Class Code 4665
Rendering Or Fertilizer Mfg
Class code 4665 applies to businesses that render animal by-products and manufacture organic or mineral fertilizers. This work combines heat processing, grinding, blending and storage operations and carries a September 1, 2026 pure premium rate of $7.994 per $100 of payroll. Understanding this classification helps California employers manage risk, compliance, and workers' compensation costs.
What Class Code 4665 Covers
Class 4665 specifically covers facilities that process animal materials (rendering) and plants that produce fertilizers through mechanical and chemical processes. Rendering operations include receiving raw carcasses and by-products, cooking, pressing, centrifuging, drying and producing tallow, protein meals, blood meal and bone meal. Fertilizer manufacturing under this code includes grinding, blending, pelletizing, granulating and bagging organic or mixed fertilizers and handling additives such as ammonium compounds, lime, or phosphate concentrates. The classification applies whether production is continuous or batch, and includes ancillary plant areas such as storage silos, bagging lines, boilers, boilers’ steam lines, and laboratory quality control when part of the production process. Work performed outside the plant (offsite hauling by plant employees) is included only when employees are directly employed by the rendering/fertilizer operator and the payroll is reported to the same employer.
Who It Applies To
- Rendering plant operators and line workers handling raw animal material
- Fertilizer production operators (mixing, pelletizing, granulating)
- Maintenance mechanics and millwrights servicing cookers, grinders and conveyors
- Bulk and bagging line operators, weighers and packers
- Plant lab technicians performing QA/QC on product samples
- On-site forklift and heavy equipment operators moving raw and finished product
Common Job Duties
- Receiving and inspecting raw materials (animal by-products, fertilizers feedstocks)
- Operating cookers, presses, centrifuges, dryers and pellet mills
- Feeding and operating hammer mills, grinders, screens and classifiers
- Mixing, blending and handling chemical additives and dry powders
- Filling, weighing, bagging and palletizing finished fertilizer products
- Routine maintenance, cleaning of equipment and confined-space entries into tanks or silos
- Operating forklifts and plant trucks to move raw materials and finished product
Common Injury Risks
Understanding the $7.994 Rate
The pure premium rate of $7.994 per $100 of payroll is the WCIRB-approved loss cost for class 4665 and represents the portion of premium intended to cover expected claim costs. Carriers multiply the pure premium by a carrier rate modifier, experience modification, policy-level adjustments and assessments to calculate the final premium. Employers can influence their final cost through loss control, accurate payroll classification, return-to-work programs and reducing claim frequency and severity.
Cal/OSHA Compliance Requirements
Cal/OSHA requirements commonly apply to rendering and fertilizer plants, including Hazard Communication (GHS) for chemical additives, Respiratory Protection for dust and ammonia exposures, Permit-Required Confined Space procedures for silos and tanks, and Control of Hazardous Energy (lockout/tagout) for machinery servicing. Facilities handling anhydrous ammonia, concentrated acids or large quantities of oxidizers should also comply with Process Safety Management and hazardous materials storage requirements and maintain up-to-date written programs, training records and emergency response plans.
How Key HR Helps Employers Under Class Code 4665
A PEO like Key HR can reduce workers' comp costs for class 4665 employers by ensuring correct classification and payroll reporting, administering robust safety programs tailored to rendering and fertilizer hazards, and managing claims and medical care to control severity. Key HR also provides OSHA-aligned written programs, on-site safety audits, training (confined space, respiratory, lockout/tagout), and return-to-work coordination to lower experience modification and long-term premium exposure.
Get a QuoteFrequently Asked Questions
Does class code 4665 include employees who drive bulk trucks for the plant?
Yes, drivers employed directly by the rendering or fertilizer plant who transport raw materials or finished product as part of the employer's operations are typically included in class 4665 payroll. Independent contractors and third-party carriers should be insured separately.
What are the most effective ways to lower workers' comp costs in a rendering/fertilizer plant?
Focus on preventing amputations and respiratory claims by instituting machine guarding, lockout/tagout, dust control and respiratory protection programs; implement thorough training, proactive maintenance, and a strong return-to-work program to shorten claim durations and reduce your experience modification.
When does Process Safety Management (PSM) apply to fertilizer plants?
PSM-like requirements apply when operations involve highly hazardous chemicals such as anhydrous ammonia or large inventories of oxidizers; employers must evaluate their inventories and processes and, if thresholds are met, implement PSM elements including process hazard analysis, mechanical integrity and emergency response.
Quick Facts
- Class Code
- 4665
- Classification
- Rendering Or Fertilizer Mfg
- Pure Premium Rate
- $7.994 / $100 payroll
- Effective Date
- September 1, 2026
- Source
- WCIRB Approved Filing
Manage Workers' Comp Through a PEO
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