Registered nurses from Kaiser Permanente hospitals and clinics in the Bay Area are planning a two-day strike next month to demand tougher Ebola safety precautions, the union that represents the health care workers, announced Thursday. National Nurses United representatives say they have been unsuccessfully pressing Kaiser to implement a set of stricter Ebola-related controls, including “optimal personal protective equipment” such as full-body hazardous material suits that leave no skin exposed or unprotected.