Unlike many other toxic substances, carcinogens often do not exhibit a clear dose response threshold. This is because even small amounts of exposure might increase the risk of cancer. Carcinogens can interact with cellular DNA, causing mutations that may lead to cancerous growths. The lack of a definitive threshold makes it challenging to establish safe levels of exposure. It is essential for researchers to identify the lowest observed adverse effect level (LOAEL) and the no observed adverse effect level (NOAEL) to assess the risk better.