To test the actual concentration of mercury in a room in which a fluorescent lamp was broken, the following test was conducted. The lamp in question was a L58W / 640, with a mercury content of approx. 5 mg in liquid form, which is a 'worse case' than lamps, especially compact fluorescent lamps offered today.

Test conditions:

In a closed room, a fluorescent lamp was physically broken.  After six minutes, the shards were removed and the room was ventilated by opening the door and window. The mercury concentration in the air was recorded continually.

Lamp type:   L58W / 640
Room temperature:   22°C
Room size:    35m²
Location of sensor: 0,5m above broken lamp
Sensor equipment:  Mercury vapour monitor  Hg-MAK 1200

Result: the mercury from the broken lamp quickly leads to a concentration peaking out at 25µg /m³. The discontinuous form of the data can be attributed to the sensitivity of the measuring equipment, and the movement of air. Similarly, the two peaks after the window is opened are due to the increased movement of air. What can be clearly seen: only three and a-half minutes after the pieces are removed and the room ventilated, the mercury concentration in the room has dropped to nearly zero.