Opening a hard drive outside a controlled environment is a death sentence for the data. The read/write head flies nanometers above the platter surface, spinning at 7200 RPM.
A dust particle is microscopic to us, but for the head, it's like a boulder on the highway. Upon impact, it causes a Head Crash, scratching the platters and turning the magnetic data into unrecoverable magnetic dust. Laboratories use Class 100 laminar flow hoods to ensure particle-free air.
