What defines a "pesticide" under California law?

Under California law, a "pesticide" is defined as any substance intended for preventing, destroying, repelling, or mitigating pests. This definition encompasses a broad range of products, not limited to those that merely kill pests.

The correct answer highlights the intent behind the use of the substance, which is crucial in determining whether a product qualifies as a pesticide. This includes substances designed to prevent pests from causing harm, which can involve various modes of action, such as repellent properties or means of reducing pest populations through behavior modification rather than direct lethality.

The other options provide overly narrow definitions that do not capture the comprehensive nature of what constitutes a pesticide according to California regulations. While only focusing on substances that kill pests or those that are specifically agricultural would exclude many products that serve valuable pest control roles, limiting the definition to natural products would disregard many effective synthetic options that are recognized as pesticides. This underscores the importance of understanding the intended use and not merely the mode of action of substances in pest management.