"Sodium percarbonate releases hydrogen peroxide. H2O2 is not effective bleach itself especially in temperatures below 60°."
Not entirely correct. Methinks you are confusing sodium perborate and sodium percarbonate. Both release oxygen (hydrogen peroxide) in water, but have different qualities.
Long the staple of "boil wash" bleaching (the original Persil was Sodium PERborate and SILicate along with soap)sodium perborate which is made from treating borax with peroxide will only effectively bleach at elevated temperatures (>60c/140F). Lower temperatures require vastly longer contact time.
OTOH sodium percarbonate (made from treating washing soda with hydrogen peroxide)will begin effectively bleaching in warm or even cold water. In the laundry world sodium percarbonate is known as the "cold water bleach" for this reason.
OTOH sodium perborate without activators was and still is sold as a "color safe" bleach. This is because one is likely not to launder colours at tempertures elevated enough to cause the perborate to bleach effectively. P&G also added small amounts of sodium perborate to Cheer powder detergent as its "ColorGuard" formula. This is because oxygen bleach and chlorine bleach to an extent cancel each other out. Most tap water in the USA is chlorinated....
To get around the elevated temperature requirements for sodium perborate bleach activators (TAED in Europe, NBOS in USA) were invented. In water these chemicals react with hydrogen peroxide to create peracetic acid, a powerful bleaching and disinfecting agent. So much so it is used to sterilize beer and ale bottles before use.
The creation of bleach activators came along during the energy crisis of the 1970's when in both Europe and the USA the population was urged to save energy. By Ariel, Persil and other TOL European detergents promised the same boil wash results even when "turning down the dial". You've heard the adverts; "when the stain says hot, but the label says not..". Well those were pushing the supposed ability of these new "activated bleach" detergents to clean even at lower temps.
Due to cost and stability issues sodium percarbonate was rarely used in laundry detergents, pre-soaks, oxygen bleaches.... However the EU has recently put borates in their crosshairs as dangerous to the environment, so sodium perborate is out, and sodium percarbonate is in. In either case Persil, Ariel, and the rest still often include TAED (bleach activator) even though it may not be needed.
In Europe the patents on TAED long ago expired which is why P&G, Unilever, Henkel and others all can use that chemical. On this side of the pond NBOS has been held under tight control by P&G, which is why you only find activated bleaching systems in their laundry detergents, bleaches, and automatic dishwasher powders.
P&G first introduced activated bleaching with BIZ, it then went onto Oxydol, then finally Tide with Bleach. Today you can find P&G's activated bleaching system in many Tide, Gain, and other laundry detergent/bleaching products as well as Cascade dishwasher powder. You can tell where it is by looking at the patent numbers listed on packet.
P&G over the years keeps tweaking their activated bleaching system and filing new patents. Thus NBOS has never come out of protection so anyone else can get at it, and P&G does not license the rights. When P&G sold off Oxydol and Biz they did not give the rights to the activated bleaching system, so both products are not the same as before.
