Pursuant to a new rule passed by the Environmental Protection Agency, all contractors, landlords, and property managers performing or hiring for painting projects that disturb lead-based paint must now become "lead-safe" certified before performing work on houses built before 1978.  The new requirement also applies to weatherization projects, and to schools, day care facilities, or other commercial properties occupied by children.  "Lead-safe" certification is meant to minimize potential airborne contamination from dust or seepage into surrounding soil form debris. 
A "lead-safe" certified professional is required for work that disturbs six square feet or more of painted surfaces indoors, or twenty square feet of painted surfaces outdoors.  The "lead-safe" certified professional must be physically present at the site where the work is taking place, and proof of certification is required to be presented to the home owner or property owner upon request.  "Lead-safe" certification is achieved through demonstrated knowledge of lead-safe procedures, like testing of dust contaminants, and cleaning and disposal of lead-based paint.  Certification typically requires an eight-hour EPA training course. 
For more information, visit:  http://www.epa.gov/lead/pubs/renovation.htm