Honeywell announced on Monday it will suspend its Amherstburg operations for at least two years.
The suspension affects 75 employees.
A statement to CBC News read:
Honeywell today is announcing a suspension for at least the next two years of hydrofluoric acid (HF) production at its Amherstburg, Ontario, site. The company is taking this step because of lower demand for HF, which is used in the production of fuels, refrigerants and other materials.
The production suspension will result in a layoff of most employees at the site beginning later this year and continuing through August 2014.
Layoffs will be conducted in phases, allowing the company to safely transition operations at the site.
The layoff will affect approximately 75 employees at the site. A few security and maintenance personnel will remain on-site.
The plant is currently undergoing regularly scheduled maintenance. Once completed, the plant will resume operations until it has depleted its current supply of raw materials
The union representing employees at the Amherstburg plant said the news came "out of the blue."
"However, there were some concerns in August when the company had indicated they were suspending shipment of the base product that is needed to make hydrofluoric," Unifor Local 1959 president Mike Wark said.
In July, Honeywell announced it would invest more than $200 million US at its four production facilities in Louisiana.
According to Honeywell, the investments are expected to generate more than 500 new direct and indirect jobs in the state.
Of the $200 million, $4 million was to be spent at the Geismar plant, the world's largest hydrofluoric acid plant.
"We are not shifting production to Geismar and no new investment have been made to Geismar for HF production. There is not investment being made for HF production," Peter Dalpe, director of external communications for Honeywell Performance Materials and Technology, said in an email to CBC News. "We are simply seeing lower demand across our entire HF business and we do not project demand to improve, making it uneconomical for us to continue production at the Amherstburg location.
"Geismar ... makes other products in addition to HF."
On its website, Honeywell said the Louisiana investment was "backed by a tax incentive framework agreement."
Dalpe said the suspension in Amherstburg will have no impact on the remediation project on the adjacent former General Chemical property there.