The suspension of air travel is costing East Midlands Airport £100,000 a day, its managing director has said.
But Penny Coates said the impact of the restrictions was "much wider" on the East Midlands region as a whole.
The ban on flights in UK airspace, due to a cloud of volcanic ash, has reached a fifth day and has now been extended until at least 0700 BST on Tuesday.
Ryanair has suspended flights from the airport at Castle Donington until at least 1300 BST on Wednesday.
BMI flights are cancelled until 1300 BST on Tuesday, Thomson flights are cancelled throughout Tuesday and Wednesday and Jet2 will not fly until Thursday.
'Shiny and sparkling'
Ms Coates said: "It's the first time we've had nothing for days like this ever, so it's a really unusual situation.
"There's a significant impact on the airport, but there's a much wider impact on the businesses on site and the wider region.
"Retailers are closed in the main - we've got a cafe and an aviation shop open and cargo is obviously impacted significantly."
She said people employed by the airport were still being asked to come in to carry out maintenance work.
"Everything's going to be shiny and sparkling clean.
"We never ever get the opportunity to paint all of the runway all in one go, it's normally a case of grabbing an hour between flights."