What is the potential risk of a pesticide with high toxicity?

A pesticide with high toxicity poses a greater risk to humans primarily due to its potential for causing significant harm upon exposure. High toxicity indicates that even small amounts of the substance can lead to adverse health effects, which may range from mild irritations to severe health complications, or even fatalities. This inherent danger necessitates stringent safety regulations, careful handling, and usage instructions to minimize risk for humans, including agricultural workers, bystanders, and consumers.

Considering the other options, the time it takes for a pesticide to work is not inherently related to its toxicity level; some highly toxic pesticides can act quickly. Additionally, while increased advertising costs might be a concern for manufacturers of any product, they are not directly linked to the toxicity of the pesticide itself. Lastly, limited availability can result from regulatory measures or market factors but does not necessarily correlate with the toxicity of a pesticide. Therefore, the key concern with high toxicity is the heightened risk it poses to human health, making the understanding of proper safety practices and regulations imperative.