Pesticides that degrade quickly in the environment are considered to be:

Pesticides that degrade quickly in the environment are classified as least hazardous because their short half-life means they break down rapidly, reducing the potential for harm to non-target species, including humans, wildlife, and beneficial insects. This rapid degradation minimizes the likelihood of residual effects in the soil or water, which is a significant concern for environmental safety.

In pest management, choosing substances that don't persist in the environment for long periods is advantageous, as it aligns with sustainable practices and reduces accumulation concerns. Longer-lasting pesticides can lead to more significant environmental and health risks, as they may accumulate in ecosystems or pose higher toxicity to non-target organisms. Thus, the designation of least hazardous for quickly degrading pesticides reflects their lower risk profile compared to others that remain in the environment for extended periods.