The contamination of milk with iodine from iodophors used in milking machine sanitation

Abstract

The retention and release of iodophor-derived iodine from milking machine materials was studied using 1311-labelled iodophor and small tubes of materials used in the construction of milking machines. After one hour's exposure to this iodophor, plastic retained 56% of the l31I label, followed by silicone rubber (31 %), rubber (IS%), steel (2 %,) and glass (0.5 %). Water rinsing after exposure to iodophor reduced these values to 49:/,, 26%, 14%, 0.5% and 0.3 % respectively. When the tubes were exposed to the iodophor and subsequently rinsed with milk, rubber released the largest amount of iodine into milk (0.099 pg I cm-2), followed by silicone (0.038 pg I cm-2), plastic (0.010 pg 1 cm-2), glass (0.009 pg I cm-2) and steel (0.002 pg I cm-"). The contact time of iodophor with a particular material influenced both the amount of iodine adsorbed, and the amount subsequently released into milk. The importance of iodine adsorption and desorption phenomena in contributing iodine to milk was compared to that iodine in milk arising from inadequate drainage of iodophor solution from a milking machine, and found to be comparable in magnitude.

Iodine Nutrition: Iodine Content of Iodized Salt in the United States

“…Specifically, the two major factors contributing to lowered U.S. iodine intake since the 1970s are the reduced use of iodine-based disinfectants/iodine in feed supplement in the dairy industry, and the reduction/elimination of iodate (IO 3 − )-based conditioners in bread ,, . The link between the milk iodine content and iodine use in the dairy industry (as well as that between the discontinuation of this practice in countries that emulated the United States and the decline in iodine nutrition there) is well established – . Udder/teat disinfection by iodine-based disinfectants actually results in absorption and re-expression .…”

Contemporary challenges to iodine status and nutrition: the role of foods, dietary recommendations, fortification and supplementation

“…promotion of milk alternatives). Simultaneously, changes have occurred in farming practices, due to thyrotoxicosis from the high levels of iodine in milk as a result of the addition of iodine in cattle feed and use of iodophor disinfectants used in sanitisation ( 111 , 112 ) . The consequences of ID are not limited to the peri-conception and pregnancy periods, since the effects of ID are often lifelong and irreversible, thereby impacting on society, with decreased productivity and increased costs ( 66 ) .…”

Control of Microorganisms

“…The widespread use of iodophors to sanitize equipment on dairy farms in Australia resulted in higher•than•normallevels of iodine in milk (Wheeler, Fleet, and Ashley 1982). This, in turn, caused thyroid problems in some consumers of dairy products.…”