Attachment 5_Dust Explosivity Report_Jan2025_Redacted.pdf

This is a laboratory report documenting the explosibility testing of dust clouds from fiberglass sanding booth material collected from Building 10 at Tobyhanna Army Depot. The analysis was conducted by EMSL Analytical, Inc. using standardized methods including OSHA ID201SG, ASTM E1226-12, and ASTM D6913-17, with testing performed in a 20-liter Siwek chamber equipped with mechanical sieve systems and X-ray fluorescence spectrometry.

The fibrous glass dust sample (EMSL Sample ID 362403510-0001) was received on December 31, 2024, and determined to be "explosive" in dust form based on Go/No Go screening tests conducted with a 5 kJ ignition source. Key combustible dust parameters include: 1.37% sieve retention at 40 mesh, 98.63% passing 40 mesh, 1.21% moisture content, 68.28% combustible material, and 67.34% combustible dust. Explosion severity testing yielded a maximum pressure (Pmax) of 8.1 ± 10% bar, maximum rate of pressure rise of 586 ± 12% bar/s, and maximum normalized rate of pressure rise (Kst) of 159 ± 12% bar m/s, classifying the material as St 1 (weak explosion). Elemental composition analysis via XRF identified silica dioxide (29.988 wt%) as the primary component, followed by calcium oxide (17.687 wt%), aluminum oxide (13.533 wt%), and titanium dioxide (11.826 wt%), among other trace elements. The report includes definitions of combustible dust hazard classifications per NFPA standards and 29 CFR 1910.399, guidance on Class II and Class III hazardous locations, and conditions that may indicate dust explosion hazards in industrial facilities.