So what does it mean to be an EPA Lead-Safe Certified Firm? 

The Lead Renovation, Repair and Painting (RRP) Rule establishes requirements for firms and individuals performing renovations, and affects contractors, property managers, and others who disturb painted surfaces.  It applies to work in houses, apartments, and child-occupied facilities (such as schools and day-care centers) built before 1978.  It includes pre-renovation education requirements as well as training, firm certification, and work practice requirements. 

https://www.epa.gov/lead/renovation-repair-and-painting-program-contractors