Rock Dust Updates from NIOSH Partnership Mtg

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1 Rock Dust Updates from NIOSH Partnership Mtg June 2, 2016 Dave Anstine - Senior Technical Leader, Building and Chemicals

2 In-Mine Development of Rock Dust & Impact on CPDM Measurements With Treated Rock Dust Which is Able to Resist Wetting & Caking; Will Treated Rock Dust Create More Respirable Dust Than Untreated Dust During Normal Mine Operation? Yes, Data From Stockton Mine Study Regular Dust Used in Mine = 500 mg/cu. m Treated Rock Dust = = 850 mg/cu. M What is the Impact of Rock Dusting at the Mine Heading Face to meet 80% Requirement? Being Researched How Does Re-entrainment From Equipment and Personnel Movement Impact CPDM? Description Untreated Rock Dust Treated Rock Dust Initial Dusting 0.3mg/cu.m 850mg/cu.m ReDust 1.2mg/cu.m 850mg/cu.m Scoop Dry Floor 0.1mg/cu.m 1.8mg/cu.m Scoop Wet Floor 0.10mg/cu.m 0.16mg/cu.m Wetting Floor Entry 0.12mg/cu.m 4.24mg/cu.m 2

3 Ideal Engineered Rock Dust Reduce the Respirable Component; Minimize Rock Dust Particles <10 microns Should Not Contribute to CPDM Readings. Should Not Contain Respirable Silica Particles Did Reduce But Did Not Eliminate Respirable Dust Fraction Should Minimize Health Hazard from Anti-Caking Additive Must Balance Respirable Component With Inerting Effectiveness Have to Maintain 20-L Chamber Inerting Limits Should Be As Effective As Current Rock Dust in Maintaining the 80% Rule Reduced the Dispersibility Within the Dispersion Chamber Will It Lift With the Smaller Coal Dust Particles? Will Remain Dispersible When Applied to Wet Surfaces Continue to Evaluate Surface Treatments 3

4 Ideal Foamed Rock Dust Applied Wet Adheres to Ribs & Roof Dries in High Humidity When Dry, Is As Dispersible As the Rock Dust Supporting the 80% Rule Inerts As Well As Rock Dust Supporting the 80% Rule 1 Part Foam Foam Structures Collapsed During Long Periods of High Humidity Foams Were Not Dispersible in Dust Dispersion Chamber or Bruceton Mine Area Top Coated With Treated Rock Dust Remained Dispersible Hydrophobic Nature of Foamed Treated Rock Dust Were Not Recovered Drying Took Several Months 2 Part Foam Multiple Densities Were Investigated All Were Relatively Light No Dust Detected Downwind 4

5 Ideal Foamed Rock Dust(continued) 2 Part Foam Some Shrinkage of Samples Dried Within the Bruceton Mine Many Samples Remained Dispersible None Met the Relative Dispersibility of the Untreated Rock Dust used to Support the 80% Rule 5

6 Comparative Cytotoxicity of Treated/Untreated Rock Dusts Summary of Study done by Martin Harper of NIOSH Health Effects Lab Objective was to compare cytotoxicity outcomes of 4 rock dusts Treated & Untreated Limestone Treated & Untreated Marble Cell viability, Cell membrane damage, Cell morphology and Inflammatory Cytokines were assessed after a hour exposure to human alveolar epithelial cells with varying concentrations of rock dust samples Following the procedures described in more detail in the NIOSH Report; No Significant Differences in Cellular Responses Were Seen After Exposure to Treated/Untreated Limestone or Marble Respirable Rock Dust Samples The Rock Dust Particles Were Able to Induce Some Inflammatory Cytokine Production in the Human Cells, However, They Were Considerably Less Potent Compared to Endotoxin (LPS), a known Lung Inflammatory Agent These Results Must Be Considered as a Preliminary Toxicological Assessment Moreover, Complex Interactions Within the Body Would Require Additional Testing To Assess the Long-Term Risk for Human Exposure, Further Studies are Needed. 6

7 Quartz Content of Four Rock Dusts 4 Rock Dust Samples Were Selected and Separated by FSP-10 Respirable Size Cyclones and Micro-Orifice Uniform Deposit Impactor Treated & Untreated Limestone Treated & Untreated Marble The FSP-10 Respirable Fractions of both the Untreated and Treated Limestone Samples Had Significantly Higher Percentages of Quartz Than the Initial Bulk Samples But The M.O.U.D.I Samples Did Not. The Untreated and Treated Marble Had Low Quartz Content and the Respirable Fractions Were Not Significantly Enriched Compared to the Bulk Samples By Any Technique Conclusion: Quartz Enhancement Can Be Different, Depending Upon the Measurement Method Used. 7

8 Next Steps Additional Field Testing Verify Re-entrainment Controls Impacts of Rock Dust on CPDM Readings Engineered Rock Dusts Balance Inerting Potential with Respirable Dust Generation Foamed Rock Dusts Pursue Different Formulations to Improve Dispersibility & Drying Time Develop New Means to Assess Additional Testing for Health Effects Long Term 8

9 Questions?

SAFETY DATA SHEET. Product Name: Fertilizer with Pendimethalin (0.66%) (0.75%) (0.86%) (1.0%) (1.15%)

SAFETY DATA SHEET. Product Name: Fertilizer with Pendimethalin (0.66%) (0.75%) (0.86%) (1.0%) (1.15%) 1. IDENTIFICATION Product Name: Fertilizer with Pendimethalin (0.66%) (0.75%) (0.86%) (1.0%) (1.15%) Product Type: Solid Granule Recommended use / restrictions of use: Professional applications or Agricultural