see attachment

Your assignment for this unit is to complete a case study of the incidents at the Hoeganaes Corporation in 2011. Review the pages 124 of the summary report from the Chemical Safety Board (CSB) concerning the Hoeganaes Corporation by clicking the attachment . Include the components listed below in your case study.

Perform a risk assessment of fire hazards at this type of manufacturing facility. Describe the major variables that you believe were responsible for causing the fires and explosions that occurred at the facility.
List the OSHA standards that you believe would apply to the fire hazards at the facility.
If you were hired as the safety officer at the facility immediately following the third incident in the report, recommend the approach you would take to mitigate the risks associated with the fire hazards and combustible dust, including any standards published by agencies other than OSHA that would be helpful in establishing your program.
How would the NFPA Life Safety Code apply to this facility?
Your case study should be a minimum of two pages in length, not counting the title and reference pages. You are required to use at least three outside sources, one of which may be your textbook. You must also cite the CSB report. All sources used, including the textbook, must be referenced; paraphrased and quoted material must have accompanying APA citations. CSB Hoeganaes Corporation Case Study 1

Hoeganaes Corporation Case Study December 2011

Case Study
U.S. Chemical Safety and Hazard Investigation Board

Hoeganaes Corporation: Gallatin, TN
Metal Dust Flash Fires and Hydrogen Explosion
January 31, 2011; March 29, 2011; May 27, 2011
5 Killed, 3 Injured
No. 2011-4-I-TN

KEY ISSUES
Hazard recognition and training
Engineering controls
Fire codes/enforcement
Regulatory oversight

CSB Hoeganaes Corporation Case Study 2

Hoeganaes Corporation Case Study December 2011

1.0 INTRODUCTION
This case study examines multiple iron dust flash fires and a hydrogen explosion at the
Hoeganaes facility in Gallatin, TN. The first iron dust flash fire incident killed two workers
and the second injured an employee. The third incident, a hydrogen explosion and resulting
iron dust flash fires, claimed three lives and injured two other workers.

1.1 HOEGANAES CORPORATION
Hoeganaes Corp. is a worldwide producer of atomized steel and iron powders. Headquartered
in Cinnaminson, NJ, Hoeganaes has facilities in the U.S., Germany, China, and Romania.

The Hoeganaes Corp. is a subsidiary of GKN, a multinational engineering company headquar-
tered in the United Kingdom. GKN has businesses in addition to powder metallurgy, including
aerospace and automotive driveline industries. GKN acquired the Hoeganaes Corp. in 1999.

The largest consumer for the powdered metal (PM1) product is the automotive industry,
which presses and sinters2 the powder into small metal parts.

1.2 FACILITY DESCRIPTION
The Hoeganaes Gallatin facility (Figure 1), located 30 miles northeast of Nashville, Tennessee,
employs just under 200 employees. Since becoming operational in the 1980s, they have increased
their manufacturing capability over 550 percent from 45,000 to over 300,000 tons.

TABLE OF CONTENTS

1.0 Introduction 2

2.0 Process Discussion 3

3.0 The Incidents 3

4.0 Analysis 6

5.0 Key Findings 24

6.0 Recommendations 24

Appendix A: Determination of
Iron Powder Explosibility from
Pressure Ratio Calculations 28

Appendix B: Determination of
Iron Powder Classification from
Explosion Severity Calculation 30

FIGURE 1

Satellite view of the
Hoeganaes Gallatin facility.

1PM is the accepted acronym by the powdered metals industry.
2Sintering is the process of solidifying PM via heat and/or pressure to form a component.

CSB Hoeganaes Corporation Case Study 3

Hoeganaes Corporation Case Study December 2011

3Ductility is the physical property of a material where it is capable of sustaining large permanent changes in shape without breaking.

2.0 PROCESS DISCUSSION
Hoeganaes receives and melts scrap steel. Various elements are added to the molten metal
to meet customer specifications, but the workhorse product, Ancorsteel 1000, is over 99
percent iron. The molten iron is cooled and milled into a coarse powder that is processed
in long annealing furnaces to make the iron more ductile.3 The furnaces are called band
furnaces, for the 100 foot conveyor belt, or band, that runs through them. A hydrogen
atmosphere is provided in the band furnace to reduce the iron by removing oxides and
preventing oxidation. The hydrogen is supplied to the facility by a contract provider, onsite.
Hydrogen is conveyed to the furnaces via pipes located in a trench under the floor and
covered by metal plates.

In the process of going through the furnace, the coarse powder becomes a thick sheet called
cake. The cake is sent to a cake breaker and ultimately crushed into the fine PM product.
The majority of the finished PM product has a particle diameter between 45-150 microns,
or roughly the width of a human hair (Figure 2).

3.0 THE INCIDENTS

3.1 JANUARY 31, 2011 (TWO FATALITIES)
PM product is transferred through the plant by various mechanisms including screw convey-
ors and bucket elevators. Bucket elevators have a tendency to go off-track when the belt
pulling the buckets becomes misaligned. Once sufficiently off-track the strain on the motor
increases until the torque is too great and the motor shuts down. On January 31, 2011, at
about 5:00 am Hoeganaes plant operators suspected bucket elevator #12 of being off-track
and a maintenance mechanic and an electrician were called to inspect the equipment.

FIGURE 2

Fine PM collected from
the Hoeganaes plant
(penny shown for scale).

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Hoeganaes Corporation Case Study December 2011

Based on their observations, they did not believe that the belt was off-track and re-
quested, via radio, that the operator in the control room restart the motor (Figure 4).
When the elevator was restarted, vibrations from the equipment dispersed fine iron
dust into the air. During a CSB interview, one of the workers recalled being engulfed in
flames, almost immediately after the motor was restarted.

City of Gallatin emer-
gency responders arrived
with ambulances and
transported the mechanic
and electrician to the
Vanderbilt Burn Center
in Nashville, TN. Both
employees were severely
burned over a large
percentage of their bodies.
The first employee died
from his injuries two days
later. The second employee
survived for nearly four
months before succumb-
ing to his injuries in late
May 2011.

3.2 MARCH 29, 2011 (ONE INJURED)

As part of an ongoing furnace improvement project, a Hoeganaes engineer and an outside
contractor were replacing igniters on a band furnace. The pair experienced difficulty in re-
connecting a particular natural gas line after replacing an igniter. While using a hammer to
force the gas port to reconnect, the Hoeganaes engineer inadvertently lofted large amounts
of combustible iron dust from flat surfaces on the side of the band furnace, spanning 20 feet
above him. As soon as the dust dispersed, the engineer recalled being engulfed in flames. He
jumped and fell from a rolling stepladder in his attempt to escape the fireball. He received
first- and second-degree burns to both thighs, superficial burns to his face, and scrapes from
his fall. After seeing the initial flash of the dust igniting, the contractor took evasive action
and escaped without injury.

FIGURE 4 (RIGHT)

Scene of January 31,
2011, incident area.

FIGURE 5

Computer graphic of
January 31 iron dust
flash fire.

FIGURE 3 (LEFT)

Computer graphic of
maintenance workers
inspecting bucket
elevator #12 just prior
to January 31 flash fire.

Elevator Enclosure

Motor

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Hoeganaes Corporation Case Study December 2011

The engineer was wearing the Hoeganaes-designated personal protective equipment, which
included pants and a shirt that were rated as flame resistant clothing (FRC). He was also
wearing an FRC rated jacket that provided extra shielding to his upper torso from the flash
fire.

3.3 MAY 27, 2011 (THREE FATALITIES, TWO INJURIES)
Around 6 am on May 27, 2011, operators near band furnace #1 heard a hissing noise that
they identified as a gas leak. The operators determined that the leak was in a trench, an area
below the band furnaces that contains hydrogen, nitrogen, and cooling water runoff pipes,
in addition to a vent pipe for the furnaces. The operators informed the maintenance depart-
ment about the hissing, and six mechanics were dispatched to find and repair the leak. One
annealing area operator stood by as the mechanics sought out the source of the leak.

Although maintenance personnel knew that hydrogen piping was in the same trench, they
presumed that the leak was nonflammable nitrogen because of a recent leak in a nitrogen
pipe elsewhere in the plant and began to try to remove trench covers. However, the trench

FIGURE 6 (LEFT)

Computer graphic of
the gas line connection
involved in the March 29
flash fire.

FIGURE 7 (RIGHT)

The gas line connection
involved in March 29, 2011,
incident.

FIGURE 8

Computer graphic of
March 29 iron dust
flash fire.

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Hoeganaes Corporation Case Study December 2011

covers were too difficult to lift without machinery. Using an overhead crane, they were able
to remove some of the trench covers. They determined that the leak was near the southern-
most trench covers, which the crane could not reach. Shortly after 6:30 am, maintenance
personnel acquired a forklift equipped with a chain on its forks, and were able to reach and
begin removing the southernmost trench covers.

Interviews with eyewitnesses indicate that just as the first trench cover was wrenched from
its position by the forklift, friction created sparks, followed by a powerful explosion.
Several days after the explosion, CSB investigators observed a large hole (approximately 3 x
7 inches) in a corroded section of piping that carried hydrogen and ran through the trench
(Figure 11).

As the leaking hydrogen gas exploded, the resulting overpressure dispersed large quantities of
iron dust from rafters and other surfaces in the upper reaches of the building. Portions of this
dust subsequently ignited. Multiple eyewitnesses reported embers raining down and igniting

FIGURE 9 (TOP)

Scene of the May 27
incident before (left, taken
during the CSBs January
31 incident investigation)
and after (right). Note
visible accumulations of
iron powder on surfaces.
Circled areas show trench
cover location.

FIGURE 10 (RIGHT)

Computer graphic of
maintenance crews
starting to remove the
trench covers using a
forklift just prior to May 27
explosion.

Feb 07 2011 May 28 2011

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Hoeganaes Corporation Case Study December 2011

multiple dust flash fires in the area. They also reported visibility so
limited in some instances that flashlights were required; one eyewit-
ness said that even with a flashlight, he could see only 3 to 4 feet
ahead due to extensive dust and smoke.

The hydrogen explosion and ensuing iron dust flash fires injured four
of the responding mechanics and the annealing operator.4 The two
mechanics near the forklift were transported to a local hospital where
they were treated for smoke inhalation and released shortly thereafter.

Two other mechanics and the operator who stood by during the
operation were rushed to Vanderbilt Burn Center. Less than a week
after the incident, two employees succumbed to their injuries. The
third seriously injured employee died from his injuries almost seven
weeks after the incident.

Due to the extensive nature of the injuries, and the abundance of both hydrogen and com-
bustible dust present at the time of the incident, it is difficult to specifically determine which
fuel, if not both, caused the fatal injuries to the victims.

3.4 EMERGENCY RESPONSE
The Gallatin Fire Department (GFD) has responded to 30 incidents of various types over
the past 12 years at the Hoeganaes Corp., including the January 31, March 29, and May 27
incidents. In June 1999, the GFD responded to a fire caused by iron dust that ignited in a
baghouse. One person suffered smoke inhalation injuries as a result of the incident.

Before the GFD arrived at each of the 2011 incidents, Hoeganaes volunteer first respond-
ers cared for the injured. Hoeganaes volunteers participate in annual training that covers
first response, CPR, and first aid. They are instructed to provide care until GFD and EMS
responders arrive.

Immediately following each incident, the volunteers provided first aid and comfort to the
injured by applying water to cool the burns and covering the victims with a burn blanket
to keep them comfortable. EMS arrived within minutes of the initial 9-1-1 call and trans-
ported the injured personnel to hospitals.

4At the time of incident, two of the mechanics and the operator were standing near the trench while the other two mechanics were positioned and
possibly shielded by the forklift when the explosion occurred.

FIGURE 11 (TOP LEFT)

Hole in 4-inch piping after
the May 27, 2011, incident.

FIGURE 12 (TOP RIGHT)

Computer graphic of the
May 27, 2011, hydrogen
explosion.

FIGURE 13 (BOTTOM)

Upward disturbance of
trench covers caused by
the hydrogen explosion in
the May 27, 2011, incident.

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Hoeganaes Corporation Case Study December 2011

4.0 ANALYSIS

4.1 COMBUSTIBLE DUST TESTING
According to National Fire Protection Association (NFPA) 484, Standard for Combustible
Metals, a facility that handles metal dust should commission one of two screening tests to
determine if a metal dust is combustible and the provisions of the standard apply (Section
4.4.1). If results from either of the two tests show that the dust is combustible or explosible,
NFPA 484 would apply to the facility either as a matter of voluntary good practice or as a
requirement by a relevant regulatory body.

The first screening test for the determination of combustibility, also known as the train test,
measures the burning rate of a dust layer over the length of a sample.5 If there is propagation
beyond the ignition point or heated zone, then the sample is considered combustible.6

The second test, for explosibility determination, serves as a basis to determine if a metal
powder or dust is capable of initiating an explosion when suspended in a dust cloud. This
test, performed in a Hartmann apparatus, determines the minimum ignition energy of a
dust cloud in air by a high voltage spark.7

If either of the screening tests produces a positive result for combustibility or explosibility, NFPA
484 requires further explosibility testing be conducted in a 20-L sphere. Several values (below)
from the explosibility test results can be used to characterize the severity of a dust explosion.

4.1.1 CSB COMBUSTIBLE DUST TESTING

4.1.1.1 Combustibility Demonstration
In order to visually demonstrate the combustibility of the Hoeganaes iron samples, a modified
Go/No-Go test was performed by the CSB. Generally, this test is performed in a closed
vessel, but the CSB was interested in directly observing any flames the dust may produce.8

EXPLOSIVITY VALUES

KSt: calculated value that compares the relative explosion severity and consequence to
other dusts (bar m/s). The higher the KSt number, the more energetic the explosion.

Pmax: maximum explosion overpressure generated in the test vessel (bar)

P/ t: maximum rate of pressure rise, predicts violence of the explosion (bar/s)

Explosion Severity (ES): Index to determine if Class II electrical equipment is required
as an OSHA requirement.

ES > 0.5, Class II Combustible
ES < 0.4, Combustible but not Class II 5UN Recommendations on the Transport of Dangerous Goods: Model Regulations Manual of Tests and Criteria, Part III, Subsection 33.2.1 6NFPA 484 defines a combustible metal dust as a particulate metal that presents a fire or explosion hazard when suspended in air or the process specific oxidizing medium over a range of concentrations, regardless of particle size or shape. 7ASTM E2019, Standard Test Method for Minimum Ignition Energy of a Dust Cloud in Air 8The Go/No-Go test is typically performed in a modified one-liter Hartmann tube; also known as the explosibility screening test as described in NFPA 484. CSB Hoeganaes Corporation Case Study 9 Hoeganaes Corporation Case Study December 2011 This test dispersed about 30 grams of iron dustsampled from the baghouse9 associated with the bucket elevator from the January 31, 2011, incidentabove an 8 inch burner. Upon being released, the dust auto-ignites in air due to the heat given off from the burner below (Figure 14). An intense white flame was produced that reached a peak diameter of 18 inches. 4.1.1.2 20-Liter (20-L) Test Method CSB investigators collected iron powder samples from various locations in the Hoeganaes facility and commissioned testing to characterize its combustibility using two different test methods, the 20-liter (20-L) and one-meter cubed (1-m3) test chambers. The 20-L test laboratory used the standard test method, ASTM E1226, Pressure and Rate of Pressure Rise for Combustible Dusts, for the selected iron powder samples. Each dust sample was injected and ignited in a 20-L spherical test vessel equipped with transducers to record a pressure-versus-time profile of the dust deflagration in the sphere. Table 1 shows data from the CSBs combustibility tests of the Hoeganaes dust and a compari- son to dust testing the CSB commissioned for previous dust incidents at other companies. The CSB test data indicate that the iron powder is combustible and is covered by the requirements of NFPA 484 (Section 4.4.1). Although values indicate that the dust produces a weak explosion relative to other dusts, the dust is considered combustible by the OSHA definition10 and can result in a flash fire capable of causing injuries and fatalities. FIGURE 14 CSB iron dust combustibility demonstration, see Section 4.1.1.1. 9Ventilation equipment that removes airborne particulate by forcing air through a specially designed filtration bag. 10 OSHA 3371-08 2009: a solid material composed of distinct particles or pieces, regardless of size, shape, or chemical composition, which presents a fire or deflagration hazard when suspended in air or some other oxidizing medium over a range of concentrations. CSB Hoeganaes Corporation Case Study 10 Hoeganaes Corporation Case Study December 2011 20-L COMBUSTIBLE DUST TEST DATA FROM CSB INVESTIGATIONS11 Hoeganaes Iron Dust 20L test12 Granulated Sugar Aluminum Dust Polyethylene Dust Phenolic Resin Pmax (bar) 3.5 5.2 9.4 8.34 7.58 P/ t (bar/s) 68 129 357 515 586 KSt (bar m/s) 19 35 103 140 165 Explosion Severity (ES) 0.077 0.22 1.08 1.38 1.43 Classification Combustible Combustible Combustible, Class II Combustible, Class II Combustible, Class II Frequently, the hazards of different combustible dusts are evaluated by their potential explosive capabilities. However, the hazards of combustible dusts are not limited to explo- sions. The Hoeganaes iron powder propagates an explosion less rapidly compared to other dusts, so there is less overpressure damage, consistent with observations by CSB investiga- tors. Dust testing results from Hoeganaes and prior CSB investigations illustrate that dusts with low KSt values can cause flash fires that result in deaths and serious injuries. Although combustible dusts can lead to explosions, combustible dust flash fires also pose a risk that must be addressed in industry. According to the 20-L standard test method, E1226, a dust sample can be defined as combustible or explosible based on a calculated pressure ratio (PR) using the pressure data recorded in the 20-L test chamber. For sample concentrations of 1,000 and 2,000 g/m3, a pressure ratio value greater than or equal to 2 is considered explosible. If the pressure ratio is less than 2, the sample is considered non-explosible. However, the test method cautions that the dust can still burn and a dust cloud may experience a deflagration depending upon conditions such as the temperature and particle size.13 The iron dust sample from baghouse #4 had a PR of 4.0 and 4.7 at concentrations of 1,000 and 2,000 g/m3 respectively, indicat- ing that the dust sample is explosible. 4.1.1.3 One-Meter Cubed (1-m3) Test Method The CSB collected a subsequent sample14 from baghouse #4 and subjected it to combustibil- ity testing using the one-meter cubed (1-m3) method, ISO 6184-1 Explosion Protection Systems: Determination of Explosion Indices of Combustible Dusts in Air. The 1-m3 test vessel is larger than the 20-L vessel, and the dust, along with air and a fuel source, is injected into the system differently. The iron powder from baghouse #4 underwent an explosibility screening test in the 1-m3 vessel in an attempt to ignite the sample. At several dust concentrations, none of the tests produced significant pressure which exceeded the test qualifications for ignition and there- fore the dust sample was considered non-explosible according to this method. TABLE 1 Combustibility data for selected materials. 11For a more detailed discussion on characteristic combustible dust values, see CSB 2006-H-1 Combustible Dust Hazard Study. 12CSB investigators collected this iron dust sample from baghouse #4 at the Hoeganaes Gallatin facility after the January 31, 2011, incident. 13American Society for Testing and Materials (ASTM), E1226-10, Pressure and Rate of Pressure Rise for Combustible Dust, ASTM International, 2010. 14 At the time this sample was taken in August 2011, the Gallatin facility had not been fully operational for about three months. As such, the sample collected did not contain fines representative of the environment at the time of the 2011 flash fire incidents. CSB Hoeganaes Corporation Case Study 11 Hoeganaes Corporation Case Study December 2011 4.1.1.4 Comparing Dust Testing Methods Both the 20-L and 1-m3 tests are accepted methods that can characterize dust explosibility; however results from the two tests may differ. There are several factors that can contribute to varying results among the dust test methods. Dust characteristics, such as particle size, moisture content, and degree of oxidation (for metals) can affect the ignitability of the sample in the test chamber. The 20-L and 1-m3 test chambers were designed to simulate dust explosions in facility settings, but each test has limitations. The main difference between the two tests is the chamber size and the dust dispersion mechanism. Since the 1-m3 test is larger, theoretically it can better simulate an open-space dust cloud explosion. However, that larger volume also makes it harder to create a uniform distribution of dust within the testing chamber. In the smaller 20-L test chamber it is easier to create a uniform distribution; however, it is possible that the smaller chamber also creates an overdriving effect. Since the 20-L chamber is smaller, the energy exerted by the igniters15 may combust enough dust creating the appear- ance of ignition16 a situation that would not occur in a facility setting. NFPA revised the 2012 edition of NFPA 484 to state that explosibility screening tests shall be performed in accordance to the 20-L test standard, E1226. However, NFPA added to the standard annex that the results of the 20-L test can be conservative and an owner or operator of a facility may elect to use a 1-m3 test for dust explosibility testing as the 20-L test may result in false positives for dusts with lower KSt values. Despite the discrepancies between the two test methods, the empirical evidence from the flash fire incidents at Hoeganaes shows that dusts with lower KSt values are capable of fueling flash fires with severe consequences. This further suggests that facilities should not rely on the 1-m3 test as a sole determination of dust combustibility hazards. Dusts with lower KSt values and characteristics similar to the iron powder at Hoeganaes may not ignite in the 1-m3 chamber but still have the ability to result in fatal flash fires. It should be noted that both tests are for explosibility screening, and alone may not convey the full combustibility hazard. 4.1.2 HOEGANAES COMBUSTIBLE DUST TESTING 4.1.2.1 Minimum Ignition Energy (MIE) In 2010, Hoeganaes contracted to test iron dust samples from the plant for combustibility as a result of an insurance audit recommendation. The test had one sample that was similar in particle size, moisture content, and location to the dust involved in the 2011 incidents. That sample gave the results seen in Table 2. The minimum ignition energy (MIE) testing determined that a continuous arc did ignite the representative samples from 2010, but a 500 mJ source did not. The conclusion from the testing was that the minimum ignition energy was greater than 500 mJ. This information is valuable in determining potential ignition sources for each of the incidents. 15 The igniter may increase the temperature in the smaller 20-L chamber, raising the overall temperature of the system and allowing a non-explosive system to appear explosive. 16Going, J et al., Flammability limit measurements for dust in 20-L and 1-m3 vessels. Journal of Loss Prevention in the Process Industries. May 2003 CSB Hoeganaes Corporation Case Study 12 Hoeganaes Corporation Case Study December 2011 4.2 IGNITION SOURCES Witnesses indicated that the May 27, 2011, hydrogen explosion was ignited by sparks generated during the lifting of the trench cover. This is reasonable considering that the MIE of hydrogen is 0.02 mJ, and the energy of mechanical sparks from metal to metal contact can be several mJ.20 The testing contracted by Hoeganaes in 2010 determined that the minimum ignition energy for representative iron dust samples was greater than 500 mJ, and that a continuous arc would ignite the samples. One witness at ground level reported hearing an electric sound at the time of the incident. The motor operating bucket elevator #12 was a likely source of ignition since it had exposed wiring, was not properly grounded, and was within a few feet of the dust cloud source. The wiring was exposed because the electrical conduit supplying power to this motor was not securely connected to the motors junction box. HOEGANAES MINIMUM IGNITION ENERGY (MIE) TEST RESULTS Sample Iron Dust Particle size (%<75 m) 99% Pmax(bar) 3.3 ( P/ t)max (bar/s) 51 KSt (bar*m/s) 15 MIE (mJ17, Cloud) >500

MIT18 (C,Cloud) 560-580

MEC19 (g/m3) 200-250

TABLE 2

Combustible dust test
results commissioned by
Hoeganaes in 2010.

FIGURE 15

Exposed electrical
wiring on elevator motor
near January 2011
incident site (motor
panel cover was rotated
post incident by fire
department).

Motor

Exposed wires

17mJ is an abbreviation for millijoules, which is a unit of energy. One Joule is equal to 1000 millijoules or approximately 0.24 calorie.
18Minimum Ignition Temperature.
19Minimum Explosible Concentration.
20V. Babrauskas, Ignition Handbook, Fire Science Publishers, Issaquah, WA, 2003.

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Hoeganaes Corporation Case Study December 2011

Prior to the CSB notifying Hoeganaes that evidence from the incident area needed to be pre-
served, the company removed and modified evidence from the scene, including the elevator
motor, wiring, and conduit. However, on examination, there were spots that appeared to be arc
marks both inside the junction box, and on the outside of the motor housing.

4.3 HOEGANAES

4.3.1 HAZARD RECOGNITION

In general industry the combustibility of metal dust is a well-established hazard, but metal
dust fires and explosions continue to claim lives and destroy property. The CSB reviewed three
publications dating back to the 1940s and 1950s that addressed metal dust (including iron dust)
hazards and explosion protection methods. The National Fire Protection Association (NFPA)
code for the Prevention of Dust Explosions, published in 1946,21 lists general precautions for all
types of dusts, including metal powder, and specific provisions for certain types of dusts.

The Building Construction section of the code states, Avoid beams, ledges or other places
where dust may settle, particularly overhead. The Gallatin facility, built in the 1980s, was not
designed to avoid significant overhead accumulations of dust. The code calls for designing and
maintaining dust-tight equipment to avoid leaks and, where this is not possible, to enforce good
housekeeping procedures.

The code also cautions against sources of ignition in areas containing dust and recommends
locating dust collectors outdoors or in separate rooms equipped with explosion venting.

In 1957, the NFPA published the Report of Important Dust Explosions which included a
summary of over 1,000 dust explosions between 1860 and 1956 in the U.S. and Canada.22 The
report listed 80 metal dust fires and explosions, including one iron dust incident that resulted in
a fatality in 1951.

A 1958 article in an American Chemical Society publication states, Powdered metals dispersed
in oxygen or air form explosive mixtures their flammability and explosibility have been
reported in considerable detail23

FIGURE 16

Mounds of iron dust
along elevated surfaces
at the Gallatin plant,
February 3, 2011.

21National Fire Codes, Vol. II. The Prevention of Dust Explosions 1946. National Fire Protection Association, Boston, MA., 1946.
22National Fire Protection Association, Report of Important Dust Explosions, NFPA, Boston, MA, 1950.
23Grosse, A.V., and J.B. Conway. Combustion of Metals in Oxygen. Industrial & Engineering Chemistry 50.4 (1958): 663-72.

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Hoeganaes Corporation Case Study December 2011

In the 1990s and 2000s, the Pittsburgh Research Laboratory of the National Institute for
Occupational Safety and Health (NIOSH) conducted a study of the explosibility of various
metals, including iron. The results of these experiments, published in scientific journals,24
showed the explosibility characteristics of iron powder to aid hazard evaluation in metal pro-
cessing industries. However, management within the Hoeganaes Corp. and GKN Corp. did
not commission an analysis of its own potentially combustible PM products and constituents
until January 200

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Sources of Knowledge Discussion

I attached the article and instructions. I chose FAITH. PLS READ ARTICLE

Purpose

To assess your ability to:
Describe the differences among some key alleged sources of knowledge: faith, intuition, perception, introspection, memory, and reason.
Discuss the limitations of the key alleged sources of knowledge: faith, intuition, perception, introspection, memory, and reason.

Overview

There are a number of key alleged sources of knowledge: faith, intuition, perception, introspection, memory, and reason. What are they, and what are their limitations as sources of knowledge?

Action Items

1. Choose
one of the alleged sources of knowledge, and post a description of it and a brief discussion of its limitations by
Thursday. THE APPEAL TO FAITH
Faith, as it is ordinarily understood, is belief that does not rest on log- ical proof or material evidence.21 To believe something on faith is to believe it in spite of, or even because of, the fact that we have insuffi- cient evidence for it. No one has expressed this cavalier attitude toward evidence better than Tertullian: It is to be believed, he said, because it is absurd.23 Saint Thomas Aquinas considered faith to be superior to opinion because it is free from doubt, but inferior to knowledge because it lacks rational justification. In the case of faith, the gap between belief and evidence is filled by an act of willwe choose to believe something even though that belief isnt warranted by the evidence. Can such a belief be a source of knowledge? No, for we cannot make something true by believing it to be true. The fact that we believe something doesnt justify our believing it. Faith, in the sense we are considering, is unquestioning, unjustified belief, and unjustified belief cannot constitute knowledge.
The problem with the appeal to faith is that it is unenlightening; it may tell us something about the person making the appeal, but it tells us nothing about the proposition in question. Suppose someone presses you about why you believe something and you say, My belief is based on faith. Does this answer help us evaluate the truth of your belief? No. To say that you believe something on faith is not to offer any justification for it; in fact, you are admitting that you have no justification. Since believing something on faith doesnt help us determine the plausibility of a proposition, faith cant be a source of knowledge.