GB2048675A - Pesticidally-active concentrated oil-in-water emulsions - Google Patents

Abstract

The invention is a pesticidally-active concentrated emulsion comprising:- 3.5-6.5 or 10-35 parts by weight of lipophilic pesticide, 3.5-6.5 or 10-35 parts by weight of hydrocarbon solvent, 0.1-10 parts by weight of an alkanol, 0.5-32 parts by weight of at least one non-ionic surfactant to stabilise the emulsion, and water to bring the total of all components of the emulsion to 100 parts by weight. The emulsions have excellent freeze/thaw stability and are generally stable over a wide range of storage temperatures. A process for the preparation of the emulsions is also claimed.

Description

SPECIFICATION Pesticidally-active concentrated oil-in-water emulsions The present invention relates to a pesticidallyactive concentrated oil-in-water emulsion and to a process for its preparation. Because pesticide formulations are stored over long periods of time under changing temperature conditions or extremes of weather, it is necessary that their formulations have a stability over the broad range of storage temperatures, including an ability to retain their integrity after being frozen.

While preformed emulsions of lipophilic substances in aqueous media are known, mainly in the cosmetic, food and pharmaceutical industries, these emulsions are incapable of undergoing repeated freeze/thaw conditions without breaking. It was desirable, therefore, to devise new emulsions, capable of undergoing extremes of temperature.

The present invention provides a pesiticidallyactive concentrated emulsion comprising: 3.5-6.5 or 10-35 parts by weight of a lipophilic pesticide, 3.5-6.5 or 10-35 parts by weight of a hydrocarbon solvent, 0.1-10 parts by weight of an alkanol, 0.5-32 parts by weight of at least one nonionic sur factantto stabilise the emulsion, and water to being the total of all components of the emulsion to 100 parts by weight.

In contrast to ordinary emulsions, which are simple mixtures, i.e., dispersions of one immiscible liquid into another made relatively stable by an emulsifying agent, the subject ofthis invention is stoichiometrically well-defined within the boundaries depicted in a three phase diagram. Further, the unusual stability of these emulsions, at temperatures in the range -18 to 120"C, appears to be associated with a definite structure which is made evident by the birefringent property of the emulsions observed in a microcell with a polarizing microscope. Birefringence is the numerical difference between the maximum and minimum refractive indices in a substance which is capable of having more than one refraction index.

The birefringence disappears when the emulsion is broken at 120CC and boiling occurs. Practical emulsions of this type were generally discussed by Stig Friberg and Inza Wirton in American Perfumes and Cosmetics 85 (i 2)27 (1 9i0). The emulsions are believed to have this unusual stability due to the formation of a structure not unlike liquid crystals.

The lipophilic pesticide may be selected from a variety of broad spectrum or selective pesticides including insecticides, acaricides, fungicides and herbicides.

Any pesticide which has lipophilic properties and low water solubility, for example, a water solubility of 100 ppm or lower, is suitable for formulation into the concentrated oil-in-water emulsions of this invention. Such pesticides include lipophilic organophosphates including organophosphorus compounds such as diethyl (2 - isopropyl - 4 - methyl - 6 - pyrimidinyl) - phosphorothioate or dimethyl S -[(4 - oxo 1,2,3 - benzotriazin - 3(4H) - yl) methyls phosphorodithioate, particularly including lipophilic vinylorganophosphates such as dimethyl 1 - (2,4,5 - trichlorophenyl) - 2 - chlorovinyl phosphate, natural products and derivatives thereof including pyrethrins, rotenones, tobacco extracts, pine oil, resin, tar or gum and the like, liphophilic aniline derivatives such as a,cy,a, trifluoro - 2,6 - dinitro - N,N - dipropyl - p -toluidine and N - butyl - N - ethyl - 2,6 - dinitro - 4 - trifluoromethylaniline or chlorinated hydrocarbons such as chlordane and numerous other lipophilic pesticides.

A particularly suitable class of pesticides are those termed "synthetic pyrethroids". Preferably, the pesticidally-active pyrethroid has the formula I

wherein A is an optionally-substituted aralkyl, alkyl or cycloalkyl group and R is hydrogen, cyano or ethynyl. Generally speaking, the alkyl, cycloalkyl, or ara Ikyl groups preferably contain up to 10 carbon atoms.

When A represents an optionally-substituted cycloalkyl group in formula I, the preferred compounds are those containing a cyclopropyl group of formula

wherein Ra and Rb each represent an alkyl group containing 1 to 6 carbon atoms, especially methyl, or a halogen atom having an atomic number of 9 to 35, inclusive, especially chlorine atom; or when Ra represents a hydrogen atom then Rb represents an alkenyl group containing 2 to 6 carbon atoms optionally-substituted by 1 to 3 chlorine or bromine atoms, especially isobutenyl or a mono- or dichlorovinyl group;Rc and Rd each represent an alkyl group containing 1 to 6 carbon atoms, or when Rc is hydrogen then Rd is an alkenyl group containing 2 to 6 carbon atoms optionally-substituted by 1 to 3 chlor ine or bromine atoms, especially a mono- or dichlorovinyl group; or at least one of Ra and Rb together or Rc and Rd together each represent an alkylene group containing 2 to 6, especially 3 carbon atoms.

Preferred because of their insecticidal properties are those pyrethroids wherein the cyclopropyl group of formula II Ra and Rb each is methyl, Rc and Rd each is methyl or when Rc is a hydrogen atom then Rd iS isobutenyl, 2,2 - dichlorovinyl, or 2,2 - dibromovinyl.

When A represents an aralkyl group in formula I, preferred compounds are those containing a substi tuted benzyl group of formula Ill

wherein Z represents a halogen atom having an atomic number of 9 to 35, inclusive, or an alkyl or alkoxy group of 1 to 4 carbon atoms, e.g. methyl or methoxy, and 0 represents an alkyl group of 1 to 6 carbon atoms, especially a branched chain group such as an isopropyl group.

The most preferred pyrethroids for use in the pest icidal emulsion according to the invention have the formula I wherein A is alpha - isopropyl - 4 - chlorob enzyl, 2,2,3,3 - tetramethylcyclopropyl, 2- (2,2 - dich- lorovinyl) - 3,3- dimethylcyclopropyl, or 2 - (2,2- dibromovinyl) - 3,3 - dimethylcyclopropyl; R is hydrogen, ethynyl or cyano.

It should be noted that optical isomers, cistrans isomers and other kinds of geometric isomers of the compounds according to formula I are within the scope of the present invention as well and mixtures of one or more of isomers of the pesticidally-active compounds according to formula I. The various isomers of the compounds according to formula I may have different pesticidal toxicities and/or knockdown potency. Thus, one may prefer two resolve mixtures of isomers to recover a more pesticidally-active isomer or diastereoisomer pair or to prepare the more active forms directly for use in the emulsions of the invention.

As stated hereinbefore, the lipophilic pesticide is present in amounts of 10-35 parts by weight. Preferably, emulsions are formulated in which the pesticide is present in amounts of 28-32 parts by weight. In the case of the synthetic pyrethroids described herein the amounts of about 30-31 parts by weight have been found especially suitable for the formation of stable emulsions.

The hydrocarbon solvent used may include any number of alkane, cycloalkane, alkene, aromatic and alkyl-aromatic hydrocarbons. Generally speaking, the alkanes, including cycloalkanes, and alkenes contain from 1-12 carbon atoms, for example, pentane, hexane, heptane, hexene, and cyclohexane, while the aromatic and alkylaromatics contain 6-20 carbon atoms and 1-2 hydrocarbyl rings, for exampie benzene, naphthalene, toluene, ethylbenzene, xylene, trimethylbenzene, p-ethyltoluene; mixtures of any of the above hydrocarbons may be used. Particularly useful are mixtures of alkyl-benzenes.One such mixture is sold under the tradename Tenneco 500-100 by Tenneco Oil Company and contains predominantly p-ethyltoluene and 1,2,4 - trimethylbenzene with minor amounts of ortho-xylene, other alkylbenzenes, C,O and heavier aromatics and nonaromatics and is especially desirable because of its high flash point Naphthas, petroleum distillates and certain lubricating fractions can also be used. In general, mixtures of aromatic hydrocarbons having a flash point by Tag Closed Cup Tester of over 1000F are preferred.

The hydrocarbon solvent is present in an amount sufficient to make the density of the solventpesticide phase equal to that of the water-alkanol phase of 10-35 parts by weight. Preferably, emulsions are formulated in which the solvent is presented in amounts of 28-32 parts by weight, or more suitably in amounts of about 30-31 parts by weight. In the case of formulations in which the above-described synthetic pyrethroids are used as the lipophilic pesticide, the solvent is preferably Tenneco 500-100. The solvent is preferably used in about the same amount (parts by weight) as the pyrethro id.

Examples of the alkanol component include monohydroxy alcohols containing 1 to 4 carbon atoms and dihydroxy alcohols containing from 2 to 4 carbon atoms, for example methanol, ethanol, isopropanol, ethylene glycol, propylene glycol, 1,3 - propandiol, and 1,2 - butandiol. Preferably, an alkandiol containing from 2 to 3 carbon atoms is used, especially ethylene glycol or propylene glycol. A trihydroxy alcohol such as glycerol may also be used.

The alkanol component of the emulsion is present in amounts of 0.1-10 parts by weight. Preferably, the alkanol is present in amounts of 2-6 parts byweight, suitably 3-5 parts by weight.

Suitable nonionic surfactants (surface-active agents) can be broadly defined as the emulsifying compounds required to give a stable emulsion with the particular hydrophile/lipophille balance of the oil phase containing the pesticidally-active ingredient as determined by the method described by A. Beerbower and M. W. Hill in McCuthcheon's Detergents and Emulsifiers, page 223 (1971) and are usually compounds, aliphatic or alkylaromatic in nature, which do not ionize in water solution. For example, a well-known class of nonionic agents is available under the tradename "Pluronic". These compounds are formed by condensing ethylene oxide with a hydrophobic base formed by the condensation of propylene oxide with propylene glycol. The hydrophobic portion of the molecule which, of course, exhibits water insolubility has a molecular weight of from about 1,500 to 1,800.The addition of polyoxyethylene radicals to this hydrophobic portion tends to increase the water solubility of the molecule as a whole and the liquid character of the product is retained up to the point where polyoxyethylene content is about 50% of the total weight of the condensation product.

Other suitable nonionic surfactants include: (1) The polyethylene oxide or propylene oxide condensates of alkyl phenols, e.g., the condensation products of alkyl phenols having an alkyl group containing about 6 to 12 carbon atoms in either a straight chain or branched chain configuration, with ethylene oxide, the said ethylene oxide being present in amounts equal to 10 to 25 moles of ethylene oxide per mole of alkyl phenol. The alkyl substituent in such compounds is derived, for example, from polymerized propylene, di-isobutylene, octene, or nonene; (2) The condensates derived from ethylene oxide and the product resulting from the reaction of propylene oxide and ethylenediamine. For example, compounds containing about 40% to about 80% polyoxyethylene by weight and having a molecularweight of about 5,000 to about 11,000 resulting from the reaction of ethylene oxide groups with a hydropho bic base constituted of the reaction product of ethyl ene diamine and excess propylene oxide, said hydrophobic bases having a molecular weight of the order of 2,500 to 3,000, are satisfactory; (3) The condensation product of fatty acids, hydr ogenated fatty acids (including hydrogenated castor oil) or aliphatic alcohols having 8 to 18 carbon atoms, in either straight chain or branched chain configuration, with propylene oxide or ethylene oxide, e.g. a coconut alcohol-ethylene oxide condensate having 10 to 30 moles of ethylene oxide per mole of coconut alcohol, the coconut alcohol fraction having 10 to 14 carbon atoms;; (4) Long chain tertiary amine oxides corresponding to the following general formula, R,R2R3N < 0, wherein R, is alkyl of about 8 to 18 carbon atoms, and R2 and R3 are each methyl or ethyl radicals.

Examples of amine oxides suitable for use in this invention include dimethyldodecylamine oxide, dimethyloctylamine oxide, dimethyldecylamine oxide, dimethyltetradecylamine oxide, dimethylhexadecylamine oxide; (5) Long chain tertiary phosphine oxides corresponding to the following formula RR'R"P 0, wherein R is an alkyl, alkenyl or monohydroxyalkyl radical ranging from 10 to 18 carbon atoms in chain length and Riand R" are each alkyl or monohydroxyalkyl groups containing 1 to 3 carbon atoms.

(6) Dialkyl sulphoxides corresponding to the following formula, RR'S < 0, wherein R is an alkyl, alkenyl, beta- or gamma-monohydroxyalkyl radical or an alkyl or beta- or gamma-monohydroxyalkyl radical containing one or two other oxygen atoms in the chain, the R groups ranging from 10 to 18 carbon atoms in chain length, and wherein R' is methyl or ethyl; (7) The ammonia, monoethanol and diethanol amides of fatty acids having an acyl moiety of about 8 to about 18 carbon atoms; (8) Mono-, poly- and di-glycerides of fat forming acids; (9) A sorbitan monoester with one or more long chain fatty acids of 8 to 20 carbon atoms or resin acids which include those sold under the tradenames "Atlox and "Atpet", including those modified by reaction with ethylene oxide or propylene oxide;; (iO) An alkylbenzene containing a straight-chain alkyl group. Suitable alkylbenzenes contain an alkyl group of 8 to 20 carbon atoms; or (i 1) Condensates of ethylene oxide or propylene oxide with fatty acids.

The use of mixtures of nonionic surfactants is also within the scope of the present invention.

The concentration of the surfactant must be higher than the critical micelle concentration (CMC). The surfactant(s) can be present in a total amount of 0.5 to 32 parts by weight, usually between 1-16 parts by weight but preferably 1-2 parts by weight and especially about 1.5 parts by weight of the concentrated emulsion according to the invention.

Preferred surfactants are one or more of polyethylene oxide condensates of alkyl phenols,.C8-C18 alkanols or fatty acids, sorbitan esters of fatty acids, polyethylene oxide sorbitan esters of mixed fatty and resin acids and polyglycerides of fatty acids, for example, NEODOLe Detergent alcohols, Tweens and Igepals.

A preferred concentrated emulsion according to the invention comprises 28-32 parts by weight of lipophilic pesticide, 28-32 parts by weight of hydrocarbon solvent, 2-6 parts by weight of an alkanol, 1-16 parts by weight of at least one nonionic surfa ctant to stabilise the emulsion, and water to bring the total of all components ofthe emulsion to 100 parts by weight.

In the concentrated emulsions of the invention water usually comprises about 48.9-17 parts by weight of the emulsion. When the emulsions are formulated with the preferred amounts of ingredients previously specified above, then water is present in amounts of about 41 -28 parts by weight or more suitably 36-21 parts by weight. The emulsion forms very readily when the ratio of oil phase (oil plus pesticide) to water phase (water plus emulsifier and alkanol) is about 1.6 to 1.

A separately-prepared stable, concentrated emulsion within the scope of the present invention comprises components of the same chemical compositions as described in relation to preferred emulsions but in different proportions. Broadly these proportions are: 3.5 to 6.5 parts by weight of at least one lipophilic pesticide, 3.5 to 6.5 parts by weight of a hydrocarbon solvent, 7 to 9.5 parts by weight of an alkanol, 6to 14 parts by weight of at least one nonionic surfactant to stabilise the emulsion and water to bring the total of all components of the emulsion to 100 parts by weight.

The preferences expressed with regard to each particular component of the first concentrated emulsion also hold true for the second, only the proportions are different. The preferred formulations of the second concentrated emulsion of the invention are; 4.5 to 5.5 parts by weight of lipophilic pesticide, 4.5 to 5.5 parts by weight of hydrocarbon solvent, 8 to 9 parts by weight of an alkanol, 9 to 11 parts by weight of at least one nonionic surfactant to stabilise the emulsion and water to bring the total of all components of the emulsion to 100 parts by weight.

The above oil-in-water concentrated emulsions may be prepared by any convenient technique but are preferably prepared by the combination of the non-ionic surfactant with a mixture of the hydrocarbon solvent and lipophilic pesticide and subsequen try the combination of the resulting threecomponent mixture with the alkanol and water, the latter step being accompanied by agitation to form the emulsion. A poorer quality emulsion results when the non-ionic surfactant (emulsifier) is added to the water phase in the emulsification step.

The concentrated emulsions of the present invention are superior in comparison with conventional concentrate formulations previously known in the art. In particular, the formulations of the invention are stable over a broad range of temperatures, e.g., from - 1 80C to 1 200C. Furthermore, the emulsions of the invention are unusual in that freezing does not cause separation of the oil and water phase and on thawing the emulsion remains unchanged. The high termal stability and optical (birefringent) properties of the concentrated emulsions of the invention are indicative of a specific three-dimensional structure having specific stoichiometry. A phase diagram, Figure 1 of the accompanying drawings, supports this view.The three variables used to plot this diag ram are: "(1) The oil phase comprising a 50% by weight sol ution of lipophilic pesticide in a hydrocarbon solv ent, e.g., 50% a - cyano - 3 - phenoxy - benzyl a isopropyl - p - chloro phenylacetate in Tenneco 500-100.

(2) The aqueous phase comprising a 10% by wei ght solution of alkanol in water, e.g., ethylene glycol in deionized water.

(3) The non-ionic surfactant, e.g., Atlox 8916-F. In the phase diagram there are two widely separated areas, "A" and "B", in which birefringent, stable emulsions are obtained. The products obtained in between these two areas are emulsions in which an aqueous layer forms below the emulsion in less than 24 hours. While the stable emulsions are formed in areas "A" and "B", the rheological properties of the two are different and it is likely that the products differ in spatial arrangements; i.e., they have differ ent crystalline structures.

An added advantage of the emulsions of the inve ntion is quantity and character of solvent. Because part of the organic solvent normally used is replaced by water, the formulations of the invention are less eye irritating, the quantity of solvent evaporated to the environment is reduced, and the formulations are less expensive. Additionally, use of high flash point solvents such as Tenneco 500-100 results in safer formulations because of their lower fire hazard characteristics. The present emulsions require about less than half the amount of solvent as conventional emulsion concentrates.

The stable, concentrated oil-in-water emulsions of this invention are effective for use as pesticide form ulations. The particular use will, of course, depend on the pesticide used, e.g., insecticide, herbicide, or fungicide. For example, when the pesticide is an ins ecticide the formulations of the invention can be eff ective for (1) control of ectoparasites in warm blooded animals, (2) control of insects on agricultu ral crops and in gardens, (3) control of insects in public places as a fumigant or space spray, (4) control of insects attacking trees, and (5) use to control insects in and around the home. The stability, reduced eye irritation and lowerfire hazard characteristics can be particularly advantageous for these uses.

Under normal use, the concentrated emulsions are diluted with water prior to application.

It should be noted that the pyrethroids of formula I are well-known for their pesticidal properties as insecticides for control of flies, mosquitoes, cockroaches, acarids, and ticks. Accordingly, the concentrated emulsions of the invention formulated using the pyrethroids of formula I are useful for the abovenoted pesticidal applications.

The invention is further illustrated by the following Examples: Example 7 Atypical concentrated oil-in-water emulsion was formed having the following ingredients in the indicated proportions: Percent Weight a-cyano-3-phenoxybenzyl a isopropyl-p-chlorophenylacetate 30.3 Tenneco 500-100 30.3 Atloxt 8916 TF Emulsifiers 1.5 (Polyoxyethylene (20) sorbitan monooleate mixed esters) Water 27.9 Ethylene glycol 10.0 100.0 The first three ingredients were combined to form a clear yellow solution which was then swirled into a water solution of ethylene glycol to obtain an opa que white oil-in-water emulsion. The emulsion was stable when held at -18"C.

Examples 2 to 7 Further concentrated oil-in-water emulsions of this invention were formed, the details of which are shown in Table 1 below: Table 1 PESTICIDAL OIL-IN-WATER CONCENTRA TED EMULSIONS Example 2 3 4 5 6 7 Percent Weight a-cyano-3-phenoxybenzyl a- 30.3 30.3 30.3 30.3 30.3 30.3 isopropyl-p-chlorophenylacetate Tenneco 500-100 30.3 30.3 30.3 30.3 30.3 30.3 Atlox 8916 Emulsifier 1.5 1.5 1.5 1.5 1.5 1.5 Water 37.4 36.9 35.9 34.4 32.9 30.4 Ethylene glycol 0.5 1.0 2.0 3.5 5.0 7.5 100.0 100.0 100.0 100.0 100.0 100.0 Similar emulsions were formulated by stubstitution of a - cyano - 3 - phenoxybenzyl 2,2,3,3 - tetramethyl - cyclopropanecarboxylate, 3- phenoxybenzyl 2,2 - dimethyl - 3 - (2,2 - dichlorovinyl) cyclopropanecarboxylate, a - cyano - 3 - phenoxybenzyl 2,2 - dime thyl - 3- (2,2 - dichlorovinyl) cyclopropanecarboxylate, or a - cyano - 3 - phenoxybenzyl 2,2 - dimethyl - 3 - (2,2 - dibromovinyl) cyclopropane - carboxylate for the a - cyano - 3 - phenoxybenzyl a - isopropyl - p chlorophenylacetate.

Example 8 A further concentrated emulsion was prepared having the following ingredients: Percent Weight Oil phase 62 131% a-cyano-3-phenoxybenzyl a isopropyl-p-ch lorophenyl acetate and 31% Tenneco 500-100) Surfactant Tween 40 1.5 (polyoxyethylene(20)sorbitan monopalmitate) Water phase (10% solution of propylene glycol in deionized water) 36.5 The required amount of the surfactantwas weighed and dissolved in the oil phase. The required amount of water phase was then added and the mixture shaken vigorously for 30 seconds to form a stable oil-in-water concentrated emulsion.

Examples 9 to 14 Following procedures similar to those of Example 8 above, stable oil-in-water concentrated emulsions were prepared using the surfactants shown in Table 2 below: Table 2 PESTICIDAL OIL -IN-WA TER CONCENTRA TED EMULSIONS Oil phase 62% (31% a - cyano - 3 - phenoxybenzyl a - isopropyl - p - chlorophenylacetate and 31% Tenneco 500-100) Water phase 36.5% (10% solution of propylene glycol in deionized water) Example Surfactants 1.5% Weight 9 Brij 58 Polyoxyethylene(20)cetyl ether 10 Brij 78 Polyoxyethylene(20)stearyl ether 11 G-2079 Polyoxyethylene(20)palmitate 12 G-1 292 Polyoxyethylene(20)hydrogenated castor oil 13 Renex 31 Polyoxyethylene(i 5)tridecyl ether 14 Geopon SF-365 Polyoxyethylene(40)castor oil

Claims (10)

1. A pesticidally-active concentrated emulsion comprising :

3.5-6.5 or 10-35 parts by weight of lipophilic pestic ide,

3.5-6.5 or 10-35 parts by weight of hydrocarbon solvent, 0.1-10 parts by weight of an alkanol, 0.5-32 parts by weight of at least one nonionic sur factantto stabilise the emulsion, and water to bring the total of all components of the emulsion to 100 parts by weight.

2. An emulsion according to claim 1 wherein the liphophilic pesticide is a synthetic pyrethroid.

3. An emulsion according to claim 1 or 2 wherein the alkanol is a monohydroxy alcohol containing 1 to 4 carbon atoms or a dihydroxy alcohol containing 2 to 4 carbon atoms.

4. An emulsion according to claim 1, 2 or 3 wherein the solvent is selected from alkanes, cycloalkanes or alkenes containing 1 to 12 carbon atoms or aromatics or alkylaromatics containing 6 to 20 carbon atoms or mixtures of these hydrocarbons.

5. An emulsion according to any one of the preceding claims wherein the emulsifier is one or more of (a) polyethyleneoxide condensates of fatty acids, hydrogenated fatty acids or alkyl phenols, (b) sorbitan esters of fatty acids, (c) polyethyleneoxide sorbitan esters of mixed fatty and resin acids, and (d) di or polyglycerides of fatty acids.

6. An emulsion according to any one of the preceding claims comprising: 28-32 parts by weight of lipophilic pesticide, 28-32 parts by weight of hydrocarbon solvent, 2-6 parts by weight of an alkanol, 1-16 parts by weight of at least one nonionic surfa ctant to stabilise the emulsion, and water to bring the total of all components of the emulsion to 100 parts by weight.

7. An emulsion according to any one of claims 1 to 5 comprising:

3.5-6.5 parts by weight of lipophilic pesticide,

3.5-6.5 parts by weight of hydrocarbon solvent, 7-9.5 parts by weight of an alkanol, 6-14 parts by weight of at least one nonionic surfa ctant to stabilise the emulsion, and water to bring the total of all components of the emulsion to 100 parts by weight.

8. An emulsion according to any one of the preceding claims wherein the lipophilic pesticide is a synthetic pyrethroid, the solvent is an aromatic hydrocarbon or a mixture of aromatic hydrocarbons, the alkanol is ethylene glycol or propylene glycol and the nonionic surfactant is a fatty acid ester of ethoxylated polyols.

9. An emulsion according to claim 1 substantially as hereinbefore described in the Examples.

10. A process for the preparation of an emulsion according to any one of the preceding claims wherein the nonionic surfactant is combined with a mixture of the hydrocarbon solvent and liphophilic pesticide and the resulting three component mixture is combined with agitation with the alkanol and water.