1) I said: TEND to settle onto innamiate objects UNLESS your pinning in a dust storm. So why do you think I specifically mentioned DUST, or must I spell it all out for YOU!
2) But so what bacteria may cling to dust particles in the air and some of that air may gain entry into a multi-dose vial, BUT to suggest such a mechanism can increase the rate of infection IS BRO-SCIENCE and that's also a FACT!
Otherwise your nurse acquaintance would be required to FILTER air which is being injected into a multi-dose vial and I KNOW BETTER!
Unless of course you can locate scientific evidence to the contrary, NOT
Why don't you spend a little more time investigating bacterial counts in AIR and compare that to YOUR SKIN bc the former pales in comparison to the latter.
Such information's based on SCIENTIFIC FACTS and has practical applications bc SKIN FLORA is the responsible for the majority of infections related to parenterally administered drugs.