Ladder Safety

Portable ladders are used at Princeton University in a wide variety of settings, both academic and administrative. Misuse of portable ladders can result in serious injuries from falls or, in the case of metal ladders, electrical shock. Portable ladders must be maintained in good condition at all times, and inspected at regular, frequent intervals.

For more information on the proper selection, use and care of ladders:



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.

Danger: Do not stand on or above this step

  • 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

Set up and placement of a ladder is important in 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 height of the ladder 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

There are several different ladder types. Selecting the proper type will depend on the task required.

Ladder Type Best Used For:
Stepladders 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.

Duty Ratings

Each ladder is rated with a specific duty rating. Remember that the capacity rating includes all personnel, tools and equipment.

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.


Composition Materials

Ladders are typically made of wood, aluminum or fiberglass. Each material has characteristics which make it best for certain 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 different standards and requirements than 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 length of climb on a fixed ladder equals or exceeds 24 feet in length. Fixed ladders must be able to 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.

Climbing Guidelines

There are a few climbing guidelines that help to prevent accidents when using a portable ladder.

  • Wear shoes with nonskid soles that are free of mud or grease. Clean ladder rungs of mud, grease, or ice before climbing.
  • Place ladders on stable bases. Boxes, barrels, or other unstable surfaces should never be used to obtain additional height.
  • If necessary, have another person hold the base of the ladder. If no one is available, the ladder should be securely lashed or fastened top and bottom to prevent it from slipping.
  • Overreaching can cause instability. A good rule of thumb is to not let one's belt buckle outside the uprights.
  • Always face the ladder and maintain a 3-point contact when climbing or descending.
  • Always check to ensure tools and equipment have been removed from the top of the ladder before moving it.
  • Only one person should climb a ladder at a time.
  • Inspect ladders on a regular basis. See the Ladder Inspection Checklist.pdf for what to look for during the inspection.

Storage and Maintenance

Proper storage and maintenance of ladders is important for safety. Whenever possible, ladders should be hung horizontally on wall hooks in a dry place not subject to extremes of temperatures. Users can do minor maintenance, like lubricating hinges and tightening hardware. However, ladder repair is specialized work and should be completed by qualified persons or the manufacturer.

If conditions exist that make a ladder unsafe for use, it should be removed from service immediately and marked with a warning such as "Dangerous - Do Not Use". If a ladder cannot be repaired, it should be destroyed prior to disposal.