ANNUAL SUMMARY REPORT ON MOLTEN METAL INCIDENTS IN 2018

October 2019

For the year 2018, 170 reports were received on incidents occurring world-wide as compared to

181 reports received for 2017 and 195 reports for 2016. The attached figures summarize the

reports for 2018 as well as the data for the years 1980 thru 2018.

SUMMARY POINTS:

• For 2018, there were 170 explosion incidents reported, which is comparable to the

historically high number of incidents reported the previous three years.

• There were 148 Force 1 explosions, 20 Force 2 explosions and two Force 3 explosions

reported in 2018. The two Force 3 incidents were both in China. The information

regarding these incidents was taken from government investigation reports and other

Chinese documents, translated into English.

• There were a total of 26 reported injuries, including 8 fatalities, 4 serious and 14 minor

injuries. The two Chinese Force 3 explosions accounted for all 8 fatalities, 2 serious and

2 minor injuries.

• Both Chinese Force 3 explosions occurred during steady state billet casting.

• Excluding the two Force 3 incidents in 2018, there were 14 injuries (2 serious and 12

minor) in 168 incidents. This would be the second lowest total number of injuries since

the beginning of the reporting program in 1981, with only 2017 being lower at 8 injuries.

• Incidents, injuries, and injury rate data were investigated in greater depth for Melting,

Casting and Transfer operations, with injuries and injury rates showing a downward

trend over the last 6-8 years for Casting and Transfer, notable considering the increase

in reported incidents over the past 4 years. Melting injuries have been very low over

the past 10 years (<4) with the exception of 2015 when there was one Force 3 incident

causing 35 Minor injuries.

• As noted in the past, this lower injury frequency can be attributed at least partially to:

1) the increased use of primary and secondary PPE; 2) improvements in PPE materials

and design; 3) an increased focus on hands-free casting operations that remove

personnel from high risk casting operations and 4) possibly increased training and

hazard awareness.

• The 8 fatalities are the highest number since 2007 when there were 19 fatalities, also

the result of a Force 3 explosion in China. For the 9 years prior to 2018 there had been

only two reported Fatalities and 4 in the last 10 years.

• This large number of fatalities in 2018 increased the average yearly fatality rate from

2.5 to 2.7 for the entire reporting period from 1981 through 2018.

• The two Force 3 explosions in 2018 are the most reported in a year over the last 10 years

with 5 years reporting one Force 3 and five years reporting zero Force 3 incidents. The

5 year and 10 year average incident rates increased to 1.0/yr. and 0.7/yr. from the

previous rates of 0.6/yr. for both the 5 and 10 year averages.

• As noted the previous two years, the Force 2 explosions continued to be high at 20; 18

in 2016 and 24 in 2017 as compared to the years 2012 through 2015, which averaged 7

per year.

• As is typical of previous years, in 2018 Reduction process plants experienced the highest

number of incidents as compared to Extrusion, Rolling and Other: 87 incidents with 7

minor injuries and one serious injury.

• Most explosions occurred during the Casting operation (71), as compared to Melting

(46), which historically has had the highest total number of incidents. Starting in 2003,

however, this trend was reversed and now total Casting incidents (1375) have passed

total Melting incidents (1336).

• Most Casting explosions occurred at Start-up, as has been the norm; 55 of the 66

incidents which had this information provided. Five Force 2 and 0 Force 3 explosions

during Start-up. The only 2 Force 3 explosions occurred during Steady-State, these were

the Chinese incidents. Termination had one Force 2 incident.

• Most Casting incidents occurred when casting either DC slab or billet; 41 total. Sow or

mold casting accounted for 29 explosions.

• Most injuries were during Casting (6 Minor, 2 Serious and 8 Fatal), with 12 of the 16

occurring in the two China incidents. Transfer operations accounted for 8 injuries (7

Minor and one Serious). Of note, is that there was only one Melting injury, but it was a

Serious injury.

• As typical of past years, most Melting explosions occurred due to wet or contaminated

scrap, 30 of the 46 incidents with 9 being Force 2. The second highest reason for Melting

explosions was related to tools and drain or skim pans; one Force 2 of the 9 reports.

• There were 40 Transfer operation incidents, all Force 1, almost the same rate as Melting

with 46 explosions. For Transfer explosions, this is almost double the incident rate

experienced the last four years, which averaged 22/yr. Transfer operations accounted

for 7 Minor and 1 Serious injury, while Melting had only one Serious injury.

EXPLANATION & DISCUSSION OF CHARTS AND DATA:

The Aluminum Association classifies molten metal explosions according to Force level, with

Force 1 being the least severe and Force 3 being the most severe. Table 1 below provides

information on the criteria used for rating Force level. Figures 1 through Figure 38 display

various charts and tables as described in the discussion below and are provided after the

discussion.

Table 1: Explosion Rating Force Criteria

LOW SEVERE

Figure 1 displays by year from 1981 thru 2018 the total number of reported incidents, 3886. The

170 explosions reported in 2018 are in the same range of total explosions as in the past three

years. From 2015 through 2018 there was decided upward trend averaging 180 reported

incidents over this timeframe. This rate is higher than the years 2000 through 2007, which

averaged 145 incidents per year.

Figures 2 thru 7 provide Force Level data for the years 1981 thru 2018 in various formats,

including the number of incidents and rates. Figure 2 displays the reported incidents each year

for all three Force Levels. In 2018 there were 148 Force 1, 20 Force 2 and 2 Force 3 explosions.

Figure 3 shows the data for only Force Levels 2 and 3 and Figure 4 displays only Force Level 3.

Both Figure 3 and Figure 4 include the average number of explosions per year for this time frame.

The two Force 3 explosions in 2018 is the first time since 2007 with more than one Force 3

explosion; 2007 had four Force 3 incidents. The average number of Force 3 explosions over the

last 5 and 10 years (1.0/yr and 0.7/yr respectively) continues to show a much lower level

compared the 3.1/yr. average for the entire reporting history from 1981 through to 2019. The

notable downward trend of Force 2 explosions observed in Figure 5 starting around 2008 and

Guidelines Force 1 Force 2 Force 3

Property

Damage None Minor Considerable

Light Minimal Flash Intense

Sound Short cracking Loud Report Painful

Vibration Short and sharp Brief rolling Massive

structural

Metal

Dispersion <15 feet >15 to 50 feet >50 feet

continuing through 2014 was reversed starting in 2016 and has continued through 2018 with an

average of 21/yr. over the past three years.

Figures 6 and 7 display a comparison of all three Force Levels for the entire reporting history

from 1981 through 2018 in two different formats: 1) bar graph and 2) pie chart. Force 1 incidents

account for 75.3% of all incidents, while Force 2 incidents account for 21.7% of the total

compared to 3.0% for Force 3.

Both Force 3 explosions occurred in China with extensive damage to the facilities and numerous

fatalities and injuries to personnel. The information regarding these incidents was taken from

government investigation reports and other Chinese documents, translated into English. One

incident involved 5 Fatalities and 1 Serious injury, while the other had 3 Fatalities, 1 Serious and

2 Minor injuries. Both explosions occurred during steady-state billet casting and were related to

extensive metal bleed-outs into the casting pit. One bleed-out was the result of a broken cable

used to lower and raise the casting table. Indirect causes were reported to be related to

maintenance, worker fatigue, production standards, safety management and inadequate

training. The other explosion involved an undetected trough or launder leak upstream of the

casting table which flowed into the casting pit. Indirect causes included long work hours,

inadequate training, procedures and unrecognized risks. It was notable that the documentation

for both explosions did not mention casting pit water levels or protective pit coatings.

Figures 8 thru 12 provide in various formats injury incident data (Minor, Serious and Fatal) for

the years 1981 thru 2018. The Figure 8 bar chart shows Minor, Serious and Fatal injuries for each

year. In 2018 there were 8 Fatalities, 4 Serious and 14 Minor injuries. As noted above, the two

China Force 3 explosions accounted for 8 Fatalities, 2 Serious and 2 Minor injuries. For the 9

years prior to 2018 there had been only two reported Fatalities and 4 in the last 10 years.

When not including the two Force 3 incidents for 2018, there were 14 injuries (2 Serious and 12

Minor) in 168 incidents. This would be the second lowest total number of injuries since the

beginning of the reporting program in 1981, with only 2017 being lower at 8 injuries. As noted

in the past, this lower injury frequency can be attributed at least partially to: 1) the increased use

of primary and secondary PPE 2) improvements in PPE materials and design, 3) an increased focus

on hands-free casting operations that remove personnel from high risk casting operations and 4)

possibly increased training and hazard awareness.

From 1981 through 2018, there is now a total of 1583 Minor, Serious and Fatal reported injuries

with Figure 9 showing the total injuries in these three categories. The Figure 10 pie chart breaks

this down into percentages: 69.7% Minor, 24.1% Serious and 6.82% Fatal. Unlike recent previous

years, the % of Minor injuries decreased compared to the Serious and Fatal injuries due to the

two Force 3 incidents.

Figure 11 looks at the % of injuries for each injury category per the total number of reported

incidents. This indicates that for each 100 incidents reported there is a 28.4% rate for Minor

injuries, a 9.8% rate for Serious injuries and a 2.6% rate of a Fatality. Since explosions are typically

more likely to be reported when there is an injury of some degree, these numbers are certainly

inflated compared to the situation if all explosions were reported, but this does provide an

indication of the potential rate of an injury per incident.

Figure 12 displays data only related to Fatalities for the reporting program from 1981 through

2018. As indicated above, there have been only two Fatalities reported over the previous 9

years, which is well below the average of 2.7 fatalities per year. Last year this average rate was

2.5/yr.

Figures 13 thru 32 provide more detailed information regarding the 170 reported explosions in

2018 along with similar charts comparing this yearly data with the entire database from 1980

thru 2018.

Figure 13 shows the 2018 data by Force Level for each of the four major categories of operations:

Melting, Casting, Transfer and Other. This can be compared to the same data for the years 1980

thru 2018 in Figure 14. In 2018, most explosions occurred in Casting (71), compared to Melting

(46), Transfer (40) and Other (11). All Other explosions occurred in the Reduction Process.

Shown in Charts 1 & 2 below are: 1) Annual Incidents by the Four Major Categories of Operation;

and 2) Annual Incidents for Melting and Casting. This specific data is only available for the years

1990 through 2018, excluding 2011. Historically Melting and Casting have been the operations

that have had the highest number of explosions. Since the beginning of the program Melting has

always had the highest total up until this year; now total Casting incidents (1375) have passed

total Melting incidents (1336). From the second plot it can be more easily seen that starting in

2003 the trend was reversed with Casting having a higher frequency than Melting.

Chart 1

0

20

40

60

80

100

120

1990 1995 2000 2005 2010 2015 2020

Annual Incidents by Operation1990 - 2018

Melting Casting Transfer Other

Chart 2

In the past, there has typically been a higher percentage of Force 2 and Force 3 explosions in

Melting compared to all the other process categories and in 2018 the data was in this direction

as well, with 12 Force 2 and zero Force 3 Melting explosions compared to 7 Force 2 and 2 Force

3 Casting explosions, no Force 2 or Force 3 Transfer explosions and one Force 2 in the Other

category. The majority of Force 2 and Force 3 explosions for the entire reporting period

continues to be related to the Melting operation by a wide margin as shown in Figure 14.

As discussed above with Figures 8 through 12, there appears to be a downward trend with

injuries. The incident data was investigated further and is newly presented in this year’s report

in Figures 15 through 20. These graphs provide Injury and Incident data for each Melting, Casting

and Transfer operations in two different formats: 1) Injuries and Incidents; and 2) # Injuries per

Incident or Injury Rate. The data is displayed by year from 1990 through 2018, excluding 2011.

Unfortunately, the data is not available for program years prior to 1990 and 2011. In general, the

data shows an expected up-swing in incidents in the early 2000’s and the last 4 years as is seen

previously in Figures 1 and 3. There appears to be a general downward trend in Injuries and

Injuries per Incident, however, over the last 6 to 8 years, especially when considering the

increase in reported incidents over the past 4 years. A downward trend can be observed

especially for the Casting and Transfer operations. Melting injuries and Injury Rate have been

very low for the last 9 years (< 0.05) with the exception of 2015 (>0.7), which had 35 Minor

injuries resulting from one Force 3 explosion when a furnace bled-out into a casting pit. For the

Injury per Incident Rate charts a best fit line is provided along with R2 values, which are very low

due to the scatter in the data. It is a positive sign that the Injury per Incident Rate is trending in

this direction. There are probably a number of reasons for this trend including improvement with

primary and secondary PPE materials, design and use, movement toward ‘hands-free’ casting

removing personnel from the casting pit during cast starts, and increased training and hazard

awareness.

0

20

40

60

80

100

120

1990 1995 2000 2005 2010 2015 2020

Annual Melting & Casting Operation Incidents1990 - 2018

Melting Casting

Figure 21 provides 2018 data regarding the type of charge materials involved in 46 Melting

incidents. As in the past, wet or contaminated scrap was the leading cause of Melting explosions,

with 21 Force 1 and 9 Force 2 incidents in this category. The next highest charging category was

wet tools and drain / skim pans with 9 explosions, followed by 7 incidents due to wet alloy

additions including Mg, Si, Mn and salt flux. There were also 6 incidents due to wet primary sows.

Figure 22 provides a compilation of the Melting explosion data over the years 1980 thru 2018 for

the various types of charging material involved. Wet or contaminated scrap continues to be the

reason for most of the Melting explosions. The second highest area is related to wet alloying

materials. The majority of Force 2 and Force 3 Melting explosions have been related to Scrap

charging. The majority of other Force 2 and Force 3 explosions are related to charging various

types of sows (primary and RSI) and t-bar.

Figure 23 provides a breakdown of the 71 Casting incidents in 2018 in two different ways: by

stage in the process and by type of casting process. As mentioned above, Casting had the highest

number of explosions in 2018. With the increased level of reports over the last 4 years the

Casting incidents have increased significantly with an average of 85 incidents / yr. over the past

4 years compared to 34 incidents / yr. over the previous 10 years. There were 6 Force 2 and 2

Force 3 explosions in 2018, with the two Force 3 China explosions discussed above. As typically

seen in the past, most of the explosions occurred during Start-up (55), with 7 during Steady-State

and 4 during Termination. There were 4 Casting incidents that did not have the casting stage

indicated on the report. The majority of the Casting incidents (41) occurred when casting DC

Billet or Slab. This included 5 Force 2 explosions and 2 Force 3 explosions. The balance of the

explosions (29) occurred with sow or mold casting, 26 Force 1 and 3 Force 2.

Figure 24 shows DC Casting incidents by drop segment for years 1980 - 2018. The historical data

is similar to the 2018 data shown in Figure 23 in that most explosions occur during Start-up,

followed by Steady-state and then Termination.

Figure 25 provides the major causes of the 75 Casting incidents in 2017. They are listed by cast

stage for DC casting and also for mold or sow casting. For DC casting, the main issues were related

to wet equipment, wet starting blocks, butt-curl control and bleed-outs or bleed-overs. Details

of the causes of the 2 Force 3 China billet explosions are discussed above. The main sow and

mold casting incidents were due to wet or cracked molds, and wet equipment. Unfortunately

there were 9 Casting incidents with No Reason for the explosion provided.

There were 40 Transfer explosions in 2018 as shown in Figure 13, Force 1. Figure 26 indicates

that 19 incidents, almost 50%, were related to wet equipment / refractory and 11 were due to

wet tools. This was followed by 9 resulting from wet or rusty drain or skim pans.

Figure 27 provides a bar chart showing the equipment involved in 798 Transfer explosions for

the years 1980 thru 2018. As in the past, Drain Pan explosions are related to the highest number

of Transfer explosions, followed by Trough and then Crucible that were wet or damp.

Injuries by Operation (Melting, Casting, Transfer and Other) resulting from the 170 explosions

in 2018 is shown in Figure 28. The highest number of injuries occurred in Casting with a total of

16. The two China Force 3 billet casting explosions discussed above accounted for 12 of the 16.

Transfer operations had 8 Injuries, with only one in Melting and one in Other (Reduction). In

2017 there were only reported 8 Injuries, with 18 Injuries in 2016 and 57 Injuries in 2015.

Figure 29 provides Injury by Operation data for 1980 thru 2018. The highest number of Minor

and Serious injuries has occurred in the Casting Operation. The Melting Operation accounts for

the highest number of Fatalities, also the highest number of Force 3 explosions as seen in Figure

14. It should be noted that a significant number of injuries have occurred in Transfer Operations,

with 7 Fatalities occurring even from this typically rather straight forward procedure.

Figures 30 and 31 provide incident data vs. the type of Process Plant (Reduction, Extrusion,

Rolling and Recycling) for 2018 and for 1980 thru 2018 respectively. In 2018, more than half (87

of the 181 explosion incidents) were reported by Reduction facilities. All but two of these were

Force 1, the other being Force 2. Rolling accounted for the nest highest at 47, 38 Force 1 and 9

Force 2. Next was Recycling with 21 incidents, 13 Force 1 and 8 Force 2. Of note is that 38% of

the Recycling incidents were Force 2. Extrusion accounted for 15 incidents, including 1 Force 2

and 2 Force 3. As shown in Figure 31, a majority of the explosions reported from 1980 thru 2018

occurred in Reduction facilities; the second highest were reported from Rolling facilities.

The main causes of the 2018 Reduction facility explosions are broken down in Figures 32 and 33.

They are listed by Melting, Casting and Transfer / Reduction incidents. Melting incidents were

related to wet charges and wet tools. The primary reason in the Casting was cracked, wet or

rusty molds for primary casting. Wet equipment and tools, wet sample molds and wet, rusty or

cracked drain pans were the major categories under Transfer and Reduction incidents.

Figure 34 is a bar chart providing 2018 Reduction plant injury information for the 6 Minor and

one Serious Injuries. Transfer operations accounted for 5 of the 7 injuries including the one

Serious injury. The primary reason for the injuries were unpreheated hand tools which resulted

in 4 Minor and 1 Serious injury: one Casting, 3 Transfer and one Reduction.

Rolling plant injuries are shown in Figure 35, which included one Serious and 4 Minor. The

Serious injury occurred from melting wet scrap. The two Minor Casting injuries resulted from

bleedouts resulting from excessive curl and high metal temperature. The two Minor Transfer

injuries were due to wet refractory and equipment.

Figure 36 displays information regarding 13 Casting injuries in Extrusion operations. 12 of the

13, which included 8 Fatalities, were from the two Force 3 China billet casting explosions

discussed above. The other Minor injury was due to a Force 1 start-up explosion due to wet

equipment.

Figure 37 summarizes the 2018 injury data by type of Process Plant and Figure 38 shows this

same data for 1980 thru 2018.

The last page of the report after the Figures provides an Aluminum Association Molten Metal

Incident Report Form or you can link to the form at:

https://www.aluminum.org/resources/electrical-faqs-and-handbooks/safety

RTR – October 31, 2019

ALUMINUM ASSOCIATION

MOLTEN METAL INCIDENT REPORT

Date of Incident: Predominant Plant Activity: SELECT ONE:

(month/year)

Explosion Force – Mark One: Force 1 Characterization: Force 2 Characterization: Force 3 Characterization: For definition of force, click arrow to see a description

Alloy Metal Temperature °F °C Approximate Amount of Metal Involved lbs kilograms

OPERATION:

Charging / Melting Type of Furnace SELECT ONE:

Furnace Capacity lbs mt % Full

Materials Charged

Outside Storage? Yes No Preheat? Yes No Preheat Time/Temp: hrs °F °C

Transfer Type SELECT ONE:

Casting Type SELECT ONE: Type of Product being Cast:

SELECT ONE:

Stage of Operation: SELECT ONE:

Other Describe

Number of Injuries by Type: Minor Severe Fatal

Provide a brief description of the incident and its root cause(s):

.

_________________________________________________________________________________________________________

_________________________________________________________________________________________________________

_________________________________________________________________________________________________________

If Charging/Melting Incident, please

select appropriate Primary and

Secondary cause(s):

Other

Other

If Contaminations (other than moisture) was

selected, please specify:

SELECT ONE:

If Transfer Incident, please select

appropriate Primary and Secondary

cause(s):

PRIMARY CAUSE:

SECONDARY CAUSE:

If Casting Incident, please select appropriate

Primary and Secondary cause(s):

PRIMARY CAUSE:

SECONDARY CAUSE:

If Bleed-out/Bleed-over is selected above, describe

reason for Bleed-out or Bleed-Over:

If Explosion due to Bleed-out/Bleed-over was selected

above, where was the location of Explosions:

SELECT ONE:

If Metal Level Control Problem was selected above,

please specify location of problem:

SELECT ONE:

Please return to:

Curt Wells

Director, Regulatory Affairs

The Aluminum Association.

1400 Crystal Drive, Suite 430

Arlington, VA 22202