Passers-by may have been confused for thinking they were either at the centre of a major criminal incident or part of a sci-fi movie as half a dozen staff – kitted out in special protective suits – tentatively made their way into crisis-hit Fleetwood JobCentre.
The building has been closed since May, amid claims it was causing illness among staff.
People who worked there are said to have developed brain tumours, multiple sclerosis, cancers, heart and thyroid problems and have suffered miscarriages.
The building is on the site of a former scrapyard and near to an old gasworks – and workers claim contamination is behind the horrific catalogue of illnesses.
"We take this very seriously," said one of the female workers clad in overalls with hoods and masks. Like all her fellow workers she did not want to be named.
She added: "One of our colleagues has developed MS, but has been asked not to come here by management because of the situation."
The Public and Commercial Services Union is currently gathering evidence for possible legal action and also wants monitoring of workers to detect any future health problems.
The group involved in the dramatic scenes were not front-office JobCentre staff, but worked on decision-making over Job Seekers' allowance.
After entering the premises, they packed personal items into storage boxes to be collected later.
They have also been told that furniture would be removed from the building by the Department of Work and Pensions and washed down.
Union representative Lynn Howes said the section had been found new working premises at St Annes, but management did not want the cost of providing new furniture and so staff had to empty the desks before moving.
The union is trying to recruit the services of the London Hazard Centre and is also arranging a meeting with MP Joan Humble to try to enlist her help.
A spokesman for the department of work and pensions said: "A local manager and six members of staff entered Fleetwood JobCentre to identify equipment and collect personal belongings. They wore protective clothing only as a precaution as test results have revealed there is no danger. The staff were under no coercion and entered of their own accord."