The decision this case can inform
Use this record when segmenting respirable-dust and silica risk by quarry, raw-feed, coal, and finished-product work instead of applying one plant-wide assumption.
Historical NIOSH industrial-hygiene survey. Results are specific to the people, tasks, materials, and standards sampled at Coplay at that time.
What the public record actually establishes
- F1
The survey evaluated total and respirable dust, quartz, trace elements, and process gases.
- F2
Four respirable nuisance-particulate samples exceeded 5 mg/m³.
- F3
Quartz was identified in 18 personal samples; six exceeded the then-applicable MSHA limit.
- F4
The report localized the principal quartz concern to quarry, raw-material, and coal-related work.
Facts and reported results are kept separate from the lesson a plant may choose to test.
Operating context
NIOSH evaluated total and respirable dust, quartz, trace elements, and gases.
Intervention or finding
Field sampling localized quartz exposure mainly to quarry, raw-material, and coal areas.
Documented result
Four respirable nuisance-particulate samples exceeded 5 mg/m3; quartz appeared in 18 personal samples and six exceeded the then MSHA limit.
Plant interpretation
Treat quarry, raw-feed, and coal systems as distinct exposure zones and verify source controls with job-specific sampling.
Transfer boundary
Historical limits; results describe sampled work and cannot be generalized to current conditions.
Questions to verify at your plant
These are decision checks, not operating instructions. Resolve them through local risk assessment, technical review, and authorization.
- 01
Are exposure groups separated by material and task, including quarry and coal-system work?
- 02
Which intermittent jobs could be diluted by full-shift averages or missed by area sampling?
- 03
Do current mineralogy data support the silica assumptions used in the exposure plan?
- 04
Are controls re-tested after feed-source, fuel, ventilation, or work-practice changes?