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Excellent summary. My grandfather worked for Monsanto/Detergents, Inc when they developed All back in the late 40s. They lived in Chicagoland later in life where phosphates were banned early (in 1969 or so)...my grandmother used the 10 lb pail detergent from Jewel which was full of soda ash and her Maytag was encrusted badly. Using a phosphate detergent...that wouldn't have occurred.
 
Can this be added to all modern machines without problems? I’m very curious about this. What other restrictions or suggestions for use are there? Can you use it with any detergent?
 
Long answer short is, yes

You can use phosphates with any modern detergent, and no it won't harm your washing machine.

That being said, and know will take some heat from certain quarters, but find the addition of STPP with TOL modern offerings of detergents like Persil (German and American versions), Ariel (European) not really necessary. Even current offerings of Tide liquid seem to give excellent results on their own.
 
To tell the truth, I stopped adding STPP to laundry a few years ago when the Persil Perls in a jug became available. To my dismay this year, however, I discovered that the Persil Perls in a jug are no longer available. So I switched to the Persil Original Liquid, which does reasonably well.

I still have plenty of STPP, which should come in handy when I start working under my cars again...
 
STPP and Bleach

Louis says you can't use STPP with chlorine bleach. As a one-time chemist, I don't understand why there would be an issue. STPP is not an acid, it does not contain ammonia, and AFAIK it doesn't react or deactivate chlorine bleach. That said, I don't use chlorine bleach in my washer anyway. I did some cursory Googling about the two but found nothing of concern if they were mixed.

Decades ago, many powdered laundry detergents contained STPP, and chlorine bleach was also used heavily for such things as diapers. If there was some incompatibility I would have thought this would not have been the case.

Louis, do you have anything to support the concern about mixing STPP and Chlorine bleach?
 
Are there any problems using STPP with certain fabrics? 99% of what I own is cotton, which would be fine but what about other things like polyester or even wool or silk?
 
While milder than washing soda, lye or caustic soda

Phosphates are still alkaline and thus shouldn't be used on protein fibers such as wool or silk. This is why for most part one shouldn't use all but the mildest soap on woolens or silks either.

It also explains why soon as light duty detergents like Dreft, Fewa and others came on market, soap for doing "fine laundry" got the push.

If one had very hard water and no other choice but to use soap, it was/is possible to use STPP for washing silks or woolens, but one had to know what one was doing to prevent damage.

Very basically protein fibers are not harmed by (mild) acids, but cellulose textiles such as cotton and linen are susceptible.

OTOH cellulose fibers can withstand alkaline pH (within reason), but again protein fibers like woolens and silks cannot.

For those who permanently color, curl or straighten their hair, same pH rules apply.

Hair is made from protein; alkaline pH substances break down the hair, cause it to swell and thus allow alteration of color, curl pattern, etc... When the process is completed an acidic solution is used to "neutralize" previously used chemicals and thus make whatever change permanent (hopefully).

Drain cleaners based on lye basically because the high pH will attack and eat protein based clogs (hair), and the Saponification reaction between a base substance and fats found in drain (clog) turn it into soap which is more easily flushed down drains.
 
Laundress is correct: while milder than the usual sodium carbonate (washing soda) in most American laundry powders, STPP is still alkaline and therefore can degrade protein based fibers like wool or silk. For such fabrics a neutral detergent like Woolite is recommended.
 
IIRC back in their days powdered detergents for wool and silk were full of phosphates but also buffered with an acid to achieve a milder but still slightly alkaline pH.

Just checked some of today`s wool wash products (Coral Wolle und Seide, Perwoll Wolle und Feines, Sanso, Woolite) and can confirm all of them, the powders as well as liquids have a pH range of 8 - 8.5
Not exactly neutral but still very mild alkaline, some inferior bar soaps can be more aggressive in pH.
Contemporary Sanso powder is even loaded with washing soda but also buffered to a milder pH of course.
I remember that liquid Perwoll used to be slightly acidic according to the msds at some time ago, but for some mysterious reason this isn`t the case anymore.

So if someone desperately wants to play chemist on washday, yes it is possible to use harsh chemicals like STPP or washing soda even for the most delicate things like wool and silk as long as the pH is properly buffered with an acid.
I wouldn`t dare doing this myself because I have no way to check the pH of the finished product accurately. I don`t think litmus paper would do in this case.[this post was last edited: 8/18/2019-13:02]
 
 
I've added STPP to every wash load for 10+ years, with any/all other additives ... chlorine bleach, oxygen bleach, or Biz powder.  Have never used borax, or washing soda (sodium carbonate) directly other than whatever amount it may be present as a "filler" in other products.  If I understand correctly, sodium carbonate is primarily used as a water softener for laundry ... but it generates a precipitate.  STPP does not (it's non-precipitating) so is a better choice, and washing soda shouldn't be needed with it.
 
Not a chemist here but if you add a weaker base substance like STPP to a stronger base like a heavy duty washing powder it would add up the total pH, wouldn`t it?

And aren`t aluminum washer parts susceptible to strong bases?
And don`t detergent manufacturers therefor add silicates like water glass, another strong base but it also forms a protective coating on metal washer parts thus acting as corrosion inhibitors.

I wonder if there really are no negative effects on washer parts to expect in the long run if STPP is added to any detergent but the silicates to other alkali ratio is not altered accordingly.
I mean if detergent is mixed with STPP you end up with a higher pH and at the same time you weaken the corrosion inhibitors of the detergent. Not an ideal combination. Or have I missed something?
 
Interestingly, I’ve just recently started using Bubble Bandit... we have hard water and have yet to install a softener, so it’s been challenging. The dishwasher was getting coated in deposits and scale, and the washer was also. Both were also just full of dinge, and it was frustrating and kind of disgusting. My thinking here was, if the machine is coated in this nastiness, I just have the feeling the dishes and clothes were too. I had the chance to add some TSP that was being used to clean a cement floor to a load of white ‘just I see’, and they care out the cleanest and whitest I’ve ever seen! So I decided that detergent with STPP in it would be good, and so far it has actually cleaned the clothes, the washer, the dishes and the inside of the dishwasher is completely clean and new looking again. I also notice that I can just load the plates into the dishwasher with absolutely no rinsing or even scraping, and they come out completely clean, dry, and spot free. Although the first couple weeks of dishes were very spotty, this stopped as soon as the dishwasher was cleaned inside.
 
add a weaker base substance like STPP to a stronger base

No, adding STPP to a stronger base like washing soda would not increase the pH (make it even more basic). That's because these chemicals have a pH point about which they like to sit. STPP's pH point is lower than washing soda's, so it might well reduce the pH of the resulting mixture, albeit probably only slightly. In more technical terms, STPP will try to buffer the solution to a lower pH.

One time a while ago I tried taking a warm bath with STPP as a sort of bath salt. The water felt wonderful and I came out feeling quite refreshed.
 

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