The National Labor Relations Board said that Crozer Chester Medical Center management acted unfairly before, during and after a two-day strike in September involving 550 nurses in the Pennsylvania Association of Staff Nurses and Allied Professionals.

A hospital spokesman was not immediately available for comment.

The NLRB said Wednesday that the hospital improperly interfered with informational leafletting and threatened other employees with retaliation, if they showed support for the nurses by honking their horns or waving signs.

The NLRB also found that the hospital wrongly refused to provide the union a copy of the contract with a staffing company that provided replacement nurses during the strike.

However, in a mixed ruling, the NLRB said the hospital had no obligation to give the union non-public reports from the Joint Commission on Accreditation of Hospital Organization on staffing levels, a key bargaining issue. But the hospital was required to bargain with the union over how to make the information available.