What is a Poison?

Although some chemicals such as arsenic compounds are popularly known as poisons it is not widely recognised that all materials have the potential to be poisonous depending on the degree of exposure. The dose is the key to the potential for adverse effects or poisoning to occur. While there is no such thing as a safe chemical, it must be realised there is no chemical that cannot be used safely by limiting the dose or exposure. Poisons can be safely used and be of benefit to society when used appropriately. For example, Warfarin is used in high doses as a rat poison but low doses are used medically to prevent blood clots after a stroke or heart attack.

All materials have the potential to be poisonous, in contrast to a common misconception that only certain chemicals and substances are poisonous. The dose is the key to the potential for adverse effects to occur, and this concept is known as the dose response relationship.