Whoa apologies for double post - but I'll just say that after my initial brief read leading to what I posted above - I've found some pretty varied data in the scholarly/regulatory literature on safe levels for atmospheric exposure ranging from the figure above ranging all the way to 2000ppm (0.2% residual) for chronic exposure and 20,000ppm (2% residual - this had ) for acute exposure in another source. I also observed a source providing a level at 1000ppm (.1% residual). Chronic exposure levels would be relevant assuming one was hypothetically going to dab this regularly. Acute exposure levels would be relevant if one were simply wanting to try this kind of product once-off. I would refer to the lowest of all safe exposure levels provided to err on the side of caution in these kinds of cases.
It seems there is/has recently been a lot of interest right now in dimethyl ether in food and even fuel applications internationally. There is a lot of new research and associated data emerging in recent times on relevant topics and I'm sure there's more to come yet. There are not OSHA exposure limits provided on this one yet.
To make things more convoluted - the question of peroxide formation in dimethyl ether may actually be the result of one or more miscategorization/typo/copy-paste mistakes in relevant publications!
A lot of discussion was had at ICmag on this one. Here is the link:
https://www.icmag.com/ic/showthread.php?t=273223&page=25
Work your way backwards from that final page to read further.
Some there and on youtube and in some other corners of the internet have reported mixed results using dimethyl ether. Some say they got something nice. Some say they got something nasty (various kinds, aside from tepictoton's comments above, there are also some who suggest that this solvent pulls unwanted green color into the mix - suggesting in some cases that this has a relationship to the length of 'wash'/contact time with material and temp at which extraction took place).
Best reports are coming back suggesting slightly lower overall yields than butane but this may be due to DME having a slightly lower dialectric constant than butane has, leading to less waxes being pulled from the material (all of this is IIRC and I may be wrong, this lower yield may actually be due to a negative cause for our purposes too!).
What this means is that DME may indeed show some promise for our purposes over other solvents - it might allow us to have a relatively 'dewaxed' (in terms of less wax being pulled out in initial extraction) extract with similar processing requirements to BHO (no winterization required). This would equate to more terps than winterized BHO and less wax than unwinterized BHO and could be judged as a gain vs BHO if this is all true (and it might not be!). DME does cost a fair chunk of change more than butane though. It also comes with all of the complications mentioned above when it comes to trying to answer basic safety questions.
I will stop short of saying DME is unsafe across the board for all extract artists.
I will say that anyone who tries to use this product really ought to be sure that they have purged it properly to lower residuals (via a certificate of analysis from a proper lab!) than relevant atmospheric exposure limits (at least! - 0ppm would be preferable, but may result in material that has lost some of the lower boiling terps and may somewhat diminish the benefits of this method over BHO/winterization, we must consider whether the end result will be worth the trouble given this)! Better safe than sorry til better information arrives for our consideration.
I will finally highlight that there are other advanced dual solvent (don't ask, this is not shit for any of us to use - this tek entails demonstrable dangers above and beyond what we normally have to deal with for BHO and other common solvents we use!) and solventless methods that already reliably produce higher terp containing material than what DME has been purported to give by anybody including the manufacturer of the DME products mentioned by skunk pharm!
I am not convinced that all safety considerations aside, DME will be worth using over existing options. Of course, when better information reveals itself to us - we might find that DME is a somewhat better option to use on balance than plain old BHO.
For now, I'll stick to advising that this be left to more qualified chemists
We're not necessarily missing out on much.
Fuck, I can't proofread this post but I'll share it anyway. Please forgive any issues that may have slipped through without editing.
