[In His Most Exalted Name
Addressed to the blessed presence of Grand Ayatullah Imam Khomeini, the great leader of the Islamic ummah- may his sublime presence endure:
After extending greetings and prayers for your grandeur it needs to be brought to your esteemed attention that as per the current trend, powdered dead fish, unlawful fish (fish that are haram for human consumption), pig-fat as well as the fats of unlawfully slaughtered animals and unlawful animals (animals that are haram for human consumption) are being extensively used in the husbandry and poultry industry for feeding chickens and other halal-fleshed (lawful) animals. Moreover, pig-fat, the fats of haram animals as well as unlawfully slaughtered animals are being used in the soap and some other similar industries. Considering this, is it lawful to use these above-mentioned items? And in case it is lawful, then in matters in which purity is not a condition and considering that the incoming profit thereof is considerably large and lucrative based upon general business acumen, is the buying and selling of these animal parts, for the sake of lawful use, permissible?]
In His Most Exalted Name
It is lawful to use the above-mentioned items in the manner described and so is their buying and selling, under the above-mentioned conditions. It is, however, recommended to avoid involvements in such transactions.
Rouhullah al-Mousawi al-Khomeini