Which rating indicates the lightest duty ladder type?

The lightest duty ladder type is classified as Type III. This rating is designed for light residential use and can support a maximum load of 200 pounds. Ladders rated at this level are generally inexpensive, making them suitable for tasks that do not require significant weight support, such as light household duties and occasional indoor tasks.

In contrast, Type IAA, Type I, and Type IA ladders are rated for higher weight capacities. Type IAA ladders can hold up to 375 pounds, making them suitable for heavy-duty jobs, while Type I ladders are rated for 250 pounds, and Type IA ladders can support 300 pounds. These classifications are important for safety and ensure that users select the appropriate ladder for the task at hand based on the weight load expected.