Twenty-four Amazon workers have been hospitalised after a bear spray can was punctured at a warehouse in New Jersey in the US on Wednesday.
One of those hospitalised is in a critical condition. Another 30 people were treated by emergency services at the scene.
It is not clear what caused the accident but Amazon is investigating.
Workers evacuated the third floor of the warehouse's south entrance during the incident on Wednesday morning.
Employees experienced breathing problems, and stinging in their throat and eyes, local officials said.
John Nalbone, a spokesperson for Robinsville Township, told the BBC there was no threat to residents in the area and that fumes were confined to within the building.
Operations at the 1.3m sq ft facility - which employs more than 3,000 people - have since resumed as normal, Mr Nalbone added.
"The safety of our employees is always our top priority and a full investigation is already underway," said Rachael Lighty, a spokeswoman for Amazon.
According to the Get Bear Smart Society, the non-lethal bear repellant causes "a nearly total, yet temporary, loss of sight and severe restriction of breathing" in bears and humans.