Apparently the milling and polishing process is getting regular external inspections: http://www.computerworld.com/s/article/9223435/Apple_confirms_aluminum_dus

Apparently the milling and polishing process is getting regular external inspections: http://www.computerworld.com/s/article/9223435/Apple_confirms_aluminum_dust_caused_Chinese_factory_explosions http://www.computerworld.com/s/article/9223435/Apple_confirm...