Gregory Milam was working for a company called Usher Transport when he was delivering about 20 tonnes of caustic soda to Smurfit Westrock's Covington paper mill in Virginia on January 21 this year.

He has claimed that a facility Smurfit Westrock had at the plant for emergency cases of corrosive chemical exposure was not working correctly and had not been maintained.

Caustic soda is used during the manufacturing process at the mill. Harvested wood or recycled paper is first turned into a pulp. That involves breaking down wood into chips, removing the bark and then dissolving the wood in a vat of hot water and chemicals that includes caustic soda.

Caustic soda at 50pc concentration has a relatively high freezing point, at about 13C.

Mr Milam claims in his lawsuit that on days when the temperature was below freezing for the chemicals being delivered, the valve on a chemical tanker making a caustic soda delivery would often freeze up during transit. Mr Milam claims that at the 126-year-old Smurfit Westrock plant, the practice of the company's employees in such circumstances was to apply steam to heat the valve on the unloading truck to thaw it.

"This steam was generated from inside the building and delivered from the pipe through a hose to the valve," he claimed. "It is not necessary, and can be extremely dangerous, to pressurise a hose while attempting to run steam through it, especially if that hose is not rated for steam."

He also claims in his lawsuit that it is standard practice to flush out chemical delivery hoses after each delivery.

On the day in January when Mr Milam was making his delivery, the outside temperature was about -3C. Before he arrived, another truck had made a delivery of caustic soda to the same delivery bay Mr Milam was directed to.

He claims that an employee of Smurfit Westrock failed to flush caustic soda from the delivery hose after that previous delivery.

"Unbeknown to plaintiff, when he arrived to make his delivery, the chemical hose contained residual caustic soda 50pc," the lawsuit alleges.

Mr Milam claims that a Smurfit Westrock employee incorrectly used a chemical hose, forcing pressurised steam through it in an effort to unfreeze the valve on the truck.

However, it's alleged the chemical hose ruptured, spraying hot steam and caustic chemicals all over Mr Milam's body.

He claims an eyewash station at the plant was frozen, so he couldn't rinse his eyes, while an emergency shower had insufficient pressure and he was unable to rinse the chemicals from his skin.

Mr Milam has claimed that Smurfit Westrock and its subsidiaries were negligent and liable for the negligence of their employee.

He is seeking a $75m award against the defendants and has demanded a jury trial.

Smurfit Westrock did not respond to a request for comment.