PS mtundu wotsiriza kumapeto kwa mafuta, mpweya wonse, wopsinjika kwathunthu komanso woyang'aniridwa kwathunthu. Mapulagi a mafuta amagwiritsidwa ntchito poletsa ma ogawiro a mafuta mu mapulogalamu omwe amapezeka kuti mafuta a mafuta sagwiritsidwa ntchito.
