My MEP team sent this to me after I forwarded a few process charts to them. They believe me when I say our industry uses vacuum ovens to purge residual solvents from oil, but asked if I knew of any instances where this section has been used to deny ovens, heating mantles, or heat guns in the lab. They say it’s pretty straight forward, but asked me for ideas on how to respond if questioned by my fire chief. They were not confident in my reply “it’s how it is done”. 
Fire departments are regulated differently everywhere, even by county and city. For ovens and mantels: Worse case you’ll need a C1D2 type room (Legally, solvents arn’t allowed in actual C1dx rooms until whatever you have is below the lower explosive limit, but fire departments still like the idea) - usually a hood, or simply routing the exaust to a vent.
Heat guns obviously shouldn’t be around any volume of flammable solvents. Vid related.
1 Like
@sidco “Shall not be used” as it is in this section has nothing to do with C1Dx.
Edit: Upon furthur thought, perhaps the argument to be made is…if the ovens vent to a fume hood as we planned, then “an explosion condition” does not exist, therefore vacuum ovens can be used to heat flammable or combustible liquids or oils containing liquified petroleum gasses.
The MEP guys just presented it to me that regardless of C1Dx being involved, an explosion condition exists, and vacuum ovens, heating mantles and heat guns are no bueno. Obviously ultimately it’s up to the fire chief to interpret and not them. I do have a fire and materials company working on this project to help with providing “unbiased, data, recommendations and opinions based on scientific and engineering principles and practices and research and testing in matters relating to failure analysis and loss investigations”, but being their first canna client, my MEP team gave me a heads up first in regards to this section.
Ahhh the joys of the process 
I would say that the machine and all off-gassing material is in a C1D1 and outside that area an explosion condition will not exist, thus it is OK to use a vac oven/heat plate.
Depends on your fire marshal and how you design your SOPs. Generally the rule of thumb for ovens and vacuum pumps is that you need to demonstrate that your process will remove enough of the solvent from the extract by the time it goes in the oven that it won’t have a chance for the solvents to build up in enough quantities to potentially cause a flash fire or explosion.
We demonstrated to the CDPH and our local fire marshal here that after we cured our jars in the c1d1 for an appropriate period of time, enough of the butane separated out and offgassed to the point where you can hold a handheld sensor up to the side of the jar, and it won’t really register any butane coming off, or at least not enough to be within the explosive range. Then we “clear” that batch to leave the curing shelf we posted up in our c1d1, and it goes to ovening. They saw that we had a procedure in place which specifically addressed that issue, and they said “OK” without really splitting any hairs.
Any other measures you can take are certainly welcomed. For example, we have an Agilent vacuum pump that is hermetically sealed on the inside, which means even if any butane accidentally got sucked through, it still wouldn’t pose a fire hazard. Then we routed the exhaust from the vacuum pump over to the exhaust from our fume hood, so the same explosion-proof exhaust that ventilates our fume hood would also carry out the exhaust from the vacuum pump. They signed off on just the Agilent, but we added that tie-in from the exhaust to the ventilation later because it also cuts down on any smells coming out of the exhaust too.
And yes, as others said, if your equipment is properly rated as “Explosion Proof” or “Intrinsically Safe” (you should also know the difference between those two terms), and is rated for use in Zone 0 / C1D1 environments (depending on who gave the safety rating), then those requirements don’t apply.
You can always get creative too. Can’t find a good C1D1 water heater? Pipe the hot water in and keep your heater outside the C1D1.
5 Likes
That’s always going to be the better (cheaper) approach. If you don’t NEED it in your C1D1 space why spend the $$$ on buying C1D1 rated gear? Heaters, chillers, etc…? Put 'em outside, don’t worry about the heatload, do your wall penetrations, fire caulk the shit out of the holes and you’re g2g.
3 Likes