I've been making Vanilla Extract for 3 yrs now, and literally many gallons of extract.  I usually am able to open the kitchen door for ventilation when working with so much alcohol and so many types of alcohols.  I've never had a problem before.  This year, I learned two very important lessons.

First, I had a hard time just wasting my vanilla beans after the year it takes to make extract.  So, after straining the liquid, I took the vanilla beans on trays to dry 48 hours.  Then I place them in the oven at 170 degrees to dehydrate until they are crisp, so I can turn them into vanilla powder. 

However, this one day, I usually stand by the oven at the kitchen island to work.  I had just got a phone call, so I sat at the table.  Barely sat down and my oven door came flying open, and a ball of fire (flash fire) came out of the oven. WOW!  If I had still been standing at the island.  Apparently there was still a lot of alcohol left IN the beans that it ignited in the oven.  Thankfully it was a flash fire, so it was out, and no damage to the oven or kitchen.  So, now I let those beans "air dry" for a week, and I use a dehydrator.

And after the year, you drain the vanilla beans from the liquid, so you can bottle the vanilla's.  So, usually again, a door can be open, but we had a blizzard, and -50 wind chills, so I did not open anything in the house.  It took me about 8 hours for 8 gallons of extract.  I noticed my eyes were so blurry, I couldn't see the computer screen.  Thought I was just getting tired.  Kept working.  All that vanilla, the house smelled very vanilla of course.  I had a couple guys who worked on snow removal mention how strong it was in the house.  Again, didn't think much about it, kept working.  Toward the end, I realized I was light headed and dizzy and sloppy speech even. 

A dear friend looked it up, and yes, this is a real thing and it's actually dangerous.  I was enumerated!  I had to look it up myself the next day.  However that evening, I had the giggles and was definitely under the influence of that alcohol without even drinking one drop.  It was not a fun experience.  Later that night I was so nauseous and I needed to vomit, but I couldn't.  Of course I couldn't it wasn't in my stomach.  The next morning I woke with one hang over severe headache and total body shaking. 

So, as I read, the vapors enter your blood stream through your lungs and into your brain far faster and harder than if you'd been drinking.  It's NOT something I'd ever want to experience again and not something I'd ever recommend.  Actually this could have been much more serious as you could actually die or pass out from these alcohol fumes.

That evening, I had the ceiling fans on the front door (yes super cold outside) propped partially opened and air purifiers on.  I went down stairs, away from the fumes, so I could try to recover.  Then I turned fans off, closed the door and went to bed.  Only to wake with the hangover symptoms. 

So, that was a few days ago.  I didn't want to attempt this again the next day but I still had gallons to process.  Today, a different approach.  The bowls full of used vanilla beans went into the garage (it's cold out there too).  I had the air purifier on high.  The vent hood over the stove on high and the ceiling fans on for more circulation.  I capped jars right away, and removed those beans as each bowl was filled.  Today, NO symptoms nothing went wrong, task is done, safely. 

I think for the home cook making a single smaller batch of vanilla, it wouldn't be a problem.  But when your processing gallons of vanilla, make sure you take precautions to have good ventilation.  Better safe than sorry.  Always safety first.  As I mentioned in the beginning, I've been making large batches like this for 3 yrs, and never had this happen before.  It was the enclosed kitchen, the winter storm preventing me opening a door for fresh air.  Lesson learned.

As for the Vanilla Extract, these were very good batches, And I'll be bottling these in larger bottles, but at a lower price.  These are not the high end very expensive vanilla beans, however, they did make a wonderful creamy vanilla.