Cement Plants & Kilns

Cement plants crush limestone, heat it to about 2,700 degrees F in a rotary kiln and grind the clinker into cement. The plant runs around the clock with heat, dust and heavy equipment, and some tasks, such as clearing buildups, are extremely hazardous.

• Plant Operators
• Maintenance
• Contractors

Hazards

• Hot meal and clinker releases: material can suddenly flush from preheater cyclones, kilns and coolers, burying and burning workers. This is the most dangerous hazard.
• Silica and cement dust: breathing it causes lung disease; cement burns skin. See Silica and Wet Cement & Concrete Burns.
• Engulfment in silos, bins and hoppers where material can bridge and collapse. See Confined Spaces and Grain Handling for similar hazards.
• Conveyors, crushers, mills and bucket elevators. See Conveyors.
• Heat stress near kilns. See Heat Illness.
• Noise, vibration, mobile equipment and quarry hazards. See Quarry & Aggregate Workers.
• Combustible dusts and fuels such as coal, coke and alternative fuels. See Combustible Dust.
• Falls from platforms and towers.

Buildup cleaning and flushes

• Use written procedures, remote methods such as air cannons, water jetting or robotic tools to clear buildups instead of manual poking when possible.
• Keep workers out of the danger zone below cyclones and ducts during cleaning.
• Use hot-work-rated PPE: face shield, aluminized or flame-resistant suit, gloves and boots. See Foundries & Molten Metal for similar PPE.
• Use lockout, permits and a rescue plan.

Controls

• Dust collection, enclosed conveyors, wet cleaning and housekeeping
• Lockout/tagout for all maintenance. See Group Lockout
• Bin and silo entry only with a permit, lockout of discharge equipment, lifeline and observer
• Respirators and exposure monitoring
• Heat stress plan with breaks, water and acclimatization
• Hearing conservation program
• Separate pedestrians from mobile equipment and haul roads

Last updated: October 8, 2026