Persil Power was a laundry detergent product developed and sold in the mid-1990s by Unilever.
In the early 1990s, Unilever's Persil detergent risked losing its market-leading position as independent tests were showing the major brands to have relatively similar performance in removing stains. Unilever decided that they needed a product with an edge in stain removal. Persil's main competitor, Ariel, had recently introduced Ariel Ultra, the first of the "super compacts" - washing powders equipped with chemical catalysts which (according to the advertising) cleaned better than ever, with less powder. Given Ariel Ultra's success, and with Persil Micro System lagging, Unilever needed a new super-compact Persil line. Thus, Persil Power was conceived.
Unilever's research teams found a manganese(IV)-based catalyst that sped up the decomposition of sodium perborate and sodium percarbonate which act as bleaches in the washing process, increasing the cleaning performance noticeably and allowing use of lower temperatures. Unilever decided that the bleaching agents would be an ideal addition to the product, but had worries over such a major alteration to the formula of one of their main products (a high profile example of this being New Coke, with a more direct example being in the late 1980s when one of Persil's competitors, Daz, introduced a new formula that also increased cleaning performance, but caused allergic reactions in a small but noticeable percentage of the population). To this end they decided to split the catalyst agent (together with some fabric softening agents) into a new product, Persil Power. In May 1994, Persil Power was launched with a large publicity campaign, but a number of problems soon became apparent.
Despite the large publicity campaign, the sales of Persil and Persil Power did not significantly increase, because Persil by itself was capable of dealing with most stains. The most serious problem was that after a few washes with Persil Power, clothes first started to lose their colour definition and then their structural integrity, ripping easily under any significant stress. Effectively, washing clothes in Persil Power had the same effect as adding bleach to the clothes. Further testing determined that while the effects weren't apparent on new clothes (which Unilever had performed most of Persil Power's testing with) they could become very quickly apparent on older clothes. The effects were largely determined to be due to Persil Power being a little too powerful in the recommended quantities, and a chemical reaction (which Unilever had not detected) occurring between the catalyst agents and dyes used commonly in clothes. Subsequently, a hasty reformulation with less catalyst was released, but that too was suspected of causing problems and was equally mired by the bad publicity.