You are correct in that BRC has some requirements for by-products but they relate to waste control:
4.13 MANAGEMENT OF SURPLUS FOOD AND PRODUCTS FOR ANIMAL FEED
Effective processes shall be in place to ensure the safety and legality of by-products of the primary processing activity of the site.
4.13.3 By-products and downgraded/surplus products intended for animal feed shall be segregated from waste and protected from contamination during storage. Products for animal feed shall be managed in accordance with relevant legislative requirements.
IFS Food does not mention animal feed in its requirements:
4.11.2 All current legal requirements for waste disposal shall be met.
4.11.6 Waste shall be collected in separate containers in accordance with the intended means of disposal. Such waste shall be disposed by authorised third parties only. Records of waste disposal shall be kept by the company.
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