What are the typical measurements for expressing LD50?

The correct answer is based on the common practice of using LD50 measurements to represent the median lethal dose of a substance for various forms of exposure. LD50, which stands for "lethal dose for 50% of the population," is typically assessed through different routes of exposure to provide a comprehensive understanding of a substance’s toxicity.

In the context of acute toxicity, both oral and dermal routes are widely studied to determine how a chemical can affect living organisms when ingested or comes in contact with the skin. Determining LD50 for these pathways provides important information on safety and regulatory standards, helping to assess risks and establish guidelines for handling such substances.

While chronic toxicities and other exposure routes, such as inhalation, are also critical in toxicological assessments, LD50 specifically focuses on acute exposures. Thus, considering both the oral and dermal routes reflects the standard method for expressing LD50, making it the most accurate representation of acute toxicity evaluations.