2010 ADA Standards for Accessible Design Pocket Guide
309 Operable Parts
Operable parts shall be placed within one or more of the reach ranges specified in 308.
Operable parts shall be operable with one hand and shall not require tight grasping, pinching, or twisting of the wrist. The force required to activate operable parts shall be 5 pounds (22.2 N) maximum.
EXCEPTION: Gas pump nozzles shall not be required to provide operable parts that have an activating force of 5 pounds (22.2 N) maximum.