WO1993009213A1

WO1993009213A1 - Nontoxic sanitizing cleaner

Info

Publication number: WO1993009213A1
Application number: PCT/US1991/008336
Authority: WO
Inventors: Robert Regutti
Original assignee: Gycor International Ltd.
Priority date: 1991-11-07
Filing date: 1991-11-07
Publication date: 1993-05-13

Abstract

A nontoxic sanitizing cleaner comprising an organic acid having a pH less than 3, a chelating agent, and a surfactant. The invention also contemplates a buffering agent in the cleaner. In a preferred embodiment, the sanitizing cleaner is in the form of a solution consisting of 94 % citric acid, 4 % EDTA, 1 % sodium lauryl sulfate, and 1 % monosodium phosphate, by weight.

Description

NONTOXIC SANITIZING CLEANER

The present invention relates generally to antimicrobial preparations and to such preparations which are capable of cleaning surfaces.

BACKGROUND OF THE INVENTION

There are many applications which require the application of a sanitizing preparation to a surface to prevent buildup of microorganisms on the surface and consequent health threats. One such application is cleaning and sanitizing processing equipment, and counters and

tables which are in contact with food, such as in restaurants. Another application is disinfecting and cleaning surfaces in hospitals and health care facilities. Also, a sanitizing preparation is desirable to remove microorganisms from the skin of a person by applying the preparation in the form of a lotion, ointment or salve directly to the skin.

In such applications, it is desirable to kill the microorganisms on such surfaces and thereafter remove the remnants of the organism by a cleaning process. In the past, most sanitizing preparations have killing power, but little cleaning power. Further, the sanitizing preparations used in the past generally contain caustic or toxic ingredients and must be rinsed off with water, or isolated from the skin of the person applying it, such as with gloves. The commonly used sanitizing preparations are based on chlorine, iodine or quaternary compounds, and require care in applying the preparation and present a storage and health hazard.

It is an object of the present invention to provide a sanitizing preparation which may be applied by hand and will not harm the skin of the person applying the preparation. It is also an object of the present invention to provide a sanitizing preparation which may be applied to the skin of a person to remove microorganisms from the skin. Further, it is an object of the invention to provide such a sanitizing preparation which is more effective than bleach in destroying the most important disease producing microorganisms. In addition, it is an object of the present invention to provide a sanitizing preparation which not only effectively destroys microorganisms, but also is an effective surface cleaner without the need of a water rinse.

SUMMARY OF THE INVENTION

It has long been known that microorganisms are inhibited by an acidic atmosphere. Accordingly, an organic acid with a pH less than three is utilized as an ingredient of the preparation according to the present invention.

While organic acids, such as citric acid, retard the growth of microorganisms, they have not been noted for the rapid destruction of such organisms.

The inventor has found that the direct kill rate of certain important bacterial organisms is increased by applying a preparation to such surfaces which adds a chelating agent to the organic acid. Further, the direct kill rate of the preparation is further increased to exceed that of chlorine by the addition of a surfactant. In addition, a preparation with an organic acid, chelating agent and surfactant functions as an effective cleaning agent. Further, the inventor has found that the ingredients of this composition may be selected of noncaustic and nontoxic materials, and the resulting sanitizing cleaner is itself noncaustic and nontoxic.

The organic acid must have a pH less than three, and creates an inhospitable environment for microorganisms. Not all microorganisms will be killed by the organic acid alone, and the addition of a chelating agent expands the organisms that will be killed by the composition and increases the kill rate. It is believed that the chelating agent functions by tying up the metals .and making them unavailable to the microorganism. Microorganisms require metals to carry out normal functions, and the effect of the chelating agent is

believed to starve the microorganisms and destroy them.

The preparation utilizes a surfactant to wet the surfaces that are subjected to the preparation and facilitate cleaning of those surfaces. The surfactant not only facilitates use of the preparation as a cleaner, but it also affects the kill rate of microorganisms. It is believed that the surfactant effects the outer protective membrane of the microorganism, and creates openings for the entry of the preparation into the microorganism to expedite the reaction of the ingredients of the preparation on

the microorganism. It is further believed that the surfactant causes the microorganism to leak protoplasm, thus reducing its defenses and impeding its ability to reproduce.

The inventor has also found that the kill rate can be increased by the addition of a buffering agent to the preparation. It is believed that the buffering agent maintains the hydrogen potential of the composition constant, thus accelerating the reaction of the preparation.

Organic acids are available which also have a chelating function, although a weaker function than available chelating agents. Also, surfactants are available which have a chelating function, although a weak function. It is thus possible to optimize the chelating function by selecting an organic acid and surfactant which will contribute to the chelating function. Water may be added to the preparation to form a solution, and it has been found that a highly dilute solution of a preparation consisting of about 85% to 98% of an organic acid, about 0.2% to about 10% of a chelating agent, and about 0.2% to about 5% of a surfactant, by weight, will function as a sanitizing cleaner. A solution of between about 0.2% and 5% of the preparation to between about 99-8% to 95% water by weight has been found to be effective- The solution will be more effective with a preparation containing between about 0.2% to about 5% of a buffering agent by weight.

The preparation may also be combined with a lotion and used as a hand cleaner . A water based lotion is particularly desirable since it also functions as a moisturizer. A combination of as little as about 1% of the preparation to about 99% water based lotion has been found to produce a sanitizing and cleaning lotion which also moisturizes the skin.

DESCRIPTION OF THE DRAWING

There is no drawing.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Among the organic acids that are useful in the preparation, citric acid has been preferred for use in the applications set forth above. Other organic acids which are suitable for practicing the invention are fumaric acid, tartaric acid, malic acid, lactic acid, and adipic acid, and mixtures of the enumerated acids-

Among the chelating agents that are suitable for use in the preparation of the invention, disodium ethylenediaminetetraacetate dihydrate, known as EDTA , and its salts are preferred. Other chelating agents suitable for practicing the invention are salicylic acid, polyphosphates, ascorbic acid and blends of these enumerated chelating agents. Even citric acid, a hydroxypolycarboxylic acid, acts as a chelating agent in this nontoxic sanitizing cleaner. The preparation requires an anionic surfactant, and the preferred surfactants are sodium lauryl sulfate or ammonium lauryl sulfate. Other suitable surfactants for practicing the invention are the sarcosinates, particularly sodium lauryl sarcosinate, the sulfoacetates, particularly sodium lauryl sulfoacetate, the sulfosuccinates, particularly disodium monoaleanida or laureth sulfosuccinate, or blends of the enumerated surfactants.

The inventor has found monosodium or potassium phosphate, or mixtures thereof to be the preferred

buffering agents. The buffering agent should have a pH less than about 5.

In the preferred embodiment of the present invention, the preparation is a mixture of citric acid, disodium ethylenediaminetetraacetate dihydrate (EDTA), sodium lauryl sulfate and monosodium phosphate. This preparation has been found to be very effective against pseudomonas, staphylococcus and salmonella, as well as the saccharomyces bailii yeast. It is believed that one of the reasons for the effectiveness of this preparation is the fact that citric acid and sodium lauryl sulfate both function as mild chelating agents, and the chelating effect of these ingredients is additive with that of EDTA.

The organic acid must be sufficiently acidic to produce a pH for the preparation as a whole less than 3, and preferably in the range of 2.0 to 2.3. In a preferred example of the present invention, the organic acid is citric acid having a formula C5IΪ8O7 obtained in anhydrous crystaline form. The chelating agent is EDTA, also known as disodium ethylenediaminetetraacetate dinydrate, marketed by W.R. Grace & Co. under the name HAMP-ENE Na (2). EDTA is obtained in crystaline powder form. The surfactant is sodium lauryl sulfate obtained from Stepan Distributors under the trade name STEPANOL ME-DRY. The sodium lauryl sulfate is obtained in dry powder form. The buffering agent is monosodium phosphate with a formula NaH₂PO₄. The monosodium phosphate is obtained in dry powder form from Harcros Chemicals, Inc. under the trade name PHOS SODA MONO ANHY GRAN.

In one of the preferred preparations, citric acid constitutes 85% to 96% of the dry preparation, EDTA constitutes 0.2% to 10% of the dry preparation, and sodium lauryl sulfate constitutes 0.2% to 5% of the preparation by weight. The preferred buffering agent for use in the preparation is monosodium phosphate, and the monosodium phosphate constitutes 0.2% to 5% of the preparation by weight- The dry ingredients are dissolved in water, preferably deionized water, and the proportion of the dry preparation to water is between 0.3% and 5% preparation to between 95% and 99.7% water, by weight.

EXAMPLE 1

A dry mixture of citric acid, EDTA, sodium lauryl sulfate and monosodium phosphate, in the proportions by weight indicated below, was mixed in a vessel to obtain a generally random mixture of the ingredients:

citric acid 94%

EDTA 4% sodium lauryl sulfate 1% monosodium phosphate 1%

A dilute solution was produced by adding water to the mixture in the proportion of 99.2% water to 0.8% mixture by weight. The mixture was dissolved in the water to produce a stable solution. The solution prepared as set forth above was compared with bleach (NaOCl) to determine the sanitizing effectiveness of the solution. The solution was found to be more effective than a 200 parts per million solution of NaOCl and water against pseudomonas aeruqinosa, staphylococcus aureus, and salmonella typhimurium as well as saccharomyces bailii yeast. The solution was also tested as a cleaner by

applying it in liquid form to a surface contaminated with dried milk, and the liquid and contamination was wiped from the surface with a paper wipe. The solution was observed to have cleaned the surface of dried milk.

EXAMPLE 2

A dry mixture of citric acid, EDTA, and sodium lauryl sulfate, in the proportions by weight indicated below, was mixed in a vessel to obtain a generally randommixture of the ingredients:

citric acid 94%

EDTA 4%

sodium lauryl sulfate 2%

A dilute solution was produced by adding deionized water to the mixture in the proportion of 99.2% water to 0.8% mixture by weight. The mixture was dissolved in the water to produce a stable solution.

The solution was compared to a bleach (NaOCl) solution to determine the sanitizing effectiveness of the solution in the same manner as described with respect to Example 1. The solution of Example 2 was also found to be more effective than a 200 parts per million solution of NaOCl and water against pseudomonas aeruqinosa, staphylococcus aureus, salmonella typhimurium and saccharomyces bailii. The solution was also tested as a cleaner by applying it in liquid form to a surface contaminated with dried milk, and the liquid and contamination was wiped with a paper wipe from the surface. The solution was observed to have cleaned the surface of dried milk. It has been tested successfully as a CIP ╌ clean in place system in beverage lines and in dairy machines, milk shake and ice cream freezers.

EXAMPLE 3

A dry mixture of nontoxic sanitizing cleaner consisting of the mixture of Example 1 hereof was mixed with water to form a 2.0% solution. Mineral oil, glycerine, and stearyl alcohol were brought to a low heat and mixed under constant slow agitation. The 2.0%

sanitizing solution was added to the heated mixture under agitation- The agitation continued until the mixture cooled to the ambient temperature.

This procedure produced an antimicrobal body lotion, in the proportions by weight indicated below:

mineral oil 40%

glycerine 2%

stearyl alcohol 8%

water 49%

sanitizing cleaner composition 1%

Cetyl alcohol may be substituted for stearyl alcohol in the above mixture. Also, a perfume may be added, to the desired aroma level, to give the lotion a desired scent.

The lotion produced by the above-disclosed process possesses all of the sanitizing effectiveness of the solution of Example 1. This lotion, however, has the added benefit of being an effective moisturizer.

EXAMPLE 4

A dry mixture of nontoxic sanitizing cleaner consisting of the mixture of Example 2 hereof was mixed with water to form a 2.3% solution. Mineral oil, olive oil. stearyl alcohol and trietbanolamine were mixed together and heated to 140 degrees Fahrenheit under agitation. The 2.3% sanitizing solution was added to the heated, agitated mixture. The resultant mixture was allowed to cool slowly to the ambient temperature.

This procedure produced an antimicrobial hand lotion, in the proportions by weight indicated below:

mineral oil 42.0%

olive oil 4.0%

stearyl alcohol 8.0%

triethanolamine 0.05%

water 44.95%

sanitizing cleaner

composition 1.0%

The lotion produced by the above-disclosed process possesses all of the sanitizing effectiveness of the solutions disclosed in Example 1 and Example 2. This lotion, however, has the added benefit of being an effective moisturizer.

It has been found that a solution of water and a mixture of an organic acid, chelating agent, and surfactant will be an effective sanitizer if the mixture is at least 0.8% of the solution and the water is not more than 99.2% of the solution by weight. Preferably, the solution water and a mixture of organic acid, chelating agent, and surfactant contains between about 1% and 5% mixture to between about 99% and 95% water by weight. If a buffering agent, such as monosodium phosphate, is an ingredient of the mixture, the same ratio of mixture to water by weight applies.

The ingredients in the mixture by weight must be

within the following ranges:

citric acid 90% to 98%

EDTA 2% to 10%

sodium lauryl sulfate 0.5% to 2%

monosodium phosphate 0% to 2%

A preferred mixture is as follows:

citric acid 94%

EDTA 4%

sodium lauryl sulfate 1%

monosodium phosphate 1%

and this mixture is preferably mixed with 98% deionized or distilled water by weight to form a 2% solution. A 2% solution has been found to be effective as a sanitizer and cleaner of hard surfaces. In addition, this mixture can be incorporated in a water based lotion with the ingredients constituting 2% of the total and the lot constituting 98% of the total by weight.

The inventor has found that by blending dry

ionizing salts, such as sodium chloride or potassium

chloride, with the dry ingredients of the nontoxic sanitizing cleaner, such as a dry powder blend, when added to ordinary tap water, acquires an increased solubilization rate as well as a greater resistance towards precipitation over time. The added salt, sodium chloride or potassium chloride, increases the ionization potential of the solution. Ordinary tap water can vary greatly in grains of hardness (metal salts) which may chemically tie up some of the chelation potential of the sanitizing cleaner without added salt. Therefore, the addition of ionizing salt or salts helps to prevent a completion of this chemical reaction. Also, such ionization salts have an additive effect to accelerate the killing of microorganisms. The ratios of nontoxic sanitizing cleaner, powder form, to salt, either sodium or potassium chloride, can be varied and is effective as such ratios 1:1, 2:1, 1:2, 1:3 These are the preferable ratios, other ratios can also be effective pending on the hardness of the water.

Preferred Ratios of Dry Ingredients

Water Grains of Nontoxic sanitizing Salt, sodium Hardness cleaner and/or

potasium chloride

Less than 8.0 2 to 1

8.0 to 10. .0 1 to 2

10 to 25 1 to 2

25 plus 1 to 3 plus

TThhee aaddddiittiioonn ooff salt, sodium chloride or potassium chioride, to sanitizing cleaner blend is preferred when using tap water (ordinary) rather than deionized or distilled water in any of the examples.

Those skilled in the art will recognize other applications for the present invention and other forms of the present invention. Therefore, it is intended that the scope of the present invention be limited not by the foregoing specification, but rather only by the appended claims.

Claims

The Invention claimed is:

1. A sanitizing cleaner composition comprising between about 85% and 98% of at least one acid, all acid of the composition being organic and consisting of the class citric acid, fumaric acid, tartaric acid, malic acid, lactic acid and adipic acid, and mixtures of the enumerated acids, between about 0.2% and 10.0% of a chelating agent, and between about 0.2% and 5.0% of a surfactant by weight, the composition having a pH less than 3.

2. A sanitizing cleaner composition comprising claim 1 in combination with a buffering agent, the buffering agent being between about 0.2% and 5.0% of the composition by weight.

3. A sanitizing cleaner composition comprising claim 1 wherein the organic acid consists of citric acid.

4. A sanitizing cleaner composition comprising claim 1 wherein the chelating agent consists of the class disodium ethylenediaminetetraacetate dihydrate and its salts, salicylic acid, polyphosphates, ascorbic acid and mixtures of the enumerated chelating agents.

5. A sanitizing cleaner composition comprising claim 1 wherein the surfactant consists of the class sodium lauryl sulfate, ammonium laurel sulfate, a sarcosinate, sulfosuccinate, and mixtures of the enumerated surfactants.

6. A sanitizing cleaner composition comprising claim 2 wherein the buffering agent consists of the class monosodium phosphate, potassium phosphate and mixtures thereof.

7. A sanitizing cleaner comprising a solution of the composition of claim 1 and water, the water constituting between about 95% and 99.5% of the solution by weight.

8. A sanitizing cleaner comprising claim 7 wherein the solution comrises an organic acid consisting of citric acid.

9. A sanitizing cleaner comprising claim 8

wherein the chealating agent consists of EDTA.

10. A sanitizing cleaner comprising claim 7 wherein the surfactant consists of sodium lauryl sulfate.

11. A sanitizing cleaner comprising a solution of the composition of claim 2 and water, the water

constituting between about 95% and 99.5% of the solution by weight.

12. A sanitizing cleaner comprising claim 11 wherein the buffering agent consists of monosodium phosphate.

13. A sanitizing cleaner composition comprising claim 7 wherein the solution consists of a composition of 94% citric acid, 4% EDTA, and 2% sodium lauryl sulfate, by weight, dissolved in water.

14. A sanitizing cleaner comprising claim 11 wherein the solution consists of a composition of 94%

citric acid, 4% EDTA, 1% sodium lauryl sulfate, and 1% monosodium phosphate, by weight, dissolved in water.

15. A sanitizing cleaner solution comprising the composition of claim 13 or 14 and water, the solution containing about 2% composition and about 98% water, by weight.

16. A sanitizing hand lotion comprising claim 13 or 14 in combination with a water based lotion, the water of the lotion forming a solution with the composition and being equal to about 98% of the composition by weight.