I have access to 10% povidone-iodine solution. How is this different? Can it be used in a similar manner to iodophor? On the package it states that it has 1% titratable iodine. Inactive ingredients are listed as citric acid, disodium phosphate, nontoxynol-9 and sodium hydroxide.
I have this formula for the dilution of iodophor: V = (0.0025*19L)/XX% where XX is the concentration of your solution, 0.0025 is 25ppm as a percentage, 19L is approximately 5 gallons, and V is the volume of your solution you need to add to five gallons of water.
If it is ok to use, do I base the dilution on the titratable percentage of 1% or 10%?
Thanks for your help!
Mac
Mac, great question!
First off, povidone-iodine solution is different than BTF Iodophor in that povidone is an FDA regulated, topical antiseptic, “medicine” regulated product. BTF Iodophor is an EPA/pesticide regulated surface sanitizer product. They both deliver Iodine to kill microbes, but are regulated by different entities for different purposes. Povidone-iodine is a ready-to-use product not necessarily designed to be diluted, BTF Iodophor is a concentrate designed to be diluted to a usage strength solution.
As an EPA registered manufacturer, we cannot suggest using a product outside of its intended, labeled use. There is a statement on our packaging that indicates “It is a violation of federal law to use this product in a manner inconsistent with its labeling.” Typically, federal authorities have other concerns than to beat down your door if you used a BTF Iodophor solution in an emergency medical situation or use a diluted povidone solution to sanitize your homebrewing equipment, but as a representative of a company that is regulated by the EPA, I can’t condone usage of a product that’s outside of its intended use.
Speaking strictly in terms of chemical activity, providone-iodine solutions diluted to 25 PPM may produce a solution that delivers enough available Iodine to kill microbes on the surface of your carboy/keg/container. However, the formulation of povidone and its other ingredients are not identical to BTF Iodophor, which is butoxy polypropoxy polyethoxy ethanol-iodine complex in a 1.6% titratable Iodine solution. I can’t verify that other ingredients in povidone, such as citric acid, disodium phosphate, nontoxynol-9 and sodium hydroxide will impact the quality of your finished beer if any residual solution enters your beverage. Ultimately, you would deliver kill strength Iodine, but you are introducing other factors.
So, in conclusion, if you try using povidone and don’t notice any ill effects and it doesn’t ruin your beer, more power to you. However, if you want a guaranteed Iodine sanitizer that has been designed, tested and regulated for sanitizing beverage contact surfaces, BTF Iodophor is the preferred tool for the job. Povidone may behave differently when in a diluted solution, such as foaming and not draining properly, whereas BTF Iodophor solution will sheet off your surface with minimal foam, drain quickly, and minimize the potential impact of residual available Iodine.