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: 272 inspection hours is too few for a stable rate. A minimum of 1,000 inspection hours is required.
Source: MSHA inspections data, updated weekly.
Principio Quarry has $7K in proposed MSHA penalties and $0 outstanding across 2 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.
$7K
proposed penalties
$7K
current assessed
$7K
paid to date
$0
outstanding
33 assessments are final orders; 2 contested dockets.
Of $529 in penalties contested before the Commission, $529 was upheld in final decisions.
As of the most recent assessment on 2026-06-11.
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.
When citations were contested
ⓘContesting a citation before the Federal Mine Safety and Health Review Commission is a lawful right. These figures state the public outcomes of that process, from MSHA's Contested Violations file.
2citations taken to the federal commission · 6% of citations on record
Stood as issued
2 · 100%
100%
S&S designation survived the contest
ⓘCounts a Significant & Substantial citation as surviving when a settlement or judge's decision kept the designation, or the contest was dismissed or defaulted so the citation stands as issued. Vacated and withdrawn citations, and settlements that removed the designation, count against.
of 1 decided S&S contests · industry: 79%
0%
Penalty reduction in decided contests
$529 proposed, $529 after decisions · industry: 39%
Source: MSHA Contested Violations file (public record), updated weekly. A dismissed or defaulted contest leaves the citation standing as issued; a vacated or withdrawn citation is removed from the violation record. Latest contest filed 2025-03-02.
Contested penalties
ⓘA reduction or dismissal at the Commission is a lawful outcome of contesting a proposed penalty. Figures are the proposed amount and the amount upheld in the docket's decision.
Largest penalties this mine contested before the Federal Mine Safety and Health Review Commission, with the outcome on record.
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: 2025-11-25
0%
of limit-tested samples over the exposure limit
11
samples
7
limit-tested
Most sampled contaminants
Quartz, respirable, >1% Qtz6
Respirable dust, <.1mg2
Arsenic fumes1
Beryllium fumes1
Show the individual readings (23)
Date
Contaminant
Concentration
Limit
Conc / limit
Occupation
2025-11-25
Respirable dust, <.1mg
0
Crusher Oper/Worker
2025-11-25
Respirable dust, <.1mg
0
Laborer, Bullgang
2025-11-25
Unlisted Particulate, respirable, <1% Qtz
0.85
Crusher Oper/Worker
2025-06-03
Quartz, respirable, >1% Qtz
0.61
0.97
0.63
Crusher Oper/Worker
2025-06-03
Quartz, respirable, >1% Qtz
0.27
0.46
0.59
Laborer, Bullgang
2025-06-03
Quartz, respirable, >1% Qtz
0.14
Front-end Loader Operator
2024-06-13
Quartz, respirable, >1% Qtz
0.42
1.15
0.37
Crusher Oper/Worker
2024-06-13
Quartz, respirable, >1% Qtz
0.39
0.52
0.75
Laborer, Bullgang
2024-06-13
Quartz, respirable, >1% Qtz
0.21
0.7
0.30
Crusher Oper/Worker
2022-12-08
Manganese fumes
0.05
5
0.01
Welder, etc.
2022-12-08
Molybdenum fumes
0
10
0.00
Welder, etc.
2022-12-08
Arsenic fumes
0
500
0.00
Welder, etc.
2022-12-08
Vanadium fumes
0
50
0.00
Welder, etc.
2022-12-08
Zinc oxide fumes
0
5
0.00
Welder, etc.
2022-12-08
Nickel fumes
0
1
0.00
Welder, etc.
2022-12-08
Beryllium fumes
0
2
0.00
Welder, etc.
2022-12-08
Cadmium oxide fumes
0
100
0.00
Welder, etc.
2022-12-08
Chromium, insoluble
0
1
0.00
Welder, etc.
2022-12-08
Cobalt fumes
0
100
0.00
Welder, etc.
2022-12-08
Copper fumes
0
100
0.00
Welder, etc.
2022-12-08
Iron oxide fumes
0.29
10
0.03
Welder, etc.
2022-12-08
Lead fumes
0
150
0.00
Welder, etc.
2022-12-08
Magnesium oxide fumes
0
10
0.00
Welder, etc.
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.
Principio Quarry recorded 0.00 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.
0.00
total case rate
0.00
days-away rate
0.000
fatality rate
Below 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 Maryland, metal and nonmetal mining averaged 1.64 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 *
0.00
0.00
0.000
2024 *
2.90
2.90
0.000
2023 *
6.28
0.00
0.000
2022 *
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
23
2025
24
2024
30
2023
33
2022
16
2021
12
Source: MSHA quarterly employment and production, updated weekly.
Principio Quarry sits in Cecil County, Maryland, 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.
Cecil County, Maryland · Population 104,366
0.1%
Mining share of county employment
$91,146
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
14,089
1
1
71.0
2026 Q1
10,441
0
0
0.0
2025 Q4
15,196
0
0
0.0
2025 Q3
13,404
0
0
0.0
2025 Q2
16,632
1
0
60.1
2025 Q1
12,528
0
0
0.0
2024 Q4
19,373
1
0
51.6
2024 Q3
17,506
0
0
0.0
Show 12 earlier quartersHide earlier quarters
Quarter
Hours worked
Citations
S&S
Per 1M hrs
2024 Q2
18,307
1
0
54.6
2024 Q1
13,703
0
0
0.0
2023 Q4
15,893
3
1
188.8
2023 Q3
15,975
0
0
0.0
2023 Q2
16,911
5
2
295.7
2023 Q1
14,920
0
0
0.0
2022 Q4
14,897
1
0
67.1
2022 Q3
12,206
1
0
81.9
2022 Q2
8,210
0
0
0.0
2022 Q1
2,435
2
1
821.4
2021 Q4
6,837
0
0
0.0
2021 Q3
6,290
0
0
0.0
No fatalities recorded at this mine.
Reportable incidents
6 on file
2026 · 2 incidents
June 2, 2026MD · Metal/Non-Metalmaintenance man, mechanic, repair/serviceman, boilermaker, fueler, tire tech, field service techPOWERED HAULAGE
Employee was attempting to track the return side of the conveyor belt by striking the frame of the roller with a hammer to move it backwards. EE missed and EE's hand got caught between the conveyor belt and roller.
Employee was tightening a bolt on Crusher 2 (CR2) with a torque wrench and torque multiplier. After tightening bolt, the torque multiplier came loose and dropped. Employee reacted by attempting to catch the multiplier. The multiplier jammed employee's left hand.
2023 · 2 incidents
September 25, 2023MD · Metal/Non-Metalbulldozer operator, universal operator, heavy equipment operator, operating engineerHANDLING OF MATERIALS