2005
Safety and occupational healthRegulator / government
Elevated valve created an avoidable fall exposure
A welder/repairman fell 37 ft.
Texas Lehigh Cement Company · Texas-Lehigh Cement Plant, Buda, Texas, USAIndustry memory
What the industry learned—and what it must not forget.
A chronological record of incidents, field studies, improvements, and compliance milestones. Individuals are omitted; systems and decisions remain visible.
1981–2025documented history
Source-backed chronology
Forty-four years of public plant experience
Historical event facts remain part of the record. Old legal limits or procedures do not become current guidance.
2005
Safety and occupational healthRegulator / government
Total dust remained a hazard in a newer facility
5 of 19 total-dust samples exceeded the then MSHA 10 mg/m3 limit; respirable limits were not exceeded and silica was absent from personal samples.
Lehigh Portland Cement Company · Union Bridge, Maryland, USA2004-2010
Reliability and maintenanceOrganization-reported
Condition monitoring and capability building at Simba Cement
Supplier reports rotary-kiln availability rose from below 83% in 2004 to above 96% in 2010.
Tanga Cement Company · Simba Cement, Tanga, Tanzania2003-2005
Reliability and maintenanceOrganization-reported
Fan-bearing redesign plus predictive maintenance
Supplier reports bearing replacement interval on main-kiln fans increased to at least 30 months from less than one year.
Holcim Slovensko · Rohoznik cement plant, Slovakia2001
Safety and occupational healthRegulator / government
Fly-ash handling and total-dust exposure
Three of seven initial workers exceeded the then 10 mg/m3 total-dust criteria; quartz results were below applicable criteria.
Lehigh Portland Cement Company · Union Bridge, Maryland, USA2000
Safety and occupational healthRegulator / government
Routine sampling beside an unguarded hot-dust pit
A laboratory technician fell into 190-200 F caustic dust and died from burns and shock.
Royal Cement Company · Logandale, Nevada, USA2000
Safety and occupational healthRegulator / government
Known burner-trolley defects carried into commissioning
The 16,636-lb burner and trolley fell, killing one mechanic and seriously injuring two.
National Cement Company of California · Lebec Cement Plant, California, USA1999
Safety and occupational healthRegulator / government
Engulfment during cement-silo cleaning
Falling cement engulfed a contractor inside the silo.
Keystone Cement Company · Bath, Pennsylvania, USA1999
Safety and occupational healthRegulator / government
Suspended scaffold failure inside a clinker silo
A weakened scaffold support failed and a worker fell about 100 ft.
Ash Grove Cement Company · Durkee Cement Plant, Oregon, USA1997
Safety and occupational healthRegulator / government
Kiln dismantling fall through a removed handrail
A temporary worker stepped on rolling cribbing and fell 28 ft through the opening.
Lafarge Corporation · Tampa Mill, Florida, USA1997
Safety and occupational healthRegulator / government
Hazardous crane motion remained available during maintenance
A drum moved after a misunderstood or incorrect radio command and drew a worker between the drums.
Lone Star Industries · Maryneal Quarry and Mill, Texas, USA1997
Safety and occupational healthRegulator / government
Ozone backdraft during kiln shutdown maintenance
Ozone measured 0.6-0.7 ppm in recreated conditions, above 0.7 ppm at a rear portal, and 4.5 ppm on a direct-reading meter.
Lehigh Portland Cement Company · Union Bridge, Maryland, USA1996
Safety and occupational healthRegulator / government
Preheater blockage and hot-material release
Two workers died and three were burned when hot material was expelled into the occupied area.
San Juan Cement Company · Cantera Espinosa, Dorado, Puerto Rico, USA1982
Safety and occupational healthRegulator / government
Task-level dust and quartz exposure at Coplay
Four respirable nuisance-particulate samples exceeded 5 mg/m3; quartz appeared in 18 personal samples and six exceeded the then MSHA limit.
Coplay Cement Company · Nazareth, Pennsylvania, USA1981
Safety and occupational healthRegulator / government
Dust and quartz exposure mapping at Cementon
3 of 65 personal samples exceeded the then nuisance-dust standard; quartz was detected in 17% of respirable samples, mainly around raw materials.
Lehigh Cement Company · Cementon, New York, USAmore than 14000 operating hours; 2024 publication
Process, quality, and energy optimizationPeer-reviewed / validated
Long-duration adaptive raw-mix control
Implementation exceeded 14000 operating hours; LSF standard deviation ranged 1.5-3 and other moduli were close to analytical reproducibility.
Heidelberg Materials Hellas · Industrial raw mill; site not stated, Greece