Sodium percarbonate (offered by Bensos as Bleaching Powder code D) is a mineral chemical, which features may be very useful for some cleaning, particularly for laundry.
Once diluted in water, its pH is alkaline (greater than 7); what does it mean? pH is a way to measure H+ ions concentrations, that is acidity, of an aqueous solution (“aqueous solution” is water with something dissolved inside). As an example, when a solution is very very acidic (pH 1), it may be corrosive; if it is few acidic (pH 5) our skin feels it good, as this is typical skin pH. Talking about alkaline pH, let’s take in consideration lower and lower H+ concentrations, at the same time reaching higher and higher values for its “opposite”, OH- ion: high values of OH- correspond with low values of H+ and with a very alkaline pH (pH 14), which is corrosive as much as very low pH (pH 1). In-between alkaline values are typically found in degreasers and in laundry products, as sodium percarbonate.
We said that sodium percarbonate is alkaline in aqueous solution, so that it has good degreasing power Laundry Detergent code H, likewise alkaline, whereas it is not recommended to mix it directly with Citric Acid (suitable to be put in place of the fabric softener, to enter the cleaning water not before the last rinsing step, when alkaline products have been yet rinsed away): it is better not to mix acidic with alkaline chemicals, because they react with each other “fighting” one another, instead of stepping up their efforts against soil!
The second feature of sodium percarbonate is the bleaching one, made up by oxygen peroxide contained into the molecule: the effervescence that develops in contact with water is “active oxygen“, able to bleach and to hygienize. The strong action of oxygen peroxide is very useful when it acts against soil and bacteria, oxydizing and inactivating them; this action is disadvantageous if it acts against the laundry detergent molecules. This is the reason why it is better not to put together concentrated detergent and percarbonate, into the same dispenser; when they will be diluted by washing water, they will find easily their “victims” in soil and microorganisms, without sparing energy in fighing themselves…
In summary: sodium percarbonate works well with laundry detergent, as long as they are put initially in two different places in the machine (two different dispensers, or two separate places in the drum). In closing, sodium percarbonate and citric acid or vinegar must not be directly mixed.