To The Editor:

John J. Nappi, Jr.

President, Liberty Industries

I was very pleased to see your coverage (“Airshower Debate Back in Spotlight,” CleanRooms, March 1995, p.11) of the recent airshower controversy generated by William Whyte`s article in September`s Microcontamination.

As a manufacturer of airshowers for over 30 years, I feel I have been fighting an uphill battle to prove the worthiness of airshowers. I had met with Mr. Whyte prior to his publishing the article and found him opposed to any argument that favored airshowers. He apparently has no interest in using an actual airshower to conduct his tests. I was appalled at the unprofessional and unscientific manner in which the test data was presented in the article. There was no scientific proof to substantiate his claims about the ineffectiveness of airshowers.

But, what really dumbfounded me was the statement by Dr. Stuart Hoenig in your article. He was quoted as saying that 15 years ago he concluded that “airshowers are worthless.” Dr. Hoenig conducted one of the five tests (“Particle Removing Efficiencies of Air Showers”) referred to in your article. In his extensive report he concluded that “the standard method of blowing particles off of the garment is over 65 percent effective.” Percentages were even higher based on the type of garment worn.

There is nothing in his report that supports his recent statement that “airshowers are worthless,” and I am at a loss as to why he would contradict himself.

Clearly, the debate on airshower effectiveness will continue to rage on, despite the fact that they only make up a small portion of the cleanroom industry. Airshower bashing is just something the industry loves to do.