Class Code 4497
Plastics – Fiber Reinforced Plastic Products Mfg
Class Code 4497 covers manufacturers who produce fiber‑reinforced plastic (FRP) products using glass or other fibers combined with resin systems. The California pure premium rate for this classification effective September 1, 2026 is $5.435 per $100 of payroll. Understanding the processes and hazards behind this rate helps employers control costs and protect workers.
What Class Code 4497 Covers
This classification includes operations that manufacture products made from fiber reinforcement (typically glass fiber) combined with thermoset resins (polyester, vinyl ester, epoxy) or similar systems. Covered activities include mold preparation, hand lay‑up, spray‑up (chopper gun), filament winding, vacuum infusion, pultrusion, compression or transfer molding, part trimming, sanding, finishing and assembly of cured FRP parts. It also covers resin mixing and catalyzation, gel coat application and post‑cure processes such as oven or autoclave curing when performed as part of production. Typical products include boat hulls, storage tanks, piping, ducts, architectural panels, ladders and custom composite parts; the code also applies to shops that repair or rework FRP components.
Who It Applies To
- Small and mid‑size boat and marine hull manufacturers and repair shops
- Producers of FRP tanks, pipes, and ducts for industrial use
- Manufacturers of architectural panels, canopies, and composite building components
- Suppliers of pultruded or molded composite parts for automotive, HVAC, or industrial equipment
- Shops performing FRP repair, rework, inspection and finishing
Common Job Duties
- Preparing molds, applying release agents, and setting up tooling
- Mixing resins and catalysts, measuring accelerators and inhibitors
- Hand lay‑up of fiber layers, applying gel coat, and using chopper guns or spray equipment
- Vacuum bagging, infusion, pultrusion operation, and autoclave/oven curing
- Trimming, sawing, sanding, grinding and finishing cured parts
- Quality inspection, dimensional trimming, tack and bond repair, and assembly
Common Injury Risks
Understanding the $5.435 Rate
The pure premium rate of $5.435 per $100 of payroll is the WCIRB's base cost estimate for expected loss costs in this classification; insurers multiply this rate by an employer's payroll (divided by 100) to get the pure premium before other adjustments. The actual premium an employer pays will also reflect the insurer's expense loads, the employer's experience modification (loss history), any schedule or merit credits, state assessments, and payroll audit results.
Cal/OSHA Compliance Requirements
FRP manufacturing is subject to California Code of Regulations, Title 8 requirements including Respiratory Protection (Section 5144) and Hazard Communication (Section 5194), plus general industry rules on ventilation, personal protective equipment and machine guarding. Employers must implement exposure control (local exhaust ventilation), provide required respirators and fit testing when controls are insufficient, maintain Safety Data Sheets and label containers, and train workers on chemical handling, curing hazards and emergency procedures.
How Key HR Helps Employers Under Class Code 4497
A PEO like Key HR can centralize workers' compensation administration, provide tailored loss‑control programs for FRP hazards (ventilation surveys, respiratory programs, chemical handling SOPs), and manage claims and return‑to‑work plans to limit experience modifier impact. Key HR also offers safety training, PPE sourcing, on‑site audits and preventative maintenance coordination to reduce incidents and control premium volatility across multi‑state operations.
Get a QuoteFrequently Asked Questions
How do I know if my shop should be coded as 4497 or a different plastics code?
Class 4497 applies when the primary product is fiber‑reinforced plastic made by combining fibers (commonly glass) and resin systems using lay‑up, spray‑up, pultrusion, filament winding or molding. If your operations are primarily extrusion of thermoplastic materials, plastic injection molding, or manufacturing commodity thermoplastic sheet, a different plastics class may apply. Review your dominant production process and materials with your broker or Key HR to confirm correct classification.
What steps most effectively reduce workers' comp costs for FRP manufacturers?
Focus on reducing frequency and severity of chemical and cutting incidents: install and maintain local exhaust ventilation, enforce respiratory and glove programs, use spray booths or capture systems for chopper guns, provide cut‑resistant gloves and eye protection, implement safe resin mixing procedures, and adopt formal return‑to‑work and claims management practices to rehabilitate injured workers quickly.
Are there specific controls for styrene exposure I must implement?
Yes. Implement engineering controls such as local exhaust ventilation and enclosed mixing where feasible, substitute lower‑styrene resins if possible, provide respirators and a written respiratory protection program when exposures exceed limits, perform exposure monitoring, and train employees on safe handling and emergency response. Maintain SDS access and ensure proper storage and grounding for flammable liquids.
Quick Facts
- Class Code
- 4497
- Classification
- Plastics – Fiber Reinforced Plastic Products Mfg
- Pure Premium Rate
- $5.435 / $100 payroll
- Effective Date
- September 1, 2026
- Source
- WCIRB Approved Filing
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