CA1157372A - Dairy sanitization - Google Patents

Abstract

ABSTRACT
"DAIRY SANITIZATION"
This invention relates to a composition for use in the dairy industry, particularly for sanitization in the dairy industry, the composition having pH of below 7 and comprising glutraldehyde, a metal ion, an emollient, and water or a mixture of water and an alcohol.

Description

,T~ TPl' TOI~ ' ~.~.
"V~T~ T';~ T(~
'~hc prese~t; inv~ntion relat~s to san~i~ation.
MOIe part;c:lLarly the present invention relates to sani-ti7ation in the dairy inlus-Gry, for exa~ple udder sanitization, using c~mpositions based on glutaralde-hyàe .
One Or the best kno~ and most efficient sterili%in~ ac;ents is glutaraldehyde. However, glutar-a:Ldehyde sufI`~rs from certain disadvantages. Glutar~
aldehyde in 3cid solu-tion is relatively stab]e but has very poor sterilizing activity. In alkaline solutions it is effective but no-t ver~r stable. Attempts have been made to overcome these disadvantages by storing the glutaralde~yde under acid conditions and then, just ~rior to use, adjusting the p~ of the aqueous æolution of glutaraldehyde to alkaline. Such ac~ion, however, i~poses an undesirable burden on the user.
Ca~eful investigations have been made into the action o glutaraldehyde (alone and in the presence Of ot'~er rnaterials) u~on bacterial cell forms in order to more fully understand the parameters which govern the effeCt;j.VenC~SS Of 3.CUeOUS glularaldeh-lde based solutions for sterili~in~ purposes. From a study of the effect of glut;ara1dehyde on the cellular activity of cell ~5 forms cf hscher~chia co'~i, it is ~elieved that , 1 15'7372 ~lutaral~e~lyd.e ac:ts vla a com~ination Or a partial seali.n~
of the outer membIane of the cell wall and inactivation of cell wall-associated or periplasmic-locatc-d enzymes.
It has been found that the presence of certain materials potentiates the effective action of glutaraldehyde by modifying the cell wall. Study of the action of sodi~m bicarbonate (which has been the tradi-tional alkalinating agent for converting stored acid glutaraldehyde solutions into more actlve alkaline glutaraldehyde solutions just prior to use) has shown that the sodium bicarbonate does not act only as a me~ns of ch~nging the pE.
The sodium ions arising from the sodium bicarbonate modify the cell wall. ~he sodium ions cause disrupti.on of the loose layer and outer membrane of the cell enabling increased uptake and penetrati.on of glutaraldehyde to its optimum site of.action. It would appear that the sodium ions assist in releasing enzymes from the cell wall constituents thus rendering them nore susceptible to inactivation by glutaralde;~yde. Similar results were ~ 20 achieved by replacing the sodi.um bicarbonate with sodium chloride, supporting the belief that the sodium ion action on the cell wall was as significant a parameter as the requirement for an alkaline pH.
Further investigations were then made into the effects of metal ions having higher valencies than sodium. It was found that such metal ions of higher valencies were more effective than monovalent ions such as sodium.
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1 15'7~72 It has bcen suggcste(l (in Bri.t;ish ~tent Specificat-ion No.1,~ 3,7~6) that d.ormant spores can be killed by ~he use of a composition havin~ a p~i o~
less than 7 and consisting of a solvent which is watcr or a mi~ture of water and a lower monohydric alcohol, glutaraldehyde and dissolved quantities of certain highly ionizable salts at temperatures above 15C. Said specification does not clearly show the applicability of such a method to bacteria.
It has also been proposed to incorporate various additives into the aqueous glutaraldehyde to produce s-table but active solutions which do not require alkalination prior to use. For example, a composition ~or sterilizing and disinfecting has been proposed which comprises water or a mixture of water and a monohydric alcohol having l to ~ carbon atoms, together with glutaraldehyde and a trivalent metal i~n. ~he composition is preferably at a pH not above 7. Such a composition may also include a surfactant, either as a separate compound from the compound providing the trivalent metal ion or as a single compound providing both the trivalent metal ion and the surfactant components..
However, it has been foun& that the use of such compos-itions in tke treatment of animals can lead to problems.
~or example, prolonged use of the composition as an . udder sanitizing agent can cause widespread inclderce . .

of teat cr~cking. Cracks or fissures in the deI~al tissue of the cow's teat act as a residence poin~ for bacterial colonies and it i.s difficu].t to pcnctrate these points wi.th any type of water.borne disi.nf~ctant.
One factor which may produce the dermatological changes resulting in cracking is the denuding of the skin's natural protective fats by a process of emulsification.
The presence of some surfactants in the workin~ formul-ations would assist this emulsi.fication.
It has now been found possible to reduce the problem of teat cracking.
According to the present invention there is provided a composition for santization in the dairy industry, said composition having a pH of below 7 and comprising: water or a mixture of water and a mono-hydric alcohol having l to 3 carbon atoms; glutaraldehyde;
a monovalent and/or divalent and/or.trivalent metal ion;
and an emollient which is soluble in, or has been solubilised in? the composition and which is based on wool I 20 grease, a derivative thereo~, an alkyl branched fatty ; . acid ester or a mixture of alkyl branched fatty acid ! esters.
According to the present invention there is also provided a method of sanitizing in the dairy industry, which comprises applying to a site on an animal to be treated a composltion having a pH of below 7 and ! ~ comprising: water or a mi~ture of water and a mono-I hydric alcohol havi.ng l to ~ carbon atoms; glutar~

1 1~'737 dehyd,?;~ a monovale~t an~/or divalent and/or triva]enl;
metal ion; and an emollient which is solu~le in, or . has been solubili%ed ;n, the composi~ion and ~/hich is based on wool grease, a derivative thereof, ~n ~lkyl branched ~atty acid ester or a mi~ture of alkyl branched ~atty acid esters r The presence of the emollient in the composition substantial'.y overcomes t'ne problem of teat cracking.
It is believed that the emollient is adsorbed into the udder dermal tissues, producing an emoliient action which succeeds in ~uppressing teat cracking. The emollient conditions the skin of animals by replacing the natural oils which may be removed, as described above, by other constituents in the compositions.
Care must be taken in the selection of the emollient for use in the present invention. Many of the well known materials suitable for use-as emollients, e.g.
glycerine and propylene glycol, are totally unsuitable for use in the present invention because, when formulated with glutaraldehyde at acid pH, they react with the glutaraldehyde to form a compound which does not display microbiocidal properties. On storage, such for~ulations gradually show a decrease in glutaraldehyde content and sanitizing activity and are not suitable for co~mercial manufacture.
Another approach to the inclusion of an emollient in a formulation comprising glutaraldehyde, water or a -1 15'7372 mixture`of water and a monohydric alcohol having l to 3 carbon atoms, ~nd a monovalent and/or divalent and/or trivalent metal ion is the inclusion of a water-insoluble emollient which has been emulsified in the formulation by the addition of a suitable surface active agent.
However, such formulations containing e~ollients otherthan those used in the formulation o~ the present inventioncan be unsuitable as the high concentration of ions present in ~hè formulation can crack do~rn the emulsion of the emoll-ient and disrupt the formulation into a non-emulsified oil ~nd aqueous mixture which is not suitable for use.
It has been ~ound that the emollients sui~able ¦ ~or use in the present invention are based on ~ool grease, a derivative thereof, an alkyl branched fatty acid ester or a mixture o~ alkyl branched fatty acid esters. The emollient is either soluble in~ or is solubilised in,the composition. I~ the emollient is solub~lised in the composition, the solubilisation is effected by means of a sur~actant.
~ ~ 20 Wool grease is the name given to the material 1 8ecreted by sheep from sebaceous glands in their skin so as to form a natural protective coating on the wool fibres. It has the physical consistency of a soft grease, i8 chemically a wax and is different from the body fat of the animal. Wool grease may, for example, be recovered from the wool by a washing process and may, - for example, be refined into derivatives which have va~ue as emollients in the present invention. Such ',',' . .

1 1 5 ~372 derivati~es wlich nave value as emollients include wool fat (.~nhydrous lanolin), 1iquid wool fat and hydrogenated wool Lat.
.
AlkoxylatiGn of wool grease or derivatives thereof with a suitable agent, e.g. ethylene oxide or propylene oxide, produces derivatives-which-may, for example, be soluble in water and use~ul as emollients in the present inventïon. In such instances the polyalkylene oxide condensate produced preferably has a minimum average chain length of approxi~ately 15 alkoxyl units.
-- The emollient is preferably a polvalkylene oxide derivative of either wool grease or a derivative of wool grease such as wool fat, liquid wool fat or hydrogenated wool fat. Suitable emollients include the polyalkylene oxide derivatives of wool fat, such as ethoxylated wool fat, particularly when the degree of ethoxylation is within the range of 40 to 70 mols of ethylene oxide. However, any other water-soluble polyalXylerLe oxide derivative of wool fat may be employed.
The emollient used in the present invention is preferably one which is soluble in aqueous solution as no solubili~ation of the emollient will be required.
¦ Such emollients which are soluble in aqueous solution ! 25 include the polyall~ylene oxide derivatives of wool grease and the polyalkylene oxide derivatives of wool grease derivatives such as wool fat, liquid wool fa~
hydro~en~ted ~rool fat ~nd chlorin~ted wool fat~

, The water-soluble polyalkyleIle oxide dcrivatives of wool grase and the water-soluble polyalkylene oxide derivatives of wool grease derivatives can tolerate high electrolyte concentrations and in the working formulations they are stable and may be stored for considerable periods of time without loss of glutaral-dehyde content or sanitizing activity and without disruption of the formulation.
The polyal~ylene oxide derivatives of wool grease and the polyalkylene oxide derivatives of wool grease derivatives also have the adv&ntage that they possess non-ionic surfactant properties. Thus, in addition to their emollient action on the skin of the animal, they enhance the microbiocidal action of the glutaral-dehyde because of a synergistic action in combination with the glutaraldehyde and metal lons. This means that the quantity of glutaraldehyde present in the mixture may be reduced to produce the desired microbiocidal effect.
It is possible, with the polyalkylene oxide derivatives of wool grease and the polyalXylene oxide derivatives of wool grease derivatives, to solubilize further quantities of the water-insoluble emollients sucn as wool fat and alkyl branched fatty acid esters ~5 w1thout additional quantities of surface acti~e agents.

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1 15'7372 g Examples of water-insoluble derivatives of wool grease which may be used in the present invention include: wool fat; wool alcohols; liquid wool fat, e.g. Arganol* 60 produced by Westbrook Lanolin Limited; hydrogenated wool fat, e.g. Satulans* produced by Croda Chemicals Limited;
and esterified wool fats such as the isobutyl derivative of liquid wool fat, e.g. Arganol* 40 produced by Westbrook Lanolin Limited.
Examples of water-soluble derivatives of wool grease which may be used in the present invention include: eth-oxylated wool grease such as Aqualose* WG 75 produced by Westbrook Lanolin Limited; alkoxylated wool fats such as ethoxylated wool fat, e.g. Aqualose* L75 or Aqualose* L30 produced by Westbrook Lanolin Limited; alkoxylated liquid wool fats such as Aqualose* LL 100 produced by Westbrook Lanolin Limited; and alkoxylated wool alcohols such as propylene oxide derivatives of wool alcohols, e.g.
Solulans* PB produced by Amerchol U.S.A., or ethoxylated wool alcohols, e.g. Aqualose* W20 produced by Westbrook Lanolin Limited.
Examples of commercially available solubilized derivatives of wool grease include: Aqualose* SLW
which is produced by Westbrook Lanolin Limited and is a blend containing approximately 20~ by weight liquid wool fat solubilized with ethoxylated wool alcohols; and Aqualose* SLT which is also produced by Westbrook Lanolin * Trade Mark B
.

.
, :

1 1 5 73~2 Limited and is a blend containing approximately 25%
by weight of natural liquid wool fat solubilized with ethoxylated straight chain fatty alcohols.
Examples of suitable commercially available alkyl branched fatty acid esters or mixtures thereof include:
PCL* liquid which is marketed by Dragoco Company and is a mixture of alkyl branched chain fatty acid esters; and Neo-PCL* which is marketed by Dragoco Company and is a mixture of an alkyl branched chain fatty acid polyglycol ester with 4 moles of ethylene oxide and an alkyl phenol polyglycol ether as a solubilizer.
The amount of emollient used can, for example, be as low as 0.1% weight/volume, e.g. at least 0.5% weight/
volume, based on the composition. The emollient can, for example, be used in amount of up to 15% weight/volume, e.g. up to 10% weight/volume, based on the composition.
However, it is preferred to use substantially 2% weight/
volume of the composition. Such concentrations are based on the solution as used in the treatment. It is, however, possible to provide the composition in a concentrated form which may be diluted, for example, ten times, prior to use.
The composition of the present invention contains a monovalent and/or divalent and/or trivalent metal ion.
In the case of monovalent ions it is preferred to use alkali metal ions, in the case of divalent ions it is pre-ferred to use alkaline earth metal ions, and in the case * Trade Mark 115 73r?2 of trivalent metal ions it is preferred to use those of Group IIm of the Periodic Table of the Elements ~e.g. aluminium). ~he metal ions can be introduced i salt form. Examples of suitable salts of monovalent 5~ metal ions include halide ~e.g. chloride), sulphate, nitrate, acetate and citrate salts of sodium and potassium. Examples of sùitable salts of divalent metal ions include halide (e.g. chloride), sulPhate, nitrate, acetate and citrate salts of magnesium and soluble salts of calcium includin~ chloride and acetate - salts of calcium. Examples of suitable salts of trivalent metal ions include aluminiu~ acetate, aluminium chlor~de and aluminium chlorohydrate.
For the sake of convenieDce, the present invention will hereinafter be particularly described with reference to the use of A~3+ or Mg2~ as the metal ion.
However, monovalent or other divalent or trivalent ¦ metal ions may be used.
I The presence of A~+ or Mg2+ in aaueous glutaral-¦ 20 dehyde solutions has been found to increase glutaral-¦ dehyde inactivation of cellular alkaline phosphatase by I caus;ng a drift of the enzyme towards the outer membrane.
I A still further increase in activity nas been demonstrated when a surfactant, preferably of the anionic t~pe, is added to the aluminium-glutaraldehyde or magnesium-glutaralde`nyde formulation and this effect s related to increa~ed upta~e of the disinfectant.

~ 1 15'737~
-12_ As mentione(l above, acidic sclutions of glu~araldei)yde have very slow activity. Tlowcvt:r, it llas been found that an aclueolls acidic solution of glutaraldehyde containing A~3+ or Mg2+ has comparable activity to an aqueous solution of glutaraldehyde made alkaline by the presence of, for example, sodium bicarbonate.
Study of the effect of varying concentrations of Ae3~ or Mg2+ on the effectiveness Gf the glutaraldehyde solution has shown increasing effectiveness up to abou~
0.2 molar but no significant increase for concentrations over 0.2 molar. However,concentrations as high as 0,5 rrlolar may be used. It is preferred to use a concentration of Aa3~ or Mg2~ of at least 0.15 Molar. However, concent-rations as low as 0.05 Molar may, for example, be used.
Extrapolation of investigations on bacteria to spores has shown similar results.
The incorporation of a surfactant into the glutaraldehyde-Ae3+ or glutaraldehyde-Mg2+ solution potentiates the effect of the glutaraldehyde. Indeed it has been found that in some cases a synergistic effect is achieved when compared with aqueous glutar-aldehyde containing Ae3+ or Mo2+ or surfactant alone.
The ~ount of surfactant present may, for ex-rple, be a~ least 0.017' by weight, e.g. at least 0~1~ by weightJ
of the compositionO The surfactant rnay, for example, be prcsent in an arlount of up to 1~^~' by Yeight~ e.g. up to 5,~ by ~ieight,of the composition.

1 15'7372 --l 3-~ he preforred surfactan~s are anionic. Suitable anionic suIfRctants include detergents ,lhich are ionizable at the p~ of acid solutions of glutaraldehyde.
~he pKa values would generally be less than 4, preferably less than 3.5. ~ne anionic surfactants may, for example, be alkyl sulphates or alkylaryl sulphonates.
~he alkyl sulphates usually have 8 to 18 carbon atoms in the alkyl group, for e~ample, lauryl or deodeGyl sulphate. ~he anionic surfactant is usually employed in an amount of less than 10% by weight, preferably less than 5% by weight, of the composition when using an alkyl sulphate.
Non-ionic surfactants such as the ethoxylated fatty alcohols or ethoxylated alkylphenols may be used.
Preferably the fatty alcohol or alkyl phenol has been ethoxylated to a degree of greater than 9 moles of ethylene oxide. However, use of a non-ionic surfactant with Ae~+ or Mg2+ has been found not to be as effective - as use of an anionic surfactant (as sodium salt) with A~3+ or Mg2~. The non-ionic surfactant is usually employed in an amount of less than 3,~ by weight, preferably 0.5 to 1.5% by weight of the co position.
Use of fairly high concentratio~s of Ae~+ or Mg2+
(or indeed monovalent or other divalent or trivalent metal ion) salts and fairly high concentrations of 3ur~actants can, however, lead in some instances to a sa~ting out effect resulting in precipitation from the 1 15'7372 solution. '~his prob]em can, however, be overcome by employin~ the Ae3+ or Mg2+ and surfactant as a sin~le compound. When using such s;ng]e compounds, the monovalent, divalent or trivalent metal ions are cations of s~rf~ct~nts, preferably anionic surfactants.
EXamples of such compounds are aluminium dodecyl or lauryl sulphate, aluminium dodecyl or lauryl benzene sulphonate, magnesium dodecyl or lauryl sulphate and magnesium dodecyl or lauryl benzene sulphonate. Indeed, if a single compound is used it is possible to produce effective formulations of glutaraldehyde containing less than the desired 0.15 Molar concentration of Ae3~ or Mg ~, even as low as 0.001 Molar.
'~he concentration of glutaraldehyde in the aqueous solution affects the time required for sanitization.
The concentration of glutaraldehyde is usually from 0.005/0 to 10%, but preferably less than 0.5%, by weight of the composition~ -'~he composition of the present invention may also contain a small quantity of an organic acid such as citric acid, propionic acid, tartaric acid or maleic - acid. The organlc acid, if used~ i3 present in an amount suf~icient to ensure an acid pH for the fo~ul-ation.
The compositions of the present invention are temperature dependent in use~ Increasing te~perature leads to lncreasing activity and indeed a synergistic ,' .

115 ~372 ,5 effect may be observecl. ~rhe compositiorls ~Ire usually employed at a temperature of at lea~t ambient ternperature.
If a mixtllre of water and alcohol is used in the composition of the present invention, the alcohol may, for example, be isopropanol. The presence of an alcohol, or indeed any other organic solvent, can be used to control the viscosity of the solution or produce a humectant èffect.
~he co~po~ition of the present invention may further comprise a corrosion inhibitor.
~ he col-lpositior. of the present inventior. may be used in saniti~ation in the presence of metallic, particularly ferrous, articles. IIowever, at the acid pH of the composition, many of the conventional additives for rust inhibition have been demonstrated to be ineffective. It has further been demonstrated that the sulphate or sulphonate derivati-res of hydroxy carboxylic acids, such as those derived from ricinoleic - and hydroxy stearic acids, are effective corrosion inhibitors for the formulations of this invention.
~he aforementioned sulphate and sulphonated derivatives of hydroxy carboxylic acids are also anionic surfactants.
It is further possible by the use of the said carboxylic acids to present the preferred ion, anionic surfactant and corrosion or rust inhibitor in the form of a single compound. The amount of corrosion or rust lnhibitor employed i~; usllrLlly 0~1 to 5~o by weifrh1., pre~ ?I' to 2~ b~ weil~ht, and more ~re~erably subst~ntiall~
by weight, of the composit.ion. A par'icularl~ useful i~libitor is sulphated caster oil (marketed by Ellis Jones & Co.), preferably in the presence of an or~an~c acid (eOg. citric acid) to ensure an acid pH.
The present invention will now be further described with reference to, but is in no manner limited to, the following examples.
EXAMP~E 1.
1.5% by weight of solubilized liquid wool fat was heated and dispersed in warm water and allowed to cool. 0.5% by weight glutaraldehyde and 2.0% by weight sodium chloride were then added and the mixture was made up to 90% of the desired volume with water. Citric acid was added to give a pH of appro~imately 5.0 and the re~sultant mixture was made up to 100% of the desired volume with water. The resulting formulation was satisfactorily used in the santizing of cows' udders.
The solubilized liquid wool fat used in this Example was Aqualose S~T which is marketed b~ Westbrook I~nolin Limited and is a mixture of natural liquid wool fat (approximately 25C~ by weight) and an ethoxylated fatty alcohol (approximately 75~ by weight).
E.~AM I.E 2.
0.1~' by weight glut~raldehyde, 4.0C~ by weight magnesium chloride hexahydrate and 2~C;, by weight .

.

,~

etho~lated ~rool fat were dispersed in ~rater. Citric acid was added in an amount sufficient to give a pH of approximately 5Ø The resulting formll]ation was Successfully used as a saniti7.ing formulatior. for dairy pur~ose;.
EXAMPIE 3.
0.5% by weight glutaraldehyde, 4.0% by weight magnesium chloride hexahydrate, 2.0% by weight etho~y-lated wool fat and 10.0,o by weight isopropanol were dispersed in water. Citric acid was added in an amou~t sufficien to give a pH of approximately 5Ø The resulting formulation satisfactorily used in the sanit-izing of cows' udders.
EXAMPLE 4.
_ 0.5% by weight glutaraldehyde, 7 0C,' by weight magnesium lauryl sulphate, 3.0~.~ by weight ethoxylated wool fat and 0.5% by weight citric acid were dispersed in water. The formulation so produced was effective in the sanitization of co~s' udders.
EXAMPL~ 5.
0.1% by weight glut~raldehyde, 4~0, by weight magnesium chl~ride he~ahydrate and 1.5-~o by weight Neo-PCI.~/clter-soluble were dispersed in water. Citric acid was added in an amount sufficient to give a pH of approximately 5Ø The resulting formula-tio~ was successfully used as a sc~nitizing agent for dairy pur,poses .

l l5'7372 _18-~.XAMPLE 6.
1.0,'.by weight of solubilized liquid wool fat wa~ heatecl and dispersed in warm water and allo~red to cool. 0.55'~by weight glutaraldehyde and 2.0% by weight sodium sulphate were added and the mixture made up to 90% of the desired volume with water. Citric acid was then added to ~ive a pH of approxima-tely 5.0 and the resultant mixture made up to 100% of the desired volu~e with water. ~he resulting formulation was satisfactorily used in the sanitizin~ of cows' udders.
In this Example the solub~ ed liquid wool fat was Aqualose SLW which is marketed by Westbrook Lanolin ~imited and is a mixture of natural liquid wool fat ~approximately 20% by weight) and ethoxylated wool alcohols (approximately 80% by weight).
~ ~ . . ... ..
~XAMP~
3% by weight of ethoxylated wool alcohols was heate~
and dispersed in warm water and allowed to cool. 0.4 by weight glutaraldehyde and 1,~ by weight aluminium - 20 acetate were added and made up to the ~esired volume with water. The resulting formulation had a pH of less than 7 and was satisfactorily used for saniti~ing cow~s udders.
E2~PIE 8

2% by weight of ethoxylated wool grease (Aqualose WG 75) was heated and dis~ersed in warm water and allowed to cool~ 0.3/~ by weight glutaraldehyde and 3~J by ~eight .. .

magnesium ch~oride hexahydrate were added and ~adc up to the d.esircd vol~me with ~rater. The resulting formulation had a pH o-f less than 7 and was satisfactorily used for . sanitizing cows' udders.

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Claims (41)

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A composition for sanitization in the dairy industry, said composition having a pH of below 7 and comprising: a medium selected from the group consisting of water and a mixture of water and a monohydric alcohol having 1 to 3 carbon atoms; glutaraldehyde; metal ions selected from the group consisting of monovalent, divalent, and trivalent metal ions, and mixtures thereof;
and an emollient which is soluble in, or has been solubilised in, the composition and which is based on a material selected from the group consisting of wool grease, derivatives thereof, alkyl branched fatty acid esters, and mixtures of alkyl branched fatty acid esters.

2. A composition according to claim 1, in which the emollient is wool fat.

3. A composition according to claim 1, in which the emollient is a polyalkylene oxide derivative of wool grease.

4. A composition according to claim 1, in which the emollient is a polyalkylene oxide derivative of wool fat.

5. A composition according to claim 3 or claim 4, in which the emollient is a polyethylene derivative.

6. A composition according to claim 3 or claim 4, in which the emollient is an ethoxylated wool fat having a degree of ethoxylation of 40 to 70 mols ethylene oxide.

7. A composition according to claim 1, in which the emollient is an alkyl branched fatty acid ester or a mixture thereof.

8. A composition according to claim 1, in which the emollient is present in an amount of at least 0.1%
weight/volume of the composition.

9. A composition according to claim 1, in which the emollient is present in an amount of up to 15% weight/
volume of the composition.

10. A composition according to claim 1, in which the monovalent metal ion is an alkali metal ion.

11. A composition according to claim 1, in which the divalent metal ion is an alkaline earth metal ion.

12. A composition according to claim 1, in which the trivalent metal ion is a group III (b) metal ion.

13. A composition according to claim 1, in which the metal ions are cations of a surfactant or surfactants.

14. A composition according to claim 13, in which the divalent metal ion is present in the form of magnesium dodecyl or lauryl sulphate or magnesium dodecyl or lauryl benzene sulphonate.

15. A composition according to claim 13, in which the trivalent metal ion is present in the form of aluminium dodecyl or lauryl sulphate or aluminium dodecyl or lauryl benzene sulphonate.

16. A composition according to claim 1, in which the monovalent metal ion is present in the form of a halide, sulphate, nitrate, acetate or citrate salt of sodium or potassium.

17. A composition according to claim 1, in which the divalent metal ion is present in the form of a halide, sulphate, nitrate, acetate or citrate salt of magnesium or is a soluble salt of calcium.

18. A composition according to claim 17, in which the soluble salt of calcium is calcium chloride or calcium acetate.

19. A composition according to claim 1, in which the trivalent metal ion is aluminum acetate, aluminium chloride or aluminium chlorohydrate.

20. A composition according to claim 1, in which the metal ions are present in a concentration of at least 0.05 molar.

21. A composition according to claim 1, in which the metal ions are present in a concentration of not more than 0.5 molar.

22. A composition according to claim 1, which also comprises a surfactant.

23. A composition according to claim 22, in which the surfactant is dodecyl or lauryl sulphate, or an ethoxylated fatty alcohol or alkyl phenol which has been ethoxylated to a degree of greater than 9 moles of ethylene oxide.

24. A composition according to claim 1, which also comprises a corrosion inhibiting agent.

25. A composition according to claim 24 in which the corrosion inhibiting agent is a sulphated or sulphonated hydroxy carboxylic acid.

26. A composition according to claim 13, in which the metal ion-containing surfactant is selected so that it has, in addition to surfactant properties, corrosion inhibiting properties.

27. A composition according to claim 26, in which the metal ion-containing surfactant is derived from a sulphated or sulphonated hydroxy carboxylic acid.

28. A composition according to claim 24, in which the corrosion inhibiting agent is present in a concentra-tion of 0.1 to 5% by weight, based on the weight of the composition.

29. A composition according to claim 1, in which the glutaraldehyde is present in a concentration of 0.005 to 10% by weight, based on the weight of the composition.

30. A composition according to claim 29, in which the glutaraldehyde is present in a concentration of less than 0.5% by weight, based on the weight of the composition.

31. A method of sanitizing in the dairy industry, which comprises applying to a site on an animal to be treated a composition as claimed in claim 1.

32. A method of sanitizing in the dairy industry, which comprises applying to a site on an animal to be treated a composition as claimed in claim 2.

33 A method of sanitizing in the dairy industry, which comprises applying to a site on an animal to be treated a composition as claimed in claim 3.

34. A method of sanitizing in the dairy industry, which comprises applying to a site on an animal to be treated a composition as claimed in claim 4.

35. A method of sanitizing in the dairy industry, which comprises applying to a site on an animal to be treated a composition as claimed in claim 7.

36. A method of sanitizing in the dairy industry, which comprises applying to a site on an animal to be treated a composition as claimed in claim 13.

37. A method of sanitizing in the dairy industry, which comprises applying to a site on an animal to be treated a composition as claimed in claim 16.

38. A method of sanitizing in the dairy industry, which comprises applying to a site on an animal to be treated a composition as claimed in claim 17.

39. A method of sanitizing in the dairy industry, which comprises applying to a site on an animal to be treated a composition as claimed in claim 19.

40. A method of sanitizing in the dairy industry, which comprises applying to a site on an animal to be treated a composition as claimed in claim 22.

41. A method of sanitizing in the dairy industry, which comprises applying to a site on an animal to be treated a composition as claimed in claim 24.