The invention comprises cyanohydroxy compounds which are (a) saturated aliphatic carboxylic acids containing 16 to 22 carbon atoms and which also contain, on vicinal carbon atoms, an hydroxy group and a cyano group; (b) nitriles of such acids; or (c) esters of such acids with saturated aliphatic alcohols. The novel compounds may be prepared by reacting, in the presence of a solvent for the reaction mixture, an alkali metal cyanide with an epoxidized saturated aliphatic carboxylic acid containing from 16 to 22 carbon atoms, a nitrile of such an acid or an aliphatic saturated alcohol ester of such an acid, and acidifying the reaction product with an acid such as hydrochloric or sulphuric acid. The cyanohydroxy compound may also be prepared by heating a reaction mixture of an alcohol, an alkali metal hydroxide, an alkali metal cyanide, and a chloro- or bromoacyloxy derivative of an appropriate acid, ester or nitrile, whereby the epoxy compound is formed in situ and reacts with the alkali metal cyanide to give the cyanohydroxy compound. Sodium cyanide is the preferred alkali metal cyanide, and mixtures of sodium and potassium cyanides may also be used. It is preferred to use an excess of two to three mols. of the cyanide for each epoxy group in each mol. of the epoxy compound. The reaction may be effected at temperatures ranging from room temperature to the decomposition point of the product, but temperatures of 50-120 DEG C. are preferred. Suitable solvents are the lower alkanols such as methanol, ethanol, propanol and butanol, ethylene glycol, glycerol, acetonitrile, tetrahydrofuran, tetrahydrofurfuryl alcohol, dimethylformamide and nitro alcohols. Specific starting materials are the epoxy derivatives of palmitic, margaric, stearic, nondecoic, arachidic, eicosic and behenic acids, and the esters and nitriles of these acids. The alcohol moieties of the esters may be monohydric or polyhydric such as methyl, ethyl, isopropyl, n-, sec-, or tert-butyl, tert-amyl, 2-ethylhexyl, lauryl, octadecyl, cyclohexyl, and benzyl alcohols; ethylene glycol, 1,2-propylene glycol, 2-ethylhexandiol-1,3, butandiol-1,3, or -1,4, dodecandiol-1,2; diethylene glycol; glycerol; and pentaerythritol. The preferred alcohols are the C1 to C5 alkanols. The glyceridic esters of epoxy acids which can be converted include epoxidized tallow, yellow grease and brown grease and epoxidized soybean, corn, cottonseed, safflower, sunflower, sesame, poppyseed, walnut, peanut, linseed, perilla and sardine oils. The epoxy compounds may be made by reaction of peracids, such as performic and peracetic acids, with ethylenically unsaturated aliphatic carboxylic acids such as oleic, erucic, eleostearic, linoleic, linolenic, clupadonic, palmitoleic and palmitolenic acids, and the corresponding nitriles or esters of these acids. The epoxy compounds may also be made by the reaction of a strong base with chloro- or bromoacyloxy derivatives of the same acids, esters and nitriles as described in Specification 813,991. In examples: (1) methyl 9,10 epoxystearate, sodium cyanide and methanol are heated p together under reflux and the product after cooling and diluting with water is acidified with hydrochloric acid and extracted with benzene to isolate methyl 9,10 and 10,9-cyanohydroxystearate; (2) the product of (1) is hydrolysed with aqueous sulphuric acid to 9,10 and 10,9-cyanohydroxy-stearic acid; the method of (1) may also be employed in the preparation of the cyano hydroxy derivatives of glyceridic and other C1-C5 alkanol esters of stearic acid; (3) a mixture of 9,10 and 10,9-chloroformoxystearic acid, alcoholic potash, sodium cyanide and ethanol are heated at refluxing temperature for 17 hours then worked up as in (1) to yield 9,10 and 10,9-cyanohydroxystearic acid; (4) similarly methyl 9,10 and 10,9-cyanohydroxystearates are obtained by reaction of potassium hydroxide and sodium cyanide with methyl 9,10 and 10,9-chloroformoxy stearates in methanol; (5) epoxidized tallow is reacted at reflux temperature with sodium cyanide in methanol to yield the cyanohydroxy derivative of tallow. The novel products may be used as plasticizers for vinyl resins such as polyvinyl chloride. Specifications 770,588 and 837,429 also are referred to.ALSO:Cyanohydroxy compounds which are saturated aliphatic carboxylic acids containing 16 to 22 carbon atoms and which also contain, on vicinal carbon atoms, a hydroxy group and a cyano group, or nitriles of such acids, or esters of such acids with saturated aliphatic alcohols, are used as plasticizers for vinyl resins, particularly polyvinyl chloride. (For preparation of the cyanohydroxy compounds see Group IV (b)). The cyanohydroxy compounds may be derived from palmitic, margaric, stearic, nondecoic, arachidic, eicosic and behenic acids and may be esters of C1-C5 alkanols, 2-ethylhexyl, lauryl, octadecyl, cyclohexyl and benzyl alcohols, ethylene glycol, 1,2-propylene glycol, 2-ethylhexandiol-1,3, butandiol-1,3, butandiol-1,4, dodecandiol-1,12, diethylene glycol, glycerol and pentaerythritol. The cyanohydroxy compounds may be derived from glycerides such as tallow, yellow grease and brown grease, and soybean corn, cottonseed, safflower, sunflower, sesame, walnut, poppyseed, peanut, linseed, perilla and sardine oils.