Dan Milholland is a pioneer in the testing of HEPA filters using particle counters. He was instrumental in the research and establishing the use of microspheres (PSL) as a filter challenge aerosol as well as correlating the particle counter probe dimensions, scan rate, challenge concentration, and minimum size of leak to be detected.

Milholland has worked with multiple filter manufacturers to set up and validate in house filter auto scan equipment. Major semiconductor manufacturers have had Milholland to audit filter manufactures quality systems in the US, Asia and Europe.

In his 30+ years experience in testing cleanroom, Milholland has served on the committee writing Federal Standard 209E, was on the US Expert Council for ISO 14644 Part 1, served 13 years on the NEBB Cleanroom Committee certifying cleanroom certifiers, is a lead instructor teaching filter testing at the Eagleson Institute, and is the current IEST Representative to US Technical Advisory Group to ISO/TC 142.