I have stuck the barcode on the OPP plastic packaging before, but is it okay to put all the warning labels (age appropriateness, suffocation, Made in China, and Prop 65) on the OPP packaging as well and not on the box?
Yes, it is generally okay to put all required labels, including age warnings, suffocation warnings, “Made in China,” and Prop 65 notices, directly on the OPP plastic packaging as long as the labels are clearly visible and properly affixed without being obscured. Amazon’s FBA requirements and general consumer safety regulations mainly care that the information is easy for customers and warehouse workers to see without opening the package.
However, if your product also comes in a retail box inside the OPP bag, it’s ideal to have critical regulatory labels (like Prop 65 or age restrictions) on both the exterior OPP bag and the box itself for full compliance, especially if you plan to sell in retail stores later or if Amazon inspects your units more closely.