citations per 100 inspection hours
ⓘThis rate is recorded citations divided by MSHA inspection hours, per 100 hours. It reflects inspection effort, not mine size or production.
Rate withheld: 606 inspection hours is too few for a stable rate. A minimum of 1,000 inspection hours is required.
Source: MSHA inspections data, updated weekly.
Corona has $8K in proposed MSHA penalties and $0 outstanding across 0 contested dockets.
Penalty disposition
ⓘDifferences between proposed and paid penalties reflect both settlements and conference reductions and amounts still owed. Outstanding is the balance currently owed.
$8K
proposed penalties
$8K
current assessed
$8K
paid to date
$0
outstanding
42 assessments are final orders; 0 contested dockets.
As of the most recent assessment on 2026-07-01.
Source: MSHA assessed-violations and conference/litigation data, updated weekly.
Violation severity profile
ⓘShares are computed over citations that carry the MSHA gravity and negligence coding; a small share of records are uncoded.
Source: MSHA violations gravity and negligence coding, updated weekly.
Health sampling
ⓘA sample is a point in time compliance measurement, not an individual exposure history. These figures describe MSHA sampling records and do not establish causation or personal dose.
Metal and nonmetal contaminants (personal samples)
ⓘMany samples are screening measurements of substances with no applicable exposure limit; they are counted as samples but excluded from every over-limit figure. Over-limit shares use only limit-tested samples.
Last sampled: 2025-05-07
0%
of limit-tested samples over the exposure limit
11
samples
5
limit-tested
Most sampled contaminants
Respirable dust, <.1mg5
Quartz, respirable, >1% Qtz3
Noise dosimeter, 80dBA threshold dose1
Noise dosimeter, 90dBA threshold dose1
Show the individual readings (11)
Date
Contaminant
Concentration
Limit
Conc / limit
Occupation
2025-05-07
Respirable dust, <.1mg
0
Laborer, Bullgang
2019-01-24
Respirable dust, <.1mg
0
Crusher Oper/Worker
2019-01-24
Respirable dust, <.1mg
0
Supervisor, Co. Official
2019-01-24
Respirable dust, <.1mg
0
Laborer, Bullgang
2019-01-24
Noise dosimeter, 80dBA threshold dose
10.5
50
0.21
Truck Driver
2019-01-24
Noise dosimeter, 90dBA threshold dose
18.1
100
0.18
Building Repair/Maint.
2015-04-28
Respirable dust, <.1mg
0
Front-end Loader Operator
2015-04-28
Quartz, respirable, >1% Qtz
0.71
0.91
0.78
Truck Driver
2015-04-28
Quartz, respirable, >1% Qtz
0.27
1.1
0.25
Supervisor, Co. Official
2015-04-28
Quartz, respirable, >1% Qtz
0.84
1.15
0.73
Supervisor, Co. Official
2015-04-28
Unlisted Particulate, respirable, <1% Qtz
0.21
Drill Operator, Rotary
Source: MSHA respirable dust, quartz, and noise sampling records, updated weekly. Metal/nonmetal contaminant figures come from MSHA's Personal Health Samples and Area Samples files (public record), updated weekly.
Corona recorded 15.06 reportable injury cases per 100 full-time workers in 2025.
Injury rate, 2025
ⓘThis rate is reportable injury cases per 100 full-time-equivalent workers per year, computed as 200,000 times cases divided by MSHA operator-reported employee-hours. Cases are injuries MSHA graded degree 01 through 07; accident-only events that hurt no one are excluded, and so are contractor injuries, whose hours do not attach to a single mine. Rates begin in 2000, when quarterly employment reporting starts, and are withheld below 20,000 hours in a year.
15.06
total case rate
5.02
days-away rate
0.000
fatality rate
Above average. The US metal and nonmetal mining average was 1.65 and the all-US-mining average was 1.97 cases per 100 workers.
In California, metal and nonmetal mining averaged 1.42 cases per 100 workers that year.
Under 100,000 employee-hours were reported that year, so a single case moves the rate by two or more. Read the figure as approximate.
Year
total case rate
days-away
fatal
2025 *
15.06
5.02
0.000
2024 *
8.57
4.29
0.000
2023 *
7.17
7.17
0.000
2022 *
3.35
0.00
0.000
2021 *
9.85
3.28
0.000
2020 *
9.99
6.66
0.000
2019 *
3.10
3.10
0.000
2018 *
0.00
0.00
0.000
* Fewer than 100,000 employee-hours that year; the rate is less stable.
Source: injury cases from MSHA accident and injury records; employee-hours from MSHA quarterly employment reports. Rate is cases per 100 full-time-equivalent workers, operator employees only.
Source: MSHA controller and operator history, updated weekly.
Workforce and production
Year
Employees
2026
22
2025
19
2024
22
2023
25
2022
26
2021
25
2020
27
2019
26
2018
34
2017
38
2016
38
2015
42
2014
22
Source: MSHA quarterly employment and production, updated weekly.
Corona sits in Riverside County, California, where the Census mining category is 0.1% of county employment.
Local economic context
ⓘCounty figures come from the US Census Bureau's American Community Survey, 5-year pooled estimates, so the 2023 vintage covers 2019 through 2023. The Census category is 'mining, quarrying, and oil and gas extraction', which is broader than MSHA jurisdiction and includes oil and gas workers no mine employs. These figures describe the surrounding county, not this mine, and are not a factor in any specific incident.
Riverside County, California · Population 2,449,909
0.1%
Mining share of county employment
$89,672
Median household income
Source: US Census Bureau, American Community Survey 2023 5-year estimates.
Quarterly safety rates
ⓘCitations per million reported employee-hours. Rates begin in 2000, when MSHA's quarterly employment data starts; earlier incidents are counted but cannot be rate-adjusted. Quarters under 100,000 reported hours are greyed: too few hours for a stable rate.
Citations per million employee-hours, as reported to MSHA
Quarter
Hours worked
Citations
S&S
Per 1M hrs
2026 Q2
12,287
0
0
0.0
2026 Q1
10,734
0
0
0.0
2025 Q4
10,578
1
0
94.5
2025 Q3
10,082
0
0
0.0
2025 Q2
9,513
3
1
315.4
2025 Q1
9,674
0
0
0.0
2024 Q4
11,491
0
0
0.0
2024 Q3
11,951
1
0
83.7
Show 41 earlier quartersHide earlier quarters
Quarter
Hours worked
Citations
S&S
Per 1M hrs
2024 Q2
12,475
0
0
0.0
2024 Q1
10,757
0
0
0.0
2023 Q4
12,055
2
1
165.9
2023 Q3
15,312
0
0
0.0
2023 Q2
13,665
0
0
0.0
2023 Q1
14,774
0
0
0.0
2022 Q4
15,719
1
0
63.6
2022 Q3
14,933
0
0
0.0
2022 Q2
14,275
4
1
280.2
2022 Q1
14,808
0
0
0.0
2021 Q4
14,381
2
0
139.1
2021 Q3
15,285
0
0
0.0
2021 Q2
15,895
2
0
125.8
2021 Q1
15,346
3
0
195.5
2020 Q4
15,453
0
0
0.0
2020 Q3
14,018
0
0
0.0
2020 Q2
13,936
3
1
215.3
2020 Q1
16,651
1
0
60.1
2019 Q4
16,118
0
0
0.0
2019 Q3
16,957
0
0
0.0
2019 Q2
15,997
0
0
0.0
2019 Q1
15,505
1
1
64.5
2018 Q4
16,216
0
0
0.0
2018 Q3
17,384
0
0
0.0
2018 Q2
16,734
0
0
0.0
2018 Q1
17,715
1
1
56.4
2017 Q4
19,867
0
0
0.0
2017 Q3
19,856
3
2
151.1
2017 Q2
19,041
0
0
0.0
2017 Q1
19,219
2
0
104.1
2016 Q4
19,906
0
0
0.0
2016 Q3
20,411
0
0
0.0
2016 Q2
19,155
2
1
104.4
2016 Q1
22,413
0
0
0.0
2015 Q4
22,695
3
2
132.2
2015 Q3
22,961
0
0
0.0
2015 Q2
17,705
4
2
225.9
2015 Q1
11,864
0
0
0.0
2014 Q4
13,944
0
0
0.0
2014 Q3
12,382
0
0
0.0
2014 Q2
4,516
2
0
442.9
No fatalities recorded at this mine.
Reportable incidents
20 on file
2026 · 1 incident
May 14, 2026CA · Metal/Non-Metalmaintenance man, mechanic, repair/serviceman, boilermaker, fueler, tire tech, field service techPOWERED HAULAGE
Miner was conducting EE's plant walk facing the sand screw, which is a noisy area due to the shaker decks above, EE stated EE heard the skid steer operating, but when EE turned to EE's left to see where it was the skid steer knocked EE off EE's feet and into the bucket, causing shin and elbow injuries.
2025 · 3 incidents
December 30, 2025CA · Metal/Non-Metallaborer, blacksmith, bull gang, parts runner, roustabout, pick-up man, pitmanHANDLING OF MATERIALS
Miner was moving a haul truck wheel chock and felt pain in EE's left shoulder. EE missed no days of work but has now been put on restrictions from EE's Dr. that won't allow EE to perform EE's work duties and will be off work until further notice as of 1/20/2026.
Miner struck thumb with a hammer while trying to unstick a valve.
January 15, 2025CA · Metal/Non-Metalmaintenance man, mechanic, repair/serviceman, boilermaker, fueler, tire tech, field service techHANDLING OF MATERIALS
Miner was using a grinding tool, and a piece of metal hit miner's R-eye. Miner claims miner was wearing miner's prescription glasses and a face shield.
June 22, 2024CA · Metal/Non-Metalmaintenance man, mechanic, repair/serviceman, boilermaker, fueler, tire tech, field service techSTRIKING OR BUMPING
Miner was doing a belt splice, was using a claw hammer for belt clips and hit L-middle finger with the hammer.
2022 · 1 incident
October 17, 2022CA · Metal/Non-Metalmaintenance man, mechanic, repair/serviceman, boilermaker, fueler, tire tech, field service techHANDLING OF MATERIALS
Robertson's · Caught in, under or between a moving and a stationary object
Miner was working on cone crusher retaining ring when EE's left ring finger got pinched between the retaining ring and the shaft.
Employee was merely walking to the primary Jaw when EE started to experience a 'sharp pain' in the left knee. EE didn't report until the next day.
March 18, 2020CA · Metal/Non-Metalmaintenance man, mechanic, repair/serviceman, boilermaker, fueler, tire tech, field service techSLIP OR FALL OF PERSON
Miner was descending down a ladder when a foot slipped while they had a grasp of the ladder with left hand. The resulting sudden pull dislocated the left shoulder.
March 3, 2020CA · Metal/Non-Metalmaintenance man, mechanic, repair/serviceman, boilermaker, fueler, tire tech, field service techSLIP OR FALL OF PERSON
While walking down a set of stairs the miner tripped over EE's own foot and fell stumbling down landing on EE's right knee on the stairs. Injuring the right knee causing a contusion to right knee.
2019 · 1 incident
May 25, 2019CA · Metal/Non-Metalmaintenance man, mechanic, repair/serviceman, boilermaker, fueler, tire tech, field service techOTHER
Walking through the plant got debris in the left eye that irritates the eye
2017 · 2 incidents
September 15, 2017CA · Metal/Non-Metalsweeper operatorOTHER
Robertson's · Absorption of radiations, caustics, toxic and noxious substances
The employee was operating the sweeper when a bee crawled up their shirt sleeve and stung them in the arm. The sting resulted in swelling on their arm.
July 25, 2017CA · Metal/Non-Metalmaintenance man, mechanic, repair/serviceman, boilermaker, fueler, tire tech, field service techELECTRICAL
Miner was changing rotation on a motor. Did not properly Lock and Tag out the equipment. An arc flash occurred and the miner received 1st degree burns to hands and forearms.
2016 · 1 incident
January 12, 2016CA · Metal/Non-Metallaborer, blacksmith, bull gang, parts runner, roustabout, pick-up man, pitmanPOWERED HAULAGE
The miner was locking the pins in on the skid steer for another miner. The injured miner locked the pins on the skid steer and stepped back. When the operator of the skid steer moved the bucket the bucket fell off causing a contusion of the left foot.
2014 · 1 incident
July 23, 2014CA · Metal/Non-Metalbulldozer operator, universal operator, heavy equipment operator, operating engineerSLIP OR FALL OF PERSON