In a recent Q&A on the FacilityCare website, consultant Brad Keyes answered a question about dust on sprinkler heads.
Q: I just had a survey and received a finding for dust on some of the sprinkler heads. I understand that foreign material is not permitted, but minute amounts of dust??
A: Dust is a foreign material, and foreign material is not permitted on sprinkler heads. I support the finding, since how much dust is too much? If you allow just a little dust, then at what point is it too much dust? Besides, any foreign material, including dust, can change the reaction time of a sprinkler head.
AI-Driven Facilities: Strategic Planning and Cost Management 
Double Homicide Suspect Hides from Police in Upstate Community Hospital
McCarthy and HOK Break Ground on Kedren Children's Village
Thousands of Healthcare Workers Laid Off
Construction Tops Off at Hackensack Meridian Health and Wellness Center