Aer Lingus check-in and ticket-sales staff walked out of Dublin Airport yesterday afternoon, causing disruption to flights, after complaining about a smell of tar.
While the airline's staff cited health and safety issues for their withdrawal, an Aer Rianta spokeswoman said there was no basis for their claims and "no problem at any time".
An Aer Lingus spokeswoman said airline staff in the main airport building complained of a strong smell of tar or asphalt from building works in the terminal. Staff at the check-in and ticket-sales desks walked out when three members became unwell and were taken to the medical centre.
The spokeswoman confirmed that building work was in progress. She added: "There was a strong smell of asphalt from the roofing, and it was dusty."
Health and safety officials at the airport inspected the area after staff withdrew. Cleaners were then brought in.
Flights to Frankfurt, Manchester, Brussels, Dusseldorf, London and Paris were all delayed, the spokeswoman said.
Later in the afternoon the health and safety officials declared the area safe, and about 30 staff members returned to work. The three people who became unwell spent only a short time in the medical centre. All were reported to be "fine".
The Aer Rianta spokeswoman said that its own health and safety officials had investigated the building. No staff from any of the other airlines had walked out. Aer Rianta officials had walked the area with Aer Lingus staff and they were satisfied that there had been no problem at any time.
Aer Rianta had communicated this to Aer Lingus at 4.45 p.m., but staff did not return until almost 6 p.m.
"It seems that Aer Lingus staff were complaining about a health and safety issue, but there was no basis for their claims whatever," she added.