The usage of materials which are used with Haram materials is forbidden without complete cleaning. Therefore, according to Buhari and Muslim (Rahimehumellah) narrated hadiths that Rasullah (P.B.H) is applied that in Khayber conquer.
Sayyiduna Anas ibn Malik (Allah be pleased with him) narrates that a person came to the Messenger of Allah (SAW) and said: “The donkeys have been (slaughtered and) eaten.” Another man came and said: “The donkeys have been destroyed.” The Messenger of Allah (SAW) ordered a caller to announce to the people: “Allah and His Messenger (SAW forbid you to eat the meat of donkeys, for it is impure.” Thus the pots were turned upside down while the (donkey’s) meat was boiling in them.” (Sahih al-Bukhari, no: 5208)
In another Hadith from Buhari and Muslim (Rahimehumellah) that Abu Saleba (Radiyallah Anhu) narrated that someone asked Rasulullah (Alayhissalam):
” O Messenger of Allah! We are living a region which Ahlul Kitab also lives. Is there any objection to eat from their pots and plates? Rasulullah said that “If you find other plates, eat from them. However, if you don’t find another, first clean them completely and then eat.”
Abû Tha`labah al-Khushanî said to Allah’s Messenger (peace be upon him): “We come from a land populated by the People of the Scripture. Can we eat from their dishes?”
The Prophet (peace be upon him) replied: “Do not eat from them unless you do not find anything else to eat from. In that case, wash them and eat from them.”
In this hadith, if najis foods are used in plates or pots, it is necessary to clean them. As a result, we understand from these narratives that there are two conditions for the stuffs and tools which treated with najis as the following;
a) Never use them
b) If there is not any other alternative, or if we don’t have a chance to find another, then we can use them after completely cleaning.
As Halal Certification body, the above mentioned second point will not be applicable at this time. So it is not acceptable to produce Halal certified products in the same line which non-Halal certified products. The Halal certified production must be totally segregated.