Safety for Aluminum Processing and Finishing Operations Involving Combustible Dust in the Die Casting Industry

1
Safety for Aluminum Processing and Finishing
Operations Involving Combustible Dustin theDie
Casting Industry

• Unit 3

2
Enabling Objectives
After completing this section of the course
students should be able to Discuss aluminum dust
producing operations and the precaution for
carrying out these operations safely
Metal Dust collector Exploded and Collapsed

• Explain procedures for housekeeping, dust
  collection, fire prevention, prevention of
  accumulation of fugitive dusts, proper storage,
  and safety procedures for aluminum and magnesium.

3
Dust Producing Operations

• Two recognized methods to capture aluminum dust
• Wet collectors located near the point of
  generation
• Dry collectors located outdoors as near as
  possible to the point of generation
• Machines fitted with hoods and capture devices
  able to capture and transport all the dust that
  is produced

4
Dust Producing Operations

• Design system so all dust moves into the hoods,
  into the ducts and is collected
• Connecting ducts must be kept as straight and
  short as possible

5
Ductwork

• Duct runs as short straight as possible!

6
Dust Producing Operations

• Metal dust-air suspension can pass into the
  explosive range in the collector!

7

• Dry-type provided with barriers or other
  protection
• Area around collector posted with Caution Sign
• Personnel outside of marked area when operating

CAUTION This dust collector can c
8

• Dedicated equipment not to be used with other
  types of metals
• Grinders, buffers posted with warning sign!

!
Warning Aluminum Metal Only Fire or
Explosion Can Result with Other Metals.
Warning Aluminum Metal Only Fire or
Explosion Can Result with Other Metals.
Kaboom!
Hi Aluminum! Im another type of metal!
9
Dust Producing Operations

• Practice Quiz
• 1. Duct runs for dust collectors should be
• A. As far away from the machine feeding into it
  as possible.
• B. Build with curves and turns to slow down the
  movement of dust.
• C. As short and straight as possible.
• 2. When dry-type dust collectors are operating
• A. They should be indoors near the point of
  generation.
• B. Barriers should be established and personnel
  should stay away.
• C. Maintenance personnel should open them up to
  ensure they are working properly.

10
Dust Producing Operations

• Practice Quiz
• 3. Grinders and buffers used for aluminum must
  be
• A. Dedicated equipment.
• B. Used for all types of metal including
  stainless steel
• C. Disconnected from dust collection units when
  used for other metals.

11
Dust Producing Operations

• Practice Quiz
• 1. Duct runs for dust collectors should be
• A. As far away from the machine feeding into it
  as possible.
• B. Build with curves and turns to slow down the
  movement of dust.
• C. As short and straight as possible.
• 2. When dry-type dust collectors are operating
• A. They should be indoors near the point of
  generation.
• B. Barriers should be established and personnel
  should stay away.
• C. Maintenance personnel should open them up to
  ensure they are working properly.

12
Dust Producing Operations

• Practice Quiz
• 3. Grinders and buffers used for aluminum must
  be
• A. Dedicated equipment.
• B. Used for all types of metal including
  stainless steel.
• C. Disconnected from dust collection units when
  used for other metals.

13
Individual Machines with Portable Dust Collection

• Permitted to be used indoors when moving work
  piece is infeasible
• Perform hazard analysis to minimize risk from
  fire shrapnel
• Limit collector capacity to lt 1 lb
• Empty daily

Filtering Media
Material Discharge
Portable Media-Type Dust Collector
14
Portable Dust Collectors

• Cyclones are less hazardous than bag-or
  media-type
• Exhaust discharge to atmosphere away from other
  operations!

15
Dust Producing Operations

• Dry collectors required to be located outdoors
• (exception small portable units
• Dry collectors provided with barriers

Filtration Media
Material Discharge
Build a barrier around the equipment!
Fixed Media Type Dust Collector NOT the best
choice!
16
Dust Collection, Ducts and Ductwork

• Collector area is to be marked and a sign posted
• NFPA 68 length of a fireball from a vented
  collector
• Collection system dedicated to aluminum only!

20'
17

• Experts indicate an eventual explosion can be
  expected from bag collectors use for aluminum
  fines!
• Multiple-series cyclone with final liquid stage
  is a better choice

Not so good
Im a better choice
Can lead to
18
Dust Collection, Ducts and Ductwork

• If the collection system used for combustible
  aluminum dust is used for other materials it
  should be disassembled and cleaned before and
  after.

19
Dust Collection, Ducts and Ductwork

• Use separate collection systems for grinding and
  buffing operations
• The dust collector should dissipate static
  electricity

20
Dust Collection, Ducts and Ductwork

• For bag-house shake-out design to minimize
  sparking
• Pulse-types less likely to create a spark because
  there are no moving parts
• Attach ground wires to bags and securely ground

Mechanical Shaker Baghouse
21
Dust Collection, Ducts and Ductwork

• For baghouse an alarm sounds for pressure drop
  across bags
• Locate baghouse or media type collector gt 50 feet
  from other operations and buildings!
• Keep personal gt 50 feet away when shaking!

At least Im outside!
22
Thermite Reaction

• Avoid letting aluminum impact oxidized iron!
• Thermite reaction possible for impact with
  aluminum rusted iron or steel
• Enough heat to produce molten iron!

Laboratory created thermite reaction
23
Dust Collection, Ducts and Ductwork

• Practice Quiz
• 1. Baghouse collectors for aluminum
• A. Are both economical and efficient.
• B. Are considered better than cyclone collectors.
• C. Have been associated with fires when used for
  aluminum.
• 2. If aluminum impacts iron oxide
• The material produced is inert.
• A dangerous thermite reaction can be initiated.
• It makes a valuable by-product that is a
  commodity.

24
Dust Collection, Ducts and Ductwork

• Practice Quiz
• 3. If a baghouse type collector is used
• A. A pulse-type is better than a mechanical
  shaker.
• B. The collector should be located outdoors at
  least 50 feet away from buildings and other
  equipment.
• C. Barriers and warning signs should be posted
  around the equipment.
• D. All of the above
• 4. Dust collection for grinding and buffing
  operations should be
• A. A single unit with adequate capacity for the
  amount of dust generated.
• B. Located between the grinder and buffer.
• Served by separate dust collection systems.

25
Dust Collection, Ducts and Ductwork

• Practice Quiz
• 1. Baghouse collectors for aluminum
• A. Are both economical and efficient.
• B. Are considered better than cyclone collectors.
• C. Have been associated with fires when used for
  aluminum.
• 2. If aluminum impacts iron oxide
• The material produced is inert.
• A dangerous thermite reaction can be initiated.
• It makes a valuable by-product that is a
  commodity.

26
Dust Collection, Ducts and Ductwork

• Practice Quiz
• 3. If a baghouse type collector is used
• A. A pulse-type is better than a mechanical
  shaker.
• B. The collector should be located outdoors at
  least 50 feet away from buildings and other
  equipment.
• C. Barriers and warning signs should be posted
  around the equipment.
• D. All of the above
• 4. Dust collection for grinding and buffing
  operations should be
• A. A single unit with adequate capacity for the
  amount of dust generated.
• B. Located between the grinder and buffer.
• Served by separate dust collection systems.

27
Explosion vents for dust collectors

• Explosion vents are usually built into the system
• If not a retrofit is a good idea!
• Locate Explosion Vents away from personnel!

Explosion Venting located away from personnel
28
Ductwork

• Ducts short and straight to maximize free airflow
• No dead ends or unused caps in ducts that could
  trap accumulations of dust
• Ducts grounded bonded to dissipate static
  electricity

29
Particles are suspended
Air velocity at least 4500 ft/min
Entrainment! is what you need!
Air velocity less than 3500 ft/min
Bad!
Build-up of dust particles
30
Duct Construction

• Ducts made of conductive material
• Lap joints face airflow direction
• No unused or capped outlets
• Duct seams away from personnel!

Smells like somethings burning!
31
Duct Construction

• No add-ons without engineering redesign of system
  and the impact the add-ons will have
• Collectors and machines that generate combustible
  dust properly bonded grounded

Prevents buildup of static charges!
Copper wire is securely fastened to the equipment
and then grounded to earth, for example by
attaching it to a metallic water pipe or other
object connected with earth.
32
Dust Collection Ductwork

• Practice Quiz
• 1. Explosion vents
• A. Should be built into collectors for
  combustible aluminum dust.
• B. Located away from personnel.
• C. Not necessary under normal circumstances.
• D. Both A B.
• 2. Ducts for dust collectors should have
• A. Dead end sections to help collect dust at the
  point of generation.
• B. Unused caps to maintain duct velocity
  pressure.
• C. No dead ends or unused caps.

33
Dust Collection Ductwork

• Practice Quiz
• 3. Dust collectors and machines
• A. Isolated from ground to prevent conducting
  electricity.
• B. Properly grounded and bonded.
• C. Designed and installed to dissipate static
  electricity.
• D. Both B C.

34
Dust Collection Ductwork

• Practice Quiz
• 1. Explosion vents
• A. Should be built into collectors for
  combustible aluminum dust.
• B. Located away from personnel.
• C. Not necessary under normal circumstances.
• D. Both A B.
• 2. Ducts for dust collectors should have
• A. Dead end sections to help collect dust at the
  point of generation.
• B. Unused caps to maintain duct velocity
  pressure.
• C. No dead ends or unused caps.

35
Dust Collection Ductwork

• Practice Quiz
• 3. Dust collectors and machines
• A. Isolated from ground to prevent conducting
  electricity.
• B. Properly grounded and bonded.
• C. Designed and installed to dissipate static
  electricity.
• D. Both B C.

36
Wet-Type Dust Collector

• Exhaust to the outside of building
• Exhaust duct as short straight as possible
• Ducts designed to withstand same explosion
  pressure as wet-type collector

37
Wet-Type Dust Collector

• Aluminum and water can produce hydrogen gas
• Extremely flammable and easy to ignite
• Dont trap in unventilated areas of the building
  or equipment!

38
Wet-Type Dust Collector

• Return air tested and approved for recirculation
• Exhaust vent inspected and cleaned frequently
• Particles can collect on the walls of the exhaust
  duct and can be highly combustible

Im forming a highly combustible cake!
Particles Collecting on exhaust duct
39
Wet-Type Dust Collector
40
Sludge Collector Sump Venting

• Wetted dust is highly flammable!
• Sludge removed regularly
• Collector sump vented!

41
Power Supply

• Interlocked with the exhaust blower and the
  liquid-level controller
• Time delay on dust producing equipment prevents
  motor starting until collector is operating

My power supply is dependent on my proper
functioning
42
Sludge Removal

• Sludge removed daily
• Covered vented containers for transport
• Containers filled to lt 50 lbs

43
Sludge Removal

• NO SMOKING ALLOWED!
• Mix with inert at 51 ratio dispose of properly
• Hot Work requires a Permit use one!

44
Wet-Type Collectors

• Practice Quiz
• 1. Wet aluminum dust
• A. Is inert
• B. Is easily removed with steel shovels
• C. Can generate explosive hydrogen gas
• 2. Exhaust air
• A. Should be vented to the outside
• B. Should be tested if it is to be returned to
  the building.
• B. Both A B.

45
Wet-Type Collectors

• Practice Quiz
• 3. Sludge from wet-type dust collectors for
  combustible aluminum dust should be
• A. Emptied daily.
• B. In containers of less than 50 lbs.
• C. Covered in vented containers for disposal
  transport.
• D. All of the above.

46
Wet-Type Collectors

• Practice Quiz
• 1. Wet aluminum dust
• A. Is inert
• B. Is easily removed with steel shovels
• C. Can generate explosive hydrogen gas
• 2. Exhaust air
• A. Should be vented to the outside
• B. Should be tested if it is to be returned to
  the building.
• B. Both A B

47
Wet-Type Collectors

• Practice Quiz
• 3. Sludge from wet-type dust collectors for
  combustible aluminum dust should be
• A. Emptied daily.
• B. In containers of less than 50 lbs.
• C. Covered in vented containers for disposal
  transport.
• D. All of the above.

48
Dry-Type Dust Collectors

• Use only where permitted
• Collection containers covered to prevent airborne
  fugitive dust
• Collector designed and maintained to ensure
  internal cleanliness!
• No accumulation of material allowed except
  discharge container

49
Dry-Type Dust Collectors

• Dust-collecting filter medium conductive with
  enmeshed noninsulated wire woven or fastened to
  it
• Not fool proof
• No force passes charge across nonconductive areas
  of the fabric
• Broken wires can hold or build-up a charge!

50
Dry-Type Dust Collectors

• Hoods regularly cleaned
• Dry collectors for aluminum dust provided with
  deflagration vents
• Air from dry dust collectors is not to be
  recycled back into the building

Courtesy of Fenwal Safety Systems
51
Dry-Type Dust Collectors

• Selection of type and location of weak sections
  or vents designed to minimize injury to personnel
  and minimize damage to nearby equipment
  structures
• Explosion venting is a very important
  consideration!
• Al high explosion pressure

Courtesy of Fenwal Safety Systems
52
Dry Type Dust Collectors

• Practice Quiz
• 1. Air from dry-type dust collectors
• A. Should be vented back into the plant to
  balance negative pressure.
• B. Should be used to provide warmth around
  grinding operations.
• Should not be recycled back into the building.
• 2. Grounding cartridge filters with wires built
  into the cartridge
• A. Is a fool proof way of ensuring static charges
  will be controlled.
• B. Does not ensure that static charges will move
  across the filter.
• C. Never done.

53
Dry Type Dust Collectors

• Practice Quiz
• 3. Dry type dust collectors should
• A. Have their hoods regularly cleaned.
• B. Be fitted with deflagration vents.
• C. Allow for no accumulation of dust except for
  in discharge containers.
• D. All of the above.

54
Dry Type Dust Collectors

• Practice Quiz
• 1. Air from dry-type dust collectors
• A. Should be vented back into the plant to
  balance negative pressure.
• B. Should be used to provide warmth around
  grinding operations.
• Should not be recycled back into the building.
• 2. Grounding cartridge filters with wires built
  into the cartridge
• A. Is a fool proof way of ensuring static charges
  will be controlled.
• B. Does not ensure that static charges will move
  across the filter.
• C. Never done.

55
Dry Type Dust Collectors

• Practice Quiz
• 3. Dry type dust collectors should
• A. Have their hoods regularly cleaned.
• B. Be fitted with deflagration vents.
• C. Allow for no accumulation of dust except for
  in discharge containers.
• D. All of the above.

56
Additional Considerations

• Cutting tools sharp sufficient coolant flow to
  prevent ignition of turnings
• Cutting grinding eq. grounded
• Chips, swarf, turnings, etc. collected in
  closed-top containers
• Removed daily to safe storage or disposal

Chips, Swarf, Turnings
57
Additional Considerations

• Coolant non-flammable filtered
• Collected solids max accumulation 5 gallons

58
Additional Considerations

• All electrical wiring conforms to NEC
• Collection systems bonded grounded
• Metallic jumpers installed when continuous
  contact is interrupted

NFPA 70
NEC
59
Housekeeping

• No accumulation of fugitive combustible dust
• Ignition of a dust cloud or layer will likely
  result in an explosion
• Often followed by a more violent explosion
• Good housekeeping is extremely important!

60
Housekeeping

• Regular cleanup using conductive non-sparking
  tools
• Soft brooms with natural bristles
• Bulk of cleanup done with scoops, shovels
  brooms
• Vacuum only small residual amounts

Non-sparking
61
Housekeeping

• Compressed air blow down is generally not to be
  permitted
• Only allowed in areas otherwise impossible to
  clean
• Only allowed under carefully controlled
  conditions
• All potential ignition sources eliminated
• All equipment shut down

62
Vacuum Cleaners

• Vacuums only for too small, dispersed or
  inaccessible dust
• Bonded grounded
• Listed or approved for use with combustible dust
• Periodic continuity tests performed
• Dusts from fixed vacuums collected to outside of
  building

Must be listed, labeled or approved
63
Fixed Vacuum Systems

• If possible locate vacuum collection outside
  facility
• 50 feet from building
• If closer enclose in open-top steel shield
• Fit suction lines with explosion vents and
  anti-flash back valves

50 ft
.
64
Water Cleanup Considerations

• Wet aluminum fines can evolve hydrogen gas!
• Keep hydrogen at or below 1 concentration in air
  using ventilation (H2 LEL 4)
• Inform management of risks
• Competent person has determined wet cleaning is
  safest method available

Applies to Aluminum Dross Wet or Hot
65
Cleaning Frequency

• Avoid excessive accumulation of dust on any
  portion of building that is not cleaned during
  regular daily operations
• Regular cleaning of buildings and machinery as
  needed
• Machines idle and
  power off

66
Housekeeping

• Practice Quiz
• 1. Cleanup of aluminum dust should be done with
• A. Non-combustible conductive tools.
• B. Brooms with soft natural bristles.
• C. Mostly scoops, shovels and brooms.
• D. All of the above.
• 2. Compressed air blown for aluminum dust
• A. Is a fast and safe way to clean up.
• B. Is a common practice.
• C. Should only be done under controlled
  procedures when no other method is feasible.

67
Housekeeping

• Practice Quiz
• 1. Cleanup of aluminum dust should be done with
• A. Non-combustible conductive tools.
• B. Brooms with soft natural bristles.
• C. Mostly scoops, shovels and brooms.
• D. All of the above.
• 2. Compressed air blown for aluminum dust
• A. Is a fast and safe way to clean up.
• B. Is a common practice.
• C. Should only be done under controlled
  procedures when no other method is feasible.

68
Housekeeping

• Practice Quiz
• 3. Cleaning dust from the facility should
• A. Include additional cleaning on all parts of
  the building where dust can accumulate that is
  not cleaned during normal operations.
• B. Be done as often as necessary.
• C. Be done with machines idle with the power off.
• D. All of the above.

69
Fire Prevention Protection

• Large scale fires in aluminum dust are very
  difficult to extinguish
• DO NOT create a dust cloud in an attempt to fight
  an aluminum dust fire!
• Attempt to control as quickly as possible with
  minimum disruption to the pile

70
Fire Extinguishers

• Ample Class D fire extinguishers should be
  available to fight incipient stage fires
• Available within 75 feet of metalworking areas.
• Required where dust is generated at least once
  every two weeks

71
Fire Extinguishers

• Install signs so other types of extinguishers are
  not used by mistake!

72
Extinguishing Agent

• Ring incipient fires with dry sand, or a Class D
  powder
• Properly ringed will form a metal oxide crust
• Apply with non sparking utensils
• Eliminate drafts, etc.

73
Extinguishing Agent

• Dry sodium chloride is very effective
• Check for caking
• Flux made of potassium and magnesium chloride and
  calcium fluoride
• Avoid Class B agents for dry powder aluminum
  fires, they will accelerate
  fires or cause an explosion!

74
Aluminum Slurry Fires

• Incipient stage fires involving a slurry (wetted)
  of aluminum powder can be fought using a Class B
  type extinguisher as long as the agent is not
  halogenated.

75
Sprinkler Systems

• No automatic sprinklers where dry aluminum powder
  is produced or handled
• Consider the hazards associated with aluminum and
  water in considering sprinkler systems

76
Fire Prevention and Protection

• Practice Quiz
• 1. Large aluminum fires
• A. Can be easily controlled with class D fire
  extinguishers.
• B. Are extremely difficult to extinguish.
• C. Are best handled with class B fire
  extinguishers.
• 2. Incipient stage aluminum fires
• A. Should be ringed with a Class D
  extinguishing agent.
• B. Should have extinguishing material applied
  with non-sparking scoops.
• C. Should be protected from drafts.
• D. All of the above.

77
Fire Prevention and Protection

• Practice Quiz
• 3. Class D fire extinguishers
• A. Are optional for aluminum dust processing
  areas.
• B. Only needed by the dust collector.
• C. Are required where combustible dust is
  produced at least once every two weeks.

78
Fire Prevention and Protection

• Practice Quiz
• 1. Large aluminum fires
• A. Can be easily controlled with class D fire
  extinguishers.
• B. Are extremely difficult to extinguish.
• C. Are best handled with class B fire
  extinguishers.
• 2. Incipient stage aluminum fires
• A. Should be ringed with a Class D
  extinguishing agent.
• B. Should have extinguishing material applied
  with non-sparking scoops.
• C. Should be protected from drafts.
• D. All of the above.

79
Fire Prevention and Protection

• Practice Quiz
• 3. Class D fire extinguishers
• A. Are optional for aluminum dust processing
  areas.
• B. Only needed by the dust collector.
• C. Are required where combustible dust is
  produced at least once every two weeks.

80
Employee Training Emergency Evacuation

• Train employees in evacuation procedures
• Only trained employees are allowed to attempt to
  fight fires
• All others must evacuate!

81
Fire Safety Training

• Familiarize fire departments with the special
  potential hazards present
• Plant safety officer to provide instruction or
  direct the efforts of fire personnel

Scrap metal fire Will burn until it runs out of
fuel
82
Fire Safety Training

• Job hazard analysis should be conducted and safe
  work practices developed
• Employees trained on hazard recognition,
  elimination and control

Dont let this happen to you!
83
Fire Prevention Control

• Set up test fires for fire department training
• Cover foreseeable scenarios and plan and prepare
  accordingly
• Train employees for the different types of fires
  possible

84
Fire Prevention Control

• Train employees on the hazards present
• Focus on proper actions, decisions procedures
• Train on location of controls, emergency supplies
  and fire extinguishers

The stuff you NEED!
85
Fire Prevention Control

• Train on proper method for fighting incipient
  stage aluminum dust fires
• Warn employees regarding the creation of a dust
  cloud or using liquids on combustible metal fires

No Good!
86
Fire Prevention Control

• Practice Quiz
• 1. If you have not been trained you should
• A. Only fight a major fire with coworkers who
  have experience.
• B. Only attempt to extinguish incipient fires.
• C. Not attempt to put out combustible dust fires.
• 2. Your training should focus on hazard
• A. Recognition.
• B. Elimination.
• C. Control.
• D. All of the above.

87
Fire Prevention Control

• Practice Quiz
• 1. If you have not been trained you should
• A. Only fight a major fire with coworkers who
  have experience.
• B. Only attempt to extinguish incipient fires.
• C. Not attempt to put out combustible dust fires.
• 2. Your training should focus on hazard
• A. Recognition.
• B. Elimination.
• C. Control.
• D. All of the above.

88
Fire Prevention Control

• Practice Quiz
• 3. It is important not to
• A. Put liquids on aluminum dust fires.
• B. Use a high pressure extinguisher that will
  create a dust cloud.
• C. Use the wrong type of fire extinguisher.
• D. All of the above.
• E. None of the above.

89
Fire Prevention Control

• Practice Quiz
• 3. It is important not to
• A. Put liquids on aluminum dust fires.
• B. Use a high pressure extinguisher that will
  create a dust cloud.
• C. Use the wrong type of fire extinguisher.
• D. All of the above.
• E. None of the above.

90
Controlling Ignition Sources

• No smoking, cutting or welding in areas where wet
  sludge is present
• Any area where hot work takes place must be free
  of all accumulations of dust
• Comply with NFPA 51B

Employees and visitors should not carry
smoking materials in any areas where combustible
dust is present!
91
Controlling Ignition Sources

• No propellant-actuated tools unless machinery is
  shutdown and cleaned
• Only non-sparking tools used on machines where
  combustible dust is present

92
Controlling Ignition Sources

• Do not dress grinding wheels when the collection
  ventilation is on!

93
Cleaning Tools

• Brooms brushes natural fiber bristles
• No synthetic bristles
• Scoops and dustpans, etc. to conductive
  non-sparking
• Do not return dry sweepings to processing

94
Proper PPE around Combustible Metal Dust

• Except for working around electricity, safety
  shoes should be worn with
• Soles and heels attached by sewing
• No nails or metal plates
• Safety toes composite or covered
• Shoes static dissipating

95
Proper PPE around Combustible Metal Dust

• Clothing clean, flame retardant and non-static
  generating
• Tight fitting, smooth fabrics from which dust can
  easily be should be used
• No cuffs or other folds where aluminum could
  collect
• No wool or silk

96
Proper PPE around Combustible Metal Dust

• Emergency procedures for clothing fires need to
  be implemented
• Use fire blankets where water is not allowed!
• Safety showers well away from dry aluminum powder
• Emergency procedures developed implemented

97
Compressed air inert gas

• Dont mistake plant air for inert gas!
• Fittings for both shall not be interchangeable!

98
Safety Inspections

• Inspection program for operations that produce
  dust!
• Performed on a regular interval
• Skilled inspectors
• Reports filed
• Deficiencies corrected!

99
Controlling Ignition Sources

• Practice Quiz
• 1. No smoking, cutting or welding in areas
• A. Accumulations of dust are present.
• B. Where wet aluminum is present.
• C. Where powder actuated tools are approved.
• D. All of the above.
• E. A B only.
• 2. Do not dress grinding wheels if
• A. If the ventilation system is turned off.
• B. If the ventilation system is still turned on.
• C. Neither A nor B.

100
Controlling Ignition Sources

• Practice Quiz
• 1. No smoking, cutting or welding in areas
• A. Accumulations of dust are present.
• B. Where wet aluminum is present.
• C. Where powder actuated tools are approved.
• D. All of the above.
• E. A B only.
• 2. Do not dress grinding wheels if
• A. If the ventilation system is turned off.
• B. If the ventilation system is still turned on.
• C. Neither A nor B.

101
Emergency Procedures

• Practice Quiz
• 3. Emergency procedures
• A. For clothing fires needs to be implemented
• B. Include fire blankets and their use where
  water is not permitted.
• C. Are often overrated and usually not necessary
• D. A B only.

102
Emergency Procedures

• Practice Quiz
• 3. Emergency procedures
• A. For clothing fires needs to be implemented
• B. Include fire blankets and their use where
  water is not permitted.
• C. Are often overrated and usually not necessary
• D. A B only.

103
PPE

• Practice Quiz
• 4. Clothing should be
• A. Clean.
• B. Non-static generating.
• C. Flame Retardant.
• D. All of the above.
• E. B C only.

104
PPE

• Practice Quiz
• 4. Clothing should be
• A. Clean.
• B. Non-static generating.
• C. Flame Retardant.
• D. All of the above.
• E. B C only.

105
Summary

• In this section we discussed safe practices for
  machining and finishing aluminum.
• We identified the importance of safe means of
  dust collection
• We looked at housekeeping issues
• Fire prevention and fire protection were also
  discussed
• We also examined proper cleaning tools and the
  correct PPE to wear when working around aluminum
  where combustible dust is present