Both federal Pacific and Zinsko panels have lost their UL ratings which means they should be replaced wherever they are installed.
Federal Pacific electric company was once one of the most common producers of circuit breakers and panels in North America from 1950 to 1980s most federal Pacific panels were installed in homes.
After a short circuit or over current federal Pacific panels overheat and become a fire hazard, it's estimated 28 million FPE stab lock breaker's are installed in the United States and certain situations may cause them to fail to trip on a shorted circuit, or overload causing electrical fires and damage to the wiring. If you find a Zinsko or Federal pacific panel in your home, it should be replaced as soon as possible to avoid problems caused by this poorly designed panel and faulty circuit breakers.