Class Code 1452
Mining – Ore Milling
Class Code 1452 covers mining ore milling operations in California, including crushing, grinding, concentrating and related plant activities. The September 1, 2026 approved pure premium is $2.006 per $100 of payroll. Proper classification and safety controls matter because ore milling combines high-energy machinery, dust/chemical exposure, and confined-space work.
What Class Code 1452 Covers
This classification applies to industrial processing plants that take mined ore and reduce, separate and concentrate metal or mineral values by crushing, grinding, screening, flotation, leaching or other milling processes. Typical operations include primary and secondary crushers, ball and rod mills, classifiers, jigs, flotation cells, thickening/filtration, cyanide or acid leaching circuits, and dust collection systems. It covers workers who operate, inspect and maintain this equipment, perform sampling and assaying in the mill, and handle process reagents on-site. Surface hauling of ore to the mill and on-plant material handling are included; extraction activities at the mine face are generally classified separately.
Who It Applies To
- Mill operators and control-room technicians at ore-processing plants
- Crusher, grinder and classifier operators and attendants
- Maintenance mechanics, millwrights and electricians serving milling equipment
- Process chemists, lab technicians and sampling personnel
- Reagent handlers (cyanide, flotation agents, acids) and chemical feed operators
- Plant supervisors and safety coordinators working on-site
Common Job Duties
- Operating and monitoring crushers, ball/rod mills, classifiers and conveyors
- Sampling, assaying and logging ore grades and process streams
- Adjusting and maintaining flotation cells, thickeners and filtration units
- Replacing liners, bearings and wear parts; millwright repair work
- Handling, measuring and feeding chemical reagents and managing storage
- Cleaning dust collectors, hoppers and elevated platforms; confined-space entry for tanks and vessels
Common Injury Risks
Understanding the $2.006 Rate
The pure premium rate of $2.006 per $100 of payroll is the part of the workers' comp premium that pays for expected claim costs for this classification. Insurers add expense loads, profit margins and apply the employer's experience modification factor (EMR) to determine the final premium; payroll mix and misclassification can change premiums significantly.
Cal/OSHA Compliance Requirements
California employers must comply with Title 8 safety standards and maintain an Injury and Illness Prevention Program (IIPP); key requirements include a written respiratory protection program, hazardous communication training for reagents, noise monitoring and hearing conservation, machine guarding and lockout/tagout for maintenance, confined-space entry procedures, and medical surveillance where exposures occur. Many ore-milling operations are also subject to federal MSHA requirements; employers should coordinate compliance with both MSHA and Cal/OSHA when applicable and document air monitoring, training and corrective actions.
How Key HR Helps Employers Under Class Code 1452
A PEO like Key HR helps employers in Class Code 1452 by ensuring payroll and job descriptions are correctly classified, providing targeted loss-control training (silica, chemical handling, lockout/tagout), coordinating California claims handling and return-to-work programs, and leveraging group purchasing to lower workers' comp costs. Key HR can also help implement written programs, schedule on-site safety audits, and connect mills with preferred medical providers experienced in mining injuries.
Get a QuoteFrequently Asked Questions
Does Class Code 1452 include crushing, grinding and flotation at a concentrator?
Yes. 1452 covers plant activities that reduce and concentrate ore—crushers, mills, classifiers, flotation cells, thickening and filtration equipment and associated material handling performed at the mill site. Raw extraction at the mine face is usually classified differently.
What are the most effective controls to reduce silica and chemical exposure in a mill?
Primary controls are engineering: water suppression at crushers, enclosed conveyors, local exhaust ventilation and high-efficiency dust collectors, plus proper reagent storage and secondary containment. Supplement with air monitoring, a respiratory protection program, medical surveillance, substitution where feasible, worker training and documented exposure-response plans.
Are independent contractors who work in the mill classified under this code?
Classification depends on whether workers are employees or true independent contractors. If they are your payroll employees performing mill operations, they fall under 1452. If contractors are independent and carry their own workers' comp, they should be separately documented. A PEO can help audit worker classification and verify contractor insurance.
Quick Facts
- Class Code
- 1452
- Classification
- Mining – Ore Milling
- Pure Premium Rate
- $2.006 / $100 payroll
- Effective Date
- September 1, 2026
- Source
- WCIRB Approved Filing
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