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MSHA DATABASEMSHA records · 16 contributing sources · snapshot Oct 13, 2026
Grupo Mexico S A B de C V→ASARCO LLC, a Delaware Limited Liability Company→SILVER BELL MINING LLC

MINE DETAILS

SILVER BELL MINING LLC

ActiveSurfaceCopper Ore NEC
MSHA MINE ID0200134
LOCATIONPima, AZ
PUBLIC RECORD6,722 linked rows

LOCATION

Mine location

1 of 1 mine with usable MSHA coordinates. Select a marker to open a mine.

Mine coordinates

2025-01-01 – 2026-10-13Applies to production, safety and portfolio metrics. Silica samples have separate filters.

2025 Q1 – 2026 Q4

JSONCSV

Database snapshot · 2026-10-13. MSHA quarterly production and employment reports.

Coal production

0

reported short tons

  1. 2025 Q10
  2. 2025 Q20
  3. 2025 Q30
  4. 2025 Q40
  5. 2026 Q10
  6. 2026 Q20
  7. 2026 Q3—No usable value reported
  8. 2026 Q4 *—No usable value reported

Hours worked

634,661

reported employee hours

  1. 2025 Q1103,493
  2. 2025 Q2107,003
  3. 2025 Q3109,927
  4. 2025 Q4101,370
  5. 2026 Q1104,267
  6. 2026 Q2108,601
  7. 2026 Q3—No usable value reported
  8. 2026 Q4 *—No usable value reported

Tons per hour

0.00

production ÷ hours worked

  1. 2025 Q10.00
  2. 2025 Q20.00
  3. 2025 Q30.00
  4. 2025 Q40.00
  5. 2026 Q10.00
  6. 2026 Q20.00
  7. 2026 Q3—No usable value reported
  8. 2026 Q4 *—No usable value reported

Missing values appear as —. Totals use available reports. Tons per hour requires production and hours for the same quarters and a nonzero hours total. * Striped bars mark partial mine coverage or an incomplete quarter. See the table for coverage.

Quarterly data and reporting coverage
Quarterly production, employment and reporting coverage for SILVER BELL MINING LLC
QuarterCoal (short tons)Hours workedTons / hourAvg. employeesCoverage
2025 Q10103,4930.002051/1 mines reporting
2025 Q20107,0030.002151/1 mines reporting
2025 Q30109,9270.002051/1 mines reporting
2025 Q40101,3700.002071/1 mines reporting
2026 Q10104,2670.002051/1 mines reporting
2026 Q20108,6010.002081/1 mines reporting
2026 Q3————No report
2026 Q4————No report

Safety and enforcement

2025-01-01 – 2026-10-13

Violations

14

2 significant & substantial (S&S)

  1. 2025 Q10
  2. 2025 Q20
  3. 2025 Q33
  4. 2025 Q40
  5. 2026 Q15
  6. 2026 Q20
  7. 2026 Q36
  8. 2026 Q4 *0

Accident records

8

0 records classified as fatality

  1. 2025 Q11
  2. 2025 Q23
  3. 2025 Q31
  4. 2025 Q40
  5. 2026 Q11
  6. 2026 Q21
  7. 2026 Q31
  8. 2026 Q4 *0

Proposed penalties · USD

10,304.00

13 of 14 violations with amounts

  1. 2025 Q1—
  2. 2025 Q2—
  3. 2025 Q3569
  4. 2025 Q4—
  5. 2026 Q17,544
  6. 2026 Q2—
  7. 2026 Q32,191
  8. 2026 Q4 *—

On-site inspection hours

127.75

11 inspections · 11 with hours

  1. 2025 Q11.00
  2. 2025 Q210.75
  3. 2025 Q325.00
  4. 2025 Q42.75
  5. 2026 Q140.75
  6. 2026 Q21.50
  7. 2026 Q346.00
  8. 2026 Q4 *0.00

Counts are published records, including contractor records. * The quarter was incomplete at the snapshot date; recent counts may rise as reports arrive. — means no reported amount or hours. Portfolio totals use current membership.

Quarterly safety data
QuarterViolationsS&SProposed USDAccident recordsFatality recordsInspectionsOn-site hours
2025-Q100—1011.0
2025-Q200—30110.8
2025-Q330569.0010125.0
2025-Q400—0012.8
2026-Q1517,544.0010340.8
2026-Q200—1011.5
2026-Q3612,191.0010246.0
2026-Q4 *00—0010.0

Most cited CFR sections

All violations issued in the selected period. Counts combine subsections.

SectionViolationsS&S
30 CFR 56.12004Electrical conductors.30
30 CFR 56.15001First-aid materials.21
30 CFR 48.27Training of miners assigned to a task in which they have had no previous experience; minimum courses of instruction.10
30 CFR 50.30Preparation and submission of MSHA Form 7000-2—Quarterly Employment and Coal Production Report.10
30 CFR 56.11001Safe access.10
30 CFR 56.12018Identification of power switches.10
30 CFR 56.14101Brakes.11
30 CFR 56.14207Parking procedures for unattended equipment.10
30 CFR 56.23002Written safety program.10
30 CFR 56.23003Requirements for written safety program.10

Safety activity

  1. inspectionF0211FF

    103 (g) Written Notification Hazard Complaint Inspectio · 0.0 on-site hours

  2. inspectionF0343E2

    103 (g) Written Notification Hazard Complaint Inspectio · 4.5 on-site hours

  3. violation5221253

    56.14101(a)(2) · S&S · $1,320.00 proposed

  4. violation5221252

    56.12004 · $151.00 proposed

  5. violation5221251

    56.12004 · $151.00 proposed

  6. violation5151833

    56.23002(b) · $267.00 proposed

  7. violation5151832

    56.23003(b) · $151.00 proposed

  8. violation5151831

    56.11001 · $151.00 proposed

  9. inspectionF014D6F

    Regular Safety and Health Inspection · 41.5 on-site hours

  10. accident220262250011

    SLIP OR FALL OF PERSON · DAYS AWAY FROM WORK ONLY

    Accident narrative

    on 8/11/2026 the company was notified it was deemed as a work-related injury. Employee engaged in non-work-related activities by rushing down the stairs to give another employee a fork when EE slipped and fell resulting in a lumbar compression fraction

  11. accident220261530006

    HANDTOOLS (NONPOWERED) · DAYS RESTRICTED ACTIVITY ONLY

    Accident narrative

    EE was assisting another employee that was working on a dozer when EE's left middle finger got in the way of the hammer and was struck causing EE to need 2 sutures.

  12. inspection6858855

    Verbal Hazard Complaint Inspections · 1.5 on-site hours

  13. inspectionF013EE3

    Verbal Hazard Complaint Inspections · 6.0 on-site hours

  14. accident220260620009

    SLIP OR FALL OF PERSON · DAYS AWAY FROM WORK ONLY

    Accident narrative

    EE was stepping off the Haul Truck ladder onto uneven ground, when EE felt and heard a loud pop, and states EE felt instant pain.

  15. violation5036985

    50.30(a) · $151.00 proposed

  16. violation5030901

    56.12018 · $151.00 proposed

  17. inspectionF00E3E0

    Regular Safety and Health Inspection · 22.0 on-site hours

  18. inspectionF004804

    Verbal Hazard Complaint Inspections · 12.8 on-site hours

  19. violation5052178

    48.27(a)(1) · $2,371.00 proposed

  20. violation5052177

    56.15001

  21. violation5052176

    56.15001 · S&S · $4,871.00 proposed

  22. inspectionF022CB2

    103 (g) Written Notification Hazard Complaint Inspectio · 2.8 on-site hours

  23. inspectionF012389

    Regular Safety and Health Inspection · 25.0 on-site hours

  24. violation9768397

    56.12004 · $267.00 proposed

  25. violation9768396

    56.4102 · $151.00 proposed

Safety sources and definitions

MSHA Violations (issue date), Accidents (accident date), and Inspections (begin date). Snapshot 2026-10-13.

Counts describe published rows, including contractor records; accident records are not distinct incidents or numbers of people injured.

Zero means no matching records in the imported sources, not proof of no events. Historical coverage differs by source; absence before a source begins reporting is not a zero incident rate. Invalid or absent dates and records after the snapshot are excluded.

S&S means SIG_SUB=Y. Fatality records use DEGREE_INJURY_CD=01. Proposed penalties are not final assessed or paid amounts; missing dollar values are omitted.

Inspection hours are SUM_TOTAL_ON_SITE_HOURS attributed to the inspection start date, without supervisor/trainee hours. Missing hours are omitted; a started inspection may still be open.

Portfolio totals use current mine membership, including events before the current owner or operator's tenure.

CFR headings link to the current Title 30 index; they are not historical legal determinations.

OWNERSHIP

Operator and controller history

Current ownership comes from MSHA Mines. Historical start and end dates come from MSHA Controller and Operator History.

CURRENT HIERARCHYGrupo Mexico S A B de C V → ASARCO LLC, a Delaware Limited Liability Company → SILVER BELL MINING LLC
HISTORY RECORDS26 relationships
INTERVAL CHECKPASScontroller/operator overlap
—

Grupo Mexico S A B de C VcontrolsASARCO LLC, a Delaware Limited Liability CompanyoperatesSILVER BELL MINING LLC

msha-controller-operator-history · controller/operator co-tenure derived on mine 0200134
—

Asarco InccontrolsSilver Bell Mining LlcoperatesSILVER BELL MINING LLC

msha-controller-operator-history · controller/operator co-tenure derived on mine 0200134
Other historical summaries · source-specific periods

RECORD SUMMARY

Production, safety and enforcement

These summaries use the periods stated on each card, independently of the reporting period above.

01 / SAFETYwatch

Accidents and injuries

185 historical accident/injury rows; 0 coded fatalities and 3,310 lost days across the published record.

ACCIDENT + INJURY RECORD24 since 2021
accidentsmine-production-quarterly
02 / COMPLIANCEwatch

Violations and penalties

447 violation rows across the full record; 77 carry an S&S flag and $181,056 appears in current assessed amounts.

ENFORCEMENT ACTIVITY44 since 2021
inspectionsviolationsassessed-violationsorders-107a
03 / HEALTHcontext

Occupational health samples

91 personal; 6 area. 0 personal-sample rows have a published C/E ratio above 1; 0 noise rows have an action-level or PEL dose above 100%. These are separate measures, not a silica exceedance count. Silica results and sample status are shown separately.

OCCUPATIONAL EXPOSURE97 samples
personal-health-samplesarea-samples
04 / PRODUCTIONcontext

Quarterly production and employment

109K employee hours and 208 summed average employees across reported subunits in the latest published quarter.

2026-Q20 tons
mine-production-quarterlymine-production-yearly
05 / LEGALwatch

Contests, conferences and decisions

44 contested-violation rows, 46 civil-penalty docket/decision rows, and 21 conference records linked by issuance number.

POST-ISSUANCE LIFECYCLE111 linked rows
conferencescontested-violationscivil-penalty-dockets-decisions
06 / CONTRACTORScontext

Contractors

Contractors are linked through this mine’s violation or accident records. Their production and hours cover all their operations, so they are not included in this mine’s totals.

ENTITY-LEVEL CONTEXT21 linked entities
contractor-production-quarterlycontractor-production-yearlyaccidentsviolations
07 / INSPECTIONScontext

Inspections

116 inspection events and 4K published inspection hours across the historical record.

OVERSIGHT COVERAGE28 since 2021
inspectionsviolations

HEALTH SAMPLING

Silica and quartz

Coal quartz, metal/nonmetal personal samples and area samples. Snapshot Oct 13, 2026. 18 silica records across the mine’s published history.

Matching records00 coal · 0 personal · 0 area
Sample status0 not voided0 voided · 0 status not reported
Personal samples with C/E > 1—0 published ratios · not a citation count

Personal silica samples · concentration / limit

Quarterly mean · published C/E ratio

  1. 2026-Q1—0 measurements
  2. 2026-Q2—0 measurements
  3. 2026-Q3—0 measurements
  4. 2026-Q4*—0 measurements

— No eligible measurements. * Quarter in progress. Means describe the available samples, not average exposure across the mine.

Quartz % is the sample’s quartz content; µg/m³ is its reported concentration. Personal C/E is the ratio to the limit published with that sample. Personal and area concentration units and void status are not specified in those source files.

2026 · No reported dates in this selection
Date / sampleDataset / analyteOccupation / areaMeasurementSample statusPublished action
No silica records match these filters. Missing samples do not establish safe conditions.
Sources and interpretation
  • Coal means use numeric concentrations from samples marked not voided, excluding control/invalid sample types and dates after the snapshot. Missing values remain null; reported zeroes remain zero.
  • Quarterly means describe available samples, not mine-wide or worker-average exposure. Quarters with no eligible measurements remain empty; the current quarter is partial.
  • Personal C/E is MSHA's published concentration-to-limit ratio. A value above 1 is not by itself a citation or a determination under the 2024 silica rule. Personal and area files do not publish a void-status field.
  • Area records include bulk-dust analyses and are kept separate from personal exposure results. Their concentration units are not specified in the source dictionary.
  • Missing samples do not establish safe conditions. Coal quartz percentage and concentration are separate measures. No compliance threshold is inferred for coal samples.

Coal quartz field definitions ↗Metal/nonmetal personal field definitions ↗Metal/nonmetal area field definitions ↗

EIA + TITLE 30

EIA production and cited regulations

EIA annual figures are reported separately from MSHA. Regulation links use the current eCFR snapshot.

EIA MINE CONTEXTNo matched record
Not present in the 2024 EIA coal workbook.

This can mean the operation is non-coal, inactive for the annual period, or outside the EIA-7A reporting population.

TITLE 30 CROSSWALKCurrent through 2026-08-19
30 CFR 56.14101Brakes.1 recent row ↗30 CFR 56.12004Electrical conductors.3 recent rows ↗30 CFR 56.23002Written safety program.1 recent row ↗30 CFR 56.23003Requirements for written safety program.1 recent row ↗30 CFR 56.11001Safe access.1 recent row ↗30 CFR 50.30Preparation and submission of MSHA Form 7000-2—Quarterly Employment and Coal Production Report.1 recent row ↗30 CFR 56.12018Identification of power switches.1 recent row ↗30 CFR 48.27Training of miners assigned to a task in which they have had no previous experience; minimum courses of instruction.1 recent row ↗

RECENT PUBLIC RECORDS

Recent violations and samples

Latest records retained for inspection; aggregates above use the full source history.

VIOLATIONS12 latest shown
522125356.14101(a)(2)S&S
522125256.12004Citation
522125156.12004Citation
515183356.23002(b)Citation
515183256.23003(b)Citation
515183156.11001Citation
503698550.30(a)Citation
503090156.12018Citation
OTHER HEALTH SAMPLES8 latest shown

Coal dust, noise and other contaminants. Silica records above ↑

Respirable dust, <.1mgTruck Driver
C/E: 00.00Concentration: 0000.00 · limit: 0000.00Source unit unspecified
Respirable dust, <.1mgTruck Driver
C/E: 00.00Concentration: 0000.00 · limit: 0000.00Source unit unspecified
Respirable dust, <.1mgFlotation/Concentrator Oper.
C/E: 00.00Concentration: 0000.00 · limit: 0000.00Source unit unspecified
Respirable dust, <.1mgFlotation/Concentrator Oper.
C/E: 00.00Concentration: 0000.00 · limit: 0000.00Source unit unspecified
Respirable dust, <.1mgFlotation/Concentrator Oper.
C/E: 00.00Concentration: 0000.00 · limit: 0000.00Source unit unspecified
Respirable dust, <.1mgFlotation/Concentrator Oper.
C/E: 00.00Concentration: 0000.00 · limit: 0000.00Source unit unspecified
Respirable dust, <.1mgTruck Driver
C/E: 00.00Concentration: 0000.00 · limit: 0000.00Source unit unspecified
Respirable dust, <.1mgBulldozer Operator
C/E: 00.00Concentration: 0000.00 · limit: 0000.00Source unit unspecified

SOURCE COVERAGE

Reporting dates and coverage

16 datasets contain linked records. Missing datasets are listed below.

DATASETROWSWINDOWSTATUS
Accident, Injuries, and Illnessessafety · contractors185Mar 31, 2000—Jul 28, 2026mine-keyed
Addresses of Recordidentity · logistics1Feb 24, 2026—Feb 24, 2026mine-keyed
Assessed Violationscompliance · legal444Mar 30, 2000—Aug 23, 2026mine-keyed
Civil Penalty Dockets and Decisionscompliance · legal46Feb 27, 2002—Nov 25, 2024mine-keyed
Coal Dust Sampleshealth · safety—No published rowsabsent / not applicable
Conferencescompliance · legal21Nov 2, 2000—Oct 12, 2021mine-keyed
Contested Violationscompliance · legal44Mar 1, 2007—Feb 18, 2026mine-keyed
Contractor Employment and Production — Quarterlycontractors · production · safety4,094Not published—Not publishedentity-linked
Contractor Employment and Production — Yearlycontractors · production · safety825Not published—Not publishedentity-linked
Controller and Operator Historyidentity · compliance2Jan 1, 1950—Mar 1, 2000mine-keyed
Mine Employment and Production — Quarterlyproduction · safety · compliance318Not published—Not publishedmine-keyed
Mine Employment and Production — Yearlyproduction · safety · compliance81Not published—Not publishedmine-keyed
Inspectionssafety · compliance116Mar 27, 2000—Oct 6, 2026mine-keyed
Minesidentity · production · logistics1Not published—Not publishedmine-keyed
Metal and Nonmetal Area Sampleshealth · safety6Mar 11, 2004—Dec 22, 2010mine-keyed
Metal and Nonmetal Personal Health Sampleshealth · safety91Mar 11, 2004—Apr 2, 2025mine-keyed
Noise Sampleshealth · safety · equipment—No published rowsabsent / not applicable
Quartz Samples — Coalhealth · safety—No published rowsabsent / not applicable
Violationscompliance · safety · legal447Mar 30, 2000—Aug 23, 2026mine-keyed
107(a) Orders Issuedsafety · compliance—No published rowsabsent / not applicable

NOTES

Limitations

  • Contractor production is entity-level and is never represented as mine-attributable.
  • Missing rows can mean no event, publication delay, identity mismatch, or inapplicability.