One person has died and 28 others are being treated in hospital following a massive pileup that involved a hazardous chemical spill on Highway 401 in eastern Ontario.

Ontario Provincial Police said the main collision occurred at around 2 p.m. near Highway 137, about a 30-minute drive east of Gananoque.

OPP said the person who died was the driver of a transport truck that was carrying a hazardous chemical. The rest of those taken to hospital include 15 civilians, and 13 first responders.

Between 7,000 and 10,000 litres of the hazardous chemical spilled in the crash according to Leeds Township Spokesperson Elaine Mallory, prompting Kingston General Hospital to implement a “Code Orange” protocol to deal with those affected.

Many of those who were transported to hospital came in contact with the hazardous chemical, Mallory said. They were all taken to a decontamination area before being admitted to Kingston General Hospital for observation.

It’s not yet clear whether the death of the transport driver was related to the hazardous material, identified by hospital officials as fluorosilicic acid.

According to hospital officials, exposure to the chemical can cause irritation to the nose, throat, respiratory system, irritation, redness or swelling of the skin and severe eye irritation.

However there was also a concern that the spilled chemical could react to form a more dangerous compound.

The Gananoque Police Service said in a social media post that firefighters advised that the material which spilled could turn into hydrofluoric acid if exposed to heat.

“Hydrofluoric acid is a highly toxic, highly corrosive and poisonous solution which is harmful to skin, lungs and eyes,” Gananoque Police said in their post.

It’s not yet clear whether any of the spilled material was converted into the more hazardous chemical.

The hospital stood down from the orange alert at around 8 p.m.  

Highway 401 remains closed both ways

A stretch of Highway 401 remains shut down in both directions between Lansdowne and Mallorytown Road as a result of the collision, which is believed to have involved more than 30 vehicles.  

“I’m told that there were about 30-plus vehicles involved including 10 to 15 transports,” OPP Const. Sandra Barr told CP24 in a phone interview Tuesday afternoon. “We have one of the transports leaking a hazardous substance so as a precaution we’re doing an evacuation of the immediate area.”

Ontario Provincial Police, hazmat crews, and local fire services responded to the pileup.

Barr said the evacuation included vehicles on the highway, as well as surrounding homes.

Police advised motorists stopped because of the collision to remain in their vehicles until they could be safely escorted away from the scene by first responders.

Barr said weather likely played a factor in the collision, with some motorists in the area reporting white-out conditions due to a winter storm.

While cleanup efforts are underway, officials said there is no estimate yet for when the highway will reopen.

“Right now we’re being advised that it will be closed indefinitely,” Mallory said. “With the size of the spill it will be a while before it is remediated out there.”

Motorists are being advised to avoid the area.