Ineos has urged Falkirk Council not to re-open Bo’ness Road which runs through the middle of its Grangemouth complex.
The petrochemical giants claim safety and security could be at risk.
It has been closed to traffic for almost a year while the site has been redeveloped to accommodate the biggest Ethane storage tank in Europe which will allow it to run at full capacity for the first time in almost a decade.
Ineos say making the route available to traffic again “defies” common sense.
John McNally, chief executive officer, said: “Having a public highway running through a massive petrochemicals plant results in obvious and unnecessary added safety concerns we have to manage and unnecessary given there is a perfectly good alternate route that runs around the periphery of the site.
“Other companies who may be planning to move to the site are also likely to have concerns about safety and security if the road remains open.”