Not muin the new ballast, just be aware tge older ones had PCB in them. Sorry I can't give you a letter code for bad ones as I forget.
This might help.
Key Methods for Identification
Manufacturing Date:
Ballasts manufactured before July 1, 1979, are considered to contain PCBs.
"No-PCB" Label:
A ballast that is not labeled "No-PCB" or "Non-PCB" should be assumed to contain PCBs.
Manufacturer Code:
For some manufacturers, specific letters or number combinations within their date or catalogue codes indicate the presence of PCBs.
Manufacturer-Specific Clues
Aerovox:
A code where the fifth digit is "F" (for "Fluorescent") indicates PCBs.
General Electric (GE):
A final letter of "N" or "A" indicates PCBs. If the code ends in "T", it may contain PCBs.