@QuasiQuadrant - I think you need to go back and read the article more carefully.
Some things that jumped out at me were -
PS-80 is synthesized from oleic acid (already in soap) and dehydrated alcohol.
I saw about 4 citations, two of which are “extremely rare” case reports (extremely rare article you linked words not mine). It was t clear to me that PS-80 was even the causative agent. Another article takes lab results to postulate a possible mechanism I didn’t follow that had something to do with E. coli poisoning. The fourth the article you linked authors used the the word “some” to describe PS-80’s impact.
What also jumped out at me was all the implied impact (on rats, high dosages, no citations) were ingested. Not for nothing, but I wouldn’t ingest lye either.
I - I’m still not following why it would be bad to use in soap.
I very rarely say anything is 'bad' or 'good' as absolutely nothing is black & white. What may on the surface seem to be benign or 'good' can actually result in far reaching negative effects. If you were a fish in the ocean, or lake, and polysorbate 80 continues leaching into your home, your water, year after year due to the soaps & other personal care products people are using, you would view this issue very differently than from the perspective of a human being. That fish may say 'this
is toxic & it's killing me & generations of my family', while you might say 'hey, I've been using this stuff for years without any issue' while wondering why the seafood you buy at the supermarket has declined in quality & availability. Perspective is everything. Observation is crucial.
From my perspective, if I can make better decisions, take more thoughtful action, I choose to do so, whatever the case may be. These are personal choices I make based on years of formulating products. Even when I wasn't soap making, I spent many years constantly formulating products, testing them, having others test them, observing their results, then working to improve them. I also have spent many years researching not only product ingredients, but also what is going on globally with people's health, the health of the planet, our children & grandchildren. I have witnessed what is going on in the various countries I have worked & lived in over at least a decade. My conclusions & choices are based on a lifetime's worth of observations & experience, in my own country & several others.
You have your own personal choices to make based on your own observations & experience, as is the case with everyone. Even remaining apathetic - as many people do - or simply choosing to not look at these things is a choice. Choosing not to choose is also a choice
I have mentioned several reasons I choose not to use polysorbate 80 - inhalation / absorption via the skin / potential negative effects on our waters. People bathe & shower. Depending on which, you'd be absorbing / inhaling the polysorbate via some means, even with soap, as would other living beings. For me that isn't an acceptable risk I am willing to take, and if I am not willing to take that risk myself, I do not feel comfortable putting that risk factor out there for my customers to deal with, or living beings in the global environment, especially when our planet has been in crisis for so long due to the
choices made by our species.
In addition, because of the fact that I spend nearly all of my time surrounded by nature, wild foraging, using nearly all which I forage in some way in my products, I am see & am very concerned with what is happening to our planet. Everything we use in combination with water - and even without - ends up in our waters, our air, our soil, our food.
This is why I choose to not use polysorbate 80 & many other substances in my products. I really don't know how to make it any clearer.
Lastly, I mentioned that not enough studies have been done for a reason, the unspoken being 'well hey just continue doing what we're doing until somebody tells us it's killing us & everything around us', as I knew this would be mentioned. Well, look around... we are dying in droves & every living thing on the planet is dying in droves....so ask yourself why these studies have not been done. Look into these things. Come to your own conclusions. Make your own free choices & decisions based on the knowledge you glean from everything you read, experience & observe. As I said before, many of the effects we see are subtle, but they are there. Many take years to show up, but we can see this if we choose to carefully observe. The effects are there & we have been experiencing the results of our actions & choices for many decades now. You don't have to be a 'scientist' or a chemist to make logical conclusions based on your personal observations & experiences. Sadly, with so many corporations funding the research being done, studies are deliberately skewed in the favour or the companies producing these chemicals in vast amounts, with no care or attention being paid to our specie's health, or the health of the planet & the many other species which live amongst us here.
As the health of the planet degrades due to all of the toxins we as humans are manufacturing, formulating with & polluting our soil, waters, air, food etc with, our health degrades as well, more & more, year after year. This is unacceptable, and I therefore make a conscious effort to reduce the amounts of toxins I purchase in my products, the substances I formulate with etc.
This has been a lifelong journey for me, and has taken countless years of researching, observing, taking note of, experimenting and so on. I have said many times that this is a whole lot more than soap making to me - this is a shift of consciousness. Not only for myself, but for our entire species.
Good luck in finding answers to your questions. They don't always come easily or quickly, but they come