Antagonisms between Surfactants: The Case of Laundry Detergents

Abstract

Interaction between surfactants forms micelles that typically lead to a reduction of the irritation potential of the mixture. The objective of this study is to illustrate that such antagonism between surfactants is applicable to actual cases of consumer products e.g. laundry detergent products. The Zein test is an in vitro assay measuring corn protein denaturation by solutions of surfactant(s) and often used to predict their acute irritation potential. The Zein test data for the surfactant mixtures from nine representative laundry detergents demonstrate that the protein denaturation by the mixtures is, in all cases, lower than the cumulative score of protein denaturation by the different surfactants tested separately. The data clearly indicate that antagonism occurs between the actual surfactants present in their exact proportions as found in the consumer laundry detergent products. These data support the view that the hazard classification of detergent products as (irritant) by the dangerous preparation directive should not be based on a simple cumulative score of the irritation properties of the individual components of the products.

Role of macromolecules in the safety of use of body wash cosmetics

“…With respect to cosmetics and detergents that are in frequent contact with the skin, one of the greatest disadvantages of surfactants is their potential to cause skin irritations and allergies [7][8]. The literature data [7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23] suggest that the highest irritant potential is associated with ionic surfactants which are used in many products as the primary washing agent [2][3][4][5][6].…”

“…Numerous studies [7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23] provide evidence showing that interactions occurring between surfactants and the SC depend primarily on the time of contact, surfactant concentration and structure. In the homologous series, the strongest interactions are noted for molecules containing 12 carbon atoms in the hydrophobic chain and at concentrations immediately below the critical micelle concentration (CMC).…”

“…Above all, surfactants exhibit an ability to bind to proteins which are present in the stratum corneum (SC). The interaction leads to degradation of the protein structure and to protein denaturation, culminating in the process referred to as SC swelling [7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23]. The activity is attributed primarily to anionic surfactants, such as sodium lauryl sulphate [10][11]14,16,18] and sodium laurate [21], due to relatively strong electrostatic interactions occurring between this group of surfactants and proteins.…”

“…Above the CMC, the interactions are not directly proportional, and their nature depends on the type of the surface active agent. Studies [7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23] point out the considerable role of surfactant monomers (the form which occurs in solutions at concentrations below the CMC) in triggering skin irritations. Owing to their small size, monomers easily enter through the pores into the SC, bind to the surface proteins and interact with the intercellular cement.…”

“…It is assumed that every activity which increases the size of micelles, stabilizes them and reduces the number of free monomers can produce a decrease in the irritant potential of surfactants [7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23]. The most common strategy employed in industrial practice to reduce the irritant potential of surfactants is using their mixtures [7][8]21].…”