spoodle - bleach and enzymes in liquids
You won't find bleach in UK liquid detergents - my brother in law works for Unilever, and he explained the science to me in detail - apparently a storage issue - hard to stop the bleach separating from the detergent it seems.
The bio/non-bio thing dates back to, as one might only expect, market forces in the late 70s and early 80s. Until the 80s, Persil was a non-bio powder (when there was only one variant), with Ariel being the bio option (the latter of course a Proctor and Gamble product). These were of course high suds powders that, along with OMO, Surf (lever), Tide and Daz (P&G), were popular with twintub users - Persil Automatic (again non-bio) and Bold (P&G) dominated the more limited front-loader market at the time.
In the 80s as front loaders began to supersede twintubs, most of the former twintub powders were launched in automatic form - so Surf Automatic, Ariel Automatic (Bio) and Daz Automatic were launched - OMO and Tide disappeared from the UK market. Lever realised that they were losing market cover to Ariel Automatic, and introduced 'New-System' Persil Automatic - a bio lower temperature powder - this was launched concurrently with the Hotpoint New Generation L.E. range - the first range designed to operate at lower temperatures. This was a success and help Lever regain dominance in the market.
Later in the 80s Lever introduced some trial brands - some people might remember Radion (appeared in about 1989 and was very short-lived - supposedly good at de-odorising), and Wisk liquid (as a trial for market acceptance of liquids - P&G had launched Ariel liquid). Lever had one big flop with Persil Power - launched as a rival to Ariel Ultra - the first super-compact powders. Persil Power was designed as an occasional use powder, but wasn't adopted as such and disappeared quickly following allegations that it caused colour loss and even fabric decay! It was quietly dropped...
The late 90s saw the marketing people coming in with an attempt to diversify the market - Persil Non-Bio was pushed as the 'traditional' powder (capitalising on a small but significant number of reported allergies to certain powders), Persil Bio (or any of its other names), with Colour (Bleach free) and other variants appearing in traditional powder, liquid and compact powder form. P&G followed suit with various versions of Ariel - notable that P&G kept the Fairy brand alive as a 'gentle' powder, whereas Lever rely on Persil non-bio. Surf was repositioned as a fragranced powder (competing with Bold), but at economy price to match Daz - Surf is marketed as OMO and ALL in various parts of the world. Persil is a Lever brand only in the British Isles and a few other areas - the German firm Henkel actually on the name, and market their own product as Persil in most of Europe.
Most US detergents tend not to include bleach (hence liquid bleach is a popular additive), whereas most UK powders (not liquids of course) include bleach - except colour powder. Additives are now popular - with Vanish being particularly popular - you may recall a large push on 'safe' bleaches over here a few years ago - ACE and the like (awfully cheesy add for ACE...), but one-scoop-in-the-wash powders seem more popular.
. Only thing I really don't like is that it is quite messy... you always get a dribble of liquid down the side of the bottle.
