grease or solid comprising these materials. In some embodiments, the cleaning formulation comprises a fla› voring agent. In some embodiments, the cleaning formu› lation comprises an edible polyhydric alcohol. The clean› ing formulation may be "self-indicating" in that the color of the ferrate(VI) indicates it is present and active and a change in color indicates it has reacted. 

In another aspect, the invention provides a formulation and/or method of cleaning a surface comprising a material that is "self-indicating" in that the color of the formulation 10 indicates it is active and a change in color indicates it has reacted. 

In a further aspect, the invention provides a method of cleaning a surface, comprising: providing a ferrate(VI) com› position that comprises ferrate and a phase transfer catalyst or a chelating agent, and applying the ferrate(VI) composition to the surface. For example, the surface may be a surface of a wall, counter, floor, toilet, sink, carpet. In some embodiments, an aqueous composition comprising a pH modifier is first applied to the surface, and then ferrate is dissolved into the aqueous composition. In some embodiments, the pH modifier comprises dipotassium hydrogen phosphate. 

In another aspect, the invention provides a method of cleaning clothing, comprising: providing a ferrate composi› tion that comprises ferrate and a phase transfer catalyst or a chelating agent, and applying the ferrate composition to the clothing. 

In yet another aspect, the invention provides a cleaning composition, comprising, ferrate, and at least one of the fol› lowing groups: a) a chelating agent; b) a phase transfer cata› lyst and a phosphate; or c) an abrasive. In a preferred embodi› ment, the ferrate(VI) in the composition comprises crystals having an aspect ratio of at least 10. 

In another aspect, the invention provides a dispenser for ferrate, comprising: a first compartment comprising dry fer› rate; and a second compartment comprising water or an aque› ous solution. 

Any of the additives described herein can be used in ferrate formulations, and, in the broadest aspects of the invention, any of the formulations can be used in any of the inventive methods. For example, the invention provides cleaning for› mulation, comprising: amatrix material; and an effective amount of ferrate dispersed in the matrix material; wherein the matrix material comprises any of the components dis› cussed herein. 

In this the description of this invention, "providing" includes obtaining a pre-made ferrate-containing composi› tion, or mixing two or more components to make a ferrate› containing composition. "Applying" means that a composi› tion is applied to an article either before, after or during the formation of a ferrate. The term "comprising" is an open term that means "including," and any of the inventive aspects that are described as "comprising," may, in alternative embodi› ments be described using the narrower terms "consisting essentially of’ or "consisting of." All"%" indicates weight% unless indicated otherwise. 

## BRIEF DESCRIPTION OF THE FIGURE 

FIG. 1 shows the AR 70-38 Hot-Dry Temperature Cycle 60 Requirement as described in Example 1. 

## DESCRIPTION OF THE INVENTION 

Ferrate(VI), or just "ferrate" is non-persistent with respect to being hazardous, toxic, or having adverse environmental impact regardless of most use conditions. It is capable of 

desirable bleaching chemistry, and is storage and temperature stable. It is also purple in color, even when formulated, and it changes to orange when in spent form ( chemically reduced to harmless and stable ferric compounds). To many consumers and those skilled in the art of staining it will be surprising that a colored composition, especially one containing iron, can be a whitener or a stain remover, and not leave a iron stain itself. It is a useful feature of the ferrate(VI) formulation of the invention that the products do not leave a "red rust" stain. 

Ferrate(VI) is sometimes termed herein as simply "fer- rate." Hence "ferrate" is used in this specification to represent ferrate(VI), and the use of oxidation state Roman numerals is also sometimes used to insure unambiguous naming of com› pounds. As used herein, "ferrate" does not refer to just any compound that contains iron; for example hexacyanoferrate (II) is not "ferrate" in the descriptions herein. 

The amount of ferrate(VI) used in a formulation of the invention can vary depending on the intended application. In some embodiments, ferrate(VI) (measured as weight% iron) is present in an at least about 0.00001 % by weight of the formulation, in some embodiments, 10% or less, preferably from about 0.001 % to about 20%, and more preferably from about 0.05% to about 10%. In some embodiments, a compo› sition contains at least 40%, or at least 50%, or at least 70%, or at least 90%, and in some embodiments is essentially pure ferrate, normally 90-99+%. 

The concentration offerrate(VI) in a sample can be deter› mined by UV/vis spectrophotometry by comparing the con› centrations of ferrate(VI) determined by dissolving in an aqueous solution of 32% NaOH and measuring the absor› bance readings at 505 and 785 nm. For the measurement to be qualitatively and quantitatively correct, the concentrations derived from each absorbance reading should be the same within 2-10%. If these two values differ more than 10%, and the spectrum is consistent with ferrate(VI) ion being the lone chromophore and that another colored material is also present. Also, the presence of colloids or particulates is indi› cated that scatter light causing a false high in the concentra› tion measurement. In this event, further purification of the analytical sample is required, by centrifugation or filtration, to remove these particulates and/or colloids and the absor› bance is then re-read at the two diagnostic wavelengths. In addition, for accurate measurement, care should be taken to avoid conditions that would change the oxidation state of iron. The NaOH solution should be free of reducing agents. If necessary, where a ferrate(VI) containing composition is strongly hydrophobic, the hydrophobic matrix may be removed (such as with toluene or phase transfer catalyst, i.e. quaternary ammonium ion, a blend of quaternary animonium ions, phosphonium ion, a blend of phosphonium ions), for example by water washing the ferrate(VI) ion from the hydro› phobic phase, just prior to dissolving the ferrate(VI) in 32% NaOH. 

Unexpectedly, unlike all peroxide materials, we found that potassium ferrate(VI) to be thermally stable as defined by Army Regulation (AR) 70-38 test conditions. Therefore potassium ferrate(VI) was determined to be stable to storage for long periods, at least 98 days at 71 ° C., and at least 82 days under conditions of cycling daily from 23° C. to 71 ° C. and back again. This result is true regardless of whether the potas› sium ferrate(VI) is pure (80-100% analytical grade) or of only moderate purity (50-80% technical grade). In these tests, losses with time varied slightly with test vials ranging from <1% to 10% (–3%) loss respectively after the test periods given. From these results, it can be estimated that the potas› sium ferrate(VI) will likely be sufficiently stable for several years of storage, at least. 

