1991 ADA Standards for Accessible Design

4.13.12* Automatic Doors and Power-Assisted Doors.

If an automatic door is used, then it shall comply with ANSI/BHMA A156.10‒1985. Slowly opening, low-powered, automatic doors shall comply with ANSI A156.19‒1984. Such doors shall not open to back check faster than 3 seconds and shall require no more than 15 lbf (66.6N) to stop door movement. If a power-assisted door is used, its door-opening force shall comply with 4.13.11 and its closing shall conform to the requirements in ANSI A156.19‒1984.