Debbie, and others,

This makes (some) sense to me; I understand that nanoparticles that are not in some matrix are prone to easy dispersal. What puzzles me is: if these tiny particles can "blow around" easily, surely they don't "blow around" more easily than some gas (NO2, H2S, etc) - do they? Could they? Seems to me that tiny molecules and tiny nanoparticles would behave about the same in this regard. Thus, if a "high" flow rate of 100 fpm is inappropriate for nanoparticles due to "excess turbulence" (I'd guess) then why would this not also apply to "regular" gases?

If we empirically KNOW that the lower flow rate for nanoparticles is appropriate then this a good guideline, of course. It just doesn't make intuitive sense to me.

Dave

David C. Finster
Professor, Department of Chemistry
University Chemical Hygiene Officer
Wittenberg University
937-327-6441
https://urldefense.proofpoint.com/v2/url?u=http-3A__userpages.wittenberg.edu_dfinster_index.html&d=BQIFAg&c=lb62iw4YL4RFalcE2hQUQealT9-RXrryqt9KZX2qu2s&r=meWM1Buqv4IQ27AlK1OJRjcQl09S1Zta6YXKalY_Io0&m=6BYvX8ZkifTQ2lIzlAHkyM7YZJ3y5_uVk44suyTlm84&s=SuVStqlUpFPjKAEmAumtf8elM-UbrmIDAeSkVmUyhcA&e=