Epoxy Terrazzo AHA (Activity Hazard Analysis / Job Hazard Analysis)
Updated 2026-06-23
An Epoxy Terrazzo AHA (Activity Hazard Analysis / Job Hazard Analysis) is the plan for installing epoxy terrazzo — a poured epoxy-resin-and-aggregate floor ground and polished to a finish — and it has two distinct hazard phases: the epoxy pour and the terrazzo grinding. This AHA is about epoxy resin poured and then ground.
Why epoxy terrazzo needs its own AHA
Epoxy terrazzo is a poured composite floor — an epoxy resin matrix filled with decorative aggregate (marble, glass, or stone chips) poured over the substrate, then ground and polished to expose the aggregate and produce a smooth, durable, decorative floor. Unlike resilient flooring (laid down), terrazzo is poured and then machined, giving it two distinct hazard phases. First, the epoxy resin pour: epoxy terrazzo uses a two-part epoxy resin (resin and hardener) mixed and poured — reactive epoxy chemistry that is a skin sensitizer (epoxy resin and hardener cause skin sensitization and allergic dermatitis, and repeated exposure can sensitize a worker for good), an irritant (skin, eye), and releases some vapor, so mixing and placing the epoxy is a chemical-exposure hazard. Second, the terrazzo grinding and polishing: after curing, the terrazzo is ground and polished with heavy grinding machines to expose the aggregate and smooth the surface — and grinding the aggregate (marble and stone chips) and matrix produces respirable crystalline silica (from the stone aggregate) and grinding dust and slurry, a serious respiratory hazard, plus the grinding-machine and slurry hazards. So the defining hazards are the reactive epoxy resin (skin sensitization, vapor) at the pour and the heavy grinding (respirable silica, slurry) at the finish — two phases, two hazard sets. Epoxy terrazzo is reactive epoxy poured, then silica-generating grinding.
Breaking epoxy terrazzo into steps
The steps pour and grind terrazzo:
- Confirm the terrazzo system, epoxy, and aggregate from the submittal
- Prepare the substrate
- Mix the two-part epoxy resin (reactive chemistry)
- Pour and place the epoxy terrazzo with aggregate (epoxy exposure)
- Cure the terrazzo
- Grind and polish the cured terrazzo (silica, slurry)
- Seal and finish; verify and clean up
The hazards step by step
The reactive epoxy resin (skin sensitization, vapor)
Epoxy terrazzo uses a two-part epoxy (resin and hardener) mixed and poured, and the reactive epoxy chemistry is a skin sensitizer and irritant: epoxy resin and especially the hardener cause skin sensitization and allergic contact dermatitis — and once sensitized, a worker can react to even small future exposures, so sensitization is a career-affecting hazard — plus skin and eye irritation and some vapor. Protect skin thoroughly from the epoxy (the key control — impervious gloves and covered skin, because skin contact is what sensitizes; avoid all skin contact with resin and hardener), protect the eyes, ventilate for the vapor, and follow the epoxy's safety data. The reactive epoxy is a skin-sensitization hazard above all — prevent skin contact to prevent sensitization. The pour phase is a chemical-exposure phase.
The terrazzo grinding and polishing (respirable silica, slurry)
After curing, the terrazzo is ground and polished with heavy grinding machines to expose the aggregate and smooth the floor — and grinding the stone aggregate (marble, granite) and matrix produces respirable crystalline silica (from the stone), a serious respiratory hazard, along with grinding dust and slurry. Grind wet where possible (wet grinding suppresses the silica dust and is common for terrazzo — the slurry) or use dust-collecting grinding, provide respiratory protection for the silica, manage the grinding-machine hazards (the heavy walk-behind grinder), and manage the slurry (slip hazard and cleanup). The grinding phase is a silica-generating phase — control the silica by wet grinding or dust collection. The heavy grinding of stone aggregate is a significant silica source.
The grinding machine and slurry
The heavy grinding/polishing machines (the walk-behind grinder — its operation, weight, and moving parts), the wet slurry (slip hazard and cleanup), and the electrical safety of the machines in the wet environment apply.
Kneeling, eye, and handling
The kneeling/bent work at the pour and detailing, eye protection (epoxy and grinding), and material handling apply.
A simple Epoxy Terrazzo AHA structure
| Step | Hazard | Control | Standard |
|---|---|---|---|
| Mix/pour epoxy resin | Skin sensitization / irritation / vapor | Impervious gloves, cover skin (avoid all contact); eye protection; ventilate | OSHA 1926.59 |
| Grind cured terrazzo | Respirable silica from aggregate | Wet grinding or dust collection; respiratory protection | OSHA 1926.1153 |
| Operate grinder | Machine / moving parts / electrical in wet | Trained operation; guarding; GFCI/electrical safety in wet | OSHA 1926.300 |
| Manage slurry | Slip / cleanup | Manage wet slurry; footing; cleanup | OSHA 1926.25 |
| Detail work | Epoxy/grinding to eye | Eye protection | OSHA 1926.102 |
Where the two phases define epoxy terrazzo
Epoxy terrazzo is defined by its two distinct hazard phases, each needing its own controls. The pour phase is a chemical phase — reactive epoxy that sensitizes skin — where the control is preventing skin contact (gloves, covered skin) to prevent the career-affecting sensitization, plus vapor ventilation. The grinding phase is a silica phase — heavy grinding of stone aggregate producing respirable silica — where the control is wet grinding or dust collection and respiratory protection. They're separated in time (pour, cure, then grind) and different in kind (chemical vs dust), so the crew shifts from chemical-exposure controls at the pour to silica controls at the grinding. Recognizing the two phases and applying the right controls to each is the heart of epoxy terrazzo safety: skin protection for the epoxy, and silica control for the grinding. Two phases, two hazard sets, two control regimes.
From the field: what actually goes wrong
The epoxy terrazzo failures split by phase. The epoxy: skin contact with the epoxy resin and hardener without adequate skin protection, causing sensitization and allergic dermatitis — and once sensitized, the worker reacts to future exposures, a career-affecting outcome, all from inadequate skin protection at the pour. The grinding: heavy grinding of the cured terrazzo (stone aggregate) without wet grinding or dust collection, releasing respirable silica — a serious exposure from the stone aggregate. Plus the grinder and slurry hazards. The epoxy terrazzo lessons are phase-specific: prevent skin contact with the reactive epoxy (to prevent sensitization) at the pour, and control the silica (wet grinding or dust collection) at the grinding. Two phases, each with its serious hazard.
The bottom line
An Epoxy Terrazzo AHA is a two-phase plan. The pour phase uses reactive two-part epoxy that sensitizes skin (prevent all skin contact with impervious gloves and covered skin — sensitization is career-affecting — plus eye protection and vapor ventilation), and the grinding phase produces respirable silica from grinding the stone aggregate (wet grinding or dust collection, respiratory protection), with the grinder and slurry hazards. Respect the two distinct phases — skin protection for the epoxy, silica control for the grinding — and epoxy terrazzo is installed safely.
Frequently asked questions
What are the two hazard phases of epoxy terrazzo?
The epoxy pour and the terrazzo grinding. The pour phase uses a reactive two-part epoxy resin — a skin sensitizer and irritant with some vapor — so it's a chemical-exposure phase. The grinding phase grinds and polishes the cured terrazzo with heavy machines, producing respirable crystalline silica from the stone aggregate — so it's a silica/dust phase. They're separated in time (pour, cure, then grind) and different in kind, so each needs its own controls: skin protection for the epoxy, silica control for the grinding.
Why is the epoxy a serious hazard?
Because the two-part epoxy (resin and hardener) is a skin sensitizer — it causes skin sensitization and allergic contact dermatitis, and once sensitized, a worker can react to even small future exposures, making it a career-affecting hazard. It's also a skin and eye irritant with some vapor. The key control is preventing skin contact: impervious gloves and covered skin, because skin contact is what sensitizes. Avoid all skin contact with the resin and hardener, protect the eyes, and ventilate for the vapor.
Why is grinding terrazzo a silica hazard?
Because after curing, the terrazzo is ground and polished with heavy machines to expose the aggregate, and grinding the stone aggregate (marble, granite) and matrix produces respirable crystalline silica from the stone — a serious respiratory hazard. Grind wet where possible (wet grinding suppresses the silica and is common for terrazzo, producing slurry) or use dust-collecting grinding, and wear respiratory protection. The heavy grinding of stone aggregate is a significant silica source, controlled by wet grinding or dust collection.
How is epoxy terrazzo different from resilient flooring?
Resilient flooring is laid down (sheets or tiles adhered), while epoxy terrazzo is poured and then machined — a reactive epoxy-and-aggregate composite poured over the substrate, then ground and polished. So terrazzo has two hazard phases resilient flooring doesn't: the reactive epoxy chemistry (sensitization) at the pour, and the silica-generating heavy grinding at the finish. It's a poured-and-ground floor, not a laid one, with correspondingly different hazards.
Related AHAs and JHAs
- Resinous Flooring AHA — the related resin flooring
- Concrete Floor Grinding AHA — the grinding-silica fundamentals
- Flooring AHA — the flooring-work fundamentals
- Terrazzo Installation JHA — the terrazzo installation fundamentals
Written by Mustafa Tok, CSP, ASP, CHST — OSHA Authorized Outreach Trainer with 14+ years of international construction safety experience across federal, heavy civil, and industrial projects.