It is unclear what the context of the question is, but assuming it is related to labeling of products, the search results provide information on labeling requirements for food, cosmetics, and drugs. Here are some reasons why certain details may not be included on product labels:

• Ingredients below 5%: If an ingredient makes up less than 5% of the food, it does not have to be listed on the label. This also applies to compound ingredients that make up less than 5% of the product, which can just be listed as the compound ingredient rather than all of its own ingredients.

• Marketing terms: Companies often use marketing terms like “naturally derived,” “nontoxic” and “clean” on labels, which sound good but are basically just marketing terms.

• Regulations: The FDA has regulations that specifically prohibit or restrict the use of certain ingredients in cosmetics and drugs, but not all chemicals are regulated.

• Unknown impurities: Substandard and falsified medical products are often produced in very poor and unhygienic conditions by unqualified personnel, and contain unknown impurities and are sometimes contaminated with bacteria.

It is important to note that the absence of certain details on product labels does not necessarily mean that the product is unsafe or ineffective. However, consumers can take steps to educate themselves on the ingredients in the products they use, such as searching for products by name or barcode on apps that provide information on ingredients of concern.