Phosphates and fading of textiles.....
Have to admit haven't been able to find anything that explicitly backs up that claim. Don't use STPP with all laundry, only whites and even then more so when using that Persil soap in my stash. Find TOL European detergents both liquid and powders perform well enough on their own.
Ammonia in laundry...
Household liquid ammonia is merely the gas ammonium hydroxide suspended in water. The whiff you get from the stuff is that gas escaping from liquid back into air.
Ammonium hydroxide has a pH of about 11.2 making it one of the weaker bases used for laundry. In comparison soda ash (washing soda) is 11.26, sodium metasilicate is 12.62, sodium hydroxide (lye) is 12.88, trisodium phosphate is 12.12, and borax is only 9.05.
PH scale is logarithmic meaning that a substance above or below another can be 10 to 100 times more base or acidic.
In terms of cleaning and laundry use base substances have been used for centuries. Everything from ashes from trees and plants to urine. Romans used urine to brush their teeth as well as for cleaning textiles.
Base substance mixed with fats or oils causes saponification which is part of the cleaning action. Quick lime is poured over dead bodies to hasten decomposition by that process.
For textiles washing at a base pH level causes various natural textile fibers to swell thus releasing dirt and soils. This is the other part of why various substances are used to raise the pH of wash water. Note all soaps in water solution are alkaline, but not all detergents which can range from neutral to either slightly acidic to various levels of base (alkaline)
Ammonia being a weaker base is used because it will "break" soils and oils from fabrics, but not cause as much damage as say sodium hydroxide, washing soda or TSP. For generations it was advised to use ammonia when washing woolens such as blankets because if used in proper amounts it shouldn't cause harm.
Commercial laundries long have and still do use a range of "breaks" and builders that are highly alkaline. These products are *NOT* meant for use in domestic/homestyle washing machines. Such appliances are often made from soft metal parts that will corrode with constant exposure to such harsh chemicals. Commercial/industrial machines are made from high quality stainless steel and other metals designed to withstand repeated exposure to harsh alkalies and acids.
Before enzymes laundry was largely based upon chemistry; alkalies were used for certain soils and stains, acids for another. Hospital laundry with blood stains in UK was routinely done with nothing more than soap, sodium metasilicate and perborate bleach. Ammonia or any other base will remove blood as well.
Asian attendants at local laundry have gotten on the ammonia bandwagon. Have seen them pour one-third to half bottle of the stuff into machines when doing service washes.
https://en.wikipedia.org/wiki/Ammonia_solution
https://www.labmanager.com/lab-health-and-safety/working-with-ammonium-hydroxide-20206