Section 460.170 - Lead Dust Monitoring(A) Lead inspectors and code enforcement lead determination inspectors shall take dust samples in accordance with a lead dust monitoring protocol issued by the Director. Dust lead levels must be measured by a laboratory with appropriate National Lead Laboratory Accreditation Program (NLLAP) certification or which at minimum participates in the appropriate Environmental Lead Proficiency Analytical Testing (ELPAT) program.(B) The lead dust monitoring protocol shall be deemed to have been satisfied if: (1) Floor lead dust levels are below 40 micrograms per square foot (µg/ft2).(2) Windowsill lead dust levels are below 250 micrograms per square foot.(3) Exterior windowsill/window well lead dust levels are below 400 micrograms per square foot.(C) If, after deleading and three cleanings, dust levels exceed the standards of 105 CMR 460.170(B), the Director may require the owner to hire a licensed deleader to perform a final clean-up in accordance with 105 CMR 460.160(D)(1), if a licensed deleader was not responsible for the final clean-up.(D) The Director may require the owner to have an authorized person seal the floors and/or other surfaces with a sealant, as specified in the lead dust monitoring protocol, if dust lead levels exceed the standards of 105 CMR 460.170(B).Amended by Mass Register Issue 1353, eff. 12/1/2017.