One picketing worker, who asked not to be named, told BBC Scotland's news website: "People think we are massively overpaid.
"When I heard stories we were getting £60,000 a year, my wife wanted to know where the rest of the money went.
"Suddenly we have ended up with the North Sea pipeline closed down. It is just mad - but we can't give up and we won't give up."
Mr Salmond, who is set to meet Prime Minister Gordon Brown over the dispute, said: "Both sides say they're willing to talk but they haven't, as yet, gone back into negotiations with each other.
"Even so, I would say that some of the language has toned down a bit."
'Bent over backwards'
Industry body Oil and Gas UK said the 48-hour walkout could cost the UK £50m a day.
Ineos general manager Gordon Grant told BBC Radio Scotland the company's current contribution to employees' pensions was "unsustainable", adding that Grangemouth needed £750m investment - or jobs would be jeopardised in a competitive sector.
He said: "We bent over backwards to try and avoid this strike but, unfortunately, the trade unions have decided to go ahead with it - premature in our view - but that's what they've done."
Mr Grant said there was ample time to have resolved the dispute without strike action, adding: "The consultation period is not finished. I think if anybody is being unreasonable in this sense, then it is the trade unions."
Motorists' reaction to the stirke at Grangemouth
Pat Rafferty, from the union Unite, told the BBC that members were still willing to speak with management and claimed the public had given the striking workers a lot of support.
And he dismissed claims from Ineos that Grangemouth may need three weeks to get up and running after the strike as "scaremongering" - insisting it could be done in about a week.
Mr Rafferty said: "We've been backed into a corner a bit by the stance the company's taking. It's something we've got no pleasure out of and that's been reflected in our members walking out."
At 0600 BST about 100 workers formed a parade as they left the plant carrying flags and banners, although some unpaid staff stayed inside the plant to provide safety cover.
Labour MP Michael Connarty, whose Linlithgow and East Falkirk seat takes in Grangemouth, claimed the refinery's billionaire owner, Jim Ratcliffe, had a lot of explaining to do.
He claimed: "Jim Ratcliffe is making it a mess. He's pulling all the strings, he's calling all the shots, he's hiding somewhere, he won't come out and talk.
"This is a very profitable plant. It's made, we reckon, about a billion pounds over the last 10 years. Why is he attacking the workers?"
The Forties Pipeline, which provides 30% of the UK's daily oil output from the North Sea and which is powered by the Grangemouth site, had to be shut by BP.
Some garages across Scotland have reported running out of fuel, some have introduced rationing and others increased prices.
The Scottish Government said about 65,000 tonnes of fuel, mostly diesel - said to be about 10 days' worth - will arrive over the next few days on seven tankers from ports across Europe.
Mr Salmond predicted some difficulties with fuel supplies in the early part of the week before Grangemouth reopened, but added: "The required fuel for Scotland is on the way."
Mr Salmond urged people to act responsibly - and asked public sector staff not to take unnecessary journeys and to use public transport.
Douglas Robertson, chief executive of the Scottish Motor Trade Association, which represents petrol retailers in Scotland, said members of the public were unnecessarily stocking up on fuel and putting supplies at risk.
"There's petrol stations, or filling stations rather, running out of fuel on a fairly regular basis throughout Scotland just now, and it's giving the public the impression that there is a fuel shortage," he said.
"And really what we really need to emphasise is there is no shortage of fuel, it's just people that are buying too much, that are panic buying."
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