1 / 18

Managing Combustible Dust in Manufacturing - My Experience in Ontario

Managing Combustible Dust in Manufacturing - My Experience in Ontario. Paul Bozek, PEng CIH ROH RT 215 Managing and Regulating Combustible Dust. Outline. Definition of “Combustible” Dusts Typical hazardous processes Typical controls and Issues (examples)

webb
Download Presentation

Managing Combustible Dust in Manufacturing - My Experience in Ontario

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Managing Combustible Dust in Manufacturing - My Experience in Ontario Paul Bozek, PEng CIH ROH RT 215 Managing and Regulating Combustible Dust

  2. Outline • Definition of “Combustible” Dusts • Typical hazardous processes • Typical controls and Issues (examples) • Regulatory Requirements/Guidelines and Programs to manage the risk

  3. Manufacturing Sites Not a comprehensive list, just example industries

  4. Definition of “Combustible Dust” [Pmax x (dP/dt)max]2 Explosion Severity = ------------------------------ (>0.5) [Pmax x (dP/dt)max]1 [MIT x MIE x MEC]1 Ignition Sensitivity = ------------------------------- (>0.2) [MIT x MIE x MEC]2 1 = Pitt Coal 2 = Subject Dust

  5. Definition of “Combustible Dust” • “…..presents risk of fire or deflagration hazard when suspended in air…. • Definition used to include, “<420 microns” • Good Aspects • Not “normally present” suspended in occupied workspaces • Min Explosive Conc. often 1000x OEL

  6. Definition of “Combustible Dust” Problems: (in Hazard Identification) • Parameters are size dependent! • “as is” testing vs “sieve <420 microns” • Full testing is expensive ($3,000+) • Testing for KST alone gives only (dp/dt)max • Moisture content, fat content affect results • MSDS’s often silent or misleading • “as is” product may be too large to be combustible but may contain fines that are combustible

  7. Typical “Settled Dust” Hazards Re-suspended Dust hazard – requires Electrical “Hazardous Location” (Class 2 Division 1 or 2).

  8. “Settled Dust” Hazard Control Positive press? Maintenance Ignition Controls Documented Cleaning Schedule

  9. Typical Hazardous Processes(Explosions Inside Equipment) • Silo and Container Filling • Pneumatic conveying • “Air Material Separators” • Dust Collectors • Cyclones • Size reduction processes (eg grinding) • Sieving, Blending • Drying (eg fluidized bed)

  10. Fireball hazard – Size? Where? Alternately, “suppression” Control: Explosion Venting Vents may be needed in ducts or piping

  11. Dust Collector :Explosion Vent - Locations Vent duct to outdoors “Flameless” Vent

  12. Directly Outside or Inside + secondary filter + “Hazloc” Dust Collector – Air Discharge Location?

  13. Drawing stamped by P.Eng Elec equipment specs meet “Hazloc” classification? Installation inspected by Electrical Authority? Lift trucks rated for Hazloc? Electrical “Hazardous Locations”

  14. Issues: Static Bonding OK?

  15. Issues: Plastic Containers/Liners Size matters – static can build-up on containers or in bulk powders during transfer

  16. Combustible Dust Policy/Programs • Identify, Assess Risk, Control • Recognizing its’ presence historically a problem • Scope of Program Requirements • OH&S Act, Fire Codes, many best practice guides (NFPA) • Change Management • A good time to review compliance/conformance • In Ontario, “Pre-Start H&S Review” requirements have triggered good project-based reviews

  17. Ontario: “Pre-Start H&S Review” Report Requirements • Legally required when new or modified processes • “process involves a risk of ignition or explosion that creates a condition of imminent hazard to a person’s health or safety” • “use of a dust collector involves a risk of ignition or explosion” • Guidelines from Ministry and PEO for P.Eng • Scope of report goes well beyond strict compliance • Includes NFPA 68, 69, 499, 505 & ACGIH Ind Vent.

  18. Thank You! – Acknowledgement: Paul Bozek, PEng CIH ROH p.bozek@utoronto.ca RT 215 Managing and Regulating Combustible Dust

More Related