The #1 thing is to search for visible changes in your product before and after the problem
Did you notice any change in appearance, color, smell?
Did it made some foam by itself? There is some precipitate at the bottom?
All these things indicate important interactions or reactions between components
The #2 things is to track the possible cause of the changes (the only one we know for now is the lack of foam after a few days)
I think the best way to find any interactions may be doing knockout experiments like describe here
The example Perry used was also for a cleansing solution so it should be quite easy to follow.
These experiments are intended to check if one or more of your ingredients is causing the problem.
Another way to go is to start simple (SDBS + SLES + CDEA + CITRIC ACID) And see if the problem persists. If so, you should then test SDBS+SLES and SDBS + CDEA.
I’ve heard bad things about formalin (I think it is not legal in some places also) but I never used so can’t really opine.
This reply was modified 2 months, 1 week ago by luttie. Reason: activate notification