Non-corrosive sterilant composition

[0001] The present invention relates to compositions which can be used to safely and effectively disinfect surfaces and articles against microbiological forms. The compositions are easily handled, tend to be non-corrosive to the types of polymeric, elastomeric and metal surfaces found in medical instruments, are relatively shelf-stable, and may be prepared quickly and easily by simply blending component solutions.

[0002] The importance of the sterilization of medical instruments and implants has been understood for more than two centuries. The need for sterilization has become even more important recently with the appearance of strains of microbiological forms which are resistant to conventional microbiocides such as antibiotics. It has become very important to sterilize medical devices to kill or remove the more resistant strains of microbiological forms before they infect a patient. Additionally, the sterilants must be generally effective against microorganisms covering a wide range of classes and species, with U.S. Government standards requiring efficacy against both bacteria and spores.

[0003] Sterilization of medical devices has been performed for many years by immersing the medical devices in an atmosphere which is antagonistic to the survival of the microbiological forms. Among the environments which have been used to attempt to sterilize medical instruments include, but is not limited to, steam, alcohols, ethylene oxide, formaldehyde, gluteraldehyde, hydrogen peroxide, and peracids. Each of these materials has its benefits and limitations. Ethylene oxide tends to be very effective against a wide range of microorganisms, but it is highly flammable and is generally used in a gas phase which may require more stringent environmental restraints than would a liquid. Alcohols are similarly flammable and must be used in very high concentrations. Steam has a more limited utility, having to be used in a controlled and enclosed environment, requiring the use of large amounts of energy to vaporize the water, and requiring prolonged exposure periods to assure extended high temperature contact of the steam with the organisms. Hydrogen peroxide has limited applicability because it is unstable and not as strong as some other sterilants. The peracids have become more favorably looked upon, but they tend to be corrosive (being an oxidizing acid) and are not shelf stable.

[0004] U.S. Pat. No. 5,508,046 describes a stable, anticorrosive peracetic acid/peroxide sterilant comprising a concentrate including peracetic acid, acetic acid, hydrogen peroxide (in a ratio of 1:1 to 11:1 total acid/hydroxide), and 0.001 to 200 parts per million of stabilizers such as phosphonic acids and sodium pyrophosphates. The concentrates are diluted about 20 to 40 times so that the maximum concentration of stabilizer in the use solution would be about 10 parts per million. The stabilizers are described as acting as chelating agents by removing trace metals which accelerate the decomposition of the peroxides.

[0005] U.S. Pat. No. 5,616,616 describes a room temperature sterilant particularly useful with hard tap water comprising an ester of formic acid, an oxidizer (such as hydrogen peroxide or urea hydrogen peroxide), performic acid and water. The use of corrosion inhibitors (such as benzotriazoles, azimidobenzene, and benzene amide) and stabilizers (unnamed) is also generally suggested.

[0006] U.S. Pat. No. 5,077,008 describes a method of removing microbial contamination and a solution for use with that method. The solution comprises a combination of five ingredients in water: 1) a strong oxidant (including, for example, organic peroxides, peracids, an chloride releasing compounds, with peracetic acid in a concentration of 0.005 to 1.0% being preferred), 2) a copper and brass corrosion inhibitor (e.g., triazoles, azoles and benzoates), 3) a buffering agent (including, for example, phosphate), 4) at least one anti-corrosive agent which inhibits corrosion in at least aluminum, carbon steel and stainless steel selected from the group consisting of chromates and dichromates, borates, phosphates, molybdates, vanadates and tungstates, and 5) a wetting agent. A sequestering agent may be used to prevent the phosphates from causing precipitation in hard water.

[0007] U.S. Pat. Nos. 4,892,706 and 4,731,22 describe automated liquid sterilization systems having a plurality of modules which store the sterilant solution and the rinse solution. U.S. Pat. No. 5,037,623 describes a sterilant concentrate injection system which is a spill resistant, vented ampule system for use with sterilization systems.

[0008] Medical devices now include many polymeric components for reasons of material costs and ease of manufacture. Many of the systems and solutions designed for the sterilization of metal medical devices are not necessarily suitable for use with polymeric components, and may cause corrosion of the polymeric materials. It is therefore necessary to formulate sterilization compositions which are compatible with both metal and polymeric components of the medical devices. It is also always desirable to provide sterilization systems with fewer components in the composition, where the sterilization solutions do not significantly sacrifice microbiocidal activity and do not corrode the materials used in medical devices.

SUMMARY OF THE INVENTION

[0009] A non-corrosive, liquid, aqueous sterilant composition (as a concentrate or ready-to-use solution), which may be provided in two parts which are mixed prior to application, may comprise a peracid (in an equilibrium solution with an underlying carboxylic acid or mixtures of alkyl carboxylic acids and peroxide), inorganic buffering agent, and water. It has been found that the use of this simplified system provides excellent sterilization ability, even in the absence of additional components which have been thought to be desirable for sterilants used on metal parts (e.g., copper and brass corrosion inhibitors, chelating agents, anti-corrosive agents) which have been found to not be necessary. The presence of these additional materials at least complicates disposal of the spent solutions and could complicate compatibility of the sterilant solutions with some polymeric materials, especially where organic materials are used as the additional components, which organic materials may interact with, dissolve or solubilize in the polymeric materials.

[0010] The concentration of the components has shown itself to be important in providing non-corrosive effects towards a wide variety of structural materials in medical devices and yet providing effective sterilization effects against spores and bacteria, including tuberculosis bacteria in an acceptable amount of time.

[0011] An aqueous sterilant use solution according to the present invention may comprise a solution having a pH of from 5.0 to 7.0 comprising from 100 to 10,000 parts per million of a peroxy acid and 30 to 5000 parts per million of buffering agent, preferably without any organic anticorrosive agents. The aqueous sterilant solution may, for example, comprise from 100 to 10,000 parts per million of a peroxy acid, 30 to 5000 parts per million of buffering agent and a catalytically effective amount of a catalyst for peroxygenation of a carboxylic acid by hydrogen peroxide.

[0012] The aqueous sterilant solution may consist essentially of a solution having a pH of from 5.0 to 7.0 comprising from 100 to 10,000 parts per million of a peroxy acid, 30 to 5000 parts per million of buffering agent and a catalytically effective amount of a catalyst for peroxygenation of a carboxylic acid by hydrogen peroxide.

[0013] The method may particularly comprise mixing a first and a second solution to form a sterilizing solution comprising a peroxy acid, said first solution comprising a carboxylic acid, hydrogen peroxide and water, and said second solution comprising a buffering agent for pH between about 5 and 7, said sterilizing solution comprising at least 100 parts per million of peroxy acid at a pH of 5 to 7, immersing said article in said sterilizing solution for at least 5 minutes to sterilize said article, said first solution and second solution being free of organic anti-corrosion agents for brass and/or copper, and said article comprising a medical article having parts made of at least two materials selected from the group consisting of metals, polymers and rubbers.

DETAILED DESCRIPTION OF THE INVENTION

[0014] The aqueous sterilant compositions of the present invention comprise a peracid, water-soluble peroxide source, and carboxylic acid in a buffered solution at pH levels between about 5.0 and 7.0. The use of an inorganic buffering agent also enables the use of slightly water-soluble, higher molecular weight carboxylic acids in the formation of peroxy acids with the peroxide source thereby reducing the amount of deposits from fatty acid residue in the solution. Phosphate buffers are effective dispersants and suspending agents for these fatty acid residues.

[0015] The peroxy acid useful in the practice of the present invention may comprise any organic peroxy acid. These acids are well known in the art to be formed from any carboxylic acid containing compound. Normally they are prepared from carboxylic acids of the formula:

CH3—(CH2)n-COOH

[0016] wherein n is 0 to 18, preferably 0 to 12 and more preferably 0 to 10, with the corresponding peroxy acid having the formula:

CH3—(CH2)n-CO3H

[0017] wherein n is as defined above. The alkyl moiety on the acid, CH3—(CH2)n- may be replaced with hydrogen or any, preferably low molecular weight, organic group so that the acid and the resulting peroxy acid may be represented by: R—CO2H and R—CO3H, respectively. The molecular weight of R could be 1, but preferably should be between 15 and 155.

[0018] Carboxylic acids which are generally useful in the invenetion are those which comprise percarboxylic acids. Percarboxylic acids generally have the formula R(Co3Hn), where R is an alkyl, arylaklyl, cycloalkyl, aromatic or heterocyclic group, and N is 1, 2, or 3 and named by prefixing the parent acid with peroxy.

[0019] The peracid normally exists in an equilibrium state with the original or fundamental acid and the peroxide source, usually hydrogen peroxide. Typical peracids include peracids of C1 to C12 carboxylic acids such as formic acid, acetic acid, propanoic acid, butanoic acid, pentanoic acid, hexanoic acid, heptanoic acid, octanoic acid, nonanoic acid, decanoic acid, undecanoic acid, dodecanoic acid, and the like. The term carboxylic acids as used in the practice of the present invention, unless otherwise limited, also includes mono- and di-hydroxycarboxylic acids such as glycolic acid, lactic acid and citric acid. An example of di-hydroxycarboxylic acid or di-hydroxy is tartaric acid, and also fumaric acid, which is an unsaturated di-hydroxycarboxylic acid. Diacids such as alpha-omega-dicarboxylicpropanoic acid, succinic acid, glutaric acid, adipic acid, and the like may also be used to form di-peracids. Peroxycarboxylic acids may also be present and included within the solutions of the present invention. Mixtures and combinations of the peracids may also be used in the systems of the invention, as well as other addenda as generally described herein.

[0020] The peroxide source is preferably an aqueous solution of hydrogen peroxide, but may also include such alternative peroxide sources as solutions of sodium peroxide, calcium peroxide, alkali salts of percarbonate and persulfate, and even organic peroxides such as dicumyl peroxide, dialkyl peroxides, urea peroxide, and the like, forming the basis of the solution of the hydrogen peroxide. The inorganic peroxides are preferred as the source of the solution of the hydrogen peroxide. The ratio of the peroxy acid to the hydrogen peroxide can also significantly influence the efficacy of the solutions of the invention, with higher ratios of the peroxy acid to the hydrogen peroxide preferred. For example, its is more desirable to have a ratio of at least 2:1 or 3:1 (peroxy acid to hydrogen peroxide), and more desirable to have higher ratios of at least 4:1, at least 5:1 or at least 8:1 or more (peroxy acid to hydrogen peroxide).

[0021] The buffering agent is a compound, again preferably an inorganic compound which will maintain a buffered pH level in the solution of the composition between 5.0 and 7.0. Buffering agents include, but are not limited to phosphates, borates, lactates, acetates, citrates, vanadates, tungstates, and combinations thereof, particularly alkali metal or alkaline metal salts of these agents. The use of phosphates exclusively or at least primarily (e.g., at least 50%, at least 65%, at least 75%, or at least 90 or 95% by weight of the buffering agents) is particularly useful. Trisodium phosphate has been found to be particularly desirable because of its ability to maintain the acid residues of the peroxy acids in solution where they will not form film in the solution which can be picked up by any sterilization apparatus or medical device which is being sterilized. It is interesting to note that phosphates have been generally taught to be avoided in sterilization solutions where hard water may be contacted because of the potential for calcium precipitation, yet in the present invention, the presence of phosphates reduces the formation of organic residue film on the surface of the solution. The buffering agent alone, even when a phosphate or especially when a phosphate and particularly trisodium phosphate, has been found to reduce corrosion by the solution on all surfaces. The use of phosphate(s) alone, in the absence of copper and brass corrosion inhibitors has been found to be an effective sterilant, and provide non-corrosive activity against a wide range of structural materials, including, but not limited to rubbers, plastics and metals, such as stainless steel, aluminum, polypropylene, teflon, acrylonitriletstyrenetbutadiene, polyolefins, vinyl resins (e.g., polyvinyl chloride, polyvinylbutyral), silicone resins and rubbers, and polyurethanes, and provide second tier protection for brass and copper. Although the peracids work more efficiently in their microbiocidal activity at highly acidic pH levels (below 4.0), those acidic levels are much more corrosive. The use of a buffering system which maintains the pH above 5.0 and preferably between about 5.0 and 7.0 still provides a microbiocidal activity at levels which meet all international standards, using anywhere from 150 to 10,000 parts per million peracid.

[0022] The sterilant can be used as a manual system or be used in an automated system. The sterilant can be provided as a one-part or preferably two part concentrate, with the peracid in one solution and the buffer in the second solution. For example, in a two-part system, a peracid concentrate may be formed having 0.01% to 1% by weight peracid (e.g., peracetic acid), 0.003% to 1% by weight ppm hydrogen peroxide, 0.01% to 1% by weight acid (e.g., acetic acid), and the buffer solution may comprise, for example, from 0.5 to 75,000 ppm buffering agent (e.g., anhydrous trisodium phosphate) in water. Mixtures of these types of addenda, including the buffering agents and peracids, are clearly useful in the practice of the present invention. It is preferred that the concentrates have active ingredient contents at the higher levels of these ranges such as 0.1% to 15% by weight peracid, 5% to 80% by weight peroxide, 5% to 80% by weight acid and 0.1% to 15% by weight buffering agents. The diluted to use solution would preferably contain sufficient actives to provide 0.01% to 1.0% by weight peracid at a pH between about 5.0 and 7.0. The use solution need not contain any effective amount of many of the additives which prior art systems have required for non-corrosive effects (such as the organic anti-corrosive agents such as the triazines, benzotriazoles, azoles and benzoates), and yet provide a wider disclosed range of non-corrosivity against the many available surfaces of medical devices. The use solutions of the present invention may comprise a simplest solution comprising peracid (along with the acid and peroxide in equilibrium), buffering agent in an amount to provide a pH of from about 5.0 to 7.0, and water (preferably deionized water). This solution may be modified by the addition of individual agents such as chelating agents, surfactants (also referred to in the literature for sterilant compositions as wetting agents), and anti-corrosion agents. A typical concentrate solution which may be diluted to a use solution might comprise, 0.1% to 15% by weight peracid, 0.1% to 15% by weight buffering agent[, with the remainder as water and other addenda as generally described herein (e.g., from 99.6 to 78% by weight water). These and other aspects of the invention will be further described by reference to the following, non-limiting examples.

[0023] These data show that a preferred range for the concentration of peroxide in the solution (particularly as evidenced by hydrogen peroxide) less than 150 ppm, preferably less than 100 up to 80,000 ppm, still more preferably less than 100, less than 75 and less than 50 ppm. In the examples, POAA represents peroxyacetic acid, AA represents acetic acid, POOA represents peroxyoctanoic acid, and Oct. Acid represents octanoic acid. Dequest™ are commercially available materials which may be used in the solutions of the present invention. Dequest™ 2000 comprises aminotri(methylene-phosphonic acid), Dequest™ 2010 comprises 1-hydroxyethylidene-1,1-diphosphonic acid, and Dequest™ 2006 comprises aminotri(methylene-phosphonic acid) pentasodium salt. Dequest acts as a chelator for heavy metals. The data also shows that sporicidal activity of compositions with higher molecular weight peracids increase with higher proportions of the peracid as compared to the acid.

[0024] The presence of a catalyst for the formation of the peracid in the sterilization compositions of the present invention also is a novel aspect of the present invention which could act to maintain the level of peracid in the solution during use.

CORROSION EXAMPLE I

[0025] Experimental

[0026] In the following comparison example, a formulation according to the present invention comprising 2.69 weight percent of a 13% solution of peracetic acid made by combining 78% glacial acetic acid, 21% hydrogen peroxide (35% by weight in water), and 1% hydroxyethylenediamine phosphonate was compared to a commercial sterilization formulation (CSF) comprising a mixture of sodium perborate and tetraacetyl ethylenediamine with a buffer to provide a use solution of pH 8, with its necessary sterilization activator. The CSF composition (referred to as Powder PAA) comprises a powder source of peracetic acid (with a solid peroxide source) without a buffering agent, and was compared to a liquid solution of peracetic acid (PAA) made according to the present invention (referred to as Liquid PAA) by admixture of acetic acid and hydrogen peroxide solution with 1% by weight of hydroxyethylenediamine phosphonate catalyst to form the solution of peracetic acid (with the equilibrium amounts of acetic acid and hydrogen peroxide) at a pH of 6.0 provided by 3.0% by weight trisodium phosphate. This commercial CSF product requires mixing of a dry powder, with a delay required for the activator TAED (tetra acetyl ethylene diamine) by reaction with sodium perborate to generate peracetic acid and microbiocidal activity in the components.

[0027] Test Parameters:

[0028] The test was performed on pieces of an Olympus flexible endoscopes using a washer/disinfector to reduce manual variables. The test parameters were room temperature conditions, with the following immersion times:

1SampleCyclesImmersion TimeLiquid PAA110 minutesPowder PAA115 minutesSampleApplication TimeLiquid PAA24 hoursPowder PAA 8 hours

[0029] The test was performed by completely immersing separate test pieces S1 to S7 and W1 to W28 in each of the solutions.

2Test PiecesItemPartsS1-S7Parts of endoscopeS8 and S9Insertion tubeS10Light guide tubeW1-W28Parats of washer/disinfectorSampleSurfaceNo.Material (base)ControlPlace of the PartsS1A5056BD-H32 Resinblackconnector to LSpaintingS2Polysulfoneblackmain bodypaintingS3SUS304 ResinEl. blackoutside (hidden)coatingS4Silicone Rubber—outsideS5Polybutadiene PB-60—outsideS6Mod. PPOblackmain bodyPolyphenyleneoxidepaintingS7A5056BD-H32 ResinblackeyepiecealumiteSPolyurethaneprimaryinsertion tubecoat ZSPolyurethaneprimaryinsertion tubecoat VSPolyurethanelight guide cableW1Stainless Steelinner pipe systemW2Stainless Steelinner pipe systemW3epoxy resin+coatingheating panelW4PolyethylenebasinW5PolypropylenebasinW6PolyacetateconnectorW7Polysulfonepart of top coverW8Silicone RubbersealingW9Polyvinyl chlorideinner pipe systemW10Polyvinyl chloride (hard)inner pipe systemW11Acrylic polymerparts in the basinW12Ethylene/propyleneinner pipe systemW13Ethylene/propylene rubberinner pipe systemW14Acrylate modifiedtop coverPolyVinylChlorideW15Butyl-nitrile rubber +parts in the basinPhenolW16Teflonname plate in basinW17Butyl-nitrile rubbersealingW18Polyurethane?W19Acrylonitrile/butadiene/top coverstyreneW20modified PPOtop coverW21Butyl rubbersealingW22fluorinated rubbersealingW23alumina ceramicparts of pump systemW24Teflonparts of pump systemW24Teflon rubberparts of pump system

CONCLUSION

[0030] The samples were carefully inspected to evaluate the cosmetic effects (corrosion effects) on the various pieces. The first examination (Item 1) was for parts of the endoscope. The second examination (Item 2) was for the insertion tube. The third examination (Item 3) was for the light guide tube. The fourth examination (Item 4) was for the washer/disinfector. The samples performed substantially identically, with both solutions showing only a slight cosmetic change in painted black surface of the endoscope (S3 surface). No functional or cosmetic changes were noted on any other sample. The simplicity of use for the Liquid PAA system was very noteworthy, with no delay in mixing or reaction time. The solutions could be directly added into an automated system while the CSF Powder PAA system would have required premixing and activation time before it could have been used in an automatic system.

CORROSION EXAMPLE II

[0031] Experimental A corrosion study was performed to evaluate peracid containing formulas with and without buffer addition upon selected metals, plastics and rubbers.

[0032] Testing was conducted with two peracid formuations of 500 ppm (parts per million) peracetic acid (A) and 5000 ppm peracetic acid (B) concentration without buffer; and, two identical formulas (C and D respectively) with exception of buffer addition admixture.

[0033] Coupons were completely immersed in 200 mls of defined test solution contained in covered 8 ounce glass jars maintained at 50° C. within an environmental chamber. Solutions were changed daily. Study was conducted over a 14 day time period. For each test material, a control was also run which is a coupon of stated material placed within a covered 8 ounce glass jar having no test solution.

[0034] Coupons were pretreated before the corrosion study began, and postreated before final comparitive measurements and visual observations were performed. Metal coupons were precleaned according to ASTM Vol. 3.02, G31-72 and 3.02, G1-90 protocol and post-treated accordingly prior to final measurement. Test conditions were modified from the ASTM protocol as explained in above paragraph. Plastic and rubber coupons were only rinsed with deionized water and air dried prior to corrosion study; and, similarly treated prior to final measurement and visual observation.

CONCLUSION

[0035] Addition of buffer admixture to peracetic acid composition test solutions significantly improves metals protection. The effect is less noticeable on test plastics; but, protection is provided selected test rubbers.

3PART IA: FORMULA - PERACID COMPONENTHIGH POAA - LOW H202 PERACID FORMULA KX-6091GM/ITEMRAW MATERIALWT. %1000010Acetic Acid 78.00 7800.0020Hydrogen Peroxide 35% 21.00 2100.0030Dequest ™ 2010 (60%) 1.00 100.00Total100.0010000.00Mixing Instructions: Batch was prepared by direct weighing on Mettler PM 16 Top Loading Balance into a 5 gal HMW/HDPE (high molecular weight/high density polypropylene) pail. The batch was mixed for 65 minutes using a lab mixer equipped with a plastic coated stir rod and blade.

[0036]

4

PART IB: FORMULA - ADMIXTURE OF IA

AND BUFFER COMPONENT

FORMULAS A, B, C, D

CORROSION STUDY USE DILUTIONS

(A)
(B)
(C)
(D)

GM/

GM/

GM/

GM/

ITEM
Material
WT. %
4500
WT. %
4500
WT. %
4500
WT. %
4500

10
Deionized
99.10556
4459.75
90.66311
4079.84
99.55756
4480.09
95.57511
4300.88

Water

20
Trisodium
0.45200
20.41
4.91200
221.04

Phosphate

Anhyd.

Gran.

30
KX-6091
0.44244
19.91
4.42489
199.12
0.44244
19.91
4.42489
199.12

(11.3%

POAA)

Total
100.00000
4500.07
100.00000
4500.00
100.00000
4500.00
100.00000
4500.00

THEORETICAL
ppm
pH
ppm
pH
ppm
pH
ppm
pH

VALUES

POAA
500
6.00
5000
6.00
500
3.00
5000
2.50

INSTRUCTIONS

Add Trisodium Phosphate Anhydrous Granules (item 20) by wt. to weighed amount of DI water and stir with Lab mixer until dissolved. Add (item 30) by wt. to buffered water and final mix 2 min.

RESULTS:

(A) - pH = 6.02

(B) - pH = 5.99

(C) - pH = 2.96

(D) - pH = 2.35

[0037]

5

PART II: CORROSION - METALS

14 day Compatibility Test of 15 different materials tested against four different Test

Solutions at 50° C. with the test solutions are changed daily.

Material
Initial Wt.
Final Wt.

Test item
Test Solution
METALS
(gms)
(gms)
TWL
CWL
AWL
mpy

1
(A) 500 ppm POAA/Buffered
316 SS
23.5792
23.5791
0.0001
0.0001
0.0000
0.0000

5
(B) 5000 ppm POAA/Buffered
316 SS
23.5194
23.5193
0.0001
0.0001
0.0000
0.0000

9
(C) 500 ppm POAA only
316 SS
23.5764
23.5762
0.0002
0.0001
0.0001
0.0031

13
(D) 5000 ppm POAA only
316 SS
23.5690
23.5689
0.0001
0.0001
0.0000
0.0000

17
CONTROL
316 SS
23.5846
23.5845
0.0001
0.0001

2
(A) 500 ppm POAA/Buffered
304 SS
17.9651
17.9650
0.0001
0.0000
0.0001
0.0031

6
(B) 5000 ppm POAA/Buffered
304 SS
17.9326
17.9323
0.0003
0.0000
0.0030
0.0938

10
(C) 500 ppm POAA only
304 SS
17.9795
17.9793
0.0002
0.0000
0.0002
0.0063

14
(D) 5000 ppm POAA only
304 SS
17.9993
17.9992
0.0001
0.0000
0.0001
0.0031

18
CONTROL
304 SS
18.1102
18.1102
0.0000
0.0000

3
(A) 500 ppm POAA/Buffered
7075
12.8716
12.8685
0.0031
0.0002
0.0029
0.2412

Aluminum

7
(B) 5000 ppm POAA/Buffered
7075
12.7575
12.7336
0.0239
0.0002
0.0237
1.9712

Aluminum

11
(C) 500 ppm POAA only
7075
12.8651
12.8392
0.0259
0.0002
0.0257
2.1376

Aluminum

15
(D) 5000 ppm POAA only
7075
12.8718
12.7439
0.1279
0.0002
0.1277
10.6213

Aluminum

19
CONTROL
7075
12.4899
12.4897
0.0002
0.0002

Aluminum

4
(A) 500 ppm POAA/Buffered
260 Brass
26.4108
26.3763
0.0345
0.0004
0.0341
0.9779

8
(B) 5000 ppm POAA/Buffered
260 Brass
26.4211
26.3307
0.0904
0.0004
0.0900
2.5809

12
(C) 500 ppm POAA only
260 Brass
26.6471
25.6695
0.9776
0.0004
0.9772
28.0233

16
(D) 5000 ppm POAA only
260 Brass
26.4949
18.9759
7.5190
0.0004
7.5186
215.6118

20
CONTROL
260 Brass
26.4352
26.4348
0.0004
0.0004

PART II: CORROSION - METALS - OBSERVATIONS

Test

Material

item
Test Solution
METALS
Visual Obervations

1
(A) 500 ppm POAA/Buffered
316 SS
Smooth, shiny silver colored material like control

5
(B) 5000 ppm POAA/Buffered
316 SS
Smooth, shiny silver colored material like control

9
(C) 500 ppm POAA only
316 SS
Smooth, shiny silver colored material like control

13
(D) 5000 ppm POAA only
316 SS
Smooth, shiny silver colored material like control

17
CONTROL
316 SS
Smooth, shiny silver colored material

2
(A) 500 ppm POAA/Buffered
304 SS
Smooth, shiny silver colored material like control

6
(B) 5000 ppm POAA/Buffered
304 SS
Smooth, shiny silver colored material like control

10
(C) 500 ppm POAA only
304 SS
Smooth, shiny silver colored material like control

14
(D) 5000 ppm POAA only
304 SS
Smooth, shiny silver colored material like control

18
CONTROL
304 SS
Smooth, shiny silver colored material

3
(A) 500 ppm POAA/Buffered
7075 Aluminum
A slt. duller, slt. whiter than control, silver material

7
(B) 5000 ppm POAA/Buffered
7075 Aluminum
A very dull, smokey brown colored material

11
(C) 500 ppm POAA only
7075 Aluminum
A dull, whitish gray colored material

15
(D) 5000 ppm POAA only
7075 Aluminum
A very dull, very whitish gray colored material

19
CONTROL
7075 Aluminum
A slt. dull, silver colored material

4
(A) 500 ppm POAA/Buffered
260 Brass
A mixture of dull gold & pink area colored material

8
(B) 5000 ppm POAA/Buffered
260 Brass
A dull, gold colored material with patches of pink

12
(C) 500 ppm POAA only
260 Brass
A darker dull gold colored material with pink areas

16
(D) 5000 ppm POAA only
260 Brass
A sparkling grainy gold colored material

20
CONTROL
260 Brass
A smooth, shiny, gold colored material

KX-6091 CORROSION STUDY

CALCULATION DATA

4 Metals
DENSITY
AREA in inches squared

316 Stainless Steel
7.98
6.5

304 Stainless Steel;
7.94
6.4

7075 Aluminum
2.81
6.8

260 Brass
8.5
6.52

Time & Temp Tested

14 days at 50° C.

mpy = (534,000 * AWL)/(A * T * D)

(A) = Area (see above)

(T) = Time (336 hrs)

(D) = Density (see above)

AWL = TWL − CWL

TWL = Pre-testing weight − Post-testing weight

CWL = Pre-testing weight of control − Post-testing weight of control

mpy = mils per year

[0038]

6

PART III: CORROSION - PLASTICS

Analytical - Observations

KX-6091 CORROSION STUDY

14 day Compatibility Test of 15 different materials tested against four differnt Test

Solutions at 50° C. with the test solutions are changed daily.

%

Initial
Initial
Initial
Initial
Final
%
Final
%
Final
%
Final
Thick

Test
Test
Material
Wt.
Ht.
Width
Thick
Wt.
Weight
Ht.
Height
Width
Width
Thick
Chang-

item
Solution
PLASTICS
(gms)
(inches)
(Inches)
(inches)
(gms)
Change
(inches)
Change
(inches)
Change
(inches)
es

21
(A) 500
Polyurethane
3.8348
2.996
0.506
0.128
3.8360
0.0313
2.996
0.0000
0.507
0.1976
0.128
0.0000

ppm

POAA/

Buffered

27
(B) 5000
Polyurethane
3.8379
2.996
0.502
0.129
3.8385
0.0156
2.998
0.0668
0.502
0.0000
0.128
−0.7752

ppm

POAA/

Buffered

33
(C) 500
Polyurethane
3.8385
2.999
0.505
0.128
3.8418
0.0860
3.004
0.1567
0.505
−0.1976
0.127
−0.7813

ppm

POAA

only

39
(D) 5000
Polyurethane
3.8151
2.995
0.504
0.127
3.7411
−1.9397
3.061
2.2037
0.509
0.9921
0.125
−1.5748

ppm

POAA

only

45
CON-
Polyurethane
3.8286
2.996
0.505
0.128
3.8200
−0.2248
2.993
−0.1001
0.504
−0.1980
0.128
0.0000

TROL

22
(A) 500
Polyethylene
1.3741
2.991
0.505
0.066
1.3736
−0.0364
2.991
0.0000
0.504
−0.1980
0.066
0.0000

ppm

POAA/

Buffered

28
(B) 5000
Polyethylene
1.3676
2.991
0.505
0.064
1.3675
−0.0073
2.991
0.0000
0.505
0.0000
0.065
1.5625

ppm

POAA/

Buffered

34
(C) 500
Polyethylene
1.3541
2.992
0.504
0.065
1.3541
0.0000
2.991
−0.0334
0.502
−0.3968
0.065
0.0000

ppm

POAA

only

40
(D) 5000
Polyethylene
1.3586
2.995
0.504
0.066
1.3593
0.0515
2.994
−0.0334
0.502
−0.3968
0.066
0.0000

ppm

POAA

only

46
CON-
Polyethylene
1.3668
2.991
0.504
0.068
1.3667
−0.0073
2.989
−0.0669
0.504
0.0000
0.068
0.0000

TROL

23
(A) 500
Polypropylene
1.3792
3.002
0.504
0.066
1.3792
0.0000
3.001
−0.0333
0.503
−0.1984
0.067
1.5152

ppm

POAA/

Buffered

29
(B) 5000
Polypropylene
1.3774
2.998
0.503
0.065
1.3775
0.0073
2.999
0.0334
0.503
0.0000
0.066
1.5385

ppm

POAA/

Buffered

35
(C) 500
Polypropylene
1.3793
2.998
0.504
0.065
1.3796
0.0218
2.998
0.0000
0.503
−0.1984
0.065
0.0000

ppm

POAA

only

Initial
Initial
Initial
Initial
Final
%
Final
%
Final

Test
Test
Material
Wt.
Ht.
Width
Thick
Wt.
Weight
Ht.
Height
Width

item
Solution
PLASTICS
(gms)
(inches)
(Inches)
(inches)
(gms)
Change
(inches)
Change
(inches)
0.0000
0.065
0.0000

47
CON-
Polypropylene
1.3812
2.997
0.503
0.065
1.3811
−0.0072
2.997
0.0000
0.503
0.0000
0.065
0.0000

TROL

24
(A) 500
Polyvinyl
2.1801
3.002
0.505
0.066
2.1843
0.1927
3.002
0.0000
0.506
0.1980
0.065
−1.5152

ppm
Chloride

POAA/

Buffered

30
(B) 5000
Polyvinyl
2.2005
2.997
0.505
0.066
2.2041
0.1636
2.997
0.0000
0.506
0.1980
0.066
0.0000

ppm
Chloride

POAA/

Buffered

36
(C) 500
Polyvinyl
2.1734
2.998
0.505
0.065
2.1777
0.1978
2.998
0.0000
0.505
0.0000
0.065
0.0000

ppm
Chloride

POAA

only

42
(D) 5000
Polyvinyl
2.1590
2.998
0.505
0.065
2.1625
0.1621
2.997
−0.0334
0.505
0.0000
0.065
0.0000

ppm
Chloride

POAA

only

48
CON-
Polyvinyl
2.2048
2.999
0.505
0.056
2.2037
−0.0499
2.998
−0.0333
0.505
0.0000
0.056
0.0000

TROL
Chloride

25
(A) 500
ABS
1.4724
2.995
0.507
0.061
1.4762
0.2581
2.999
0.1336
0.508
0.1972
0.061
0.0000

ppm

POAA/

Buffered

31
(B) 5000
ABS
1.5167
3.003
0.507
0.063
1.5201
0.2242
3.006
0.0999
0.506
−0.1972
0.063
0.0000

ppm

POAA/

Buffered

37
(C) 500
ABS
1.5082
3.000
0.507
0.062
1.5132
0.3315
3.004
0.1333
0.508
0.1972
0.062
0.0000

ppm

POAA

only

43
(D) 5000
ABS
1.4971
2.995
0.505
0.062
1.5047
0.5076
3.000
0.1669
0.510
0.9901
0.062
0.0000

ppm

POAA

only

49
CON-
ABS
1.4822
2.995
0.507
0.062
1.4813
−0.0607
2.995
0.0000
0.508
0.1972
0.062
0.0000

TROL

26
(A) 500
Polyacetal
4.4596
3.003
0.507
0.133
4.5033
0.9799
3.010
0.2331
0.508
0.1972
0.134
0.7519

ppm

POAA/

Buffered

32
(B) 5000
Polyacetal
4.3970
3.003
0.507
0.131
4.4302
0.7551
3.009
0.1998
0.507
0.0000
0.132
0.7634

ppm

POAA/

Buffered

38
(C) 500
Polyacetal
4.4967
3.004
0.506
0.134
4.5441
1.0092
3.014
0.3329
0.508
0.3953
0.135
0.7463

ppm

POAA

only

44
(D) 5000
Polyacetal
4.3832
3.003
0.507
0.131
4.4264
0.9856
3.012
0.2997
0.508
0.1972
0.132
0.7634

ppm

POAA

only

50
CON-
Polyacetal
4.4498
3.002
0.506
0.133
4.4454
−0.0989
3.000
−0.0666
0.506
0.0000
0.133
0.0000

TROL

Test

Material

item
Test Solution
PLASTICS
Visual Observations

21
(A) 500 ppm POAA/Buffered
Polyurethane
Dull opaque orange material with semi-transparent boarder

27
(B) 5000 ppm POAA/Buffered
Polyurethane
Dull opaque orange material with semi-transparent boarder

and slt. tacky

33
(C) 500 ppm POAA only
Polyurethane
Dull darker opaque orange material with semi-transparent

boarder and slt. tacky

39
(D) 5000 ppm POAA only
Polyurethane
Very dark orange, very tacky, completely opaque material that

stuck to drying surface resulting in loss of material

45
CONTROL
Polyurethane
A dull, dirty, slt. yellow tinted, semi-transparent material

22
(A) 500 ppm POAA/Buffered
Polyethylene
Slt. whiter material than control

28
(B) 5000 ppm POAA/Buffered
Polyethylene
Slt. whiter material than control

34
(C) 500 ppm POAA only
Polyethylene
Slt. whiter material than control

40
(D) 5000 ppm POAA only
Polyethylene
Slt. whiter material than control

46
CONTROL
Polyethylene
A dull, grayish white material

23
(A) 500 ppm POAA/Buffered
Polypropylene
A white filmy, faintly transparent, more cloudy material than

control

29
(B) 5000 ppm POAA/Buffered
Polypropylene
A white filmy, faintly transparent, more cloudy material than

control

35
(C) 500 ppm POAA only
Polypropylene
A white heavy filmed, faintly transparent, more cloudy

material than control

41
(D) 5000 ppm POAA only
Polypropylene
A white filmy, faintly transparent, more cloudy material than

control

47
CONTROL
Polypropylene
A dull gray, semi-transparent material

24
(A) 500 ppm POAA/Buffered
Polyvinyl
Slt. less shiny and slt. less dark gray material than control

Chloride

36
(C) 500 ppm POAA only
Polyvinyl
A dull med. gray material

Chloride

42
(D) 5000 ppm POAA only
Polyvinyl
A dull light to medium gray material

Chloride

48
CONTROL
Polyvinyl
A dark, shiny gray material

Chloride

25
(A) 500 ppm POAA/Buffered
ABS
A slt. dull, whiter material than control

31
(B) 5000 ppm POAA/Buffered
ABS
A slt. dull, whiter material than control

37
(C) 500 ppm POAA only
ABS
A slt. dull, much whiter white material than control

43
(D) 5000 ppm POAA only
ABS
A slt. dull bright white material

49
CONTROL
ABS
A slt. dull, vanilla white material

26
(A) 500 ppm POAA/Buffered
Polyacetal
A dull, cleaner white appearance than control

32
(B) 5000 ppm POAA/Buffered
Polyacetal
A dull, cleaner white appearance than control

38
(C) 500 ppm POAA only
Polyacetal
A dull, cleaner white appearance than control

44
(D) 5000 ppm POAA only
Polyacetal
A dull, cleaner white appearance than control

50
CONTROL
Polyacetal
A dull, dirty white material

[0039]

7

PART IV: CORROSION - RUBBERS

Analytical - Observations

KX-6091 CORROSION STUDY

14 day Compatibility Test of 15 different materials tested against four different Test

Solutions at 50° C. with the test solutions are changed daily.

Initial
Initial
Initial
Initial
Final
%
Final
%
Final
%
Final
%

Test

Material
Wt.
Ht.
Width
thick
Wt.
Weight
Ht.
Height
Width
Width
Thick
Thick

item
Test Solution
RUBBERS
(gms)
(inches)
(inches)
(inches)
(gms)
Change
(inches)
Change
(inches)
Change
(inches)
Change

51
(A) 500 ppm
Silicon
14.2724
2.930
0.928
0.254
14.2553
−0.1198
2.930
0.0000
0.933
0.5388
0.254
0.0000

POAA/

Buffered

56
(B) 5000
Silicone
15.5707
2.999
1.007
0.249
15.5665
−0.0270
2.995
−0.1334
1.008
0.0993
0.249
0.0000

ppm

POAA/

Buffered

61
(C) 500 ppm
Silicone
15.6958
3.013
0.995
0.252
15.7755
0.5078
3.019
0.1991
1.004
0.9045
0.252
0.0000

POAA only

66
(D) 5000
Silicone
15.1443
2.977
0.994
0.246
15.3760
1.5299
3.003
0.6734
1.005
1.1066
0.249
1.2195

ppm

POAA only

71
CONTROL
Silicone
15.6702
2.970
1.001
0.253
15.6417
−0.1819
2.970
0.0000
1.013
1.1988
0.254
0.3953

52
(A) 500 ppm
Butyl
1.9074
2.999
0.507
0.069
1.9852
4.0789
3.008
0.3001
0.507
0.0000
0.071
2.8986

POAA/

Buffered

57
(B) 5000
Butyl
1.9082
2.999
0.505
0.069
1.9263
0.9485
3.008
0.3001
0.505
0.0000
0.069
0.0000

ppm

POAA/

Buffered

62
(C) 500 ppm
Butyl
1.9026
2.996
0.505
0.068
2.0729
8.9509
3.017
0.7009
0.513
1.5842
0.075
10.2941

POAA only

67
(D) 5000
Butyl
1.9097
2.998
0.507
0.069
2.2216
16.3324
3.029
1.0340
0.494
−2.5841
0.078
13.0435

ppm

POAA only

72
CONTROL
Butyl
1.9001
2.998
0.507
0.069
1.8939
−0.3263
2.998
−0.0867
0.504
−0.5917
0.069
0.0000

53
(A) 500 ppm
Vison
23.3725
3.057
1.031
0.248
23.4407
0.2918
3.071
0.4580
1.033
0.1940
0.248
0.0000

POAA/

Buffered

58
(B) 5000
Vison
21.3847
2.984
1.014
0.237
21.4843
0.5598
2.998
0.4692
1.025
1.0848
0.238
0.4219

ppm

POAA/

Buffered

68
(D) 5000
Vison
22.4157
2.964
1.012
0.251
23.7728
6.0542
3.064
3.3738
1.053
4.0514
0.260
3.5857

ppm

POAA only

73
CONTROL
Vison
22.0694
2.988
1.012
0.244
22.0584
−0.0498
2.991
0.1004
1.012
0.0000
0.244
0.0000

54
(A) 500 ppm
EPDM
17.0399
3.042
1.005
0.277
17.1763
0.8005
3.053
0.3616
1.009
0.3980
0.285
2.8881

POAA/

Buffered

59
(B) 5000
EPDM
16.9577
3.033
1.006
0.278
17.2265
1.5851
3.036
0.0989
1.012
0.5964
0.285
2.5180

ppm

POAA/

Buffered

64
(C) 500 ppm
EPDM
16.9824
3.059
1.015
0.275
16.9653
−0.1007
3.068
0.2942
1.012
−0.2956
0.282
2.5455

POAA only

69
(D) 5000
EPDM
17.4875
2.985
1.072
0.274
17.9757
2.7917
3.020
1.1725
1.079
0.6530
0.284
3.6496

ppm

POAA only

74
CONTROL
EPDM
16.7254
2.964
1.016
0.278
16.6918
−0.2009
2.959
−0.1687
1.015
−0.0984
0.278
0.0000

55
(A) 500 ppm
BUNA N
15.8678
2.960
1.006
0.242
16.3169
2.8303
2.970
0.3378
1.012
0.5964
0.247
2.0661

POAA/

Buffered

80
(B) 5000
BUNA N
15.9576
2.980
1.020
0.240
16.4275
2.9447
2.989
0.3020
1.019
−0.0980
0.246
2.5000

ppm

POAA/

Buffered

85
(C) 500 ppm
BUNA N
16.2737
2.977
1.016
0.246
18.9478
4.1423
2.992
0.5039
1.024
0.7874
0.259
5.2846

POAA only

70
(D) 5000
BUNA N
15.8516
2.956
1.014
0.242
16.5043
4.1176
2.956
0.0000
1.029
1.4793
0.264
9.0909

ppm

POAA only

75
CONTROL
BUNA N
16.0735
2.936
1.107
0.247
16.0328
−0.2532
2.937
0.0341
1.014
−0.2950
0.247
0.0000

Test

Material

item
Test Solution
RUBBERS
Visual Observations

51
(A) 500 ppm POAA/Buffered
Silicone
A dull, med. - dark orange material similar to

control

56
(B) 5000 ppm POAA/Buffered
Silicone
A dull, med. - dark orange material similar to

Control

61
(C) 500 ppm POAA only
Silicone
A dull, med. - dark orange material similar to

Control

66
(D) 5000 ppm POAA only
Silicone
A dull, med. - dark orange material similar to

Control

71
CONTROL
Silicone
A dull, med. - dark orange material

52
(A) 500 ppm POAA/Buffered
Butyl
A dull black material with slt. tacky, slt. rough

surface that stuck to drying surface resulting in loss

of material

57
(B) 5000 ppm POAA/Buffered
Butyl
A dull black material with very slt. tacky, smooth

surface

62
(C) 500 ppm POAA only
Butyl
A black material with tacky, dull, rough surface

that stuck to drying surface resulting in loss of

material

67
(D) 5000 ppm POAA only
Butyl
A dull black material with very tacky, very rough,

surface that stuck to drying surface resulting in loss

of material

53
(A) 500 ppm POAA/Buffered
Vison
A dull, charcoal black material with smooth surface

58
(B) 5000 ppm POAA/Buffered
Vison
A dull, charcoal black material with smooth surface

63
(C) 500 ppm POAA only
Vison
A dull, charcoal black material with slt. rough

surface

68
(D) 5000 ppm POAA only
Vison
A dull, charcoal black material with slt. rough

surface

73
CONTROL
Vison
A dull, charcoal black material with smooth surface

54
(A) 500 ppm POAA/Buffered
EPDM
A dull, black material with slt. rough surface

59
(B) 5000 ppm POAA/Buffered
EPDM
A dull, black material with slt. blistered surface

64
(C) 500 ppm POAA only
EPDM
A dull, black material with slt. rough surface

69
(D) 5000 ppm POAA only
EPDM
A dull black material with slt. rough surface

containing a large blister

74
CONTROL
EPDM
A dull, black material with smooth surface

55
(A) 500 ppm POAA/Buffered
BUNA N
A dull, (darker than control) black material with slt.

rough surface

60
(B) 5000 ppm POAA/Buffered
BUNA N
A dark black material with very slt. shiny, fairly

smooth surface

65
(C) 500 ppm POAA only
BUNA N
A dark black material with very slt. shiny, slt.

blistered surface

70
(D) 5000 ppm POAA only
BUNA N
A dark black material with very slt. shiny, blistered

surface

75
CONTROL
BUNA N
A dull, grayish black material with smooth surface

[0040] I. Tuberculocidal Efficacy—US Method

[0041] The peracetic acid product was tested against Mycobacterium bovis (bCG) using the AOAC Confirmatory Test with product concentrations as listed below. The product was diluted in buffer to achieve the pH 6 prior to test. The diluent tested was either tap or distilled water. Test exposure time was 10 minutes. A result of ten no growth tubes per ten tubes tested is required for a passing result Conclusion: successful tuberculocidal results were achieved at product concentrations as low as 1000 ppm POAA.

8Number of no growth tubes/Product Concentrationanumber of tubes testedb1000 ppm POAA10/10 - pass2000 ppm POAA10/10 - pass3000 ppm POAA10/10 - pass4000 ppm POAA10/10 - pass5000 ppm POAA10/10 - passaDiluent was tap or distilled water with pH adjusted to 6. bTest results reflect data achieved in three test media, Proskauer-Beck, Kirshners and Middlebrook.

[0042] II. Suspension Test—Olympus Method

[0043] We have completed the suspension test as requested with the Olympus procedure versus Bacillus subtilis. The product was diluted in buffer to achieve the pH 6 prior to test The diluent tested was tap water. Test exposure times are listed below. The data are represented as log reduction of bacterial numbers. Note: the spores were counted after the heat shock treatment, although the test was conducted on a non-heat treated bacterial suspension. Conclusion significant log reductions in microbial numbers were achieved within 10 minutes using 500 ppm POAA. Additional product concentration or exposure time did not increase the efficacy of the product.

9Bacillus subtilis Log Reduction at 20° C.(ppm POAA)1500 ppm2000 ppmExposure time(Henkel-Ecolab(Ecolab test(minutes)250 ppm500 ppm1000 ppmtest only)only) 5 minutes4.556.139.487.709.7810 minutes7.989.789.787.689.7820 minutes9.489.789.787.719.7860 minutes9.489.789.787.749.78Neutralization control 0.10ATotal Inoculum3.4 × 105 cfu/ml6.0 × 109 cfu/mlSpore Inoculum9.0 × 106 cfu/ml3.3 × 105 cfu/mlANeutralizer is 1% sodium thiosulfate and is effective in this test procedure for chemical neutralization of the test substance.

[0044] III. Carrier Test—Olympus Method

[0045] We have completed the carrier test as requested using the Olympus procedure versus Bacillus subtilis and Mycobacterium terrae. The product was diluted in buffer to achieve the pH 6 prior to test. The diluent tested was tap water. Test exposure times are listed below. Note: the spores were counted after the heat shock treatment, although the test was conducted on a non-heat treated bacterial suspensions. Conclusion: successful results achieved using 250 ppm POAA within five minutes exposure against both subtilis and Mycobacterium terrae. Additional product concentration or exposure time did not increase the efficacy of the product.

10250 ppm1000 ppm2500 ppm5000 ppmExposure timeCARRIERACARRIERCARRIERCARRIER(minutes)RESULTSABBCRESULTSABRESULTSABRESULTSABBacillus subtilis at 20° C.(ppm POAA) 0 minutes0/22.3 × 1041.9 × 104 5 minutes2/2<1<12/2<1<12/2<1<12/2<1<110 minutes2/2<1<12/2<1<12/2<1<12/2<1<120 minutes2/2<1<12/2<1<12/2<1<12/2<1<160 minutes2/2<1<12/2<1<12/2<1<12/2<1<1Mycobacterium terrae at 20° C.(ppm POAA) 0 minutes0/23.2 × 1042.1 × 104 5 minutes2/2<1<12/2<1<12/2<1<12/2<1<110 minutes2/2<1<12/2<1<12/2<1<12/2<1<120 minutes2/2<1<12/2<1<12/2<1<12/2<1<160 minutes2/2<1<12/2<1<12/2<1<12/2<1<1ANumber of negative carriers per number of carriers tested. BPlate A is the average cfu/ml of product plus neutralizer mixture. CPlate B is the average cfu/ml of stripper. D Neutralizer is 1% sodium thiosulfate and is effective in this test procedure for chemical neutralization of the test substance.

[0046] IV. Sporicidal Efficacy—US Method

[0047] The peracetic add product was tested against Clostridium sporogenes using the AOAC Spodcidal Activity of Disinfectants Test with product concentrations as listed below. The product was diluted in buffer to achieve the pH 6 prior to test The diluent tested was tap water. Test exposure time was 3, 4 or 6 hours. A result of twenty no growth tubes per twenty tubes tested is required for a passing result. Conclusion: successful results were achieved at 5000 ppm POAA with an exposure time of 6 hours.

11Number of no growth tubes/ProductExposurenumber of tubes testedbConcentrationaTimePrimary SubcultureSecondary Subculture4000 ppm3 hours20/20 0/20POAA4 hours20/20 1/206 hours19/2020/205000 ppm3 hours19/20 6/20POAA4 hours20/2017/206 hours20/2020/207000 ppm3 hours20/2010/20POAA4 hours20/2011/206 hours20/2020/20aDiluent was tap or distilled water with pH adjusted to 6. bTest results reflect data achieved in three test media, Proskauer-Beck, Kirshners and Middlebrook after heat-shock treatment and reincubation for 72 hours.

[0048] Objective:

[0049] The objective of this analysis was to evaluate the effect of hydrogen peroxide and acetic acid concentration on the sporicidal efficacy of 150 ppm peracetic acid at 40° C.

[0050] Test Method:

[0051] Ecolab Microbiological Services SOP CB02104; Rate of Kill Antimicrobial Efficacy. Following exposure to the formula and subsequent neutralization, spores were heat shocked for 13 minutes at 80° C. before plating.

[0052] Method Parameters:

12Chemical Properties of Each Test FormulaTheoreticalTheoreticalTheoreticalFormulappm POAAppm H2O2ppm Acetic AcidpHA150 311593.75B150 313093.67C1502751593.75D1502753093.68E1505291593.77F1505293093.68Test Substances: Each formula was prepared using a “stock” POAA material (34.1% POAA, 7.13% H2O2 and 36.1% acetic acid - Aldrich Chemical) to achieve 150 ppm POAA. H2O2 or acetic acid was then added as needed. Please refer to the data #sheet attached to this report for preparation information. Since chemical analyses of solutions prepared exactly like those prepared for this study were done previously, and concentrations were found to be accurate, additional #chemical analysis for this study was not perfomed (see MSR #960351, J. Hilgren). Test System: Bacillus cereus spore crop N1009 Test Temperature: 40° C. Exposure Times: 0.5, 1.0, 1.5, 2.0, 2.5, 3.0 and 3.5 hours Neutralizer: Fluid Thioglycollate Medium Plating Media: Dextrose Tryptone Agar Incubation: 32° C. for 48 hours

[0053] Results:

13Inoculum NumbersInoculum Test Replicate (CFU/mL)AverageOrganism123(CFU/mL)B. cereus Spores30 × 10626 × 10626 × 1062.7 × 107Reduction of B. cereus Spores at 40° C.Exposure TimeFormula(hours)Survivors (CFU/mL)Log ReductionA0.5<1.0 × 101>6.43Low Acetic,1.0<1.0 × 101>6.43Low H2O21.5<1.0 × 101>6.432.0<1.0 × 101>6.432.5<1.0 × 101>6.433.0<1.0 × 101>6.433.5<1.0 × 101>6.43B0.5<1.0 × 101>6.43High Acetic,1.0<1.0 × 101>6.43Low H2O21.5<1.0 × 101>6.432.0<1.0 × 101>6.432.5<1.0 × 101>6.433.0<1.0 × 101>6.433.5<1.0 × 101>6.43C0.5 1.7 × 1070.20Low Acetic,1.0 6.0 × 1060.65Medium H2O21.5 2.5 × 1061.032.0 9.0 × 1051.482.5 2.1 × 1052.113.0 6.0 × 1042.653.5 1.5 × 1043.26D0.5 1.5 × 1070.26High Acetic,1.0 4.9 × 1060.74Medium H2O21.5 2.2 × 1061.092.0 4.6 × 1051.772.5 1.2 × 1052.353.0 3.1 × 1042.943.5 1.1 × 1043.39E0.5 1.5 × 1070.26Low Acetic,1.0 5.1 × 1060.72High H2O21.5 1.4 × 1061.292.0 3.1 × 1051.942.5 3.4 × 1042.903.0 4.0 × 1033.833.5 5.6 × 1024.68F0.5 1.4 × 1070.29High Acetic,1.0 4.7 × 1060.76High H2O21.5 1.7 × 1061.202.0 4.3 × 1051.802.5 3.3 × 1042.913.0 5.0 × 1033.733.5 8.1 × 1024.52

[0054]

CONCLUSIONS

[0055] The sporicidal activity of 150 ppm POAA at 40° C. against Bacillus cereus spores was most effective when in the presence of relatively low concentrations of H2O2 (≈30 ppm as in Formulas A and B). Reduced B. cereus sporicidal efficacy was observed using POAA with the medium and high concentrations of H2O2 (≈160 and 300 ppm as in Formulas C through F).

[0056] Objective:

[0057] The objective of this analysis was to evaluate the effect of hydrogen peroxide and acetic acid concentration on the sporicidal efficacy of 150 ppm peracetic acid at 60° C.

[0058] Test Method:

[0059] Ecolab Microbiological Services SOP CB02104; Rate of Kill Antimicrobial Efficacy. Following exposure to the formula and subsequent neutralization, spores were heat shocked for 13 minutes at 80° C. before plating.

[0060] Method Parameters:

14Analytical Chemistry Results - A&P Methods 9403201, 9600300Formula Properties(≈ 2 Hours Post Preparation/After 40 min. at 60° C.)Formulappm POAAppm H2O2ppm Acetic AcidpHA147/14431/33174/1663.76/3.67B145/14433/37346/3463.71/3.55C151/148277/281141/1433.79/3.69D151/151283/280301/2913.70/3.60E157/154526/514136/1483.81/3.71F160/159 533/240*293/3243.71/3.62*No obvious error in analysis was detected, but the result remains in question. Test Substances: Each formula was prepared using a “stock” POAA material (34.1% POAA, 7.13% H2O2 and 36.1% acetic acid - Aldrich Chemical) to achieve 150 ppm POAA. H2O2 or acetic acid was then added as needed. Please refer to the data #sheet attached to this report for theoretical concentrations and preparation information. Test System: Bacillus cereus spore crop N1009 Test Temperature: 60° C. Exposure Times: 10, 15, 20, 25, 30 and 40 minutes Neutralizer: Fluid Thioglycollate Medium Plating Media: Dextrose Tryptone agar Incubation: 32° C. for 48 hours

[0061]

15

Inoculum Numbers

Inoculum Test Replicate (CFU/mL)
Average

Organism
1
2
3
(CFU/mL)

B. cereus
Spores
28 × 106
22 × 106
29 × 106
2.6 × 107

[0062]

16

Reduction of B. cereus Spores at 60° C.

Exposure Time

Formula
(min.)
Survivors (CFU/mL)
Log Reduction

A
10
<1.0 × 101
>6.41

Low Acetic,
15
<1.0 × 101
>6.41

Low H2O2
20
<1.0 × 101
>6.41

25
<1.0 × 101
>6.41

30
<1.0 × 101
>6.41

40
<1.0 × 101
>6.41

B
10
<1.0 × 101
>6.41

High Acetic,
15
<1.0 × 101
>6.41

Low H2O2
20
<1.0 × 101
>6.41

25
<1.0 × 101
>6.41

30
<1.0 × 101
>6.41

40
<1.0 × 101
>6.41

C
10
4.1 × 104
2.80

Low Acetic,
15
2.0 × 102
5.11

Medium H2O2
20
<1.0 × 101
>6.41

25
<1.0 × 101
>6.41

30
<1.0 × 101
>6.41

40
<1.0 × 101
>6.41

D
10
2.6 × 104
3.00

High Acetic,
15
7.0 × 101
5.57

Medium H2O2
20
<1.0 × 101
>6.41

25
<1.0 × 101
>6.41

30
<1.0 × 101
>6.41

40
<1.0 × 101
>6.41

E
10
2.4 × 104
3.03

Low Acetic,
15
2.4 × 102
5.03

High H2O2
20
<1.0 × 101
>6.41

25
<1.0 × 101
>6.41

30
<1.0 × 101
>6.41

40
<1.0 × 101
>6.41

F
10
1.1 × 104
3.37

High Acetic,
15
7.0 × 101
5.57

High H2O2
20
<1.0 × 101
>6.41

25
<1.0 × 101
>6.41

30
<1.0 × 101
>6.41

40
<1.0 × 101
>6.41

[0063]

CONCLUSIONS

[0064] The sporicidal activity of 150 ppm POAA at 60° C. against Bacillus cereus spores was most effective when in the presence of relatively low concentrations of H2O2 (a 30 ppm as in Formulas A and B). A decrease in B. cereus sporicidal efficacy was observed using the medium and high concentrations of H2O2 (a 160 and 300 ppm as in Formulas C through F).

[0065] Further testing using Formulas A-F will be conducted at 20° C. to determine the effect of H2O2 and acetic acid concentration on sporicidal efficacy of POAA at low temperature.

[0066] Objective:

[0067] The objective of this analysis was to evaluate the effect of hydrogen peroxides octanoic acid and peroctanoic acid concentration on the sporicidal efficacy of 150 ppm peracetic acid at 40° C.

[0068] Test Method: Ecolab Microbiological Services SOP CB02104; Rate of Kill Antimicrobial Efficacy. Following exposure to the formula and subsequent neutralization, spores were heat shocked for 13 minutes at 80° C. before plating. Method Parameters:

17Chemical Properties of Each Test FormulaTheoreticalTheoreticalTheoreticalTheoreticalTheoreticalFormulappm POAAppm H2O2ppm AAppm POOAppm OApH11493628212393.65214952928212393.6231493628250393.64414952928250393.63514936282121383.646149529282121383.63714936282501383.648149529282501383.65Test Substances: Each formula was prepared using a “stock” POAA material (33.5% POAA, 7.03% H2O2 and 37.2% acetic acid - Aldrich Chemical) and a “stock” octanoic/peroctanoic material (11.4% octanoic, 3.4% POOA, 10.29% POAA, 3.70% H2O2 - Falcon 15). Hydrogen peroxide, octanoic acid or peroctanoic acid were then added as needed. Please refer to the data sheet attached to this report for preparation information. # Prior to this study, chemical analyses of formulas exactly like those used for this study were conducted to determine if ingredient concentrations were close to theoretical and if they were stable over the duration of the efficacy test. Results showed ingredient concentrations to correlate with theoretical and to be stable. Test System: Bacillus cereus spore crop N1009 Test Temperature: 40° C. Exposure Times: 5, 10, 15, 20, 25 and 30 minutes Neutralizer: Fluid Thioglycollate Medium Plating Medium: Dextrose Tryptone Agar Incubation: 32° C. for 48 hours

[0069]

18

Inoculum Numbers

Inoculum Test Replicate (CFU/mL)
Average

Organism
1
2
3
(CFU/mL)

B. cereus
Spores
56 × 106
42 × 106
35 × 106
4.4 × 107

Reduction of B. cereus Spores at 40° C.

Exposure Time

Formula
(minutes)
Survivors (CFU/mL)
Log Reduction

1
5
3.0 × 101
6.17

Low H2O2,
10
<1.0 × 101
>6.64

Low POOA,
15
<1.0 × 101
>6.64

Low OA
20
<1.0 × 101
>6.64

25
<1.0 × 101
>6.64

30
<1.0 × 101
>6.64

2
5
6.4 × 106
0.84

High H2O2,
10
4.3 × 106
1.01

Low POOA,
15
1.8 × 106
1.39

Low OA
20
4.0 × 105
2.04

25
1.2 × 105
2.56

30
8.1 × 104
2.73

3
5
<1.0 × 101
>6.64

Low H2O2,
10
<1.0 × 101
>6.64

High POOA,
15
<1.0 × 101
>6.64

Low OA
20
<1.0 × 101
>6.64

25
<1.0 × 101
>6.64

30
<1.0 × 101
>6.64

4
5
3.4 × 105
2.11

High H2O2,
10
1.6 × 104
3.44

High POOA,
15
1.9 × 103
4.36

Low OA
20
3.0 × 101
6.17

25
<1.0 × 101
>6.64

30
<1.0 × 101
>6.64

5
5
<1.0 × 101
>6.64

Low H2O2,
10
<1.0 × 101
>6.64

Low POOA,
15
<1.0 × 101
>6.64

High OA
20
<1.0 × 101
>6.64

25
<1.0 × 101
>6.64

30
<1.0 × 101
>6.64

6
5
4.4 × 106
1.00

High H2O2,
10
4.1 × 105
2.03

Low POOA,
15
7.7 × 104
2.76

High OA
20
5.3 × 104
2.92

25
1.4 × 104
3.50

30
5.8 × 103
3.88

7
5
<1.0 × 101
>6.64

Low H2O2,
10
<1.0 × 101
>6.64

High POOA,
15
<1.0 × 101
>6.64

High OA
20
<1.0 × 101
>6.64

25
<1.0 × 101
>6.64

30
<1.0 × 101
>6.64

8
5
1.2 × 105
2.56

High H2O2,
10
2.0 × 103
4.34

High POOA,
15
4.0 × 101
6.04

High OA
20
<1.0 × 101
>6.64

25
<1.0 × 101
>6.64

30
<1.0 × 101
>6.64

CONCLUSIONS

[0070] Effect of H2O2:

[0071] The sporicidal activity of 150 ppm POAA at 400C against Bacillus cereus spores was most effective when in the presence of relatively low concentrations of H2O2 (=36 ppm as in Formulas 1, 3, 5 and 7). Reduced B. cereus sporicidal efficacy was observed using POAA with the higher concentrations of H2O2 (=529 ppm as in Formulas 2, 4, 6 and 8).

[0072] Effects of Octanoic and Peroctanoic Acid:

[0073] The sporicidal activity of 150 ppm POAA at 40° C. against Bacillus cereus spores increased when the concentrations of octanoic or peroetanoic acid increased. This phenomenon was clearly evident in formulas containing the high concentrations of H2O2 (formulas 2, 4, 6 and 8).

[0074] On a weight basis, peroctanoic acid had a greater effect on the sporicidal efficacy of 150 ppm POAA against B. cereus than octanoic acid. An increase of 38 ppm POOA resulted in a greater log reduction of B. cereus spores than an increase of 99 ppm octanoic acid. An additive effect was observed when POOA and octanoic acid were combined.

	Number	Date	Country
Parent	09447328	Nov 1999	US
Child	10385230	Mar 2003	US

Non-corrosive sterilant composition

Information

Publication Number

Date Filed

Date Published

Inventors

Original Assignees

CPC

US Classifications

International Classifications

Abstract

Description

Claims

Continuations (1)