Workers have staged unofficial strikes at a number of industrial sites over pay.
Sources told the PA news agency that the action has affected construction and maintenance work.
The walkouts are the latest in a series of stoppages hitting sectors including the railways, courts and postal services amid growing unrest in the face of the worsening cost-of-living crisis.
An Ineos spokesperson at the Grangemouth site in central Scotland said: “We can confirm that a number of contractors employed by third parties are taking unofficial industrial action at the Ineos Grangemouth site as part of a nationwide protest event.
“Our manufacturing and fuel distribution operations are unaffected.
“The site has a very good working relationship with the contracting companies and their employees at Grangemouth, including those operating under the NAECI agreement.
“We are disappointed that the protesters have chosen to use the Ineos Grangemouth site as one of their backdrops for their unofficial action today.”
A union source told PA: “During Covid, these workers were incredibly flexible in keeping essential sites going.
“Now they are being offered a pay rise massively below inflation as the cost-of-living crisis becomes a catastrophe.
“There is an explosion of anger and fear from workers across the country who are rapidly reaching the end of the road.”