Laureth

When ammonium lauryl sulfate is reacted with ethylene oxide, the result is the larger molecule ammonium laureth sulfate. This molecule has the same detergent and surfactant qualities, but it is larger consequently it does not penetrate the skin and hair as easily. The term laureth is actually a contraction of lauryl ether. The full name is ammonium lauryl ether sulfate. 

The most common ingredient in shampoos is also the most common detergent in use in other products a class of surfactants known as straight-chain alkyl benzene sulfonates. Examples are ammonium lauryl sulfate, its sodium relative, and the slightly larger but related molecule ammonium lauryl ether sulfate (sometimes abbreviated as ammonium laureth sulfate). 

Due to the good lime soap dispersing properties it is possible to improve the foaming properties of hard water-susceptible surfactants. Improvement of the formulation of a fatty acid soap by laureth-17 carboxylic acid, sodium salt [57,62], and an amidether carboxylate [62] has been described. 

FIG. 7 Skin irritation according to the human patch test of alkyl ether carboxylic acids compared to other mild cosurfactants. CFTA-names 1, cocamidopropylbetaine 2, sodium PEG-6 cocamide carboxylate 3, sodium laureth-11 carboxylate 4, cocoamphocarboxypropionate 5, protein hydrolyzate 6, disodium laureth-3 sulfo-succinate SLES, sodium laureth sulfate. (From Ref. 68.)... 

Simple mixtures—like in alkyl sulfosuccinates—can be run using only one solvent. For more complex systems (e.g., ethoxylated fatty alcohol sulfosuccinates) a gradient technique is strongly recommended Technical mixtures of disodium laureth sulfosuccinate could be separated [68]. The separation was so effective that resolution of single homologs of ethoxylates was possible. The detection limit of this method lies at around 0.5 pg. Therefore reverse phase ion pair chromatography seems to be an excellent tool to analyze sulfosuccinates directly without the use of any kind of manipulation. 

Disodium PEG-5 lauryl citrate sulfosuccinate (and) sodium laureth sulfate DCLS Disodium cocoyl gluceth-10 sulfosuccinate DCBG... 

FIG. 6 Long-term storage test of disodium laureth sulfosuccinate, actives. 

The sulfosuccinates must be individually evaluated under varying conditions to obtain optimum results. For example, disodium laureth-5 sulfosuccinate (DLFS) is excellent for finely dispersed lattices styrene-homo- and copolymers, styrene-acrylate copolymers, acrylate-homo- and copolymers, and vinyl acetate-homo-and copolymers. DLFS is used in a concentration (related to monomer) of 3-5%. Table 19 shows possible application areas of dialkyl sulfosuccinates. 

Comparative primary skin irritation scores of surfactant solutions (15% active content) show various types of sulfosuccinates as being the least irritant materials, well below sodium laureth-3 sulfate. It was also shown that an increase in degree of ethoxylation reduces skin and eye irritation, leading to laureth-3 (lauryl alcohol with 3 mol ethylene oxide) as the ideal organic raw material [17]. The results are given in Fig. 9 for eye irritation and in Fig. 10 for skin irritation. 

In a broad evaluation also the sulfosuccinate disodium laureth sulfosuccinate (DLSS) was a part of a variety of surfactants tested for their dermatological mildness, and some different test methods were applied [16]. Products were compared applying in vitro methods (Zein test, hemolysis) and in vivo methods (Duhring-Chamber test, skin mildness by intracutaneous test on mice and topical application on hairless mice, mucous membrane irritation according to the Draize procedure on rabbit eyes). In the Duhring-Chamber test the DLSS elicited no reactions in the animal tests it ranged in the least irritant third of the 15 products tested. 

Ammonium ion removal, molecular sieves in, 16 846-847 Ammonium lactate, 14 117 Ammonium laureth sulfate, cosmetic surfactant, 7 834t... 

Aungst BJ, Rogers NJ (1988a) Site dependence of absorption-promoting actions of laureth-9, Na salicylate, Na2EDTA, and aprotinin on rectal, nasal, and buccal insulin delivery. Pharm Res 5 305-308... 

The authors acknowledge the technical assistance from Richard Keeler, Drew Lassen, Jeffery O Neil, Maricella Castaneda, Kaitlin Ergun, Tiffany Coleman, and Arthhur Wojicicki. The authors also thank Chemron corp. for gift samples of sodium laureth sulfate. 

Are you poisoning your family Is your bathroom killing you Yes proclaim numerous Web sites, where there s much discussion about the culprits, sodium laureth sulfate (sles) and sodium lauryl sulfate (sls). What are these molecules, and why... 

What has inspired the outlandish accusations Scientific ignorance is at least partially responsible. There is much discussion on the Web sites in question about the degree to which SLS and sees are contaminated with carcinogenic nitrosamines. While it is true that trace amounts of nitrosamines have been found in some shampoos, they have nothing to do with sodium lauryl or laureth sulfate. Ethanolamine lauryl sulfates, substances found in a few products, accounted for the insignificant levels of contamination. The similarity in names, I guess, led the chemically illiterate to slur the much more common detergents. 

Ammonium Lauryl Sulfate 26% Ammonium Laureth (4) Sulfate (60%) Monateric CAB-LC Monalux CAO-LC Nonoxynol 10... 

Dodecylbenzene Sulfonic Acid 21.5 Caustic Soda (50%) 5.4 Sodium Laureth Sulfate (60%) 4.0 Mackam 35 (Cocamidopropy) 8etaine) 5.5 Sodium Xylene Sulfonate (40%) 8.0 Water, Dye, Fragrance qs to 100.0... 

RAW MATERIAL Rhodapex ES-2 CHEMICAL DESCRIPTION Sodium laureth (2) sulfate SOURCE Rhone... 

Aqua, caprylic/capric triglyceride, Avene aqua, paraffinum liq-uidum, propylene glycol, glyceryl stearate, PEG-100 stearate, squa-lane, BHT, butyl paraben, C13-14 isoparaffin, carbomer, disodium EDTA, laureth-7, phenoxyethanol, polyacrylamide, propylparaben, Cl 17200, retinal, tocopheryl glucoside and triethanolamine. 

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