FYI all -
https://www.acs.org/content/acs/en/molecule-of-the-week/archive/u/urea.html
I found that article interesting. Doesn't talk about Diesel fuel much though, mostly fertilizer and such. Which should be another concern.
I guess it's time to start stocking up slowly again (not panic hoarding, but stocking up). The rumors at work are flying (not any industry specific work, or specific info, just unrelated industry shop talk) about stocking up and diesel shortages coming. Probably driven by the same social media y'all are discussing. Without getting "political" or taking "sides" on all this, one has to wonder why the USA isn't more independent on these things. Nat gas and even crude. I mean we were "energy independent" (produced at least as much as we used) back when Obama was in office.
And I don't know what the hell this "DEF/AdBlue" stuff is. Is that common in your diesel car/truck or is it industrial?
P.S.
Maybe gas stations need to install special urinals and we all pee into them to recycle the urea.........

Waste not want not!