2010 ADA Standards for Accessible Design Pocket Guide
404.2.8 Closing Speed.
Door and gate closing speed shall comply with 404.2.8.
Door closers and gate closers shall be adjusted so that from an open position of 90 degrees, the time required to move the door to a position of 12 degrees from the latch is 5 seconds minimum. [S.H. 4.13.10]
Door and gate spring hinges shall be adjusted so that from the open position of 70 degrees, the door or gate shall move to the closed position in 1.5 seconds minimum.