O-N Minerals (Chemstone Company) safety activity

MSHA Violations (issue date), Accidents (accident date) and Inspections (begin date).

Violation titles use current CFR headings to identify the cited rule; they are not the inspector’s account of what happened.

Status is from the current MSHA Mines snapshot, not the selected reporting period. Closed records can retain their last reported controller/operator.

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.