US laws regarding health apply to unionized and non-unionized employees.
Family and medical leave
The Family and Medical Leave Act of 1993 (FMLA) is a US federal law that permits workers who work for an employer with 50 or more employees and have worked at least 12 months for the business for a total of at least 1,250 hours to take up to 12 weeks of unpaid leave to care for:
A newborn or newly adopted or foster child,
To recover from the employee's own serious illness, or
To care for a child, spouse, or parent with a serious health condition.
The United States Department of Labor (USDOL) is the official site to find out answers to questions about workplace injuries...How to treat them, how to file a claim, and get independent medical exams.
Worker's Compensation This is a form of insurance providing wage replacement and medical benefits to employees injured in the course of employment in exchange for mandatory relinquishment of the employee's right to sue his or her employer for negligence.
You can check with the Worker's Compensation Commissions in your state: