Wisconsin grain milling company fined $1.8 million after fatal dust explosion

20 November 2017

The US Occupational Safety and Health Administration (OSHA) has announced it will fine Didion Milling Inc. a total of $1.8 million for not complying with federal safety standards, which investigators say could have prevented the huge explosion on May 31 at its Wisconsin grain mill which killed five workers and injured a dozen others.

OSHA said on November 17 that its five-month investigation found that the mill in Cambria, 40 miles north of the state capital, Madison, failed to control highly combustible grain dust in its plant and did not properly inspect and maintain safety controls on equipment. The agency found similar violations during previous inspections of the plant between 2010 and 2014, and issued a number of fines for failing to install equipment to protect workers from combustible dust.
OSHA’s investigation found 14 willful violations, which are issued when employers knowingly fail to uphold workplace safety standards. Eight of those citations were also classified as 'egregious' because they happened repeatedly. Five other were considered 'serious.'
These citations were issued under OSHA’s grain handling standards for machine maintenance and dust control. The company was cited for failures to shut down ignition sources, prevent static electricity, provide adequate employee protective equipment, correct malfunctioning dust collectors and maintain safety controls.
Other issues included failing to provide workers with fire resistant clothing, failing to install an alarm system, failing to inspect and maintain safety controls on equipment, and failing to ensure that air filters worked properly.
OSHA said the company did not regularly shut down milling equipment for inspection, lubrication and removal of debris to reduce risk of heat and sparks that could ignite dust. The company did not have a written dust-removal plan and schedule, and allowed workers to use compressed air to clear dust from surfaces around machinery that could ignite it.
The serious citations included violation of rules requiring dust filtering machinery installed inside a building to be equipped with explosion-suppression devices.
"Didion Milling could have prevented this tragedy if it had addressed hazards that are well-known in this industry," said OSHA Regional Administrator Ken Nishiyama Atha. "Instead, their disregard for the law led to an explosion that claimed the lives of workers, and heartbreak for their families and the community."
Three workers were killed instantly by the blast and two others succumbed to their injuries days later. One employee suffered a double leg amputation and 11 others experienced injuries of varying seriousness.
OSHA said this was the largest fine ever to emerge from a single investigation in Wisconsin. The company has been placed in OSHA’s Severe Violator Enforcement Program, which allows OSHA to inspect its other facilities.
Didion had previous citations for explosion hazards, and was inspected seven times between 2010 and 2014.
The company faced fines from OSHA in 2011 for failing to install equipment to protect workers from dust that can ignite and explode.
An OSHA inspection report said Didion did not keep its corn processing facility “free from recognized hazards that caused or were likely to cause death or serious physical harm. Employees were exposed to the hazards associated with dust explosion, deflagration or other fire hazards.”
Six filters set up to collect dust in the facility weren’t equipped with explosion protective systems and conveyor equipment wasn’t properly bonded to ducts that are used to control particulate matter, inspectors said then.
Records show Didion paid a $3,465 fine and the case was closed in September 2013. OSHA had not cited the plant for anything since. The records also show that in 2011 OSHA informally settled without fines several citations alleging Didion did not provide adequate respiratory protection for employees.
In 2010 Didion agreed to pay the state $1.05 million to settle state Department of Justice lawsuits alleging the company violated air and water pollution regulations dozens of times over the previous decade. The air violations related to inadequate measures to prevent dust from escaping the plant and polluting the air outside. The water violations concerned pollution from Didion’s ethanol operation.
Didion issued a statement saying it disagreed with the severity of the penalties and is working with its attorney on a response. Company officials also said they had hired their own experts to investigate the cause of the explosion.
The company has 15 business days to either comply with the citations or contest the findings.

In the last 35 years, more than 500 grain dust explosions have been recorded in the US, killing more than 180 people and injuring more than 675, according to OSHA.