(1) Thaum lub sijhawm teeb tsa, cov npoo ntawm galvanized steel kav yuav tsum muaj kev tawm hws thiab muaj cua sov;
(2) Ua kom muaj kev ua pa kom zoo rau cov chaw cia khoom, nrog cov av noo kom huv si rau sab nraum {{1% ntau;
(3) Tsis txhob cia rau hauv cov chaw muaj kev phom sij lossis cov plua tshauv ntau dhau;
(4) Thov kev tiv thaiv kev tiv thaiv mus rau zinc txheej loj, xws li roj, kev kho mob passive, lossis cov organic txheej.
