As these scrubbers are used repeatedly until they diminish in size and their cutting power is lost, they often become contaminated with heavy metals such as cadmium, chromium, and lead.
Karena scrubber ini digunakan berulang kali sehingga ukurannya berkurang dan daya potongnya menjadi semakin hilang, mereka jadi sering terkontaminasi oleh logam berat seperti cadmium, kromium, dan timah.