Pennsylvania is an at will employment state, which means that either the employer or employee can end the working relationship at any point without a reason. Even though this sounds like employers can terminate employees for any reason, they actually can't. It is possible for an employee to sue an employer for wrongful termination if the reason is illegal.
There are a few reasons why you shouldn't terminate an employee. These include retaliation for something like making a complaint about illegal activities at the business, and discrimination or harassment based on race, age, gender, sexual orientation or any other protected status. If you let an employee go because of one of those reasons, you open your company up to legal action that can be both time-consuming and costly.
Protections for employees are covered in the Family and Medical Leave Act (FMLA), the Americans with Disabilities Act (ADA), the Age Discrimination in Employment Act (ADEA), the Equal Pay Act (EPA) and the Civil Right Act. Other laws might also apply, depending on the circumstances, so looking at situations individually can help you decide what to do to protect your company.
You should relay the message about suitable termination policies to anyone who has the power to fire employees. One thing that is important to remember is that these laws don't apply only to termination. Instead, they have to do with any negative employment action, including bypassing someone for a promotion or moving them to a less desirable shift. Setting a clear standard and checking each case individually may prevent employment litigation.