Asbestos

Berlaymont building: found to have 0.67-0.86 asbestos fibres per cubic metre (Photo: These Tides)
Highly dangerous substance subject to common EU rules intended to protect workers against it.
The rules allow 0.001 asbestos fibres per cubic metre of air.

Notes

The EU Commission headquarters in the Berlaymont-building were found to have 0.67-0.86 fibres per cubic metre and have consequently been under reconstruction since 1992.