Use of a combination of surfactants, chelating agents and essential oils for effective disinfection

The present invention relates to the use, in a composition, of a combination of a chelating agent, a surfactant, and an essential oil or an active thereof, to provide disinfecting properties to said composition.

TECHNICAL FIELD 
The present invention relates to antimicrobial compositions which can be 
used to disinfect and clean various surfaces including hard surfaces or in 
laundry applications. 
BACKGROUND 
Antimicrobial compositions include materials which have the ability to 
disinfect. It is generally recognised that a disinfecting material greatly 
reduces or even eliminates the microorganisms existing on a surface. 
Antimicrobial compositions have been described in the art which include 
strong disinfecting materials which are not fully satisfactory from an 
environmental and/or human safety point of view. For example, typical 
disinfecting materials used in antimicrobial compositions include 
quaternary ammonium. 
Also, a drawback associated with antimicrobial compositions based on strong 
disinfecting materials like peracids and/or halogen-releasing compounds, 
e.g., hypochlorite, is that they may damage surfaces onto which they are 
contacted to perform their disinfecting action. Indeed, such antimicrobial 
compositions based on peracids and/or hypochlorite are perceived by the 
consumers as being not safe to various surfaces including hard-surfaces 
and fabrics, especially delicate fabrics like silk, wool and the like. 
It is therefore an object of the present invention to provide effective 
disinfection using ingredients which are perceived to have a limited 
detrimental impact on surfaces and/or to be environmental friendly. 
This object can be met by combining in a composition a surfactant, a 
chelating agent and an antimicrobial essential oil, or an active thereof. 
Indeed, it has been found that the incorporation, in a composition, of the 
combination of a surfactant, a chelating agent and an antimicrobial 
essential oil, or an active thereof, provides disinfecting properties to 
said composition. Actually, a composition comprising said combination 
provides excellent disinfection on a surface, even at high dilution 
levels, i.e., up to dilution levels of from 1:100 (composition:water). 
By combining a chelating agent, a surfactant and an essential oil or an 
active thereof, disinfection may be provided on all types of surfaces 
including hard-surfaces as well as in laundry applications, or even in 
human application. 
An advantage of the present invention is that excellent disinfection is 
provided on a broad range of bacterial pure strains including Gram 
positive and Gram negative bacterial strains and more resistant 
micro-organisms like fungi. 
Another advantage of the present invention is that beside the disinfection 
properties delivered, good cleaning is also provided. 
Representative of the prior art is for example EP-B-288 689 which discloses 
a liquid for hard-surfaces comprising antimicrobial effective amounts of 
pine oil and at least one oil soluble organic acid. 
U.S. Pat. No. 5,403,587 discloses aqueous antimicrobial compositions which 
can be used to sanitise, disinfect, and clean hard-surfaces. More 
particularly, U.S. Pat. No. 5,403,587 discloses aqueous compositions (pH 1 
to 12) comprising essential oils (0.02% to 5%), which exhibit 
antimicrobial properties efficacy such as thyme oil, eucalyptus oil, clove 
oil and the like, and a solubilizing or dispersing agent sufficient to 
form an aqueous solution or dispersion of said essential oils in a water 
carrier. 
Co-pending European patent application number 96870017.9 discloses 
disinfecting compositions comprising hydrogen peroxide, an antimicrobial 
essential oil, optionally surfactants and chelating agents. 
None of these prior art documents discloses that by combining a chelating 
agent, a surfactant and an antimicrobial essential oil or an active 
thereof excellent disinfecting properties are delivered to a surface, even 
under diluted conditions. 
SUMMARY OF THE INVENTION 
The present invention encompasses the use, in a composition, of a 
combination of a chelating agent, a surfactant and an antimicrobial 
essential oil or an active thereof, to provide disinfecting properties to 
said composition. 
DETAILED DESCRIPTION OF THE INVENTION 
A first essential ingredient of the present invention is a chelating agent, 
or a mixture thereof. Suitable chelating agents to be used herein may be 
any chelating agent known to those skilled in the art such as the ones 
selected from the group comprising phosphonate chelating agents, amino 
carboxylate chelating agents or other carboxylate chelating agents, or 
polyfunctionally-substituted aromatic chelating agents or mixtures 
thereof. It has now been found that a chelating agent in combination with 
a surfactant when added on top of an antimicrobial essential oil and/or an 
active thereof, in a composition, improves the disinfecting properties of 
said composition. 
Such phosphonate chelating agents may include etidronic acid 
(1-hydroxyethylidene-bisphosphonic acid or HEDP) as well as amino 
phosphonate compounds, including amino alkylene poly (alkylene 
phosphonate), alkali metal ethane 1-hydroxy diphosphonates, nitrilo 
trimethylene phosphonates, ethylene diamine tetra methylene phosphonates, 
and diethylene triamine penta methylene phosphonates. The phosphonate 
compounds may be present either in their acid form or as salts of 
different cations on some or all of their acid functionalities. Preferred 
phosphonate chelating agents to be used herein are diethylene triamine 
penta methylene phosphonates. Such phosphonate chelating agents are 
commercially available from Monsanto under the trade name DEQUEST.RTM.. 
Polyfunctionally-substituted aromatic chelating agents may also be useful 
in the compositions herein. See U.S. Pat. No. 3,812,044, issued May 21, 
1974, to Connor et al. Preferred compounds of this type in acid form are 
dihydroxydisulfobenzenes such as 1,2-dihydroxy-3,5-disulfobenzene. 
A preferred biodegradable chelating agent for use herein is ethylene 
diamine N,N'-disuccinic acid, or alkali metal, or alkaline earth, ammonium 
or substitutes ammonium salts thereof or mixtures thereof. Ethylenediamine 
N,N'-disuccinic acids, especially the (S,S) isomer have been extensively 
described in U.S. Pat. No. 4,704,233, Nov. 3, 1987 to Hartman and Perkins. 
Ethylenediamine N,N'-disuccinic acid is, for instance, commercially 
available under the tradename ssEDDS.RTM. from Palmer Research 
Laboratories. 
Suitable amino carboxylate chelating agents useful herein include ethylene 
diamine tetra acetate, diethylene triamine pentaacetate, diethylene 
triamine pentacetate (DTPA), N-hydroxyethylethylenediamine triacetate, 
nitrilotri-acetate, ethylenediamine tetraproprionate, 
triethylenetetraaminehexa-acetate, ethanoldiglycine, propylene diamine 
tetracetic acid (PDTA) and methyl glycine di-acetic acid (MGDA), both in 
their acid form, or in their alkali metal, ammonium, and substituted 
ammonium salt forms. Particularly suitable to be used herein are 
diethylene triamine penta acetic acid (DTPA), propylene diamine tetracetic 
acid (PDTA) which is, for instance, commercially available from BASF under 
the trade name Trilon FS.RTM. and methyl glycine di-acetic acid (MGDA). 
Further carboxylate chelating agents to be used herein include malonic 
acid, salicylic acid, glycine, aspartic acid, glutamic acid, dipicolinic 
acid and derivatives thereof, or mixtures thereof. 
Typically, the chelating agent, or a mixture thereof, is present in the 
composition at a level of from 0.001% to 5% by weight, preferably from 
0.002% to 3% by weight and more preferably from 0.002% to 1.5%. 
A second essential ingredient of the present invention is a surfactant or a 
mixture thereof. 
Suitable surfactants to be used herein may be any surfactant known to those 
skilled in the art including anionic, nonionic, cationic, amphoteric 
and/or, zwitterionic surfactants. Said surfactants are desirable as in 
combination with a chelating agent and an essential oil or an active 
thereof they provide improved disinfecting performance on the surfaces 
treated therewith. Also surfactants contribute to the cleaning performance 
of a composition comprising said combination. 
Particularly suitable anionic surfactants to be used herein include water 
soluble salts or acids of the formula ROSO.sub.3 M wherein R is preferably 
a C.sub.6 -C.sub.24 hydrocarbyl, preferably an alkyl or hydroxyalkyl 
having a C.sub.10 -C.sub.20 alkyl component, more preferably a C.sub.12 
-C.sub.18 alkyl or hydroxyalkyl, and M is H or a cation, e.g., an alkali 
metal cation (e.g., sodium, potassium, lithium), or ammonium or 
substituted ammonium (e.g., methyl-, dimethyl-, and trimethyl ammonium 
cations and quaternary ammonium cations, such as tetramethyl-ammonium and 
dimethyl piperdinium cations and quaternary ammonium cations derived from 
alkylamines such as ethylamine, diethylamine, triethylamine, and mixtures 
thereof, and the like). 
Other suitable anionic surfactants to be used herein include 
alkyl-diphenyl-ether-sulphonates and alkyl-carboxylates. Other anionic 
surfactants can include salts (including, for example, sodium, potassium, 
ammonium, and substituted ammonium salts such as mono-, di- and 
triethanolamine salts) of soap, C.sub.9 -C.sub.20 linear 
alkylbenzenesulfonates, C.sub.8 -C.sub.22 primary or secondary 
alkanesulfonates, C.sub.8 -C.sub.24 olefinsulfonates, sulfonated 
polycarboxylic acids prepared by sulfonation of the pyrolyzed product of 
alkaline earth metal citrates, e.g., as described in British patent 
specification No. 1,082,179, C.sub.8 -C.sub.24 
alkylpolyglycolethersulfates (containing up to 10 moles of ethylene 
oxide); alkyl ester sulfonates such as C.sub.14-16 methyl ester 
sulfonates; acyl glycerol sulfonates, fatty oleyl glycerol sulfates, alkyl 
phenol ethylene oxide ether sulfates, paraffin sulfonates, alkyl 
phosphates, isethionates such as the acyl isethionates, N-acyl taurates, 
alkyl succinamates and sulfosuccinates, monoesters of sulfosuccinate 
(especially saturated and unsaturated C.sub.12 -C.sub.18 monoesters) 
diesters of sulfosuccinate (especially saturated and unsaturated C.sub.6 
-C.sub.14 diesters), acyl sarcosinates, sulfates of alkylpolysaccharides 
such as the sulfates of alkylpolyglucoside (the nonionic nonsulfated 
compounds being described below), branched primary alkyl sulfates, alkyl 
polyethoxy carboxylates such as those of the formula RO(CH.sub.2 CH.sub.2 
O).sub.k CH.sub.2 COO--M.sup.+ wherein R is a C.sub.8 -C.sub.22 alkyl, k 
is an integer from 0 to 10, and M is a soluble salt-forming cation. Resin 
acids and hydrogenated resin acids are also suitable, such as rosin, 
hydrogenated rosin, and resin acids and hydrogenated resin acids present 
in or derived from tall oil. Further examples are given in "Surface Active 
Agents and Detergents" (Vol. I and II by Schwartz, Perry and Berch). A 
variety of such surfactants are also generally disclosed in U.S. Pat. No. 
3,929,678, issued Dec. 30, 1975 to Laughlin, et al. at Column 23, line 58 
through Column 29, line 23 (herein incorporated by reference). 
Preferred anionic surfactants for use in the compositions herein are the 
alkyl benzene sulfonates, alkyl sulfates, alkyl alkoxylated sulfates, 
paraffin sulfonates and mixtures thereof. 
Suitable amphoteric surfactants to be used herein include betaine and 
sulphobetaine surfactants, derivatives thereof or mixtures thereof. Said 
betaine or sulphobetaine surfactants are preferred herein as, they help 
disinfection by increasing the permeability of the bacterial cell wall, 
thus allowing other active ingredients to enter the cell. 
Furthermore, due to the mild action profile of said betaine or 
sulphobetaine surfactants, they are particularly suitable for the cleaning 
of delicate surfaces, e.g. delicate laundry or surfaces in contact with 
food and/or babies. Betaine and sulphobetaine surfactants are also 
extremely mild to the skin and/or surfaces to be treated. 
Suitable betaine and sulphobetaine surfactants to be used herein are the 
betaine/sulphobetaine and betaine-like detergents wherein the molecule 
contains both basic and acidic groups which form an inner salt giving the 
molecule both cationic and anionic hydrophilic groups over a broad range 
of pH values. Some common examples of these detergents are described in 
U.S. Pat. Nos. 2,082,275, 2,702,279 and 2,255,082, incorporated herein by 
reference. Preferred betaine and sulphobetaine surfactants herein are 
according to the formula 
##STR1## 
wherein R1 is an alkyl radical containing from 1 to 24 carbon atoms, 
preferably from 8 to 18, and more preferably from 12 to 14, wherein R2 and 
R3 contain from 1 to 3 carbon atoms, and preferably 1 carbon atom, wherein 
n is an integer from 1 to 10, preferably from 1 to 6 and more preferably 
is 1, Y is selected from the group consisting of carboxyl and sulfonyl 
radicals and wherein the sum of R1, R2 and R3 radicals is from 14 to 24 
carbon atoms, or mixtures thereof. 
Examples of particularly suitable betaine surfactants include C12-C18 alkyl 
dimethyl betaine such as coconut-betaine and C10-C16 alkyl dimethyl 
betaine such as laurylbetaine. Coconutbetaine is commercially available 
from Seppic under the trade name of Amonyl 265.RTM.. Laurylbetaine is 
commercially available from Albright & Wilson under the trade name Empigen 
BB/L.RTM.. 
Other suitable amphoteric surfactants to be used herein include amine 
oxides having the following formula R.sub.1 R.sub.2 R.sub.3 NO wherein 
each of R1, R2 and R3 is independently a saturated substituted or 
unsubstituted, linear or branched alkyl group of from 1 to 30 carbon 
atoms, preferably of from 6 to 30 carbon atoms, more preferably of from 10 
to 20 carbon atoms, and most preferably of from 8 to 18 carbon atoms. 
Preferred amine oxides for use herein are for instance natural blend 
C8-C10 amine oxides as well as C12-C16 amine oxides commercially available 
from Hoechst. Suitable short chain amine oxides to be used according to 
the present invention are amine oxides having the following formula 
R.sub.1 R.sub.2 R.sub.3 NO wherein R1 is a C6 to C10 alkyl group, 
preferably a C8 to C10 alkyl group and wherein R2 and R3 are independently 
substituted or unsubstituted, linear or branched alkyl groups of from 1 to 
4 carbon atoms, preferably of from 1 to 3 carbon atoms, and more 
preferably are ethyl groups. R1 may be a saturated linear or branched 
alkyl group. referred short chain amine oxides for use herein are for 
instance natural lend C8-C10 amine oxides available from Hoechst. 
In a preferred embodiment of the present invention, the surfactant is a 
surfactant system comprising an amine oxide and a betaine or sulphobetaine 
surfactant, preferably in a weight ratio of amine oxide to betaine or 
sulphobetaine of 2:1 to 100:1, more preferably of 6:1 to 100:1. Using such 
a surfactant system together with a chelating agent and an antimicrobial 
essential oil or active thereof, in a composition, provides not only 
effective disinfecting properties and effective cleaning performance to 
said composition but also provides the cleaned surfaces with a shiny 
effect, i.e., the amount of filming/streaking left on the cleaned surface 
that has been treated with said composition is minimal. 
Suitable nonionic surfactants to be used herein are fatty alcohol 
ethoxylates and/or propoxylates which are commercially available with a 
variety of fatty alcohol chain lengths and a variety of ethoxylation 
degrees. Indeed, the HLB values of such alkoxylated nonionic surfactants 
depend essentially on the chain length of the fatty alcohol, the nature of 
the alkoxylation and the degree of alkoxylation. Surfactant catalogues are 
available which list a number of surfactants, including nonionics, 
together with their respective HLB values. 
Suitable chemical processes for preparing the nonionic surfactants for use 
herein include condensation of corresponding alcohols with alkylene oxide, 
in the desired proportions. Such processes are well known to the man 
skilled in the art and have been extensively described in the art. As an 
alternative, a great variety of alkoxylated alcohols suitable for use 
herein is commercially available from various suppliers. 
Particularly suitable to be used herein as nonionic surfactants are 
hydrophobic nonionic surfactants having an HLB (hydrophilic-lipophilic 
balance) below 16, preferably below 15, more preferably below 12, and most 
preferably below 10. Those hydrophobic nonionic surfactants have been 
found to provide good grease cutting properties. 
Preferred hydrophobic nonionic surfactants to be used in the compositions 
according to the present invention are surfactants having an HLB below 16 
and being according to the formula RO--(C.sub.2 H.sub.4 O).sub.n (C.sub.3 
H.sub.6 O).sub.m H, wherein R is a C.sub.6 to C.sub.22 alkyl chain or a 
C.sub.6 to C.sub.28 alkyl benzene chain, and wherein n+m is from 0 to 20 
and n is from 0 to 15 and m is from 0 to 20, preferably n+m is from 1 to 
15 and, n and m are from 0.5 to 15, more preferably n+m is from 1 to 10 
and, n and m are from 0 to 10. The preferred R chains for use herein are 
the C.sub.8 to C.sub.22 alkyl chains. Accordingly, suitable hydrophobic 
nonionic surfactants for use herein are Dobanol.sup.R 91-2.5 (HLB=8.1; R 
is a mixture of C9 and C.sub.11 alkyl chains, n is 2.5 and m is 0), or 
Lutensol.sup.R TO3 (HLB=8; R is a C.sub.13 alkyl chains, n is 3 and m is 
0), or Lutensol.sup.R AO3 (HLB=8; R is a mixture of C.sub.13 and C.sub.15 
alkyl chains, n is 3 and m is 0), or Tergitol.sup.R 25L3 (HLB=7.7; R is in 
the range of C.sub.12 to C.sub.15 alkyl chain length, n is 3 and m is 0), 
or Dobanol.sup.R 23-3 (HLB=8.1; R is a mixture Of C.sub.12 and C.sub.13 
alkyl chains, n is 3 and m is 0), or Dobanol.sup.R 23-2 (HLB=6.2; R is a 
mixture of C.sub.12 and C.sub.13 alkyl chains, n is 2 and m is 0), or 
Dobanol.sup.R 45-7 (HLB=11.6; R is a mixture of C.sub.14 and C.sub.15 
alkyl chains, n is 7 and m is 0) Dobanol.sup.R 23-6.5 (HLB=11.9; R is a 
mixture of C.sub.12 and C.sub.13 alkyl chains, n is 6.5 and m is 0), or 
Dobanol.sup.R 25-7 (HLB=12; R is a mixture Of C.sub.12 and C.sub.15 alkyl 
chains, n is 7 and m is 0), or Dobanol.sup.R 91-5 (HLB=11.6; R is a 
mixture of C.sub.9 and C.sub.11 alkyl chains, n is 5 and m is 0), or 
Dobanol.sup.R 91-6 (HLB=12.5 ; R is a mixture of C.sub.9 and C.sub.11 
alkyl chains, n is 6 and m is 0), or Dobanol.sup.R 91-8 (HLB=13.7; R is a 
mixture of C.sub.9 and C.sub.11 alkyl chains, n is 8 and m is 0), 
Dobanol.sup.R 91-10 (HLB=14.2; R is a mixture of C.sub.9 to C.sub.11 alkyl 
chains, n is 10 and m is 0), or mixtures thereof. Preferred herein are 
Dobanol.sup.R 91-2.5, or Lutensol.sup.R TO3, or Lutensol.sup.R AO3, or 
Tergitol.sup.R 25L3, or Dobanol.sup.R 23-3, or Dobanol.sup.R 23-2, or 
mixtures thereof. These Dobanol.sup.R surfactants are commercially 
available from SHELL. These Lutensol.sup.R surfactants are commercially 
available from BASF and these Tergitol.sup.R surfactants are commercially 
available from UNION CARBIDE. 
Suitable zwitterionic surfactants contain both cationic and anionic 
hydrophilic groups on the same molecule at a relatively wide range of 
pH's. The typical cationic group is a quaternary ammonium group, although 
other positively charged groups like phosphonium, imidazolium and 
sulfonium groups can be used. The typical anionic hydrophilic groups are 
carboxylates and sulfonates, although other groups like sulfates, 
phosphonates, and the like can be used. A generic formula for some 
preferred zwitterionic surfactants is 
EQU R.sub.1 --N.sup.+ (R.sub.2)(R.sub.3)R.sub.4 X.sup.- 
wherein R.sub.1 is a hydrophobic group; R.sub.2 and R.sub.3 are each 
C.sub.1 -C.sub.4 alkyl, hydroxy alkyl or other substituted alkyl group 
which can also be joined to form ring structures with the N; R.sub.4 is a 
moiety joining the cationic nitrogen atom to the hydrophilic group and is 
typically an alkylene, hydroxy alkylene, or polyalkoxy group containing 
from 1 to 4 carbon atoms; and X is the hydrophilic group which is 
preferably a carboxylate or sulfonate group. Preferred hydrophobic groups 
R.sub.1 are alkyl groups containing from 8 to 22, preferably less than 18, 
more preferably less than 16 carbon atoms. The hydrophobic group can 
contain unsaturation and/or substituents and/or linking groups such as 
aryl groups, amido groups, ester groups and the like. In general, the 
simple alkyl groups are preferred for cost and stability reasons. 
Other specific zwitterionic surfactants have the generic formulae: 
EQU R.sub.1 --C(O)--N(R.sub.2)--(C(R.sub.3).sub.2).sub.n --N(R.sub.2).sub.2 
(.sup.+)--(C(R.sub.3).sub.2).sub.n --SO.sub.3 (.sup.-) 
EQU or 
EQU R.sub.1 --C(O)--N(R.sub.2)--(C(R.sub.3).sub.2).sub.n --N(R.sub.2).sub.2 
(.sup.+)--(C(R.sub.3).sub.2).sub.n --COO(.sup.-) 
wherein each R.sub.1 is a hydrocarbon, e.g. an alkyl group containing from 
8 up to 20, preferably up to 18, more preferably up to 16 carbon atoms, 
each R.sub.2 is either a hydrogen (when attached to the amido nitrogen), 
short chain alkyl or substituted alkyl containing from one to 4 carbon 
atoms, preferably groups selected from the group consisting of methyl, 
ethyl, propyl, hydroxy substituted ethyl or propyl and mixtures thereof, 
preferably methyl, each R.sub.3 is selected from the group consisting of 
hydrogen and hydroxy groups and each n is a number from 1 to 4, preferably 
from 2 to 3, more preferably 3, with no more than one hydroxy group in any 
(C(R.sub.3).sub.2) moiety. The R.sub.1 groups can be branched and/or 
unsaturated. The R.sub.2 groups can also be connected to form ring 
structures. A surfactant of this type is a C.sub.10 -C.sub.14 fatty 
acylamidopropylene(hydroxypropylene)sulfobetaine that is available from 
the Sherex Company under the trade name "Varion CAS sulfobetaine".RTM.. 
Typically, the surfactant or mixtures thereof is present in the composition 
at a level of from 0.01% to 50% by weight of the total composition, 
preferably from 0.01% to 30% and more preferably from 0.1% to 10%. 
A third essential ingredient of the present invention is an antimicrobial 
essential oil or an active thereof, or a mixture thereof. 
Suitable antimicrobial essential oils to be used herein are those essential 
oils which exhibit antimicrobial activity. By "actives of essential oils" 
it is meant herein any ingredient of essential oils that exhibit 
antimicrobial activity. It is speculated that said antimicrobial essential 
oils and actives thereof act as proteins denaturing agents. Also, said 
antimicrobial oils and actives thereof are compounds which contribute to 
the safety profile of a composition comprising them when it is used to 
disinfect any surface. A further advantage of said antimicrobial oils and 
actives thereof is that they impart pleasant odor to a composition 
comprising them without the need of adding a perfume. Indeed combining 
said antimicrobial essential oil or an active thereof with a surfactant 
and a chelant, in a composition, allows to deliver not only excellent 
disinfecting properties on surfaces to be treated with said composition 
but also good scent while being safe to the surfaces. 
Such essential oils include, but are not limited to, those obtained from 
thyme, lemongrass, citrus, lemons, oranges, anise, clove, aniseed, pine, 
cinnamon, geranium, roses, mint, lavender, citronella, eucalyptus, 
peppermint, camphor, sandalwood, rosmarin, vervain, fleagrass, lemongrass, 
ratanhiae, cedar and mixtures thereof. Preferred antimicrobial essential 
oils to be used herein are thyme oil, clove oil, cinnamon oil, geranium 
oil, eucalyptus oil, peppermint oil, mint oil or mixtures thereof. 
Actives of essential oils to be used herein include, but are not limited 
to, thymol (present for example in thyme), eugenol (present for example in 
cinnamon and clove), menthol (present for example in mint), geraniol 
(present for example in geranium and rose), verbenone (present for example 
in vervain), eucalyptol and pinocarvone (present in eucalyptus), cedrol 
(present for example in cedar), anethol (present for example in anise), 
carvacrol, hinokitiol, berberine, ferulic acid, cinnamic acid, methyl 
salycilic acid, methyl salycilate, terpineol and mixtures thereof. 
Preferred actives of essential oils to be used herein are thymol, eugenol, 
verbenone, eucalyptol, terpineol, cinnamic acid, methyl salycilic acid 
and/or geraniol. 
Thymol may be commercially available for example from Aldrich, eugenol may 
be commercially available for example from Sigma, Systems--Bioindustries 
(SBI)--Manheimer Inc. 
Typically, the antimicrobial essential oil or actives thereof or mixture 
thereof is present in the composition at a level of at least 0.003% by 
weight of the total composition, preferably from 0.006% to 10%, more 
preferably from 0.1% to 4% and most preferably of from 0.03% to 2%. 
It has now been found that by combining a surfactant, a chelating agent and 
an antimicrobial essential oil or active thereof, in a composition, that 
improved disinfecting properties are delivered, even when used under 
highly diluted conditions. By "improved disinfecting properties" it is 
meant herein that the disinfection delivered by combining a surfactant, a 
chelating agent and an antimicrobial essential oil and/or an active 
thereof, in a composition, is improved as compared to the disinfection 
delivered by using only one or two of said ingredients, in said 
composition. 
Excellent disinfection is obtained by combining a surfactant, a chelating 
agent and an antimicrobial essential oil or active thereof according to 
the present invention on a variety of microorganisms including Gram 
positive bacteria like Staphylococcus aureus, and Gram negative bacteria 
like Pseudomonas aeroginosa as well as on fungi like Candida albicans 
present on surfaces, even if used in highly diluted conditions. 
Disinfection properties of a composition may be measured by the 
bactericidal activity of said composition. A test method suitable to 
evaluate the bactericidal activity of a composition is described in 
European Standard, prEN 1040, CEN/TC216 N 78, dated November 1995 issued 
by the European committee for standardisation, Brussels. European 
Standard, prEN 1040, CEN/TC216 N 78, specifies a test method and 
requirements for the minimum bactericidal activity of a disinfecting 
composition. The test is passed if the bacterical colonies forming units 
(cfu) are reduced from a 10.sup.7 cfu (initial level) to a 10.sup.2 cfu 
(final level after contact with the disinfecting product), i.e. a 10.sup.5 
reduction of the viability is necessary. A composition comprising a 
surfactant, a chelating agent and an antimicrobial essential oil or an 
active thereof passes this test, even if used in highly diluted 
conditions. 
The combination of ingredients according to the present invention may be 
formulated in a composition being either in a solid, pasty or liquid form. 
In the case where the compositions according to the present invention are 
formulated as solids, they will be mixed with an appropriate solvent, 
typically water, before use. In liquid form, the compositions are 
preferably but not necessarily formulated as aqueous compositions. Liquid 
compositions are preferred herein for convenience of use. 
In the embodiment, where the compositions according to the present 
invention are aqueous liquid cleaning compositions, they preferably have a 
pH as is of not more than 12.0, more preferably from 1 to 10, and most 
preferably from 2 to 9. The pH of the compositions can be adjusted by 
using organic or inorganic acids, or alkalinising agents. 
As effective disinfection is provided with the combination of ingredients 
of the present invention the compositions comprising said combination do 
not require the addition of other antimicrobial compounds. However, if 
desired in one embodiment of the present invention said compositions may 
further comprise, as optional ingredients, other antimicrobial compounds 
like a peroxygen bleach, or mixtures thereof. Preferred peroxygen bleach 
is hydrogen peroxide, or a water soluble source thereof, or mixtures 
thereof. 
It is believed that the presence of peroxygen bleach especially hydrogen 
peroxide, persulfate and the like, further contributes to the disinfecting 
properties of the compositions according to the present invention. Indeed, 
peroxygen bleach may attack the vital function of the micro-organism 
cells, for example it may inhibit the assembling of ribosomes units within 
the cytoplasm of the micro-organism cells. Also peroxygen bleach like 
hydrogen peroxide, is a strong oxidizer that generates hydroxyl free 
radicals which attack proteins and nucleic acids. Furthermore, the 
presence of peroxygen bleach, especially hydrogen peroxide, provides 
strong stain removal benefits which are particularly noticeable for 
example in laundry and hard surfaces applications. 
As used herein a hydrogen peroxide source refers to any compound which 
produces hydrogen peroxide when said compound is in contact with water. 
Suitable water-soluble sources of hydrogen peroxide for use herein include 
percarbonates, persilicate, persulphate such as monopersulfate, perborates 
and peroxyacids such as diperoxydodecandioic acid (DPDA), magnesium 
perphthalic acid and mixtures thereof. 
In addition, other classes of peroxides can be used as an alternative to 
hydrogen peroxide and sources thereof or in combination with hydrogen 
peroxide and sources thereof. Suitable classes include dialkylperoxides, 
diacylperoxides, preformed percarboxylic acids, organic and inorganic 
peroxides and/or hydroperoxides. 
The compositions herein may comprise up to 15% by weight of the total 
composition of a peroxygen bleach or a mixture thereof, preferably from 
0.5% to 10%, and more preferably from 1% to 8%. 
The compositions according to the present invention may comprise other 
antimicrobial ingredients that further contribute to the antimicrobial 
activity of the compositions according to the present invention. Such 
antimicrobial ingredients include parabens like ethyl paraben, propyl 
paraben, methyl paraben, glutaraldehyde or mixtures thereof. 
The compositions herein may further comprise a variety of other optional 
ingredients such as solvents, builders, stabilisers, bleach activators, 
soil suspenders, dye transfer agents, brighteners, perfumes, anti dusting 
agents, enzymes, dispersant, dye transfer inhibitors, pigments, perfumes, 
radical scavengers and dyes. 
The compositions herein may be packaged in a variety of suitable detergent 
packaging known to those skilled in the art. The liquid compositions 
herein may desirably be packaged in manually operated spray dispensing 
containers, which are usually made of synthetic organic polymeric plastic 
materials. Indeed, said spray-type dispensers allow to uniformly apply to 
a relatively large area of a surface to be disinfected the liquid 
disinfecting compositions suitable to be used according to the present 
invention, thereby contributing to disinfection properties of said 
compositions. Such spray-type dispensers are particularly suitable to 
disinfect vertical surfaces. 
Suitable spray-type dispensers to be used according to the present 
invention include manually operated foam trigger-type dispensers sold for 
example by Specialty Packaging Products, Inc. or Continental Sprayers, 
Inc. These types of dispensers are disclosed, for instance, in U.S. Pat. 
No. 4,701,311 to Dunnining et al. and U.S. Pat. No. 646,973 and U.S. Pat. 
No. 4,538,745 both to Focarracci. Particularly preferred to be used herein 
are spray-type dispensers such as T 8500.RTM. commercially available from 
Continental Spray International or T 8100.RTM. commercially available from 
Canyon, Northern Ireland. In such a dispenser the liquid composition is 
divided in fine liquid droplets resulting in a spray that is directed onto 
the surface to be treated. Indeed, in such a spray-type dispenser the 
composition contained in the body of said dispenser is directed through 
the spray-type dispenser head via energy communicated to a pumping 
mechanism by the user as said user activates said pumping mechanism. More 
particularly, in said spray-type dispenser head the composition is forced 
against an obstacle, e.g. a grid or a cone or the like, thereby providing 
shocks to help atomise the liquid composition, i.e. to help the formation 
of liquid droplets. 
The compositions of the present invention may also be executed in the form 
of wipes. By "wipes" it is meant herein disposable towels, e.g., paper 
towels where a composition according to the present invention is 
incorporated. In a preferred execution said wipes incorporate a liquid 
composition. Preferably said wipes are packaged in a plastic box. The 
advantage of this execution is a faster usage of a disinfecting 
composition by the user, this even outside the house, i.e. there is no 
need to pour the liquid compositions according to the present invention on 
the surfaces to be treated/disinfect and to dry it out with a cloth. In 
other words, wipes allow disinfection of surfaces in one step. 
The compositions according to the present invention may be applied onto any 
surfaces for disinfection purpose. By "surface" it is meant herein any 
surface including hard-surfaces like bathroom, kitchen, table tops, 
refrigerators, and the like as well as fabrics, clothes, carpets and the 
like. Said compositions according to the present invention may be applied 
to the surface to be disinfected in its neat form or in its diluted form. 
By "diluted form" it is meant herein that the compositions to be used being 
either in a liquid or solid form may be diluted by the user typically up 
to 100 times their weight of water, preferably into 80 to 30 times their 
weight of water, and more preferably 60 to 40 times.