When manufacturing soap, they add fatty substances from dead cows; what is the ruling on using that soap?

The questioner : It is the same thing; in soap manufacturing, they add fatty substances, which are the marrow from dead cows. The bones of cows are transformed and do not remain in their natural state. Does their transformation permit their use?

The Shaykh : This is what was discussed with the father. Did you not hear it?

The questioner: No.

The Shaykh : He used to hold the view that it was not permissible. Then I mentioned to him that the issue requires study: if these forbidden fats retain their identity through this mixing, they are forbidden; but if they are transformed, they become pure through the transformation. He told me, "I want to ask the director of customs in Aqaba." So he asked him, and he told him that they are transformed.