The International Firestop Council has issued a statement on CPVC and Firestopping.
The source of the document comes from the following passage at the Plastic Pipe and Fittings Association’s website, https://www.ppfahome.org/page/CPVC,
“Don’t Do’s For All Construction –
Do not use petroleum or solvent based sealants, lubricants, or fire stop materials.”
As with all compatibility issues, verify compatibility with the specific manufacturers of the firestop materials that might come in contact with CPVC, and also the CPVC Manufacturers, listed at the PPFA website.