Synergistic disinfection enhancement

Information

  • Patent Grant
  • 9872930
  • Patent Number
    9,872,930
  • Date Filed
    Friday, September 8, 2017
    7 years ago
  • Date Issued
    Tuesday, January 23, 2018
    7 years ago
Abstract
An aqueous disinfectant solution comprising peroxyacetic acid and a surfactant such as a polyoxyethylene alkyl ether phosphate, (polyethylene glycol p-(1,1,3,3-tetramethylbutyl)-phenyl ether) or cocoamidopropylamino oxide. The solution is preferably adjusted to provide a pH in the range 5-8 by a pH adjusting agent such as a phosphate buffer; hydroxide; carbonate; bicarbonate; a combination of carbonate and hydroxide; or a combination of carbonate and bi carbonate.
Description
FIELD OF THE INVENTION

The present invention relates to compositions suitable for use in disinfecting or sterilizing instruments, exposed surfaces or spaces which may be infected with bacteria, fungi, viruses, fungal or bacterial spores, prions, and the like.


BACKGROUND

Any discussion of the prior art throughout the specification should in no way be considered as an admission that such prior art is widely known or forms part of common general knowledge in the field.


BACKGROUND OF THE INVENTION

“Sterilization” has been defined as the process of destroying all microorganisms, spores and their pathogenic products. A 6 log reduction in the amount of such pathogens is generally required to provide a suitable sterility assurance level. “Disinfection” is a similar process, the difference being that it results in a lesser degree of biocidal effect, particularly on bacterial spores. Disinfection is thus easier to achieve than sterilization.


Sterilants or disinfectants are usually liquids and can be applied to articles requiring disinfection or sterilization in a variety of ways. In recent years, the use gas or aerosol dispensing technologies to dispense sterilants or disinfectants has become widespread. Gas or aerosol processes are particularly attractive since they reduce the amount of liquid sterilant or disinfectant used. The primary benefit of using micro volumes of liquid is that rising steps can sometimes be eliminated and drying times are often significantly reduced compared to using say, soaking baths. This shortened cycle time reduces the turnaround time for any given instrument which in turn translates into a much smaller capital outlay is tied up in instruments.


Gas or aerosol processes also tend to be conducted in closed systems, which means that operator safety is also enhanced relative to conventional methods that expose workers to large volumes of open sterilant or disinfectant solutions.


Aerosol based approaches in which nebulisation takes place by ultrasonication of a bulk liquid are known and are a particularly good way to achieve high sterilization efficacies using micro volumes of sterilant.


In recent years there has been a marked increase in the number, variety and levels of resistance of micro-organisms which have been identified as particularly problematic in hospital and medical environments. The use of hydrogen peroxide or peroxyacetic acid as a disinfectant has become greatly preferred in that time. Prior to the 1990s these peroxides were considered too unstable and hazardous to be used.


Peroxyacetic acid is particularly effective against microorganisms. It is a very broad spectrum germicidal agent, effective against both gram negative and gram positive bacteria, fungi and yeasts and viruses under suitable conditions. It is also considered to be sporicidal. It is efficacious in low concentrations and it remains highly effective even in the presence of relatively high organic loads. The decomposition products of peroxyacetic acid, namely acetic acid, water and oxygen are also environmentally friendly.


Peroxyacetic acid is advantageous over hydrogen peroxide, since, unlike hydrogen peroxide it is not deactivated by microorganisms' catalase or peroxidase. There is also little or no habituation of microorganisms to peroxyacetic acid.


Aqueous peroxyacetic acid solutions are commercially available. Peroxyacetic acid typically exists in equilibrated aqueous mixtures of hydrogen peroxide and acetic acid as represented by the following equation:

H2O2+CH3CO2Hcustom characterCH3CO3H+H2O


One example of such a commercially available peroxyacetic acid solution is Proxitan from Solvay which contains approximately 5% peroxyacetic acid, 7.5% acetic acid and 24% H2O2. These amounts typify the ratios found in such equilibrated mixtures, namely peroxyacetic acid:acetic acid:hydrogen peroxide in a ratio of 1:1.5:5.


Peroxyacetic acid solutions are quite acidic and are highly corrosive. When using these in the field of sterilization it is usually necessary to add a buffering component to reduce pH to reduce corrosion and to produce a much more generally physiologically acceptable pHs. Phosphate buffers are typically used for this purpose.


It is an object of the present invention to overcome or ameliorate at least one of the disadvantages of the prior art, or to provide a useful alternative.


SUMMARY

According to a first aspect the invention provides an aqueous disinfectant solution comprising:

    • peroxyacetic acid; and
    • a surfactant.


Unless the context clearly requires otherwise, throughout the description and the claims, the words “comprise”, “comprising”, and the like are to be construed in an inclusive sense as opposed to an exclusive or exhaustive sense; that is to say, in the sense of “including, but not limited to”.


According to a second aspect, the invention provides an aqueous disinfectant solution comprising:

    • peroxyacetic acid;
    • a surfactant; and
    • a buffer to provide a pH in the range 5-8.


According to a third aspect, the invention provides an aqueous disinfectant solution comprising:

    • peroxyacetic acid;
    • hydrogen peroxide;
    • a surfactant; and
    • a buffer to provide a pH in the range 5-8.


According to a fourth aspect, the invention provides an enhanced aqueous disinfectant solution comprising:

    • peroxyacetic acid;
    • hydrogen peroxide;
    • acetic acid;
    • a surfactant; and
    • a buffer to provide a pH in the range 5-8.


Preferably the concentration of peroxyacetic acid is greater than 0.1 wt %, although in alternative embodiments is can be greater than 0.15 wt % or greater than 0.2 wt %. It is generally preferred if the amount of peroxyacetic acid is 0.10 to 0.30 wt %.


Preferably, where hydrogen peroxide is present, the ratio of hydrogen peroxide:peroxyacetic acid is 5:1 or greater, although in alternative embodiments the ratio of hydrogen peroxide:peroxyacetic acid is 10:1 or greater, 15:1 or greater; or even 30:1 or greater.


In one preferred embodiment, the surfactant is an amine oxide. Examples of suitable amine oxides include: cocamidopropylamine oxide (RCONH(CH2)3N(CH2)2→O) where R is a cocoalkyl group; dodecyldimethylamine oxide (C14H31N→O); ((CH2)13(CH2)2N→O); or ((CH2)12-18(CH2)2N→O).


In an alternative preferred embodiment, the surfactant is a non-ionic surfactant, such as Triton X-100, (polyethylene glycol p-(1,1,3,3-tetramethylbutyl)-phenyl ether) or Tween-80 (polyethlyene (20) sorbitan monooleate).


In an alternative preferred embodiment, the surfactant is a cationic surfactant. This includes quaternary ammonium compounds such as benzalkonium chloride or hexadecylpyridinium bromide.


In a further alternative preferred embodiment, the surfactant is a phosphate ester based anionic surfactant. Such compounds include polyoxyethylene alkyl ether phosphates, such as those sold by Croda under the trade name Monafax M1214 or Multitrope 1214; phosphate esters (mono- and/or diester of phosphoric acid with aliphatic alcohols of chain length C1-C22 and/or aliphatic diols and/or aliphatic polyols of chain length C2-C22) such as Hordaphos 1306 or Hordaphos MDGB from Clariant, which is a diester of phosphoric acid with butanol and ethylene glycol respectively; and Excellene T5 NF which is a blend of ethylhexylphosphate ester and alcohol ethoxylate phosphate ester potassium salts, available from Whewell chemical manufacturers.


Preferably, the buffer provides a pH in the range 6-7, most preferably between 5.5 and 6.5.


Preferably the solution is adjusted to provide a pH in the range 5-8 by a pH adjusting agent selected from the group consisting of a phosphate buffer; hydroxide; carbonate; bicarbonate; a combination of carbonate and hydroxide; or a combination of carbonate and bicarbonate.


Preferably the solution is adjusted by a carbonate buffer that comprises hydrogen carbonate anions and hydroxide anions or hydrogen carbonate anions and carbonate anions.


The disinfectant solution may also include a corrosion inhibitor, such as a benzotriazole or urea.


The disinfectant solution may, for preference include an antifoaming agent.


According to a fifth aspect the invention provides a method of disinfection of an article comprising contacting the article with an aqueous disinfectant solution according to the previous aspects.


Preferably the method is carried out in a temperature range of from 15-40° C., more preferably from 20-35° C. and most preferably at ambient temperature.


The time required is preferably that to achieve a resultant load on microorganisms that is acceptable for the intended use of the article. Put alternatively, the time required by the aqueous disinfectant of the present invention to achieve a 6 log reduction in microorganism load at room temperature is preferably less than 5 minutes, or even more preferably less than 4 minutes.


The present invention is applicable both to the disinfection or sterilization of instruments and articles placed in small disinfection chambers, biological safety cabinets, isolators, glove boxes, incubators, materials airlocks and the like. The invention is also applicable for disinfection or sterilization of food containers or the like and manufacturing machinery and is also applicable for the disinfection of very large spaces.







DESCRIPTION

Peroxyacetic acid is generated by the addition of acetic acid to a peroxidising agent such as hydrogen peroxide or a peroxy salt. The most common and inexpensive method used to generate peroxyacetic acid is to use a combination of acetic acid and aqueous hydrogen peroxide, in which case the peroxyacetic acid is in equilibrium with a number of other species as shown:

H2O2+CH3CO2Hcustom characterCH3CO3H+H2O


As mentioned, the native ratios found in such equilibrated mixtures typically provide peroxyacetic acid:acetic acid:hydrogen peroxide in a ratio of 1:1.5:5. That is, the ratio of the active disinfectant species, peroxyacetic acid and hydrogen peroxide, in such systems is typically around 1:5.


Peroxyacetic acid can also be generated from solid peroxide precursors such as sodium perborate, sodium percarbonate, carbamide peroxide (urea peroxide) or potassium fluoride peroxosolvate in combination with acetic acid to generate peroxyacetic acid. Although slightly more expensive than the acetic acid/hydrogen peroxide approach, these sources of peroxyacetic acid are seen as desirable since they do not include large amounts of hydrogen peroxide, which is regarded as a less potent biocide than peroxyacetic acid.


In some cases, solid peroxide precursors can be used in combination with hydrogen peroxide/acetic acid systems.


Regardless of how it is produced, the pH of peroxyacetic acid is very low, around 2.8. Such a low pH means that it is highly corrosive. Such a low pH is also fundamentally incompatible with systems that are to be used in intimate contact with patients. This means that in order to be used in sensitive medical instruments, it is generally desired that pH is controlled by way of a pH adjusting agent such as a basic agent or buffer. An ideal pH range that will result in minimal corrosion with maximum compatibility for human contact is between about pH 5.5 and pH 7, more particularly between about pH 5.5 and pH 6.5.


Phosphate buffers can be used to control the pH of peroxyacetic acid systems. However, other common bases, such as hydroxide or carbonate, have also been used to adjust the pH of peroxyacetic acid.


In buffers comprising hydrogen carbonate anions and hydroxide anions, the molar ratio of hydrogen carbonate:hydroxide is about 0.9:1 to about 1.1:1, more preferably about 1:1. In the preferred sodium salt form, the w:w ratio of hydrogen carbonate:hydroxide is from about 2.5:1 to 2:1, more preferably about 2.3:1, or the ratio of carbonate:hydroxide is from about 2.9:1 to 2.4:1, more preferably about 2.65:1.


In buffers comprising hydrogen carbonate anions and carbonate anions, the molar ratio of hydrogen carbonate:carbonate is about 0.15:1 to about 0.25:1, more preferably about 0.18:1. In the preferred sodium salt form, the w:w ratio of hydrogen carbonate:carbonate is from about 0.1:1 to about 0.2:1, more preferably about 0.14:1.


Although the term “buffer” is used, it is important to understand that the components need not form a true buffer system—The important consideration is the adjustment of the peroxyacetic acid to a pH of between 6.3 and 6.8 in the final working solution. It has been found that the buffer is most advantageously added in an amount to keep the pH between 5.5 and pH 7 and if possible around 6-6.5.


Surprisingly, the present applicant has found that the biocidal activity of peroxyacetic acid, even against spores, is potentiated by the presence of a surfactant. This is the case even at very low concentrations. This effect is also observed to take place in solutions that are adjusted to physiological pH's.


It is surprising that the presence of a surfactant can also increase the biocidal efficacy of such disinfectant solutions.


The effects of adding a wide range of surfactants to buffered peracetic acid were tested against B. subtilis.


Amine oxide surfactants tested included cocamidopropylamine oxide (RCONH(CH2)3N(CH2)2→O) where R is a cocoalkyl group; dodecyldimethylamine oxide (C14H31N→O); ((CH2)13(CH2)2N→O); or ((CH2)12-18(CH2)2N→O).


Non-ionic surfactants tested included Triton X-100, (polyethylene glycol p-(1,1,3,3-tetramethylbutyl)-phenyl ether) or Tween-80 (polyethlyene (20) sorbitan monooleate).


Cationic surfactants tested included quaternary ammonium compounds such as benzalkonium chloride or hexadecylpyridinium bromide.


Phosphate ester based anionic surfactants tested included polyoxyethylene alkyl ether phosphates, such as those sold by Croda under the trade name Monafax M1214 or Multitrope 1214; phosphate esters (mono- and/or diester of phosphoric acid with aliphatic alcohols of chain length C1-C22 and/or aliphatic diols and/or aliphatic polyols of chain length C2-C22) such as Hordaphos 1306 or Hordaphos MDGB from Clariant, which is a diester of phosphoric acid with butanol and ethylene glycol respectively; and Excellene T5 NF which is a blend of ethylhexylphosphate ester and alcohol ethoxylate phosphate ester potassium salts, available from Whewell chemical manufacturers.


The surfactants were mainly, but not in every case, tested in combination with a phosphate buffer. The exact concentrations of peracetic acid, pH, and initial populations of B. subtilis were not standardised across the whole range of surfactants tested, so it is not possible to state quantified relative efficacies. However, each surfactant was tested against an appropriate control system (differing only in the absence of the surfactant) so it is possible to conclusively state that in every case an increased efficacy was noted when a surfactant was added. The results of the study were not optimised.


A particularly preferred class of surfactants which gave improved performance were phosphate based anionic surfactants, particularly polyoxyethylene alkyl ether phosphates, such as those sold by Croda under the trade name Monafax M1214 or Multitrope 1214. The results for this class of compound were investigated further and are shown in the examples below.


EXAMPLES

Test Method


The test method employed and described below is typical of all the test methodology used in the present invention to determine biological loads.


The working solution was tested against spores of the appropriate organism at room temperature. Media was TSB+1% Na-thiosulfate+10% Tween 80+1 ml Catalase.


The test method involved taking a 9 ml sample and adding 1 ml culture (with 5% horse serum) and then incubating at the desired temperature if necessary. 1 ml of the incubated sample was then removed at each time point and neutralized with 9 ml neutralizer. The resultant was diluted with saline, plated out and the plates incubated at 37° C. for 48 hr. The results were then able to be expressed in terms of a log reduction. As is usual in the art, a log reduction is a log10 reduction. A 4 log reduction means 1 in 104 organisms survived, 5 log reduction corresponds to 1 in 105 organisms surviving and so on. High level disinfection is widely defined and understood as a reduction of 6 log or greater, than is, no more than 1 in 1,000,000 microorganisms survives the process.


Results


Table 1 shows the biocidal effect against Bacillus subtilis spores achieved by adding a surfactant to a pH controlled aqueous peracetic acid solution (0.2%) that contained also acetic acid and hydrogen peroxide. It can be seen that the addition of the surfactant had only a very minimal effect upon the pH of the solution, only changing it by around 0.0 to 0.5 pH units.


However, the effect upon the biocidal efficacy was quite dramatic. The addition of just 0.25% surfactant led to between an increase in biocidal efficacy of between 1 and 1.6 log10, that is, the surfactant increased the efficacy of peracetic acid by between 10 and about 40-fold.


Table 2 illustrates similar experiments to those in table 1, with the exception that the wt % of peroxy acetic acid was reduced to 0.1%. The surfactant at 0.30% did not exert any adverse effect upon the pH of the mixture.


However, the effect upon the biocidal efficacy was still quite significant. The addition of 0.30% surfactant led to between an increase in biocidal efficacy of between 0.4 and 0.9 log10, that is, the surfactant increased the efficacy of peracetic acid by between 3 and about 8-fold.


Table 3 shows the biocidal effect against Candida albicans spores obtained by adding a surfactant to a pH controlled aqueous peracetic acid solution (0.05%) that contained also acetic acid and hydrogen peroxide. It can be seen that the addition of the surfactant had only a very minimal effect upon the pH of the solution, changing it from around 0.0 to 0.5 pH units.


Again, the effect upon the biocidal efficacy was quite dramatic. The addition of just 0.23% surfactant led to between an increase in biocidal efficacy of between 0.7 and 1.6 log10, that is, the surfactant increased the efficacy of peracetic acid by between 5 and about 40-fold.


Table 4 shows the fungicidal effect against Aspergillus niger of adding a surfactant to a pH controlled aqueous peracetic acid solution (0.2%) that contained also acetic acid and hydrogen peroxide. It can be seen that the addition of the surfactant had only a very minimal effect upon the pH of the solution.


However the effect upon the fungicidal efficacy was quite dramatic. The addition of just 0.30% surfactant led to between an increase in biocidal efficacy of between 0.5 and 0.9 log10, that is, the surfactant increased the efficacy of peracetic acid by between 3 and about 8-fold.


In summary, a surprising increase in the efficacy of peroxy acetic acid was achieved by the addition of a surfactant. Surfactants are well known not to have any significant biocidal activity in their own right.









TABLE 1







Sporicidal efficacy of biocides on the base of peroxyacetic acid against



Bacillus subtilis spores (ATCC 19659) at room temperature (suspension test)












pH of working solution

Log10 Reduction














Compo-

Wt % of
without
with 0.25%
Exposure
without
with 0.25%


sition
Ingredient
ingredient
Surfactant
Surfactant*
time (min)
Surfactant
Surfactant*

















I
peroxyacetic acid
0.2
6.56
6.51
3
4.7
5.7



acetic acid
0.3








H2O2
1








phosphate buffer








II
peroxyacetic acid
0.2
6.57
6.53
3
5.5
5.6



acetic acid
0.3








H2O2
1








basic buffer (NaOH)








III
peroxyacetic acid
0.2
6.52
6.52
3
5.0
6.2



acetic acid
0.3








H2O2
1








carbonate buffer I









(NaHCO3 + NaOH)








IV
peroxyacetic acid
0.2
6.52
6.50
3
4.7
6.2



acetic acid
0.3








H2O2
1








carbonate buffer II









(Na2CO3 + NaHCO3)





*Surfactant was Monafax M1214 which also contained 0.01% Antifoaming component AF 86/013 (from Basildon Chemical Company Ltd)













TABLE 2







Sporicidal efficacy of biocides on the base of peroxyacetic acid against



Bacillus subtilis spores (ATCC 19659) at room temperature (suspension test)












pH of working solution

Log10 Reduction














Compo-

Wt % of
without
with 0.30%
Exposure
without
with 0.30%


sition
Ingredient
ingredient
Surfactant
Surfactant*
time (min)
Surfactant
Surfactant*

















I
peroxyacetic acid
0.1
6.40
6.39
5
1.4
1.8



acetic acid
0.15








H2O2
0.05








phosphate buffer








II
peroxyacetic acid
0.1
6.45
6.41
5
1.1
1.7



acetic acid
0.15








H2O2
0.05








basic buffer (NaOH)








III
peroxyacetic acid
0.1
6.41
6.41
5
1.5
2.4



acetic acid
0.15








H2O2
0.05








carbonate buffer I









(NaHCO3 + NaOH)








IV
peroxyacetic acid
0.1
6.44
6.39
5
1.5
2.4



acetic acid
0.15








H2O2
0.05








carbonate buffer II









(Na2CO3 + NaHCO3)





*Surfactant was Monafax M1214 which also contained 0.01% Antifoaming component AF 86/013 (from Basildon Chemical Company Ltd)













TABLE 3







Biocidal efficacy of biocides on the base of peroxyacetic acid against



Candida albicans (ATCC 10231) at room temperature (suspension test)












pH of working solution

Log10 Reduction














Compo-

Wt % of
without
with 0.23%
Exposure
without
with 0.23%


sition
Ingredient
ingredient
Surfactant
Surfactant*
time (min)
Surfactant
Surfactant*

















I
peroxyacetic acid
0.05
6.60
6.58
0.5
5.3
6.9



acetic acid
0.075








H2O2
0.025








phosphate buffer








II
peroxyacetic acid
0.05
6.60
6.56
0.5
5.4
6.9



acetic acid
0.075








H2O2
0.025








basic buffer (NaOH)








III
peroxyacetic acid
0.05
6.53
6.55
0.5
5.8
6.9



acetic acid
0.075








H2O2
0.025








carbonate buffer I









(NaHCO3 + NaOH)








IV
peroxyacetic acid
0.05
6.52
6.55
0.5
6.2
6.9



acetic acid
0.075








H2O2
0.025








carbonate buffer II









(Na2CO3 + NaHCO3)





*Surfactant was Monafax M1214 which also contained 0.01% Antifoaming component AF 86/013 (from Basildon Chemical Company Ltd)













TABLE 4







Fungicidal efficacy of biocides on the base of peroxyacetic acid against



Aspergillus niger (ATCC 16404) at room temperature (suspension test)












pH of working solution

Log10 Reduction














Compo-

Wt % of
without
with 0.30%
Exposure
without
with 0.30%


sition
Ingredient
ingredient
Surfactant
Surfactant*
time (min)
Surfactant
Surfactant*

















I
peroxyacetic acid
0.1
6.16
6.16
2
1.0
1.9



acetic acid
0.15








H2O2
0.05








phosphate buffer








II
peroxyacetic acid
0.1
6.25
6.13
2
0.9
1.4



acetic acid
0.15








H2O2
0.05








basic buffer (NaOH)








III
peroxyacetic acid
0.1
6.13
6.21
2
1.2
2.1



acetic acid
0.15








H2O2
0.05








carbonate buffer I









(NaHCO3 + NaOH)








IV
peroxyacetic acid
0.1
6.24
6.18
2
1.9
2.6



acetic acid
0.15








H2O2
0.05








carbonate buffer II









(Na2CO3 + NaHCO3)





*Surfactant was Monafax M1214 which also contained 0.01% Antifoaming component AF 86/013 (from Basildon Chemical Company Ltd)





Claims
  • 1. An aqueous disinfectant solution comprising: 0.10 to 0.30 wt % peroxyacetic acid;hydrogen peroxide;acetic acid;a surfactant; anda buffer to provide a pH in the range 5-8;wherein the buffer is a combination of carbonate and hydroxide; or a combination of carbonate and bicarbonate.
  • 2. An aqueous disinfectant solution according to claim 1 wherein the solution is adjusted to provide a pH in the range 5.5-7.
  • 3. An aqueous disinfectant solution according to claim 1 wherein the solution is adjusted to provide a pH in the range 6-7.
  • 4. An aqueous disinfectant solution according to claim 1 wherein the solution is adjusted to provide a pH in the range 5.5-6.5.
  • 5. An aqueous disinfectant solution according to claim 1 wherein the concentration of peroxyacetic acid is greater than 0.2 wt %.
  • 6. An aqueous disinfectant solution according to claim 1 wherein the ratio of hydrogen peroxide:peroxyacetic acid is 5:1 or greater.
  • 7. An aqueous disinfectant solution according to claim 1 wherein the ratio of hydrogen peroxide:peroxyacetic acid is 10:1 or greater.
  • 8. An aqueous disinfectant solution according to claim 1 wherein the ratio of hydrogen peroxide:peroxyacetic acid is 15:1 or greater.
  • 9. An aqueous disinfectant solution according to claim 1 wherein the ratio of hydrogen peroxide:peroxyacetic acid is 30:1 or greater.
  • 10. An aqueous disinfectant solution according to claim 1 wherein the surfactant is a non-ionic surfactant.
  • 11. An aqueous disinfectant solution according to claim 1 wherein the surfactant is selected from the group consisting of polyoxyethylene alkyl ether phosphates, (polyethylene glycol p-(1,1,3,3-tetramethylbutyl)-phenyl ether) and cocoamidopropylamino oxide.
  • 12. An aqueous disinfectant solution according to claim 1 wherein the surfactant is a polyoxyethylene alkyl ether phosphate.
  • 13. An aqueous disinfectant solution according to claim 1 wherein the surfactant is a phosphate ester based anionic surfactant.
  • 14. An aqueous disinfectant solution according to claim 1 including a corrosion inhibitor.
  • 15. An aqueous disinfectant solution according to claim 14 wherein the corrosion inhibitor is a benzotriazole.
  • 16. An aqueous disinfectant solution according to claim 1 including an antifoaming agent.
  • 17. A method of disinfection of an article comprising contacting an article with an aqueous disinfectant solution according to claim 1.
  • 18. A method according to claim 17 when carried out in a temperature range of 15-40° C.
  • 19. A method according to claim 17 when carried out in a temperature range of 20-35° C.
  • 20. A method according to claim 17 when carried out at ambient temperature.
Priority Claims (1)
Number Date Country Kind
2012905482 Dec 2012 AU national
REFERENCE TO CORRESPONDING APPLICATIONS

The present application is a continuation of U.S. application Ser. No. 14/651,595, filed Sep. 11, 2015, which is a U.S. National Stage Application of International Application No. PCT/AU2013/001462, filed Dec. 13, 2013, and claims priority to Australian Patent Application No. 2012905482, filed Dec. 14, 2012, the entire contents of which are incorporated herein by reference.

US Referenced Citations (60)
Number Name Date Kind
1535529 Hopkins Apr 1925 A
2454541 Bock et al. Nov 1948 A
3341418 Moses et al. Sep 1967 A
3488287 Seglin et al. Jan 1970 A
3554289 Webb Jan 1971 A
3708431 Prussin Jan 1973 A
4051059 Bowing et al. Sep 1977 A
4522738 Magid et al. Jun 1985 A
4743447 Le Rouzic et al. May 1988 A
5154917 Ibraham et al. Oct 1992 A
5168048 Quax Dec 1992 A
5269959 Schreibman Dec 1993 A
5314687 Oakes et al. May 1994 A
5344652 Hall, II et al. Sep 1994 A
5480575 Altieri et al. Jan 1996 A
5489706 Revell Feb 1996 A
5545374 French et al. Aug 1996 A
5643862 Jones et al. Jul 1997 A
5656302 Cosentino et al. Aug 1997 A
5804546 Hall Sep 1998 A
5900256 Scoville, Jr. et al. May 1999 A
6080712 Revell et al. Jun 2000 A
6168808 Hamon Godin et al. Jan 2001 B1
6511546 Bivins et al. Jan 2003 B1
6514509 Tabasso Feb 2003 B2
6583103 Klinkhammer Jun 2003 B1
6589565 Richter et al. Jul 2003 B1
6699828 De Buzzaccarini et al. Mar 2004 B1
6726936 Asano et al. Apr 2004 B1
6767874 Gonzalez Jul 2004 B2
7056536 Richter et al. Jun 2006 B2
7189385 Montgomery Mar 2007 B2
7205000 Einziger Apr 2007 B2
7271137 Tucker et al. Sep 2007 B2
8012411 Betty et al. Sep 2011 B1
8377421 Giniger Feb 2013 B2
8546120 Dicosimo et al. Oct 2013 B2
8969283 Kaiser et al. Mar 2015 B2
20030129254 Yasuhara et al. Jul 2003 A1
20050036904 Kajander et al. Feb 2005 A1
20050282722 McReynolds et al. Dec 2005 A1
20060198797 Giniger Sep 2006 A1
20060204453 Giniger Sep 2006 A1
20060229226 Giniger et al. Oct 2006 A1
20070161243 Mellies Jul 2007 A1
20070166398 Bobbert Jul 2007 A1
20070185000 Zushi et al. Aug 2007 A1
20070258915 Kielbania Nov 2007 A1
20090061017 Pedersen et al. Mar 2009 A1
20090285871 Cunningham et al. Nov 2009 A1
20090324508 Bobbert Dec 2009 A1
20100068295 Bobbert Mar 2010 A1
20100196503 Heisig et al. Aug 2010 A1
20100196505 Kaiser et al. Aug 2010 A1
20100227000 Ames et al. Sep 2010 A1
20100294987 Kater Nov 2010 A1
20110081693 Dicosimo et al. Apr 2011 A1
20110085991 Giniger Apr 2011 A1
20120171301 Koenig et al. Jul 2012 A1
20120219636 Li et al. Aug 2012 A1
Foreign Referenced Citations (43)
Number Date Country
701927 Jun 1995 AU
102090393 Jun 2011 CN
102964285 Mar 2013 CN
0745665 Dec 1996 EP
0752466 Jan 1997 EP
0733097 Oct 1998 EP
1123655 Aug 2001 EP
1829558 Sep 2007 EP
1293215 Nov 2007 EP
2436265 Apr 2012 EP
1987121 Mar 2013 EP
2293157 Mar 1996 GB
S58191800 Nov 1983 JP
S5966499 Apr 1984 JP
2003-292996 Oct 2003 JP
2004-285154 Oct 2004 JP
2011-121912 Jun 2011 JP
8808667 Nov 1988 WO
9116435 Oct 1991 WO
9414321 Jul 1994 WO
9516023 Jun 1995 WO
1996019558 Jun 1996 WO
9811777 Mar 1998 WO
9833880 Aug 1998 WO
9837762 Sep 1998 WO
9846715 Oct 1998 WO
2000078153 Dec 2000 WO
2005055963 Jun 2005 WO
2006016145 Feb 2006 WO
2006016145 Feb 2006 WO
2006089139 Aug 2006 WO
2007051957 May 2007 WO
2007080187 Jul 2007 WO
2008033206 Mar 2008 WO
2008140974 Nov 2008 WO
2009027857 Mar 2009 WO
2009064856 May 2009 WO
2009118714 Oct 2009 WO
2010102188 Sep 2010 WO
2011008225 Jan 2011 WO
2012021520 Feb 2012 WO
2012128734 Sep 2012 WO
2013096814 Jun 2013 WO
Non-Patent Literature Citations (12)
Entry
The Merck Index, Encyclopedia of Chemicals, Drugs and Biologicals, 6601. Octoxynol, Windholz et al., Eds., Tenth Edition, Copyright 1983, 4 pages.
TRITON X-100, Product Information Sheet, Sigma-Aldrich, Apr. 21, 1999, 2 pages.
Silocone Antifoams, Antifoam 86/103, Basildon Chemicals, http://www.baschem.co.uk/products/product-type/silicone-antifoams/antifoam-86013/[Sep. 12, 2013 3:52:37 PM], 2 pages.
English Abstract of KR1020080098157A with EPO Machine Translation, 13 pages, Published Nov. 7, 2008.
Multitrope (aka Monafax) 1214 MSDS; downloaded Aug. 27, 2015, 1 page.
Genapol EP 2564 MSDS Product Data Sheet; Clariant; downloaded Aug. 27, 2015, 2 pages.
Triton X-100 Surfactant, Product Information Sheet, The Dow Chemical Company, Form No. 119-01882-1207, 2 pages, Dated Apr. 18, 2013.
International Search Report dated Feb. 28, 2014, in PCT/AU2013/001462, 5 pages.
Written Opinion dated Feb. 28, 2014, in PCT/AU2013/001462, 10 pages.
Chemical Abstracts, vol. 101, No. 4, Jul. 23, 1984, p. 102, No. 25407e, Columbus, Ohio US; Kasei K.K.: “Sprayable Foaming Cleaning Compositions” & Jpn. Kokai Tokkyo Koha JP 58,191,800/83,191,8007, 1 page.
“pH Curves and Indicators”, 2003, Nigel Saunders N-ch4-05, 3 pages.
Extended European Search Report dated Jul. 19, 2016, in European Patent Application No. 13862176.8, 8 pages.
Related Publications (1)
Number Date Country
20170368217 A1 Dec 2017 US
Continuations (1)
Number Date Country
Parent 14651595 US
Child 15699336 US