Regs around documenting record disposal and destruction

I work for a company regulated by the FDA under CFR 21 Part 111 and 117. Does anyone know if we need to keep a specific record or log of when we destroy documents? We have a shredding bin where we can dispose of documents to be shredded every month but we dont keep a log or records of what is thrown in the bin. We have a record retention SOP that dictates how long we keep documents but not for what we do when we destroy them and records of what is being destroyed

The limiting factor after you have a records retention period defined is predominantly up to your own liability and confidentiality tolerances.  The govt doesn't really care how you dispose of them.