When the polysilicon rods have cooled, the reactor is vented to atmosphere and purged with clean nitrogen. A series of approximately twenty pressure and vent cycles remove silane and hydrogen from the reactor until the hydrogen concentration is below 50% of the lower explosive limit. Then, with the power supply and the silane and hydrogen gas supplies locked out in a safe mode, the reactor is opened using an overhead crane to lift off the bell jar.
The polysilicon rods are harvested either manually or by mechanical assist, taking care to avoid surface contamination with human dander, dust or non-silicon surfaces. Care is especially needed to avoid contact between the clean polysilicon rods and the powder coated reactor surfaces.