The ethics of selling expired makeup is a topic that warrants serious discussion. As a professional in the field of clean beauty and skincare, I can attest to the potential harm that expired makeup can cause to the skin.

Firstly, it's essential to understand that makeup, like any other product, has a shelf life. This is typically indicated by a small symbol on the packaging, often a jar with an open lid, followed by a number and the letter 'M'. This symbol represents the 'Period After Opening' (PAO), which indicates the number of months the product is safe to use after it has been opened.

Expired makeup can harbor bacteria and fungi, which can lead to skin infections, allergic reactions, and other adverse effects. The risk is particularly high for products that come into contact with the eyes or mouth, such as mascara or lipstick.

From an ethical standpoint, selling expired makeup is a breach of trust between the seller and the consumer. Consumers trust that the products they purchase are safe and effective. Selling expired products not only compromises this trust, but it also puts the consumer's health at risk.

Moreover, the efficacy of the product diminishes over time. The active ingredients in makeup products, whether chemical or natural, degrade and lose their effectiveness. This means that even if an expired product doesn't cause an adverse reaction, it's unlikely to perform as well as it should.

In conclusion, the practice of selling expired makeup is not only unethical but also potentially harmful. It is crucial for retailers to uphold their responsibility to provide safe, effective products and for consumers to be aware of the shelf life of the products they purchase.