How to package bath bombs for FBA?

I have been selling a bath bomb 4-pack in a sturdy box. But now I am about to try to sell them individually. Each bomb is shrink wrapped in plastic with a scent label on it. I am planning on putting each bomb into a 4″ x 5″ plastic polybag, with the UPC code sticker on the outside of it. I will also have a small slip of paper in each bag showing a QR code for an ingredients and instructions URL link.

I labeled the product in the product details as the size of the bath bomb (2.5″ all dimensions)– ignoring the plastic bag, since it will mold or fold as needed.

I am scared to send out this product– that something will go wrong on the first sale. As far as I can tell, as long as the bag has a UPC code on it, I should be fine. Does anyone see any risks here? I would prefer to send out a large quantity right now rather than test the waters with a very small shipment of 10.