Pasi pehutongi hwakasimba hwemhando, zvigadzirwa zvedu zvesarufa zvinopa kuita kwakanakisa, hunhu hwakavimbika uye kuchena kwakanyanya, kubva pa5N kusvika 7N (99.999% kusvika 99.99999%), kusangana nezvinodiwa zveminda yakasiyana inoda zvinhu zvemhando yepamusoro zvesarufa. Ngatitarisei zvakanyanya kune akawanda mabhenefiti uye mashandisirwo ayo zvigadzirwa zvedu zvesarufa zvakakosha mumhando dzakasiyana dzemaindasitiri.