Ladder Safety
Portable ladders are used in various academic and administrative settings at Dartmouth College. Misuse of portable ladders can result in severe injuries from falls or, in the case of metal ladders, electrical shock. Portable ladders must always be maintained in good condition and inspected before each use and at regular intervals. Dartmouth recommends new ladder purchases be fiberglass and Type 1A.
Stepladders
Stepladders (or A-frame ladders) are designed to be self-supporting. There are several important points when using stepladders:
- The spreaders must be fully extended and locked in place before climbing
- The maximum working height of a stepladder may not be exceeded.
- Paint trays are not steps and should only be used for holding paint cans and trays
- Unless designed for such use, the back of the ladder may not be used for climbing
- Stepladders should never be leaned against a wall for use as a straight ladder.
Straight Ladders
The setup and placement of a ladder are important for safe use. Straight ladders should be positioned:
- So that the ladder is set to a 75-degree angle from the ground. There are several ways to approximate this angle:
- To measure this, the horizontal distance between the foot of the ladder and the support against which it is placed is equal to one-fourth the ladder's height at the top point of support.
- So that both upper contact points rest firmly against the structure
- So that the ladder extends at least three feet above the point of support
Users should make sure that both rung locking mechanisms are fully engaged.
Ladder Selection
Ladders come in a variety of types, duty ratings, and composition materials. Selecting the right ladder for the task is extremely important.
Ladder Types & Duty Ratings
There are several different ladder types. Selecting the proper type will depend on the task required.
Stepladders
- Best used for temporary tasks. Minimal storage space required.
Straight or extension ladders
- Generally used for higher climbing heights. Extension ladders allow for a variation in height.
Platform ladders
- Combination ladder/scaffold allows for both climbing structure and work surface
Rolling staircases
- More gradual climbing angle and stable work platform. Requires larger area for storage.
| Ladder Type | Duty Rating | Load Capacity |
|---|---|---|
| Light Duty Household | Type III | 200 lbs. |
| Medium Duty Commercial | Type II | 225 lbs. |
| Heavy Duty Industrial | Type I | 250 lbs. |
| Extra Heavy Duty Industrial | Type IA | 300 lbs. |
| Special Duty Industrial | Type IAA | 375 lbs. |
Light Duty Household
Type III
200 lbs.
Medium Duty Commercial
Type II
225 lbs.
Heavy Duty Industrial
Type I
250 lbs.
Extra Heavy Duty Industrial
Type IA
300 lbs.
Special Duty Industrial
Type IAA
375 lbs.
Composition Materials
Ladders are typically made of wood, aluminum, or fiberglass. Each material has characteristics that make it best for specific situations. Only wood or fiberglass ladders may be used for electrical work or where exposure to electrical equipment may occur.
Fixed Ladders
Fixed ladders are subject to standards and requirements different from portable ladders. The following are just some of the requirements for fixed ladders.
Ladder safety devices, such as cages or climbing systems, are required if the total climb on a fixed ladder equals or exceeds 24 feet in height. Fixed ladders must support at least two loads of 250 lbs. each. Rungs must be shaped to minimize slipping.
For more information on the requirements for fixed ladders, see the OSHA Standard, 29 CFR 1910.27 Fixed Ladders.