270 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS tion must be given to the absence of metallic contamination. The use of EDTA in the acid form solubilized with the desired base for compatibility should prevent this darkening with age and also assist in the cleaning function of the preparation. Simply add the EDTA acid before the addi- tion of the base. This brings up the question of the toxicity of EDTA and DTPA. In the concentration necessary to accomplish the ends described previously in this paper, and within the pH limitations of cosmetic products, neither of these materials presents any toxicological problems. Actually the utility and amounts used in cosmetic products place their relative toxicity far below that of alkalis, reducing or oxidizing agents commonly used by the cosmetic industry. Chelation is spreading into many new cosmetic formulations but old products and soap preparations are areas where chelation can improve the end-use performance and make such products very competitive with syn- thetics. When employed correctly, either EDTA or the new chelating agent, DTPA, should be the solution to problems involving trace metal ions. The cosmetic chemist should look to these two chelating agents for the solution of problems dealing with interplay of metal ions and competing anions as well as enhancement of many soap-based cosmetic preparations. The writer gratefully acknowledges the foam protection data proved by Dr. A. K. Prince and Mr. Norman Picard of the Technical Service and Development Department, The Dow Chemical Company, Midland, Mich- igan. THE PRESENT ROLE OF DETERGENTS IN TOILET BAR MANUFACTURE BY JOHN W. McCuTCHEON* Presented •Yune ¾, 1955, New York City IT Is ^ mistake to think that the introduction of synthetic detergents into bar form is a recent innovation. Experiments along these lines have been carried out over a quarter of a century. The fact that during most of these years they met only limited success under special conditions indicates the enormity of the problem. The initial attack was to incorporate the detergent with binders and to frame and cut the product as a laundry bar. The salt water bar used by the Navy during World War II is an example. The use of synthetics in toilet bars made its appearance about a dozen * John W. McCutcheon, Inc., New York 17, N.Y.

270 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS tion must be given to the absence of metallic contamination. The use of EDTA in the acid form solubilized with the desired base for compatibility should prevent this darkening with age and also assist in the cleaning function of the preparation. Simply add the EDTA acid before the addi- tion of the base. This brings up the question of the toxicity of EDTA and DTPA. In the concentration necessary to accomplish the ends described previously in this paper, and within the pH limitations of cosmetic products, neither of these materials presents any toxicological problems. Actually the utility and amounts used in cosmetic products place their relative toxicity far below that of alkalis, reducing or oxidizing agents commonly used by the cosmetic industry. Chelation is spreading into many new cosmetic formulations but old products and soap preparations are areas where chelation can improve the end-use performance and make such products very competitive with syn- thetics. When employed correctly, either EDTA or the new chelating agent, DTPA, should be the solution to problems involving trace metal ions. The cosmetic chemist should look to these two chelating agents for the solution of problems dealing with interplay of metal ions and competing anions as well as enhancement of many soap-based cosmetic preparations. The writer gratefully acknowledges the foam protection data proved by Dr. A. K. Prince and Mr. Norman Picard of the Technical Service and Development Department, The Dow Chemical Company, Midland, Mich- igan. THE PRESENT ROLE OF DETERGENTS IN TOILET BAR MANUFACTURE BY JOHN W. McCuTCHEON* Presented •Yune ¾, 1955, New York City IT Is ^ mistake to think that the introduction of synthetic detergents into bar form is a recent innovation. Experiments along these lines have been carried out over a quarter of a century. The fact that during most of these years they met only limited success under special conditions indicates the enormity of the problem. The initial attack was to incorporate the detergent with binders and to frame and cut the product as a laundry bar. The salt water bar used by the Navy during World War II is an example. The use of synthetics in toilet bars made its appearance about a dozen * John W. McCutcheon, Inc., New York 17, N.Y.