3M = nextel = xc-116
Lance from steammonkey dot com posted a while back as he was trying to become a supplier for it
http://www.reddit.com/r/electronic_cigarette/comments/1epnbj/monkey_university_5202013_wicks_201/
Here is the relevant quote
Looking at rbasupplies they appear to understand the risks involved and are doing what they can to mitigate them. Their MSDS states
Due to their large size (7-13 microns in diameter), these Nextel (TM)
Ceramic Fibers are considered non-respirable and therefore are not expected to pose a cancer risk. Fibers are defined as respirable by
WHO convention if the length is larger than 5 microns and the diameter is less than 3 microns with a length to diameter ratio
greater than 3:1.
They also heat treat it at 1650 for 12 hours (it's rated up 2200f), even though 3m recommends 900f for 4 hours, is this a good thing..who knows. As long as the wick is fully saturated while in use I wouldn't expect fiber inhalation to be a concern, especially on a treated wick which should be partially rigid.
If you seriously have an interest in supporting the creators in the mod/rba community sadly it requires effort beyond going to a webstore and adding something to your cart 99% of the time. The most common being getting on the modders list (after waiting who knows how long, he is currently busy producing,finishing,shipping the last batch) on ecig forums or facebook. They are unable to meet the demand, china stepped in and saved the day, making it easy to buy and cheap. I don't blame people for buying clones..I just can't personally bring myself to do it.
An example of one such creator would be Perseas who runs
http://www.vapourart.com all his products are top notch and the customer service is amazing. However one of his mods would cost you $130-$260 and you would have to wait for the countdown timer on his website to start the sale before you can buy anything (there is one in 4 days, yay.) That night you will sleep like a baby knowing your purchase/donation will be going towards supporting the fair wages of a Bulgarian machine shop worker as well as the creator/designer, or not.