Abstract: A method of treating hair that has been damaged and/or dulled as a result of an alkaline hair treatment including contacting the hair with a solution of weak acid having a pH in the range of about 2.0 to about 5.0, preferably about 2.0 to about 3.8 and having at least 0.75 milliequivalent of free acid per milliliter of solution, to restore natural shine to the dulled hair and to repair uplifted cuticles, if any, that have resulted from the alkaline hair treatment.

Abstract: A hair shampoo-conditioner composition including an anionic cleansing surfactant, such as an alkyl sulfate or an alkyl ether sulfate, and a polymeric conditioning compound having the formula: ##STR1## wherein n is a number in the range of from two to about 1000; m is a number in the range of from one to about 18; p and r are numbers in the range of from one to about four, in a suitable carrier, and having a pH of from about 2.5 to less than 7, to cleanse the hair, to generate a copious and stable foam volume and to impart improved wet stage and improved dry stage conditioning properties to the hair in a single application of the composition is disclosed.

Abstract: A hair setting composition that includes a water-insoluble amino- or substututed amino-containing compound, such as octylamine or an amino-functionalized silicone, and an ionizable metal salt, wherein the metal has a valence of at least II, such as aluminum chloride or zinc chloride, in a molar or molar-equivalent ratio of ionizable metal salt to water-insoluble amino-containing compound of at least 1:1, and having a pH in the range of about 2.7 to about 4.5, to provide unexpectedly durable hair set retention properties after application to human hair.

Abstract: A nitrophenylenediamine dye composition includes a long chain alkyl (8 to 18 carbon chain length) sulfate detergent, such as sodium lauryl sulfate or ammonium lauryl sulfate together with a sultaine (sulfobetaine) surfactant in a ratio of sulfate/sultaine in the range of 1:1 to 10:1, and particularly in the range of 6:1 to 9:1 to achieve unexpectedly increased deposition of specific nitrophenylenediamine dyes onto human hair.

Abstract: A dialkyl quaternary ammonium compound falling within the formula ##STR1## wherein R.sup.1 and R.sup.2 are the same or different straight chain alkyl radicals C.sub.n H.sub.2n+1 wherein n is predominantly at least 12, and particularly where n equals predominantly 12-16, unexpectedly prevents Ext. D & C Violet No. 2 dye from staining skin while providing better deposition of the Ext. D & C Violet No. 2 onto human hair and wool to decrease or eliminate hair and wool yellowing. These fatty radicals R.sup.1 and R.sup.2 are generally derived from coconut oil, lauric acid, myristic acid, or palmitic acid and An.sup.- is any anion, particularly the halogen ions and particularly the chloride ion.