Scotland's First Minister Alex Salmond said: "This news is a tremendous fillip for the workforce and the whole Grangemouth community, following what could have been a potential disaster.
"It's been a great team effort from all concerned, including the unions and workforce, the management, Governments - and BP, who have made a material contribution to help defend and secure Scottish jobs and livelihoods.
"I am delighted that people have rallied round to protect these jobs, and now we can all agree that Grangemouth has an outstanding future."
Grangemouth owners Ineos are in last ditch talks with the workers' union, but the workforce is just one of the problems facing the plant.
Thousands of jobs are under threat after a dispute over conditions led to a shock decision to close the petrochemical site in Grangemouth.