces impurities that could cause discoloration, odor, or inconsistent curing. Proper purification helps deliver a more stable, reliable resin for flooring and coating formulations.
5. Modifying and Blending the Epoxy Resin
The purified base resin can be blended with reactive diluents, flexibilizers, or specialty modifiers. These additions fine-tune properties like flexibility, chemical resistance, and application thickness. Manufacturers design different blends to match specific uses, from thin primers to high-build industrial floor systems.
6. Quality Control and Testing
Samples from each batch undergo laboratory testing for viscosity, epoxide equivalent weight, color, and gel time. These tests confirm the resin meets internal specifications and customer expectations. If results fall outside limits, adjustments or reprocessing occur before the material is released.
7. Packaging for Formulators and System Manufacturers
Once approved, the epoxy resin is packaged in drums, pails, totes, or bulk containers. Packaging materials are chosen to protect against moisture, contamination, and temperature extremes. From there, formulators and manufacturers combine the resin with hardeners and additives to create complete epoxy systems.
Different Types of Epoxy Resins
Not all epoxy resins perform the same way once they hit the concrete. Different chemistries are designed for specific performance demands. Here are the main epoxy resin types you’ll find from most suppliers:
- Bisphenol A Epoxy Resins. Bisphenol A epoxies are among the most common, offering balanced strength, adhesion, and chemical resistance. They work well for general-purpose coatings and flooring.
- Bisphenol F Epoxy Resins. Bisphenol F epoxies have lower viscosity than Bisphenol A, allowing better penetration and easier handling. This makes them ideal for primers, thin coats, and detailed work.
- Novolac Epoxy Resins. Novolac epoxies provide very high chemical and heat resistance compared to standard epoxies. Because of this, they are often used in harsh industrial or secondary containment environments.
- Cycloaliphatic Epoxy Resins. Cycloaliphatic epoxies offer excellent electrical properties and improved weathering resistance. These characteristics make them useful in outdoor coatings, electrical insulators, and specialized industrial applications.
- Waterborne Epoxy Resins. Waterborne epoxies disperse in water instead of traditional solvents, reducing odor and VOC emissions. As a result, they are commonly specified for indoor projects and occupied spaces.
- Flexible or Modified Epoxy Resins. Flexible epoxies include modifiers or flexibilizers to increase impact resistance and reduce brittleness. This flexibility helps them handle movement, vibration, and thermal cycling without cracking.
- UV-Curable Epoxy Resins. UV-curable epoxies harden when exposed to ultraviolet light instead of relying solely on chemical hardeners. They enable very fast curing for specialized coatings, electronics, and clear finishes.
If you’re looking for a specific type of epoxy resin, you can always contact ASTC Polymers directly. We’ll discuss your preferences to ensure we supply you with the correct epoxy type.
Is Epoxy Resin Toxic to Humans?
Whenever epoxy is mixed or applied, safety should matter just as much as performance. Uncured resins and hardeners can irritate skin and lungs, especially in busy commercial or industrial environments. However, properly cured commercial flooring systems are generally low risk for occupants when installed and maintained correctly.
If you want to guarantee the safety of your business and employees, follow these practical steps below:
- Provide Proper PPE. Businesses should supply gloves, safety glasses, and protective clothing suited to the specific epoxy system being used. Consistent PPE use reduces direct skin contact and helps prevent allergic reactions or chemical burns.
- Improve Ventilation. Work areas should have good airflow, using exhaust fans or local ventilation where possible. Proper ventilation helps reduce exposure to vapors, especially in enclosed spaces.
- Train on Safety Data Sheets. Workers should review Safety Data Sheets and technical data before handling any epoxy materials. Clear training helps employees understand hazards, mixing instructions, and emergency procedures.
- Choose Low-VOC Systems. Selecting low-odor, low-VOC, or waterborne epoxies can reduce airborne irritants. These systems help maintain better indoor air quality, particularly during busy operations.
- Standardize Mixing Procedures. Designate mixing areas with spill protection, clear labeling, and dedicated tools. Standardized procedures reduce mistakes, cross-contamination, and unexpected reactions during installation.
- Improve Housekeeping and Spill Response. Clean tools, containers, and work areas regularly to avoid the buildup of uncured material. A clear spill-response plan ensures quick, safe cleanup when incidents occur.
- Control Access and Cure Time. Limit access to active installation areas to trained staff only. After application, allow full cure and adequate ventilation before regular foot or equipment traffic resumes.
Trust ASTC Polymers as Your Epoxy Resin Supplier
When your projects demand consistent, high-performance epoxy systems, partner with ASTC Polymers as your trusted supplier. With over 35 years of polyurethane and epoxy innovation, we formulate, test, package, and ship directly from our facility. Whether you need ASTC-branded products or turnkey private label lines, we deliver technical guidance, dependable supply, and fast fulfillment.
Call us today to discuss your project requirements and secure reliable epoxy and polyurethane materials for your business.