Passengers who used a Rotterdam metro station which has been closed since the discovery of asbestos do not run any danger, local transport officials said on Wednesday.

Laboratory tests have shown the asbestos was present in lower levels than the maximum permitted by law, officials from the city’s RET transport company said.

Station Stadhuis was checked for the presence of asbestos in 2009 but none was found, a spokesperson told Nu.nl. How and when it came to be there is now being investigated.

The asbestos fibres were released into the air following demolition work to construct four extra emergency exit tunnels. The RET has changed the filters of trains that passed the station and has called on travellers who were at the station to contact customer service for advice.

Chances that people who inhaled the fibres, are facing an acute health risk are small, according to asbestos expert Eva Angel, who advises housing corporations about the removal of asbestos. ‘It would be different if they inhaled the fibres for months on end,’ she told the broadcaster NOS .

Nevertheless, she said the decision to close the station was a good one. ‘It’s important to determine how far the contamination has spread. You don’t want travellers to spread the fibres. If the extent of the problem is known, the clean-up can begin.’

The use of asbestos, which can cause cancer, has been banned in the Netherlands since 1993 and Europe-wide in 2005. Recently, the government decided that all roofs containing asbestos have to be removed by 2024.