Millwright Level 1 Practice Exam

The designation of Medium Duty in CSA ratings for ladders is correct because this classification is specifically intended for light commercial use. Medium Duty ladders are designed to support a higher number of uses compared to lighter, residential ladders, while ensuring a balance of strength and weight for ease of use in commercial settings. These ladders typically support a maximum load of 225 pounds, making them suitable for tasks such as maintenance, access to low heights, and light commercial work. In contrast, other ratings such as Light Duty are primarily designed for household applications and do not support the same weight capacities or frequency of use that is often required in light commercial settings. Heavy Duty ladders provide stronger support for more demanding applications but are not categorized for light commercial use. Extra Heavy Duty is reserved for industrial applications and significantly higher load requirements, thus exceeding what is needed for typical light commercial tasks.