If I understand you correctly from another post, you are going to be mixing the ingredients, but making a kit type product for the consumer to mix themselves /with their child? If so, I would assume that the parts of the kit would be labeled with the ingredients that are natural, common, household products,. like cornstartch, salt, and flour. not really any chemical type substances? I think those are covered by FDA or USDA regulations,
As far as CPSIA tracking labels, yes in your case, depending on the packaging, if each item included in the kit doesn't need it's own label and is always sold as a set in the kit, then perhaps one label would work. Otherwise, for example, lets say you have a set with a baby blanket that you made, it would need both a CPSIA label and a FTC label, a purchased body suit that you appliqued a name on, your CPSIA label over the Companies labeling, a purchsed bottle and diaper cover in origial packaing with original labeling. If you sold them in a basket/box, then a final hangtag on the outside with your company name, location assembled and made in the USA and the date would work. I have woven ribbon FTC labels and CPSIA label sewn into my garments, I also have decorative hangtags that I attach to each garment with the style information on the back. You could use something like that as the final tag. But if individual elemetns of the "kit" are ever sold seperately or in a different manner then they should be indidually labeled. At least that is my understanding of the law.