AU693463B2

AU693463B2 - Anti-microbial composition

Info

Publication number: AU693463B2
Application number: AU73074/94A
Authority: AU
Inventors: Brian Brown
Original assignee: ANHAY INVESTMENTS Pty Ltd
Current assignee: ANHAY INVESTMENTS Pty Ltd
Priority date: 1994-09-19
Filing date: 1994-09-19
Publication date: 1998-07-02
Anticipated expiration: 2014-09-19
Also published as: AU7307494A

Description

1 ANTIMICROBIAL COMPOSITIONS This invention relates to antimicrobial compositions and methods for their use.

This invention has particular but not exclusive application to antimicrobial compositions and methods suitable for use in cold-rooms and other like food and beverage applications, and for illustrative purposes reference will be made to such application. However, it is to be understood that this invention could be used in other applications, such as general cleaning applications and cleaning of air conditioning heat exchangers.

It is well known hat cold-rooms, beer lines and the like are subject to mould and/or fungal growth and bacterial proliferation, particularly in high humidity conditions and tropical climates. The mould often infests heat exchangers, blowers or the like as well as door seals, walls, floors and ceilings of cold rooms and within beer lines. Such infestation may also perish or harden door seals and such like. Unless controlled, moulds and/or fungus can eat away beer lines. Access doors or doorways to cold rooms may .20 become damaged or corroded beyond repair and motors in blower i units may seize up. Mould may be quick spreading when it Sgets on exterior surfaces of cold-rooms.

There are existing chemical cleaners and formulations capable of being used to remove mould and/or fungus az well as function as a general cleaner. However, prior art formulations have generally suffered from one or more of the Wt .:r.zi 2 disadvantages of requiring removal or dismantling in part or in full of motors and other machinery associated with and within the coldroom which is costly and compels downtime, and are generally toxic or at least not prescribed as an allowable contaminant.

The present invention aims to alleviate one or more of the above disadvantages and to provide cleaning compositions and methods for their 'se which will be reliable and efficient in use.

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e With the foregoing in view, this invention in one aspect resides broadly in a cleaning composition which avoids the necessity of being taken up into an aqueous medium, said cleaning composition including:a mineral oil; an essential oil added thereto in an amount sufficient to form a mixture of said mineral oil and said essential oil which is substantially antimicrobially effective characterised in that said mineral oil is lipophilic and said composition includes no aqueous surfactant.

The mineral oil may be n-elected from relatively non volatile paraffin oils. Such cleaning compositions preferably include a mineral oil having added thereto an antimicrobially effective amount of an essential oil. In the past it has been regarded as conventional wisdom to apply compositions of aqueous or at least water dispersible character to provide for water rinsing of these generally petroleum based and often toxic products. Accordingly, detergents, water soluble or dispersible oil emulsifying oils and the like have typically been used.

Whilst the biological activity of essential oils is recognized, it has now been surprisingly determined that the use of mineral oil compositions having an antimicrobially gi i

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3 effective amount of an essential oil achieves the objects of the prior art formulations without the need for rin!sing, and if rinsed, provides a protective film of mineral oil bearing a deterrent-effective amount of residual antimicrobial activity.

Preferably, the mineral oil is selected from relatively non volatile paraffin oils such as those including the material known as clear fine white oil. For use in food industry applications, the mineral oil is preferably a food or medicinal grade paraffin. The particular oil selected will of course be determined by the application to which the composition is to be put, having regard to the rheological properties desired in the composition. Accordingly, different viscosities of oil may be selected for various applications, or blends of oils used, to achieve in combination with the essential oil, the desired rheological and other physical properties.

Preferably, the mineral oil is selected from those having no or minimal human toxicity, and are preferably relatively inert to rubbers and synthetic polymers, paints, metals and other materials used in coldroom construction of food process industries. Preferably, the oil is odorless, tasteless water white oil such as that which traditionally is used in the manufacture of cosmetics, creams, hair care and veterinary products and as a lubricant in food processing and food packaging machinery.

The essential oil may be selected from those recognized

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I i Vf iE~t V.~s o C9' P 2 K~«e .i 4 as having antimicrobial activity such as eucalyptus oils or any other of the broad scope of essential oils of plant origin or functional analogues thereof (whether produced from the plant or by synthesis), exhibiting antimicrobial activity. Preferably, the essential oil is selected from the relatively volatile essential oils, for example, those having boiling ranges commencing below 150'C, It will be appreciated that the upper boiling range of 150 0 C may be used as a guide only, and that essential oils with a boiling range below a value slightly higher than this may be effective. In general, such volatile essential oils will comprise a mixture of volatile oils and/or higher alcohols, may be evolved by steam distillation of the source plant materials, and generally have poor solubility in water and good solubility in oily or alcoholic media.

aThe essential oil may also be selected for its particular smell in use. Preferably, the volatile essential oil is toxically effective, at relatively low concentrations S.n in lipophilic carriers, against fungal organsms such as 20 'moulds, mildews and the like as well as preferably being effective against common contaminant organisms such as sk .bacteria, for example, Legionella and Salmonella.

Whilst such oils are generally regarded as relatively aggressive solvents and as such are not generally used in the 25 region of plastics or paints, it has been surprisingly determined that at concentrations below about 10% by volume in paraffinic oil, the composition has substantially no i deleterious effect on such materials.

ireferably, the essential oil is selected from the variL.t cuts of Australian tea tree oil, the steam distillate of the leaves of Melaleuca alternifolia. Such essential oil comprises a mixture including a significant proportion of terpinen-4-ol together with other terpene alcohols or terpineols, sesquiterpenes, 1,8 cineole, p-cymene and other minor constituents. Preferably, the essential oil is obtained from hand cut Melaleuce alternifolia.

Preferably, the essential oil is selected from any essential oil having at least 45% cineole and less than terpineol. Such essential oils may be selected from any one of eucalyptus oil, tea tree oil, yarrow oil, levant wormseed oil, cardamom oil or niaouli oil, this last which may be extracted from Melaleuca viridiflora. It will be appreciated Sthat a mixture of any combination of such oils may be used.

Additionally, such oils as camphor oil, juniper oil, myrtle oil, lavender oil or marjoram oil are believed to be effective although it is not certain that the constituents of such oils fall within the ranges set forth above. It will be appreciated that these oils may be blended with each other or with the selected essential oils eucalyptus oil, tea tree oil, yarrow oil, levant wormseed oil, cardamom oil or niaouli oil to achieve a mixture having constituents within the range .25 of at least 45% cineole and less than 10% terpineol.

o m The oil is highly antimicrobial or microbiostatic and of v 6 low mammalian toxicity (LD 50 in rat, 3 ml/kg). Compositions in accordance with the preferred embodiments of the present invention are substantially non-toxic to mammals, at theoretical LD 50 in rat of greater than 160 ml/kg.

Preferably, the essential oil is utilized at a concentration of between 2% to 5% by volume added to the mineral oil, although it is envisaged that concentrations outside this range may achieve the objects of the present invention, depending on the properties of the essential oil selected and the end use to which the composition is to be put. Preferably, the oil of Melaleuca alternifolia is of a purity such that the oil is substantially colourless.

The compositions in accordance with the present invention may be applied to a surface by any suitable means such as brushing, spraying or wiping on the parts to be treated. Preferably, the method of applicatfon is selected to continuously coat the surface to be treated, such that the affected surface is sufficiently coated/impregnated to leave a residual coating 0.001 mm to 0.004 mm thick.

It has been surprisingly discovered that cleaning T compositions in accordance with this invention may restore hardened rubber seals and such like, remove corrosion from aluminium surfaces, and leaves a protective coating which inhibits further contamination and/or surface deterioration.

25 Rubber seals may thus be restored and protected by application of the cleaning composition.

It is believed that the use of a mineral oil as a hashc ye 7I carrier for the essential oil may offer a synergistic effect, such as by polymerisation of one or more components to form a varnish or such like which may have active groups exposed to maintain the antimicrobial effect.

In order that this invention may be more easily understood and put into practical effect, reference will now be made to the following Example which illustrate a preferred embodiment of the invention.

EXAMPLE

Oil of Melaleuca alternifolia, medicinal grade, of bailing range 116°C to 265°C, terpinen-4-ol content of at least 35% and 1,8 cineole content of about was admixed with a clear, water-white fine paraffin mineral oil of specific gravity 0.858 and viscosity 16.5 centistokes at a rate of 1 volume of essential oil to 30 volumes of paraffin oil. The composition was sprayed onto the painted walls, metal surfaces and plant in cold-rooms subject to a variety of use regimes, in hotels, sporting clubs and food storage cold-rooms. The non-toxic clear spray successfully cleaned the surfaces by runoff or with light rinsing, leaving an anti-corrosion coating not detrimental to the surface treated free of mould/fungus. Yeast mould growing on beer line connection points and lines was 'emoved leaving a protective coating having a polished appearance.

An advantage of compositions and methods in accordance with the foregoing embodiment is that no inconvenience will b experienced in carrying out an inspection and follow up *lte: a o i i ;xx 8 service. Tests to date indicate that half yearly service is generally sufficient, with quarterly service being advantageous in high humidity areas.

The preferred composition is useful also in air conditioners, the formulation in accordance with the present invention being effective to combat the spread of legionella.

Nicotine/tar deposits in air conditioners are also removed by the preferred compositions. The compositions are also useful for general anti-corrosion, anti microbial cleaning of the exterior of houses particularly in coastal regions subject to salt spray, in particular for window screens, metal doors and frames of steel or aluminum. The preferred composition also exhibits insecticidal and/or arachnicidal and/or vermin deterrent activity in addition to providing the antimould finish.

The compositions clean operating equipment without the need to dismantle or even switch off operating plant while treatment is conducted so that, where a build up of mould has occurred the mould will cease to hold on to the existing surface. The mould dies and falls off leaving a clean surface having a residual coating of the composition which then continues to provide a resistance to regeneration of mould build up or creation, with a rust preventative action.

It will of course be realised that while the above has 25 been given by way of illustrative example of this invention, all such and other modifications and variations thezato as would be apparent to persons skilled in the art are deemed to SO 0 0* *000

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Claims

1. A cleaning composition which avoids the necessity of being taken up into an aqueous medium after use, said cleaning composition including:- a mineral oil; an essential oil added thereto in an amount sufficient to form a mixture of said mineral oil and said essential oil which is substantially antimicrobially effective, characterised in that said mineral oil is lipophilic and said composition does not include an aqueous surfactant.

2. A cleaning composition as claimed in claim 1, wherein said mineral oil is selected from relatively non volatile paraffin oils.

3. A cleaning composition as claimed in claim 1 or claim 2, 15 wherein said mineral oil is clear fine white oil. o

4. A cleaning composition as claimed in claim 1 or claim 2, wherein said mineral oil is a food grade paraffin or medicinal grade paraffin. i t A cleaning composition as claimed in claim 1 or claim 2, wherein said mineral oil is odorless, tasteless water white oil such as that which traditionally is used in the manufacture of cosmetics, creams, hair care and veterinary .o p^- I L. ii 11 products and as a lubricant in food processing and food packaging machinery.

6. A cleaning composition as claimed in any one of the preceding claims, wherein said essential oil is selected from those recognized as having antimicrobial activity.

7. A cleaning composition as claimed in any one of the preceding claims, wherein said essential oil is selected from the relatively volatile essential oils.

8. A cleaning composition as claimed in claim 7, wherein said essential oil has a boiling range commencing below 150°C.

9. A cleaning composition as claimed in any one of the preceding claims, wherein said essential oil is toxically effective, at relatively low concentrations in lipophilic carriers, against fungal organisms as well as being toxically effective against bacteria. ij 10. A cleaning composition as claimed in any one of the preceding claims, wherein said essential oil is selected from the steam distillate of the leaves of Melaleuca alternifolia. t A 12

11. A cleaning composition as claimed in claim 10, wherein said essential oil includes a significant proportion of terpineol, sesquiterpenes, 1,8 cineole, p-cymene and other minor constituents.

12. A cleaning composition as claimed in any one of claims 1 to 9, rherein said essential oil is selected from any essential oil having at least 45% cineole and less than terpineol.

13. A cleaning composition as claimed in claim 12, wherein said selected essential oil is selected from a named essential oil including any one of eucalyptus oil, tea tree oil, yarrow oil, levant wormseed oil, cardamom oil or niaouli oil. **ti **et

14. A cleaning composition as claimed in claim 13, wherein S 15 said essential oil includes a mixture of any combination of Ssaid named essential oils. A cleaning composition as claimed in claim 10, wherein said essential oil includes camphor oil, juniper oil, myrtle 4" oil, lavender oil or marjoram oil. it t 9* .u; ix. 13

16. A cleaning composition as claimed in claim 10, wherein said essential oil includes a blend of any combination of camphor oil, juniper oil, myrtle oil, lavender oil or marjoram oil.

17. A cleaning composition as claimed in claim 16, when blended with said named essential oils of claim 14.

18. A cleaning composition as claimed in claim 16 or claim 17, wherein said essential oil is blended to achieve a mixture having constituents within the range of at least cineole and less than 10% terpineol. .0 1 I 2

19. A cleaning composition as claimed in any one of the preceding claims, wherein said essential oil is at a concentration of between 2% to 5% by volume added to said mineral oil. A method of treating a surface including applying a cleaning composition of the type claimed in any one of the preceding claims to said surface.

21. A method as claimed in claim 20 wherein said surface is continuously coated or impregnated to leave a residual coating having a thickness of between 0.001 mm and 0.004 mm. i i i r- L Z 'Vr I. >1 S*^'n i ii 1 14

22. A cleaning composition as substantially hereinbefore described with reference to any one of the accompanying examples. DATED THIS twenty-second ANHAY INVESTMENTS PTY. LTD. DAY OF May 1998. by PIZZEYS PATENT AND TRADE MARK ATTORNEYS o rr o o ~r a r o rr~r r r r rr r 1 t r r d -x ABSRACT A cleaning composition including a mineral oil and an essential oil added thereto in an amount sufficient to form a mixture which is substantially antimicrobially effective. The mineral oil may be selected from relatively non volatile paraffin oils such as clear fine white oil. The essential oil may be selected from the relatively volatile essential oils having boiling ranges commencing below 150*C. Preferably, the essential oil is selected from the steam distillate of the hand cut leaves of Melaleuca alternifolia comprising a mixture including a significant proportion of terpinen-4-ol and other terpene alcohols or terpineols, sesquiterpenes, 1,8 cineole and p-cymene. The essential oil is selected from any essential oil having at least cineole and less than 10% terpineol. Such essential oils may be selected from any one of eucalyptus oil, ti tree oil, yarrow oil, levant wormseed oil, cardamom oil or niaouli oil, this last which may be extracted from Melaleuca viridiflora S or a mixture of any combination of such oils. Such oils as camphor oil, juniper oil, myrtle oil, lavender oil or marjoram oil are believed to be effective and may be blended with each other or with the selected essential oils eucalyptus oil, ti tree oil, yarrow oil, levant wormseed oil, cardamom oil or niaouli oil to achieve a mixture having constituents within the range of at least 45% cineole and Sless than 10% terpineol. 4 I~