David Bell, professor of economics at Stirling University, said any collapse of the Ineos-owned plant in Grangemouth would hit both the domestic and export markets, with a resulting impact on consumers and other industries across Scotland.
Bell said he could not think of any other business in the Scottish manufacturing that could equal Grangemouth refinery in terms of turnover.
He explained: "It has an annual £5 billion turnover and it supplies consumers in Scotland, mainly through purchasing petrol and diesel, and it also supplies a lot of industries in Scotland and also exports a lot.
"If it were to collapse, Scotland would have to import its petrol and diesel, there would be a lot of other industries that would need to find other suppliers and then Scotland would lose one of its major exporting enterprises."
Losing a business with a £5bn turnover would also have a major impact on jobs, as there is no obvious alternative employer, Bell said.
"[It] affects employees who might find it difficult to find a job with the same terms and conditions. Certainly in Scotland, there isn't any alternative, unless you go into the oil industry."