Experiences are described for the development of aerosol formulations of CIPC [isopropyl N-(3-chlorophenyl)carbamate]. CIPC is the most important potato sprout inhibitor that is used in the commercial storage of potatoes and is especially critical to the efficient manufacture of french fries and potato chips with the light color that is typical of these products.
The aerosol formation process consists of feeding a liquid formulation to a thermal aerosol generator where it is vaporized and then mixing the vapor with air to cool the vapor and form the aerosol. The aerosol is then applied to the stored crop. The application process was effective, but the very high cost of the loss of sprout control provided the incentive to drive the effort that was needed to better understand the application process.
The physical chemistry of aerosols guided the work. A relatively simple aerosol evaluation procedure was developed and is described. The “old” 4A, 4 pound per gallon (480 g/L), aerosol formulation was reformulated into a new 7A, 7 pound per gallon (840 g/L) formulation. The factors that were considered to arrive at the 7A formulation are discussed. Adjustment of the feed rate of the 7A formulation to the aerosol generator enabled the retention of 4A performance and made possible new higher aerosol concentrations. The 7A formulation is simple and very effective.