OVERVIEW COMBUSTIBLE DUST QUIZ: Management Level Produced under OSHA Susan Harwood Grant SH

What SIZE of dust is Combustible? ANSWER: What is Dust less than 420 microns in size. (passing a #40 sieve). HAZARD ASSESSMENTS

What is the BEST WAY to prevent, Fire Hazards, Deflagration, or Explosion? ANSWER: What is a Self-Assessment, Self- Scoring, INSPECTION CHECKLIST? HAZARD ASSESSMENTS

What is the NFPA Code that serves as the GO- NO GO DECISION POINT for the Inspection Checklist? ANSWER: What is NFPA 91 & 654? IF ONLY non-combustible particulate solids are present, the “checklist” does not apply! HAZARD ASSESSMENTS

What are the things OSHA looks for while on a Combustible Dust inspection? ANSWER: What is dust presence and accumulation? Dust that is present at greater than 5% of surface area, 1/32 of an inch accumulation, and accumulation on overhead surfaces will get you cited! HAZARD ASSESSMENTS

What is a SECONDARY EXPLOSION? ANSWER: What is an explosion of dust that gets shaken loose from overhead accumulations because of the primary explosion? HAZARD ASSESSMENTS

What’s a passive way to prevent dust accumulation on walls? ANSWER: What are OUTWARDLY SLOPING WALLS? They’re designed with a curve away from walls so that dust slides off. PRACTICAL HOUSEKEEPING & IGNITION SOURCE CONTROL

What are the benefits of FREQUENT dust clean-up? ANSWER: What is preventing dust accumulation. PRACTICAL HOUSEKEEPING & IGNITION SOURCE CONTROL

Name as many sources of mechanical friction that can generate heat very quickly? ANSWER: What are Conveyor Belts, or Metal on Metal or failing Bearings? PRACTICAL HOUSEKEEPING & IGNITION SOURCE CONTROL

Name as many small and portable IGNITION SOURCES as you can remember… ANSWER: What is open flame from matches, lighters, space heaters, heat guns, and welding equipment? PRACTICAL HOUSEKEEPING & IGNITION SOURCE CONTROL

Name as many ELECTRICAL sources of ignition as you can you remember… ANSWER: What are exposed electrical wires, damaged electrical equipment and wires, static electricity, or open breaker panels? PRACTICAL HOUSEKEEPING & IGNITION SOURCE CONTROL

What is the National Fire Protection Association? ANSWER: What is an Association that researches and publish standards based on industry experience and best practices? NFPA ENGINEERING CONTROLS, BUILDING DESIGN, EXPLOSION PROTECTION

Under NFPA, must engineering controls for Deflagration prevention be “Acceptance Tested”? ANSWER: What is YES NFPA ENGINEERING CONTROLS, BUILDING DESIGN, EXPLOSION PROTECTION

Should controls be on a periodic inspection and maintenance schedule? ANSWER: What is YES. NFPA ENGINEERING CONTROLS, BUILDING DESIGN, EXPLOSION PROTECTION

MUST engineering controls be checked against NFPA requirements for Operation, Maintenance, and Safety Requirements? ANSWER: What is YES NFPA ENGINEERING CONTROLS, BUILDING DESIGN, EXPLOSION PROTECTIOn

Name some types of deflagration engineering controls or components listed in the NFPA codes… ANSWER: What is 1-Oxidant reduction concentration (which prevents combustion), 2-Passive Isolation System (isolates system problems), Pre-Deflagration detection system, 4-Deflagration Suppression and Explosion venting. NFPA ENGINEERING CONTROLS, BUILDING DESIGN, EXPLOSION PROTECTION

What is a Deflagration Condition Assessment? ANSWER: What is analyzing conditions to see if you have a potential for a deflagration or dust explosion. NFPA ENGINEERING CONTROLS, BUILDING DESIGN, EXPLOSION PROTECTION

What MUST you do IF you are a wood processing location and you’re NOT SURE if you meet NFPA Code requirements relating to wood dust hazard controls? ANSWER: What is REVIEW NFPA CODES in detail, and DEVELOP A PLAN of ACTION to prevent hazards. NFPA ENGINEERING CONTROLS, BUILDING DESIGN, EXPLOSION PROTECTION

Name some NFPA Standards BY NUMBER and purpose... ANSWER What is NFPA: 68 – Explosion Protection by Deflagration Venting 69 – Explosion Prevention Systems 70 – National Electrical Code 77 – Recommended Practice on Static Electricity 79 – Electrical Standard for Industrial Machinery 499 – Combustible Dusts-Classified Locations-Chemical Process Areas 654 – Prevention of Fire & Dust Explosions, Handling of Combustible Solids 664 – Prevention of Fires & Explosions in Wood Processing and Wood Working Facilities. NFPA ENGINEERING CONTROLS, BUILDING DESIGN, EXPLOSION PROTECTION

What are some PRACTICAL WAYS to control Deflagrations? ANSWER What are ENGINEERED SYSTEMS that ISOLATE, REDIRECT, CONTAIN, or EXTINGUISH deflagrations within enclosed process equipment? NFPA ENGINEERING CONTROLS, BUILDING DESIGN, EXPLOSION PROTECTION

What is the MOST CRITICAL component for ANY engineered system? ANSWER: What is OPERATOR TRAINING! Employees who control and interpret the information from engineering controls MUST know how to properly operate the system for start-up, operation, shut- down, and ANY other condition! NFPA ENGINEERING CONTROLS, BUILDING DESIGN, EXPLOSION PROTECTION

What is a THERMOGRAPHIC IMAGER? ANSWER: What is an Infrared Camera. (Remember that the detection of infrared radiation is converted to visual images with a temperature scale. This analytical method allows you to detect sources of ignition using visual means). DETECTING HAZARDOUS CONDITIONS with THERMOGRAPHIC IMAGERY

What is the AUTO-IGNITION temperature of WOOD DUST? ANSWER: What is 399 *F to 500 *F. (Remember, contact with wood dust at this temperature will cause it to ignite)! DETECTING HAZARDOUS CONDITIONS with THERMOGRAPHIC IMAGERY

What is the surface temperature range of a Metal Halide Lamp? ANSWER: What is 400 *F to 700 *F. Also, failure of this type of light source is “catastrophic”, it can shatter and explode. DETECTING HAZARDOUS CONDITIONS with THERMOGRAPHIC IMAGERY

A Halogen lamp is uncovered and wood dust is suspended in air. Using TI, the lamp’s surface temperature was determined to be at 552 degrees Fahrenheit – Is this ABOVE or BELOW the auto-ignition temperature of wood dust? ANSWER: What is ABOVE it? The auto-ignition temperature for wood dust is 399 to 500 degrees Fahrenheit, and this is an IGNITION SOURCE. With dust suspended in air, DEFLAGRATION CONDITIONS exist. DETECTING HAZARDOUS CONDITIONS with THERMOGRAPHIC IMAGERY

Wood dust has accumulated next to an electrical panel, and a Thermographic Image of the panel shows a surface temperature of 700 degrees Fahrenheit. Is it a cause for concern? ANSWER: What is YES! In this case, the surface temperature alone is enough to auto-ignite the dust! You have FIRE TRIANGLE conditions at this point, and will have a deflagration hazard if dust becomes suspended in air. DETECTING HAZARDOUS CONDITIONS with THERMOGRAPHIC IMAGERY