Freight Rail Workforce Health and Safety Act This bill requires Class I railroad carriers to provide employees with at least seven days of paid sick leave per calendar year. Other forms of accrued leave or unpaid leave (e.g., personal days and vacation) do not count as days of paid sick leave. An employee's unused paid sick leave must carry over annually on January 1. An employee must be permitted to use paid sick leave for reasons including a physical or mental illness, injury, or medical condition; obtaining diagnosis, care, or preventive care; caring for the child, parent, spouse, or domestic partner of an employee, or other related individual; or an absence resulting from domestic violence, sexual assault, or stalking. An employee must request leave seven days in advance for foreseeable leave and as soon as practicable for unforeseeable requests. Use of leave cannot be contingent on the requesting employee finding a replacement to cover any work time to be missed. Further, a railroad carrier may not retaliate against an employee (e.g., dismiss, suspend, discipline, or deny promotion) for requesting the use of or having used paid sick leave. The bill includes an enforcement provision prohibiting the Department of Transportation from approving a mandatory plan under the Risk Reduction Program for any railroad carrier that has not complied with the bill's paid sick leave requirements.