One of the questions, tho, concerns the delivery system, does it need to be that close to the machine ("if some is good, is more better?"). And at this time, my sources tell me "no." In the absence of available objective data, it would be beneficial to gather PFT data on those people who are using aromatherapy in this concentrated fashion for extended periods, especially with heated humidification. Screening spirometry at the annual physical isn't a bad idea, with diffusion testing done at the first sign of any symptoms related to shortness of breath. This should be done regardless, and if those people with 1500-2500 contact hours per year start developing symptoms, that information that should be reported out.
Meanwhile, for those of us who are a little more budget-minded, we might want to consider a more economical EO source. This guy has a heckuva profit margin:
A gallon (3785 ml) of essential oil costs 358.00:

5 ml bottles (757 of them) cost 60 bucks. Selling this stuff on eBay:

Clears $4,903.15.
Who's helping who here?
You can buy 2 to 6 times that quantity on Amazon, eBay, ANYWHERE, for the same price, and if the key component is the "Diffuser System", you can use the new and improved
"SAG 'n Sleep II"
including the revolutionary adhesive anchor system, that you can make yourself with items found around the house.

For the less mechanically inclined, step-by-step instructions are available for $9.95 plus $4.95 shipping and handling.
SAG