Employers must maintain employee-handler use records for which scenario?

Employers are required to maintain employee-handler use records specifically for organophosphate pesticides labeled with the signal words "DANGER" or "WARNING." This requirement stems from the heightened toxicity and potential health risks associated with organophosphates, which are known to affect the nervous system.

The use of these signal words indicates a higher level of hazard, necessitating close monitoring and documentation of how these substances are handled by employees. By keeping detailed records, employers can ensure compliance with safety standards and facilitate informed decision-making regarding workplace safety and health. This record-keeping practice also supports regulatory oversight, allowing for accountability in managing potentially dangerous chemicals.

In contrast, while other options mention scenarios involving pesticides, they do not carry the same stringent record-keeping requirements as organophosphates with "DANGER" or "WARNING" labels. This highlights the importance of understanding the specific regulations related to different pesticide categories and their usage.