Amboy Limestone Quarry has $925 in proposed MSHA penalties and $0 outstanding across 0 contested dockets, plus health sampling and the full incident record.
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Fatalities
0
Total incidents
2
Years on record
2008
Latest incident
May 2008
Compliance record
MSHA citations since 2004
10
citations
0
significant & substantial
$925
proposed penalties
$925
paid to date
100% of proposed penalties paid to date, a $0 gap.
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: 178 inspection hours is too few for a stable rate. A minimum of 1,000 inspection hours is required.
Source: MSHA inspections data, updated weekly.
Amboy Limestone Quarry has $925 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.
$925
proposed penalties
$925
current assessed
$925
paid to date
$0
outstanding
10 assessments are final orders; 0 contested dockets.
As of the most recent assessment on 2020-01-22.
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: 2020-01-22, 6 years ago
0%
of limit-tested samples over the exposure limit
5
samples
4
limit-tested
Most sampled contaminants
Nuisance dust, total, <1% Qtz4
Respirable dust, <.1mg1
Show the individual readings (5)
Date
Contaminant
Concentration
Limit
Conc / limit
Occupation
2020-01-22
Respirable dust, <.1mg
0
Truck Driver
2009-03-03
Nuisance dust, total, <1% Qtz
0.86
10
0.09
Truck Driver
2009-03-03
Nuisance dust, total, <1% Qtz
1.41
10
0.14
Truck Driver
2009-03-03
Nuisance dust, total, <1% Qtz
1.8
10
0.18
Front-end Loader Operator
2009-03-03
Nuisance dust, total, <1% Qtz
3.39
10
0.34
Truck Driver
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.
Source: MSHA controller and operator history, updated weekly.
Workforce and production
Year
Employees
2026
5
2023
1
2020
6
2011
1
2009
10
2008
5
2007
8
2006
2
2005
3
2004
3
2003
3
2002
2
2001
3
2000
2
Source: MSHA quarterly employment and production, updated weekly.
Amboy Limestone Quarry sits in San Bernardino 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.
San Bernardino County, California · Population 2,187,816
0.1%
Mining share of county employment
$82,184
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
4,050
0
0
0.0
2026 Q1
856
0
0
0.0
2023 Q2
329
0
0
0.0
2023 Q1
586
0
0
0.0
2020 Q1
1,911
1
0
523.3
2011 Q2
452
0
0
0.0
2011 Q1
392
0
0
0.0
2009 Q2
1,789
0
0
0.0
Show 33 earlier quartersHide earlier quarters
Quarter
Hours worked
Citations
S&S
Per 1M hrs
2009 Q1
4,563
1
0
219.2
2008 Q4
1,018
0
0
0.0
2008 Q2
2,236
0
0
0.0
2008 Q1
3,745
0
0
0.0
2007 Q4
2,183
0
0
0.0
2006 Q4
46
0
0
0.0
2006 Q3
92
0
0
0.0
2006 Q2
42
0
0
0.0
2006 Q1
53
0
0
0.0
2005 Q4
36
0
0
0.0
2005 Q3
24
0
0
0.0
2005 Q2
157
0
0
0.0
2005 Q1
97
0
0
0.0
2004 Q4
136
0
0
0.0
2004 Q3
134
0
0
0.0
2004 Q2
153
0
0
0.0
2004 Q1
120
0
0
0.0
2003 Q4
90
0
0
0.0
2003 Q3
72
0
0
0.0
2003 Q2
217
0
0
0.0
2003 Q1
320
0
0
0.0
2002 Q4
104
0
0
0.0
2002 Q3
0
0
0
2002 Q2
14
0
0
0.0
2002 Q1
422
0
0
0.0
2001 Q4
172
0
0
0.0
2001 Q3
113
0
0
0.0
2001 Q2
14
0
0
0.0
2001 Q1
1,078
0
0
0.0
2000 Q4
0
0
0
2000 Q3
1,068
0
0
0.0
2000 Q2
1,557
0
0
0.0
2000 Q1
692
0
0
0.0
No fatalities recorded at this mine.
Reportable incidents
2 on file
2008 · 2 incidents
May 5, 2008CA · Metal/Non-Metalassayer, geologist, metallurgist, engineer, engineer managementSLIP OR FALL OF PERSON