Warshadaha biraha waa qayb muhiim u ah wax soo saarka alaabta ceeriin, oo inta badan loo yaqaan "laf-dhabarka warshadaha." Guud ahaan waxa loo qaybiyaa biraha birta ah, oo ay ku jiraan birta iyo birta, iyo biraha aan birta ahayn, taas oo ku lug leh habaynta biraha sida copper, aluminum, lead, zinc, nikkel, iyo dahab. SHPHE waxay khibrad ballaaran u leedahay habka sifaynta aluminium oksaydhka.