No OSHA fine for explosion....

We repeatedly state the following because of the influx of new readers our blog has been receiving: It is not this blog's intention to place blame on neither company nor worker(s), but the hope that awareness of these accidents brings education and prevention of recurrence. If an incident involves an injury or fatality we omit the company name and location. Because in all honesty and frankly it simply does not matter where the incident occurred. What matters in our heart is that an accident is never repeated. The only people who care about where an incident occurred are the widows and orphans of the deceased. Here is a followup from an incident that shocked our industry in 2016.

A loss of power and subsequent rising level of water caused the 2016 explosion at an aluminium plant in the USA. An investigation by the U.S. Occupational Safety and Health Administration found no violations, but OSHA did make some recommendations to decrease the likelihood of similar incidents in the future.

A government investigation into the 2016 explosion at an aluminium company that injured five workers turned up no violations of federal safety regulations and didn’t result in any fines, but the company was advised on multiple precautions.

The U.S. Occupational Health and Safety Administration released the 100-plus page report of its investigation to local news media during the week of January 22, 2017.

The explosion, which caused significant damage to the casting area of the aluminum-extrusion plant, was the result of a loss to power to certain components of the aluminum casting operation.

Alarms and a sump pump that should have activated did not, as a result of the power outage, according to the report.

During the casting operation, molten aluminum leaves the furnace and runs down troughs to a “sow pan” and then to the molds, which are set on a hydraulic table above a 26-foot-deep pit. Aluminum flows into the molds and becomes “billets.” Water is then sprayed on the billets to help cool and harden the metal.

Typically in the event of a power outage, the operator aborts the casting process, stopping the flow of molten aluminum. “Emergency water” flows to clear out the metal from so that the metal does not harden, according to the OSHA report. 

There are alarms that are supposed to go off when water levels in the pit go over 16 feet. There are two pumps in the pit – one to make sure water is always available, and one to remove water when it reaches 14 feet.

Though the alarms, both audio and visual, are powered by battery backups, they did not activate.

The power outage was limited to the circuit that controls the casting process – the overhead lights and the furnaces continued operating, according to the report. “There were no indicators of loss of power unless the operator was watching the control panel screen,” the report states.

The casting process had begun shortly before the explosion. An employee had just opened the gate that allows the liquid aluminum to flow into the sow pan. But because the water in the pit had overflowed, due to the failure of the sump pump, there was water in the pan. The water was encased by the molten metal and turned to steam, causing the explosion.

OSHA did recommend that the aluminium company take three actions: ensuring that the cast operator continuously monitors the control panel and does not engage in tasks that draw attention away from the operation, installing a gravity drain in the pit at 20 feet to ensure water stays at a safe level, and installing a backup sump pump to keep the water level below 14 feet in the event of a power outage.

When asked if the aluminium company had acted on those recommendations, company spokesman said in an emailed statement, “as we work to rebuild our casting operation, we remain committed to a safety-first approach, and have integrated the recommendations from OSHA and our own investigation, which further build on our strong safety systems and training.”

“The findings of the investigation indicated that there were no violations of any OSHA requirements, demonstrating that we have strong safety systems in place, and that our employees are well-trained and follow those guidelines,” company spokesman said in the statement. “This event also reminds us of the importance of focusing on safety every single day.”

Interviews with employees which were included in the OSHA report show that employees were aware of the need for a drain in the pit.

“I think we need our own generator, also a drain to let the water out so it doesn’t get too high,” said one employee. “Casting department needs a backup generator. Emergency drain would help as well,” said another.Another employee said he’d never heard the alarms go off during a power loss, and that the pumps have required repairs “quite a bit.”

“The pump has been an issue,” the employee said. He said that a new pump system had been ordered but had not arrived. He said there is a need for upgrades and an emergency drain. An upgrade to the casting pit was done in 2007.

Two employees stated that a worker has other things to do besides just watching the control panel during the casting process.

The explosion blew a hole in the roof of the casting area, sending fire brick and molten aluminum into the sky, striking neighboring buildings and even starting a small fire in a boat at a nearby business.

Included in the report is the narrative from an employee who was injured and taken to a hospital by air ambulance. The man said he had taken a break and was in the nearby smoking area. At the time of the explosion he started running and tripped. Then something hit him in the back. Everything had been normal when he went on break, he said.

As part of the company’s investigation, the aluminium company conducted “non-destructive” testing of the casting pit control system and the “uninterruptible power supply” backup system.

The explosion destroyed the roof above the casting pit and a portion of the end walls, according to an engineer’s report. The main building structure sustained little damage. There was roof damage in adjacent areas. The roof areas remained structurally sound but not capable of withstanding storm force winds because of broken tension rod bracing. Falling debris punctured the roof in some other areas of the plant.

The aluminium company was given the go-ahead to begin repair of the casting area in early July. That work is ongoing. “They hope to reopen sometime mid-year,” company spokesman said.

Other than the casting house, the plant has been operational since the day after the incident, company spokesman said. Because casting isn’t being done on site, raw materials are being brought in, “which is quite normal in the industry,” he said. All casting house employees have been reassigned, and there have been no layoffs related to the explosion, he said.

In addition to the OSHA and aluminium company investigations, one was done by a union, which represents union members at the plant.

The editors were made aware of this explosion with an hour of it occurring. We immediately prayed for every worker and the first responders who rushed to the scene.

For the readers who are unfamiliar with this blog and our industry. We would like to take a moment (or 500 words!) to explain why this incident sent a shock (pun not intended) through our industry.

Every industry is known for its catastrophes. From the beginning our industry was known for our molten metal explosions. 

In the beginning of our industry plants would regularly suffer explosions of varying severity. Workers would be injured or killed. Production would be stopped. These explosions only reflected poorly upon the individual company or individual plant. The feeling back then between companies was “look what happened at (competitor). That all changed when an explosion occurred in Alabama, USA in 1967. The severity of that explosion shocked the aluminium industry into realizing that the hazard of molten metal explosions was no longer an individual plant or company issue but an industry issue. Soon thereafter our industry work collectively to investigate molten metal explosions. That research continued in different ways over the next 40+ years. Our industries knowledge of molten metal explosions is to the point now where mitigation is possible. On a side note this initial research involved competing companies that cooperated and shared safety information. Which planted the seed to where our industry reaps the fruit. Our industry is one of the few where plant managers of competing companies can call each other and ask about safety related topics. One does not see that in any other metals industry. We commend the aluminium industry from continuing to cooperate among themselves resulting in making our industry safer.

Back to this incident. The severity of this incident was amazing. In the past we have seen explosions with similar result where a chemical reaction involving the bonding of Aluminum and Oxygen (in water) which releases Hydrogen. In these incidents the force generated from one kilogram of molten Aluminium is equivalent  of 3 kilograms of TNT. Very very large explosions can occur. The Aluminium Plant Safety Blog has posted a similar incident that generated an earthquake radiating out for 74 kilometers from the destroyed casthouse. When an explosion occurs from the chemical reaction there is no solidified metal left, the result is white powder in the form of aluminium oxide.

But, this explosion did not occur as the result of a chemical reaction but of a physical phenomenon where two materials with widely different temperatures come into contact. The high temperature of molten aluminium covered water. In this incident the water occurred when a loss of power stopped the water pumps from empting the pit. Upon contact with molten metal water will expand rapidly. How quickly? Imagine a marble expanding to the size of a beach ball in the speed of a blink of the eye. With this expansion the molten metal gets thrown or propelled. In this incident a majority of the molten metal that was propelled upward. Removing the roof joists, the sheet metal and being thrown outward. We have never seen a physical phenomenon explosion result in this amount of force and destruction. It blew a large hole in the roof. Then the molten metal exited the aluminum company property and landed on surrounding businesses. We could go on and on about the results that this explosion had upon equipment, property, etc. Nevertheless, we are so thankful no one was killed in this incident. We pray that the injured workers recover fully from the physical and any metal injuries they may have suffered. We hope that the company will continue to provide mental counseling to their workers.

Finally, we pray that our industry never experiences another explosion of this magnitude. 

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