Regarding OTC products, which of the following is required for safe public use?

The requirement for understandable directions for use on over-the-counter (OTC) products is crucial for safe public use. OTC drugs are designed for consumer access without the need for a prescription, meaning that individuals with varying levels of health literacy will be able to purchase and use these products. Clear, concise, and easily understandable instructions help ensure that users can correctly follow the intended dosage, administration, and safety precautions associated with the product. This is vital to prevent misuse or overdose and to ensure that the consumer achieves the intended therapeutic effects.

In contrast, complex medical terminology might alienate or confuse consumers, hindering their ability to safely use the product. Approval by a medical professional is not a requirement for OTC medications, as these products are typically evaluated by regulatory agencies for general safety and efficacy before being made available to the public. Lastly, substitution of ingredients for safety is not a standard requirement for the public to use OTC products safely; rather, all active ingredients must be listed on the packaging, allowing consumers to make informed choices.

Thus, option B is essential for promoting safe and effective use of OTC medications by the general public.