As Salaamu aliakum,Mufti Sahab,Nowadays In most bakeries the brush used to apply oil in the pan is made from pigs hair? Is it lawful to eat such breads which are baked on this type of pan?
If it is established through research that it is made of pig's hair, then, it is not permissible to consume cake, bread etc. which are made in pans oiled with such brushes and it is necessary to avoid. Further it is incumbent upon the bakery owners as well to refrain from using such brushes.
ففي البحر الرائق: وأما الخنزير فشعره وعظمه وجميع أجزائه نجسة اھ (1/ 113)
و في حاشية ابن عابدين: قال العلامة المقدسي: و في زماننا استغنوا عنه أي فلا يجوز استعماله لزوال الضرورة الباعثة للحكم بالطهارة (1/ 206) والله اعلم بالصواب