73% of proposed penalties paid to date, a $180,328 gap.
Source: MSHA violations data, updated weekly.
Inspection activity
MSHA inspections since 2000
342
inspections on record
18,119
inspection hours
9.9
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.
1,788 citations across 18,119 inspection hours.
Source: MSHA inspections data, updated weekly.
Penalty disposition
ⓘDifferences between proposed and paid penalties reflect both settlements and conference reductions and amounts still owed. Outstanding is the balance currently owed.
$671K
proposed penalties
$611K
current assessed
$491K
paid to date
$120K
outstanding
1,763 assessments are final orders; 20 contested dockets.
Of $111K in penalties contested before the Commission, $50K was upheld in final decisions.
As of the most recent assessment on 2026-06-05.
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.
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.
3.37
total case rate
0.92
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.
Year
total case rate
days-away
fatal
2026
3.08
1.23
0.000
2025
3.37
0.92
0.000
2024
4.29
1.84
0.000
2023
3.29
0.90
0.000
2022
2.43
0.30
0.000
2021
2.52
1.57
0.000
2020
3.34
1.34
0.000
2019
1.85
0.31
0.000
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.
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: 2026-06-04
1%
of limit-tested samples over the exposure limit
121
samples
75
limit-tested
Most sampled contaminants
Quartz, respirable, >1% Qtz91 over
Nuisance dust, respirable, <1% Qtz31
Respirable dust, <.1mg28
Arsenic fumes14
Area samples (mill and shop air)
Last sampled: 2010-01-27, 16 years ago
6
samples
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.
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.
34citations taken to the federal commission · 2% of citations on record
Settled
21 · 62%
Stood as issued
3 · 9%
Vacated or withdrawn
3 · 9%
Still open
7 · 21%
73%
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 11 decided S&S contests · industry: 79%
56%
Penalty reduction in decided contests
$102K proposed, $45K 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 2026-05-27. Vacated and withdrawn citations are removed from the file this view attributes through, so that outcome is slightly undercounted here.
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 operator contested before the Federal Mine Safety and Health Review Commission, with the outcome on record.
O-N Minerals (Michigan) Company · Caught in, under or between a moving and a stationary object
Supervisor pick-up was struck by haul truck, resulting in a fatality.
For insurers, brokers, and safety consultants
Where O-N Minerals (Michigan) Company stands on silica, penalties, and injury rate
MSHA's standard limits respirable silica to 50 micrograms per cubic metre, but MSHA publishes
dust and quartz as separate files and never the silica figure itself. We derive it per sample,
score it against the limit, and set the operator's injury rate against a benchmark built from
the full MSHA operator record. With the 26-year penalty trail, contest posture, and fatality
history. Delivered as a PDF with the underlying data as CSV.