Four employees affected by anhydrous ammonia leak at Farbest

Four employees reported symptoms after ammonia from a rooftop cooling system was drawn into the facility; one was taken to the hospital.

A small anhydrous ammonia leak at Farbest in Huntingburg was quickly located and stopped by Farbest employees on Tuesday morning.

Huntingburg Fire Chief Donnie Heim said the leak originated from a failed gasket in the rooftop piping used for the facility’s cooling system.

Four workers reported symptoms after ammonia was drawn into the building. Three workers experienced throat scratchiness and refused medical transport, returning to work. One worker, who reported difficulty breathing, was taken to the hospital by ambulance.

Heim said he believed the worker was released after being checked out, though he noted he could not confirm that with certainty.

He added that there were other employees in the vicinity of the four affected employees and that a nearby breakroom was busy as the incident occurred around lunch, but no one else reported any symptoms.

By the time Heim arrived on scene, air quality readings inside the building had already returned to zero. He said Farbest employees acted quickly and effectively to contain the situation.

Heim said workers first detected the problem by smell, as ammonia has a distinct odor, and quickly located and isolated the source.

“Farbest did a great job. They contained the leak very quickly. They shut off the valves, they isolated it, and so it wasn’t very much that got in there,” Heim said.

To provide context on the exposure levels, Heim outlined several established safety thresholds for ammonia. The Acute Exposure Guideline Level 1 (AEGL-1) for a 10-minute exposure is 30 parts per million. The OSHA permissible exposure limit for an eight-hour workday is 50 parts per million. The level immediately dangerous to life and health is 300 parts per million.

Readings at the source of the leak measured approximately 20 parts per million before the leak was contained.

The 20 parts-per-million reading recorded at the rooftop source was below all those thresholds. Heim noted that because the ammonia had to travel from the roof into the building, concentrations inside were likely even lower than at the source, based on his readings upon entry and the extent of dilution that would have occurred before it reached the room.

Heim said the incident was consistent with the types of hazmat scenarios the department regularly trains for. The department is required to complete hazmat training throughout the year, targeting at least 10 to 20 hours annually in various forms.

“We’ve done several drills with anhydrous ammonia and chlorine, which are our biggest proponents that come through our area,” he said.

Heim said the incident, while minor in outcome, had the potential to be more serious under different circumstances.

Heim said the quick action by Farbest employees was a key reason the incident remained contained.

The fire department was called out at approximately 11:28 a.m. and departed the scene at 11:54 a.m., spending roughly a half hour on site. Ten firefighters responded with four trucks, though Heim turned two trucks around as it became clear the incident was not as serious as initially feared.

Heim said the department’s three hazmat technicians were available, but the situation did not warrant calling in the full hazmat team.

Deaconess Memorial Emergency Medical Services responded and treated the employees.