Patent Abstract:
An anticorrosive, penetration enhancing composition for cleaning decontaminating and rinsing includes electrochemically activated (ECA) water as the decontamination agent. The anticorrosive decontamination composition has, as the anticorrosive agent, a compound or mixture of compounds capable of inhibiting corrosion of various metals used in sterilization decontamination and rinsing systems and objects such as medical instruments. Preferred anticorrosive compounds include phosphates, azoles, and sulfates. Other additives, including wetting agents, are added to reduce the surface energy of the ECA water. This reduced surface energy permits the ECA water to penetrate into objects of complex design thus permitting complete decontamination of the treated object.

Full Description:
This application is a continuation-in-part of U.S. application Ser. No. 08/984,752, filed Dec. 4, 1997 now abandened. 
    
    
     BACKGROUND OF THE INVENTION 
     The present invention relates to the decontamination and cleaning arts. It finds particular application in conjunction with the decontamination of medical instruments and equipment. It will be appreciated, however, that the invention is also applicable to the microbial decontamination, including disinfection or sterilization, of other articles such as food processing equipment, pharmaceutical processing equipment, animal cages, and other equipment. 
     Various methods and apparatus are known for decontaminating and/or sterilizing medical instruments and devices. For example, medical instruments and other devices are commonly sterilized in a steam autoclave. Autoclaves kill life forms with a combination of high temperature and high pressure. However, steam autoclaves have several drawbacks. The pressure vessels are bulky and heavy. Also, the high temperature and pressure tend to reduce the useful life of medical devices having rubber and plastic components. The medical devices must be precleaned before being placed in the autoclave to remove bodily tissues and fluids. Moreover, the autoclave sterilization and cool-down cycles take an excessive amount of time, especially in light of the need to minimize the “down time” of expensive, reusable medical devices. 
     Another known sterilization method utilizes ethylene oxide gas. Ethylene oxide gas sterilization and aeration cycles are even longer than steam autoclave sterilization and cool-down cycles. Ethylene oxide is also hazardous to humans and, therefore, environmental concerns are associated with its use. 
     Low temperature liquid disinfection and sterilization devices are also known. These devices typically utilize one of several known liquid anti-microbial solutions such as peracetic acid, glutaraldehyde, alcohol, aqueous hydrogen peroxide, and the like. In general, these low temperature liquid systems have been found to be effective. However, hospitals and other health care facilities continue to demand improved sterilization effectiveness and efficiency to reduce the risk of infection and to reduce the percentage of time that expensive medical devices are out of use for sterilization procedures. Also, certain low temperature liquid anti-microbial solutions have fallen out of favor. For example, the use of glutaraldehyde presents environmental concerns and also requires an excessively long cycle time to sterilize, rather than simply disinfect, medical devices. The environmentally harmful glutaraldehyde must be specially disposed of, increasing the cost of sterilization. Other agents, such as alcohols, have been found to be destructive to certain plastic components of medical instruments. 
     Recently, there has been an increased emphasis on the effective cleaning of post-operative debris from the medical instruments and devices. Most known sterilization equipment require that the contaminated medical devices be precleaned before the sterilization cycle. Others simply sterilize without regard to cleaning which results in a sterile device having sterile debris adhered thereto. 
     Certain sterilization devices rely upon the filtering of water with a 0.2 μm or smaller pore size microbe-removal filter media to provide a sterile rinse liquid. However, it would be desirable to provide an additional safeguard against the recontamination of medical devices with rinse liquid by ensuring a virus-free rinse solution. A virus-free rinse solution may not be assured with simple filtration of the rinse liquid. Therefore, there has been found a need to provide a sterilization apparatus that ensures a bacteria and virus free rinse liquid to prevent the accidental recontamination of the sterilized medical device during rinsing operations. 
     Most recently, the cleaning and decontamination properties of solutions formed via the electrolysis of water under special conditions have been explored. Electrolysis devices are known which receive a supply of water, such as tap water, commonly doped with a salt, and perform electrolysis on the water to produce (I) an anolyte produced at the anode of the electrolysis unit; and, (ii) and catholyte produced at the cathode of the electrolysis unit. The anolyte and catholyte may be used individually or as a combination. The anolyte has been found to have anti-microbial properties, including anti-viral properties. The catholyte has been found to have cleaning properties. 
     To create these anolyte and catholyte solutions, tap water, often with an added electrically conducting agent such as halogen salts including the salts sodium chloride and potassium chloride, is passed through an electrolysis unit or module which has at least one anode chamber and at least one cathode chamber which may be separated from each other by a membrane. An anode contacts the water flowing in the anode chamber, while the cathode contacts the water flowing in the cathode chamber. The anode and cathode are connected across a source of electrical potential to expose the water to an electrical field. The membrane may allow the transfer of electron carrying species between the anode and the cathode but limits fluid transfer between the anode and cathode chambers. The salt and minerals naturally present in and/or added to the tap water undergo oxidation in the anode chamber and reduction in the cathode chamber. The solution resulting at the anode (anolyte) and the solution resulting at the cathode (catholyte) remain separate or are recombined and can be used for a wide variety of different purposes. 
     However, electrochemically activated (ECA) water is not without shortcomings. ECA waters have high surface energies comparable to the incoming water. The high surface energies of ECA water have been found to cause lower penetration ability of the ECA water. In the medical instrument field, for example, high penetration ability is desired due to the complex nature of medical instruments. A sterilant must be able to penetrate even the smallest crevices in order to ensure the sterility of the instrument. The high surface energy of ECA water does not allow for penetration of the ECA water into creviced areas of medical instruments. Thus, complete kill may not be achieved. 
     Further problems have arisen on metal surfaces coming into contact with the ECA water, including the sterilization equipment and metal medical devices. The ECA water is corrosive to metal. Stainless steel, used to produce many medical devices, is particularly susceptible to corrosion by ECA water. 
     ECA water as a decontamination and cleaning agent can therefore produce some results which are problematic when decontaminating complex metal objects such as stainless steel medical equipment. 
     The present invention contemplates an improved ECA water solution. The improved ECA water solution has enhanced penetration ability and reduced corrosiveness compared to prior ECA water solutions. 
     SUMMARY OF THE INVENTION 
     In accordance with a first aspect of the present invention, an anticorrosive composition for cleaning and decontaminating is provided which comprises electrochemically activated (ECA) water as the decontamination agent. The anticorrosive decontamination composition has, as the anticorrosive agent, a compound or mixture of compounds capable of inhibiting corrosion of various metals used in sterilization systems and objects such as medical instruments. 
     In accordance with another aspect of the invention, other additives, including wetting agents, are added to reduce the surface energy of the ECA water. This reduced surface energy permits the ECA water to penetrate into complex objects thus permitting complete decontamination of the treated object. 
     A further aspect of the invention includes a method for decontamination of metal objects, including medical equipment, by using ECA water which contains anticorrosive agents. The ECA water may additionally contain wetting agents to enhance penetration of the ECA water into crevices of objects to be treated. This assures complete decontamination of the treated object. 
     One advantage of the present composition is that metal objects may be effectively decontaminated using ECA water with considerably reduced metal corrosion. 
     Another advantage of the present invention resides in its improved solution penetration into complex objects due to lower surface energy of the solution. 
     A further advantage relates to the use of the treated ECA water as a final rinse solution in a sterilization apparatus without corroding the sterilization apparatus or instruments being sterilized therein. 
     Still other advantages and benefits of the invention will become apparent to those skilled in the art upon a reading and understanding of the following detailed description of the preferred embodiments. 
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Water to be used in a sterilization procedure is introduced into a suitable water electrolysis apparatus. Such an apparatus includes at least one electrolysis unit or module having an anode chamber and a cathode chamber and may be separated by a membrane. The membrane, if present, divides the water into two parts, a first part in the anode chamber and a second part in the cathode chamber. In flow through systems, incoming water is divided into two flows that are channeled to the anode and cathode chambers, respectively. Examples of such water electrolysis units are as described in U.S. Pat. Nos. 5,635,040; 5,628,888; 5,427,667; 5,334,383; 5,507,932; 5,560,816; and 5,622,848 whose disclosures are incorporated herein by reference. Any other suitable water electrolysis units may be used, including an electrolysis unit that utilizes a batch type electrochemical activation. The invention is not meant to be limited to any particular electrolysis apparatus. 
     The electrode chamber of an electrolysis unit includes an anode electrode and a cathode electrode that contacts the passing water. The membrane, if present, prevents the anolyte and catholyte from mixing. The membrane allows electron carrying species to transfer between the anode and cathode chambers. A source of electric potential is connected across the anode and the cathode to expose the water to an electric field that produces an oxidation reaction at the anode and a reduction reaction at the cathode. These reactions convert the water into an anolyte solution and a catholyte solution. If desired, first and second reservoirs or holding tanks may be provided in fluid communication with the outlets of the chambers in a system separating the anolyte and catholyte to hold the catholyte and anolyte solutions, respectively, as they are produced so that these solutions may be used subsequently for decontamination and/or cleaning, including disinfection, sterilization, and rinsing operations. 
     In a first embodiment, corrosion inhibiting and surface energy reducing additives are introduced into the water prior to or during electrolysis. The corrosion inhibitors and surface energy reducing additives which are added to the water prior to or during the electrolysis are those which are not decomposed upon passage through the electrolysis unit. Consequently, the additives, such as corrosion inhibitors, retain their anticorrosive activity upon circulation through the electrolysis unit. Further, the ECA water&#39;s decontamination properties are not compromised by the inclusion of the additives prior to or during electrochemical activation of the water. 
     In a second embodiment, the additives (corrosion inhibitors and/or surface energy reducing agents) are added after electrolysis. If added after electrolysis, the additives may be added to the catholyte or the anolyte. Other additives, including, but not limited to, detergents and pH buffers, may also be added to the catholyte and/or anolyte solution. 
     The corrosion inhibitory agents are selected in accordance with the nature of the materials in the items being cleaned and/or decontaminated with the electrochemically activated water. Corrosion inhibitors which protect against corrosion of aluminum and steel, including stainless steel, include phosphates, sulfates, chromates, dichromates, borates, molybdates, vanadates, and tungstates. Some additional aluminum corrosion inhibitors include 8-hydroxyquinoline and ortho-phenylphenol. 
     More specifically, phosphates are preferred for inhibiting stainless steel corrosion. Preferred phosphates include, but are not limited to, monosodium phosphate (MSP), disodium phosphate (DSP), sodium tripolyphosphate (TSP), sodium hexametaphosphate (HMP), and sodium sulfate either alone or in combination. Preferred borates include sodium metaborate (NaBO 2 ). 
     The copper and brass corrosion inhibitors include triazoles, azoles, benzoates, tolyltriazoles, dimercapto-thiadiazoles, and other five-membered ring compounds. Preferably, the copper and brass corrosion inhibitors include sodium salts of benzotriazole and tolyltriazole which are preferred due to their stability in the presence of strong oxidizing compounds. Mercaptobenzothiazole can also be utilized but is apt to be oxidized or destabilized by strong oxidizers. Salicylic acid is an example of an acceptable benzoate corrosion inhibitor. 
     In hard water, the phosphates tend to cause calcium and magnesium salts present in hard water to precipitate and coat the instruments being decontaminated and/or cleaned and also leaves deposits on parts of the electrolysis system. A sequestering agent appropriate to prevent precipitation such as sodium hexametaphosphate (HMP), or trisodium nitrolotriacetic acid (NTA Na 3 ) is preferably provided. Because sodium hexametaphosphate is also a corrosion inhibitor, it serves a dual purpose, both as a corrosion inhibitor and as a sequestering agent. Other sequestering agents include sodium polyacrylates. Of course, if soft or deionized water is utilized, the sequestering agent may be eliminated. However, to ensure universal applicability with any water that might be utilized, the presence of a sequestering agent is preferred. It is noted that the sequestering agent can be added to the water prior to, during or after electrochemical activation of the water without any negative impact on the decontamination properties of the ECA water or the activation of the water in general. 
     A surface energy reducing agent is added to the electrochemically activated water in order to reduce the surface energy of electrochemically activated water thereby increasing the ability of the electrochemically activated water to penetrate into crevices of items being treated. This is particularly important when cleaning and decontaminating complex medical instruments which may contain microbial contaminants in crevices, joints, and lumens. 
     Surface energy reducing agents usable in accordance with the present invention include various wetting agents. Such wetting agents include anionic, cationic, nonionic, amphoteric, and/or zwitterionic surfactants. Specific classes of wetting agents which useful include anionic and nonionic surfactants or combinations thereof. Examples of nonionic wetting agents usable in the present invention include surfactants such as fatty alcohol polyglycol ethers, nonylphenoxypoly (ethyleneoxy) ethanol, and ethoxylated polyoxypropylene. Specific examples include Genapol UD-50™ (Oxoalcohol polyglycol ether), Igepal™ (Nonylphenoxypoly (ethyleneoxy) ethanol), Fluowet™ (Fluoroxo-alcohol polyglycol ether), and Pegal™ (Ethoxylated polyoxypropylene). The wetting agents set forth above may be used alone or in combination with each other. 
     In a first embodiment, corrosion inhibitors such as monosodium phosphate, disodium phosphate, and sodium hexametaphosphate, either alone or in combination, are added to water along with a wetting agent prior to or during electrochemical activation. Addition of such corrosion inhibitors prior to or during electrochemical activation of water, wherein said corrosion inhibitors are passed through the electrolysis unit during actual electrochemical activation of the water, does not decompose the corrosion inhibitory activity of the agent. Further, addition of such corrosion inhibitory agents prior to or during electrochemical activation of the water does not negatively affect the decontamination properties of the activated water. The above treated water is especially useful as a decontamination and/or cleaning agent for stainless steel medical instruments wherein the treated instrument remains free of corrosion but is microbially decontaminated. In addition, the above treated water is highly effective as a rinsing agent for use in conventional sterilization systems. The ECA water acts not only as a rinse but as an antimicrobial-anticorrosive protective rinse. By adding the corrosion inhibitors and wetting agents prior to or during electrochemical activation, the sterilization system and instruments are protected from corrosion and decontamination from the rinse solution. 
     A second embodiment introduces the corrosion inhibitors and/or wetting agents to the catholyte or anolyte produced after electrolysis of the water. The same advantages described above remain readily realized. 
     Amounts of corrosion inhibitor and wetting agents to be added to the electrochemically activated water will vary depending upon the type of agent being added and whether or not one or more agents are added. 
     The inorganic corrosion inhibitors are preferably present in amounts ranging from about 0.01% to 20.0% weight per volume (w/v). Organic corrosion inhibitors are preferably present in amounts ranging from about 0.01% to 5.0% w/v. Phosphates are preferably effective at rates in the range of about 0.01% to about 11.0% w/v. 
     The wetting agents are preferably present in amounts ranging from about 0.0001% to about 5.0% w/v. More preferably, the wetting agent is present in amounts ranging from about 0.0001% to about 0.5% w/v. 
    
    
     FORMULATION EXAMPLE 
     An example of a formulation according to the invention is set forth below: 
     FORMULATION 1 
     Component 1) Disodium phosphate (DSP) 4.766 g/L (corrosion inhibitor) 
     Component 2) Monosodium phosphate (MSP) 0.40 g/L (corrosion inhibitor) 
     Component 3) Sodium hexametaphosphate (HMP) 0.330 g/L (corrosion inhibitor) 
     Component 4) Genapol 462 μl/L (wetting agent) 
     The following are examples that illustrate the corrosion inhibiting effectiveness, anti-microbial, and surface tension reducing properties of the compositions of the present invention. 
     The examples below all utilize the composition identified hereinbefore as Formulation 1. Additionally, the ECA solution was prepared according to the method described hereinbefore. 
     Surface Tension Reduction 
     Surface tension of ECA solutions without additives vs. surface tension of ECA solutions with additives (Formulation 1) are given in Table 1: 
     
       
         
               
               
               
             
               
               
               
             
           
               
                   
                 TABLE 1 
               
               
                   
                   
               
               
                   
                 ECA Solutions 
                 ECA Solutions 
               
               
                   
                 Without Additives 
                 With Additives 
               
               
                   
                   
               
             
             
               
                   
               
             
          
           
               
                 Surface Tension 
                 69.9, 64.1, 72.8 
                 28.7, 28.6, 28.0, 
               
               
                 (dynes/cm) 
                   
                 28.3, 28.4 
               
               
                   
               
               
                 Note:The surface tension of deionized water at 25° C. is 72.8 dynes/cm.  
               
             
          
         
       
     
     As can be seen, when using the formulation of the invention with ECA water, surface tension decreased to less than half of the amount present in an untreated ECA solution. 
     Antimicrobial Properties 
     D-value comparison for ECA solution without additives vs. ECA solution with additives (Formulation 1) are given in Table 2: 
     
       
         
               
               
               
               
               
               
             
               
               
               
               
               
               
             
           
               
                 TABLE 2 
               
               
                   
               
               
                   
                   
                   
                   
                 Longest 
                   
               
               
                 Test 
                   
                   
                 Avg. linear reg. 
                 endpoint 
                 Test 
               
               
                 Solution 
                 Temp., ° C. 
                 n 
                 D-value (sec) 
                 (sec) 
                 organism 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                 ECA 
                 20 
                 7 
                 28.4 ± 6.6 
                 240 
                 
                   B. subtilis 
                 
               
               
                 ECA 
                 20 
                 1 
                 33.0 
                 210 
                 
                   B. subtilis 
                 
               
               
                 w/Formu- 
               
               
                 lation 1 
               
               
                   
               
               
                 n = number of tests  
               
             
          
         
       
     
     As is evident from the above comparison, the additives do not adversely affect the antimicrobial properties of the ECA water. 
     Corrosion Inhibitory Properties 
     The data in Table 3 compares the corrosion occurring on materials exposed to ECA water (without additives) and a bleach solution. Both the ECA water and bleach solution have ˜300 ppm free chlorine. As can be seen from the results, metallic materials show a more significant degree of degradation than polymeric materials. 
     
       
         
               
             
               
               
               
             
               
               
               
               
               
             
               
               
               
               
               
             
           
               
                 TABLE 3 
               
             
             
               
                   
               
               
                 MATERIALS COMPATIBILITY IN ELECTROCHEMICALLY ACTIVE SOLUTION AND BLEACH SOLUTION 
               
               
                 The following materials were tested in ECA Solution or in a bleach use dilution (˜300 ppm). 
               
               
                 One hour of solution exposure is equivalent to 1 cycle. 
               
             
          
           
               
                   
                 ECA SOLUTION 
                 BLEACH SOLUTION 
               
             
          
           
               
                 MATERIAL 
                 Cycles 
                 Observations 
                 Cycles 
                 Observations 
               
               
                   
               
             
          
           
               
                 Aluminum, 6061-T6 
                 24 
                 ˜70% surface discoloration 
                 24 
                 ˜70% surface discoloration 
               
               
                 Anodized Aluminum 6061-T6 
                 720 
                 no change 
                 672 
                 75-80% anodization degraded 
               
               
                 Aluminum 1100 (Calgon Vestal) 
                 24 
                 ˜50% surface discoloration 
                 24 
                 ˜70% surface discoloration 
               
               
                 Anodized Aluminum (Calgon Vestal) 
                 672 
                 no change 
                 672 
                 75-80% anodization degraded 
               
               
                 Brass 
                 24 
                 ˜50% surface discoloration 
                 24 
                 ˜70% surface discoloration 
               
               
                 Borosilicate 
                 720 
                 no change 
                 600 
                 no change 
               
               
                 CDA 110 (Calgon Vestal; 99.9% copper) 
                 24 
                 ˜50% surface discoloration 
                 24 
                 ˜50% surface discoloration 
               
               
                 CDA 443 (Calgon Vestal; 75% copper, 28% zinc) 
                 24 
                 ˜50% surface discoloration 
                 24 
                 ˜50% surface discoloration 
               
               
                 Ethylene propylene 
                 720 
                 no change 
                 600 
                 no change 
               
               
                 Ethylene propylene diamine (EPDM) 
                 720 
                 no change 
                 600 
                 no change 
               
               
                 Fluorosilicone (Viton O-ring) 
                 720 
                 no change 
                 600 
                 no change 
               
               
                 Latex (medical glove) 
                 600 
                 little elasticity 
                 600 
                 elasticity in tact; 
               
               
                   
                   
                   
                   
                 material “bleached” to white color 
               
               
                 Polycarbonate 
                 720 
                 no change 
                 600 
                 no change 
               
               
                 Polyethylene (high density) 
                 720 
                 no change 
                 600 
                 no change 
               
               
                 Polytetrafluoroethylene (Gore-tex tubing) 
                 600 
                 no change 
                 600 
                 no change 
               
               
                 Polypropylene 
                 720 
                 no change 
                 600 
                 no change 
               
               
                 Polyurethane 
                 48 
                 white label slightly discolored; 
                 N/A 
                 N/A 
               
               
                   
                   
                 tackiness 
               
               
                 Polyvinyl chloride (Tygon tubing) 
                 720 
                 no change 
                 600 
                 no change 
               
               
                 Polyvinyl chloride (Tygon tubing - medical grade) 
                 720 
                 no change 
                 600 
                 no change 
               
               
                 Polyvinyl chloride (UPVC) 
                 720 
                 no change 
                 600 
                 no change 
               
               
                 Silicone (0-ring) 
                 720 
                 cracking 
                 600 
                 cracking 
               
               
                 Stainless Steel 17-4P11 
                 24 
                 &lt;5% surface discoloration; 
                 24 
                 &lt;5% surface discoloration; 
               
               
                   
                   
                 pitting (˜3 mm diam.) 
                   
                 pitting (˜3 mm diam.) 
               
               
                 Stainless Steel 316L 
                 24 
                 &lt;10% surface discoloration 
                 24 
                 &lt;2% surface discoloration; 
               
               
                   
                   
                   
                   
                 pitting (˜2 mm diam.) 
               
               
                 Stainless Steel 316 (Calgon Vestal) 
                 24 
                 &lt;10% surface discoloration 
                 24 
                 &lt;2% surface discoloration; 
               
               
                   
                   
                   
                   
                 pitting (˜2 mm diam.) 
               
               
                   
               
             
          
         
       
     
     The data in Table 4 demonstrates the ability of the additives of the invention, such as Formulation 1 above, to reduce corrosion attributed to untreated ECA water. 
     
       
         
               
             
               
               
               
               
             
               
               
               
               
             
           
               
                 TABLE 4 
               
             
             
               
                   
               
               
                 ECA SOLUTION MATERIALS COMPATIBILITY SUMMARY 
               
               
                 The following materials were tested in ECA solution, Formulation #1, and in a bleach use dilution ˜300 ppm). 
               
               
                 One hour of solution exposure is equivalent to one cycle. All solutions had a 300 ± 30 ppm 
               
               
                 free chlorine concentration, which were evaluated spectrophotometrically. 
               
             
          
           
               
                   
                 *BLEACH USE DILUTION 
                 *ECA SOLUTION 
                 *FORMULA #1 
               
               
                   
                   
               
             
          
           
               
                 Aluminum 6061 
                 @ 24 cycles: 
                 @ 24 cycles: 
                 @ 24 cycles: 
               
               
                   
                 ˜70% surface discoloration 
                 ˜70% surface discoloration 
                 ˜5% surface corrosion 
               
               
                 Aluminum 6061 - anodized 
                  @ 672 cycles: 
                 no change 
                 no change 
               
               
                   
                 ˜75-80% anodization degraded 
               
               
                 Brass 
                 @ 24 cycles: 
                 @ 24 cycles: 
                 @ 24 cycles: 
               
               
                   
                 ˜70% surface discoloration 
                 ˜50% surface discoloration 
                 ˜10% surface discoloration 
               
               
                 Stainless Steel 316L 
                 @ 24 cycles: 
                 @ 24 cycles: 
                 @ 24 cycles: 
               
               
                   
                 &lt;2% surface corrosion; pitting 
                 ˜10% surface discoloration 
                 ˜5% surface discoloration 
               
               
                   
                 in small area (˜3 mm diam.) 
               
               
                 Stainless Steel 17-4PH 
                 @ 24 cycles: 
                 @ 24 cycles: 
                 @ 24 cycles: 
               
               
                   
                 &lt;5% surface corrosion; pitting 
                 ˜5% surface corrosion; pitting 
                 ˜2% surface discoloration 
               
               
                   
                 in small area (˜3 mm diam.) 
                 in small area (˜3 mm diam.) 
               
               
                   
               
               
                 *All solutions had a 300 ± 30 ppm free chlorine concentration, which were evaluated spectrophotometrically.  
               
             
          
         
       
     
     As can be seen from Table 4, ECA with Formulation #1 additives substantially reduced corrosion in comparison to untreated ECA and a bleach solution on aluminum, brass, and stainless steel. As noted hereinbefore, these are the main metals used in medical equipment. 
     An additional test was conducted which compared untreated ECA water with ECA water having Formulation #1 added on PENTAX® medical device components. Below, in Table 5, is a comparative analysis of the results. 
     
       
         
               
             
               
               
               
             
               
               
               
               
               
             
               
               
               
               
               
             
           
               
                 TABLE 5 
               
             
             
               
                   
               
               
                 MATERIALS COMPATIBILITY OF PENTAX MEDICAL DEVICE COMPONENTS 
               
               
                 IN ELECTROCHEMICALLY ACTIVE SOLUTION OR FORMULA #1 
               
               
                 The following materials were tested in ECA Solution with additives, Formula #1 in ECA solution. 
               
               
                 One hour of solution exposure is equivalent to one cycle. 
               
             
          
           
               
                   
                 ECA SOLUTION 
                 ECA FORMULA #1 SOLUTION 
               
             
          
           
               
                 MATERIAL 
                 Cycles 
                 Observations 
                 Cycles 
                 Observations 
               
               
                   
               
             
          
           
               
                 Black, plastic cylinder 
                 120 
                 no change 
                 120 
                 no change 
               
               
                 Thin, black collar 
                 120 
                 no change 
                 120 
                 no change 
               
               
                 Treated metal tube 
                 8 
                 black “specks”—qty increases with time; 
                 120 
                 no change 
               
               
                   
                   
                 possible inner corrosion 
               
               
                 Screw w/wide threads 
                 1-120 
                 40% surface corrosion at 120 cycles 
                 120 
                 no change 
               
               
                 Screw w/narrow threads 
                 72 
                 &lt;1% corrosion 
                 120 
                 no change 
               
               
                 Thin metal piece w/1 hole 
                 120 
                 no change 
                 120 
                 no change 
               
               
                 Thin, bent metal piece w/4 holes 
                 120 
                 no change 
                 120 
                 no change 
               
               
                 Metal nut 
                 8-120 
                 corrosion at 15 minutes; 
                 1-120 
                 corrosion at 24 hrs.; 
               
               
                   
                   
                 increased corrosion over time; 
                   
                 increased corrosion over time; 
               
               
                   
                   
                 possible leeching of metal-metal 
                   
                 possible leeching of metal-metal 
               
               
                   
                   
                 binding adhesive 
                   
                 binding sdhesive 
               
               
                 Air/water valve 
                   
                   
                 120 
                 no change 
               
               
                 Metal inlet/outlet port 
                 1-120 
                 corrosion at 1 hr; 
                 120 
                 no change 
               
               
                   
                   
                 increased corrosion over time; 
               
               
                   
                   
                 all corrosion appears at 
               
               
                   
                   
                 soldered joints/pieces 
               
               
                 Black,metal sleeve w/threads 
                   
                   
                 120 
                 no change 
               
               
                   
               
             
          
         
       
     
     As can be seen from Table 5, those components of PENTAX medical equipment which were susceptible to corrosion due to ECA water were either not corroded when Formulation #1 was added or the corrosion was substantially reduced in the presence of the additives. 
     Further, testing has been conducted which demonstrates that the functionality of corrosion inhibitors is maintained and not destroyed by circulation through an electrolysis unit during electrochemical activation of water. 
     The following Example demonstrates that the corrosion inhibition activity of corrosion inhibitors which are added to ECA water during electrochemical activation does not destroy the corrosion inhibitory activity of the corrosion inhibitors. 
     EXAMPLE 1 
     Hard water containing 400 ppm CaCO 3  was circulated through an electrolysis unit at 12 A (current) and a flowrate of 80L/hr to generate 10.0L of ECA solution having the following properties: 
     
       
         
               
             
               
               
               
             
           
               
                   
               
               
                 10.0L ECA Solution 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                   
                 pH = 8.24 
                 Conductivity = 10.31 mS/cm 
               
               
                   
                 free chlorine = 264 ppm 
                 Surface tension = 65.3 dynes/cm 
               
               
                   
                 Temp. = 50° C. 
                 ORP = 770 mV 
               
               
                   
                   
               
             
          
         
       
     
     To the 10.0L ECA solution, while in the electrolysis unit, the following components were added: 
     monosodium phosphate (MSP) at 4.00 g 
     disodium phosphate (DSP) at 47.66 g 
     sodium hexametaphosphate (HMP) at 3.30 g 
     Genapol (wetting agent) at 4620 μL 
     The resulting modified ECA solution had the following properties: 
     
       
         
               
             
               
               
               
             
           
               
                   
               
               
                 Modified ECA solution 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                   
                 pH = 7.70 
                 Conductivity = 14.5 mS/cm 
               
               
                   
                 Free Chlorine = 246 ppm 
                 Surface Tension = 29.4 dynes/cm 
               
               
                   
                 Temp = 53° C. 
                 ORP = 805 mV 
               
               
                   
                   
               
             
          
         
       
     
     Bovine serum art 0.1% was then added to the modified ECA solution. 
     The bovine/modified ECA solution had the following properties: 
     
       
         
               
             
               
               
               
             
           
               
                   
               
               
                 Bovine/Modified ECA solution 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                   
                 pH = 7.69 
                 Conductivity = 14.5 mS/cm 
               
               
                   
                 free chlorine = 199 ppm 
                 Surface tension = 29.3 dynes/cm 
               
               
                   
                 Temp = 53° C. 
                 ORP = 803 mV 
               
               
                   
                   
               
             
          
         
       
     
     Five coupons of various metals were then introduced into the solution in the electrolysis unit and the solution was allowed to continue to recirculate through the unit. The free chlorine of the solution was monitored during recirculation until it reached 300 ppm. After seven (7) minutes, a twelve (12) minute timer was set and the solution parameters were measured after twelve minutes. The solution, after the twelve (12) minute period had the following properties: 
     
       
         
               
             
               
               
               
             
           
               
                   
               
               
                 Modified ECA solution after 12 minute circulation period 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                   
                 pH = 7.86 
                 Conductivity = 14.86 mS/cm 
               
               
                   
                 free chlorine = 393 ppm 
                 Surface tension = 30.1 dynes/cm 
               
               
                   
                 Temp. = 50° C. 
                 ORP = 820 mV 
               
               
                   
                   
               
             
          
         
       
     
     A control hard water bath was also provided which had 400 ppm (CaCO 3 ) at 53.3° C. (±3° C.). The five coupons were also placed in the control water bath. 
     The following results were observed from the coupons introduced into the electrolysis unit containing the modified ECA solution according to the invention and from the control hard water bath: 
     
       
         
               
               
               
             
           
               
                   
               
               
                   
                   
                 Control 
               
               
                 Metal Coupon 
                 Modified ECA Solution 
                 (hard water) 
               
               
                   
               
             
             
               
                 Brass 
                 &lt;5% Corrosion 
                 NC 
               
               
                 Aluminum (6061) 
                 NC 
                 NC 
               
               
                 Anodized Aluminum 
                 NC 
                 NC 
               
               
                 (6061) 
               
               
                 Stainless Steel 
                 NC 
                 NC 
               
               
                 316L (S.S. 316L) 
               
               
                 Stainless Steel 
                 NC 
                 NC 
               
               
                 (S.S. 17-4 PH) 
               
               
                   
               
             
          
         
       
     
     As is evident from the above, even after recirculation through the ECA system for at least 12 minutes, the corrosion inhibitor continued to function to reduce the corrosive properties of the ECA water. 
     In addition to the above, five additional test runs were conducted in accordance with the procedure of Example 1. The results from these tests are provided below: 
     
       
         
               
               
               
               
               
               
             
               
             
               
               
               
               
               
               
             
               
             
               
               
               
               
               
               
             
               
             
               
               
               
               
               
               
             
               
             
               
               
               
               
               
               
             
               
             
               
               
               
               
               
               
             
           
               
                   
               
             
             
               
                 Test No. 
                 2 
                 3 
                 4 
                 5 
                 6 
               
               
                   
               
             
          
           
               
                 10L ECA 
               
             
          
           
               
                 pH 
                 7.95 
                 8.10 
                 8.21 
                 8.30 
                 8.24 
               
               
                 free C1 −  (ppm) 
                 312 
                 340 
                 323 
                 308 
                 337 
               
               
                 Temp. (° C.) 
                 52 
                 51 
                 54 
                 54 
                 53 
               
               
                 Conductivity 
                 11.06 
                 11.64 
                 11.74 
                 10.66 
                 11.70 
               
               
                 (mS/cm) 
               
               
                 Surface tension 
                 64.0 
                 63.8 
                 64.1 
                 64.0 
                 65.4 
               
               
                 (dynes/cm) 
               
               
                 ORP (mV) 
                 798 
                 804 
                 800 
                 758 
                 796 
               
             
          
           
               
                 Modified ECA 
               
             
          
           
               
                 pH 
                 7.68 
                 7.72 
                 7.71 
                 7.71 
                 7.69 
               
               
                 free C1 −  (ppm) 
                 298 
                 319 
                 298 
                 284 
                 294 
               
               
                 Temp. (° C.) 
                 53 
                 53 
                 53 
                 54 
                 54 
               
               
                 Conductivity 
                 15.78 
                 16.23 
                 15.12 
                 14.60 
                 14.96 
               
               
                 (mS/cm) 
               
               
                 Surface tension 
                 28.0 
                 27.8 
                 31.0 
                 27.4 
                 28.4 
               
               
                 (dynes/cm) 
               
               
                 ORP (mV) 
                 820 
                 825 
                 820 
                 825 
                 825 
               
             
          
           
               
                 0.1% Bovine Solution 
               
             
          
           
               
                 pH 
                 7.70 
                 7.73 
                 7.69 
                 7.65 
                 7.71 
               
               
                 free C1 −  (ppm) 
                 250 
                 258 
                 233 
                 228 
                 219 
               
               
                 Temp. (° C.) 
                 53 
                 53 
                 53 
                 53 
                 53 
               
               
                 Conductivity 
                 15.71 
                 17.5 
                 15.28 
                 13.81 
                 15.7 
               
               
                 (mS/cm) 
               
               
                 Surface Tension 
                 28.4 
                 28.4 
                 29.9 
                 28.3 
                 28.7 
               
               
                 (dynes/cm) 
               
               
                 ORP (mV) 
                 815 
                 845 
                 840 
                 840 
                 840 
               
               
                 Circulation 
                 4 
                 4 
                 3 
                 4 
                 3.5 
               
               
                 Time to get 300 ppm 
               
               
                 Free chlorine (min.) 
               
             
          
           
               
                 After 12 minute recirculation 
               
             
          
           
               
                 pH 
                 7.75 
                 7.70 
                 7.65 
                 7.69 
                 7.80 
               
               
                 free C1 −  (ppm) 
                 383 
                 408 
                 504 
                 399 
                 453 
               
               
                 Temp. (° C.) 
                 50 
                 50 
                 51 
                 50 
                 51 
               
               
                 Conductivity 
                 15.62 
                 17.60 
                 &lt;20 
                 15.28 
                 15.3 
               
               
                 (mS/cm) 
               
               
                 Surface Tension 
                 32.4 
                 30.4 
                 31.9 
                 30.0 
                 30.1 
               
               
                 (dynes/cm) 
               
               
                 ORP (mV) 
                 831 
                 840 
                 850 
                 850 
                 844 
               
               
                   
               
             
          
           
               
                 Changes in coupons 
               
             
          
           
               
                 (Test/control) 
                 2 
                 3 
                 4 
                 5 
                 6 
               
               
                   
               
               
                 Brass 
                 &lt;5%/NC 
                 &lt;5%/NC 
                 &lt;5%/5% (color) 
                 &lt;5%/5% (color) 
                 &lt;5%/&gt;5% (corrosion) 
               
               
                 Aluminum 
                 NC/NC 
                 NC/NC 
                 NC/NC 
                 NC/NC 
                 NC/NC 
               
               
                 Anod. Aluminum 
                 NC/NC 
                 NC/NC 
                 NC/NC 
                 NC/NC 
                 NC/NC 
               
               
                 S.S 316L 
                 &lt;5% (color)/NC 
                 &lt;5% (color)/NC 
                 &gt;5% (color)/NC 
                 &gt;5% (color)/NC 
                 &lt;5% (color)/NC 
               
               
                 S.S. 17-4 pH 
                 NC/NC 
                 NC/NC 
                 NC/NC 
                 NC/NC 
                 NC/NC 
               
               
                   
               
             
          
         
       
     
     Based on the results as shown above, it is evident that the functionality of the corrosion inhibitor in the ECA water, during electrochemical activation of the water, did not get destroyed by the electrochemical activation system. Also, the surfactants were not modified during the recirculation because surface tensions did not change significantly. 
     Further, based on the above comparative tests, the advantages of reduced corrosion and enhanced penetration attained from using ECA water with the above-described corrosion inhibitors and/or surface tension reducing agents are readily apparent wherein the treated ECA water can be utilized without any loss in its biocidal properties. 
     The invention has been described with reference to the preferred embodiments. Obviously, modifications and alterations will occur to others upon reading and understanding the preceding detailed description. It is intended that the invention be construed as including all such modifications and alterations insofar as they come within the scope of the appended claims or the equivalents thereof.

Technology Classification (CPC): 2