In most countries, industrial ladders must conform to specific safety guidelines; in the US, these are established by the American National Standards Institute, which categorizes them into three types according to their duty rating and the weight they can support. Type 1 industrial ladders are for heavy-duty use and must support 250 lbs (113 kg), type 1A must support 300 lbs (136 kg), and type 1AA industrial ladders are for extra heavy-duty usage and must support 375 lbs (170 kg). Step, extension, and mobile ladders intended for industrial use in a warehouse, at a dock, in an orchard, or in any other work environment must also conform to size requirements to ensure worker safety.
Industrial stepladders can have a maximum length of 20 feet (6 m) and the treads must be at least 11.5 in (29 cm) wide. While they can be longer than commercial or household stepladders, the tread width requirement is the same for all types. Industrial stepladders, particularly ones rated 1AA, often have extra tread reinforcement, reinforced spreaders, and non-conductive rails. The length of the legs can sometimes be adjusted for use on stairs and other uneven surfaces.
Single-section extension ladders, or straight ladders, can have a maximum height of 30 ft (9 m), those with two sections can reach up to 48 ft (14.5 m), and those with three 60 ft (18 m). The rungs must be at least 12 in (30.5 cm) wide, and those on 2- or 3-section ladders must have overlap stops. Stepladders that fold out to become extension ladders are called articulating ladders, and these can usually be adjusted to function as stairway ladders. Industrial ladders do not differ from commercial or household ladders in these requirements, but they must be rated to hold more weight.
Other types of industrial ladders include mobile ladders, such as rolling warehouse ladders with lockable casters. Certain varieties of these can be folded for easy storage, and some have spring-loaded casters so the ladder automatically becomes stationary when it is supporting a weight. Alternating step ladders simulate a stairway and have a handrail on either side so the user can ascend or descend while facing away from the ladder, while dock ladders have brackets that can be bolted or welded onto a vertical surface. Industrial scaffolding provides a comfortable, flat surface for working at great heights, while step stools, step stands, and ladder/carts provide just enough height for tasks that are just out of reach. All are manufactured to conform to the weight requirements for industrial ladders.
