OSHA Fines Horizon Biofuels Inc. Nearly $148,000 for 2025 Fatal Explosion and Fire

The Occupational Safety and Health Administration (OSHA) has fined Horizon Biofuels Inc. for $147,542 in proposed penalties for willful and serious safety violations.

The citation follows a fatal explosion and fire at the Fremont, Nebraska, facility that produced wood pellets and wood mulch for animal bedding.

Shortly before noon on July 29, 2025, there was a sudden release of dust or smoke from Horizon Biofuels’ tower. That was followed by flames and a major blast that caused significant structural damage.

The day shift operator was trapped inside the collapsed structure. Investigators found the operator, who was the only employee at the facility at the time, initially survived the explosion and had called his wife and plant manager. Tragically, the instability of the structure prevented emergency personnel from entering until the next day.

The employee had brought his two daughters, ages 8 and 12, to work with him to take them to a medical appointment after his shift ended around 4:30 p.m. The girls were in the break room but were also killed in the explosion.

The explosion caused severe damage within the facility, road closures for several days and affected vehicles on-stie and nearby. Multiple fires broke out at the facility and combustible material at the facility smoldered for more than a month.

OSHA cited Horizon Biofuels for, among other violations:

• combustible dust buildup,
• failure to ensure the equipment within the facility was protected from creating an ignition source and
• lack of fall protection for employees working at heights greater than 4 feet.

The U.S. Chemical Safety and Hazard Investigation Board (CSB) conducted its own independent investigation. In an update from September 2025, CSB Chairperson said, “This terrible tragedy should not have happened. Preliminary evidence points to a combustible wood dust explosion, a well-known—and completely avoidable—hazard in wood processing.”

According to reporting from Nebraska Public Media News, the Nebraska Department of Water, Environment and Energy had investigated a dust complaint at the facility in February 2025. Dust was found to have covered vehicles parked outside the facility. The finding was not reported to OSHA because the plant wasn’t operational at the time of its investigation, which only looked into issues with outside air.

OSHA previously issued Horizon Biofeuels four serious citations in 2012, including lockout/tagout, hazard communication and woodworking machinery requirements. After informal settlement, the company was fined $6,000.

For these latest citations, Horizon Biofuels has 15 business days from receipt to comply, request an informal conference with OSHA or contest OSHA’s findings.

It is not clear whether Horizon Biofuels is still operating. The company's Google business listing says permanently closed, and the listed phone number is not in service. The company's website returns an error message. Horizon Biofuels has a LinkedIn page, but it has never posted anything. 

Images of the plant and additional reporting can be found from local outlets WOWT and Nebraska Public Media.