6O JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS SECTION C 5. Write brief notes on FOUR of the following:- (a) Sachets (b) Roll-on containers (c) Polyethylene tubes (d) Aluminium tubes (e) Squeeze packs. t3. Describe what tests you would do in order to determine the shelf life of toothpaste in an aluminium tube. What tests would you do initially to determine whether or not a particular tube is satisfactory for the formulation? SECTION D 7. Write (a) (b) (c) (d) (e) (f) (g) explanatory notes on FOUR of the following:- Dermatophytes Staphylococcus aureus Bacterial growth curve Water sterilisation The yeast cell "Glove juice" test Cationic detergents. 8. Give an account of the physical methods of controlling the growth of micro-organisms. Which of these methods could be used in preventing (a) aerial contamination, (b) water-borne contamination? SECTION E 9. Give a definition of dental caries and outline the possible causes of tooth decay. Outline the various approaches that have been made with regard to the control of caries. 10. Distinguish between eccrine and apocrine sweat glands. Give an account of the factors affecting sweating and outline the various theories on the mechanism of the antiperspirant activity of materials such as aluminium chlorhydrate.

SOCIETY OF COSMETIC CHEMISTS OF GREAT BRITAIN 61 PAI•ER II (Wednesday, 19th June 1968) Candidates should ansxver FIVE questions from not less than FOUR sections. SECTIO• A 1. Review the use of surface active agents in hair preparations. Particular attention should be paid to showing how the specific properties and structures of different types of surfactant makes them particularly suitable for different product types. 2. Describe the maximum bubble pressure method for measuring surface tension. Discuss the effect of (a) detergent concentration, (b) tem- perature on the surface tension of a detergent solution. The equation log cmc:A - BNc (where A and B are constants and Nc is the number of carbon atoms) has been postulated for calculating the cmc of a homologous series of compounds. For the potassium soaps. log cmc is •.60 - octanoate •.02 - decanoate •.52 - laurate •.86 - myristate •.28- palmitate Using the graph paper provided, calculate A and B. SECTION B 3. A sample of an oily material, claimed to be a non-drying vegetable oil, is offered for sale. What analytical tests xvou]d you apply to it in order to (a) verify its claimed nature, (b) assess its probable suitability for use in cosmetic preparations. Justify your choice of tests. 4. Give an account of the chemistry of oxidative rancidification. What structural features are likely to make a mineral or vegetable oil suscept- ible to the development of rancidity? Briefly describe the practical measures that you would take in order to prevent, minimise or delay the development of rancidity in stored cosmetic raw materials or products.