I was curious about what it’s in, so I looked up Wikipedia:

Diethanolamine is widely used in the preparation of diethanolamides and diethanolamine salts of long-chain fatty acids that are formulated into soaps and surfactants used in liquid laundry and dishwashing detergents, cosmetics, shampoos and hair conditioners.[5] In oil refineries, a DEA in water solution is commonly used to remove hydrogen sulfide from sour gas. It has an advantage over a similar amine, ethanolamine, in that a higher concentration may be used for the same corrosion potential. This allows refiners to scrub hydrogen sulfide at a lower circulating amine rate with less overall energy usage.

In things found at home it appears to be mainly soaps and cosmetics. These substances in particular:

Some of the most commonly used diethanolamides include:

   - Cocamide DEA
   - DEA-Cetyl Phosphate
   - DEA Oleth-3 Phosphate
   - Lauramide DEA
   - Myristamide DEA
   - Oleamide DEA

In all seriousness, alcohol tends to kill bacteria so I would expect that it would make them sad. But we know so little about our gut microflora, either way.

I’d love to see changes over time too. May be tricky to visualise on a map?