Amagwiritsidwa ntchito kuyesa, kuwunika ndikuyesa momwe nsalu imagwirira ntchito m'madzi amadzimadzi. Zimatengera kuzindikira momwe nsalu imakanira madzi, momwe imakanira madzi komanso momwe imayamwira madzi, kuphatikizapo mawonekedwe ndi kapangidwe ka mkati mwa nsalu komanso momwe nsalu imakokera ulusi ndi ulusi wa nsalu.
Amagwiritsidwa ntchito poyesa chitetezo cha nsalu ku kuwala kwa ultraviolet pansi pa mikhalidwe inayake.