FAQS ABOUT UV AND DAIRY PROCESSING
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FAQS ABOUT UV AND DAIRY PROCESSING Manufacturers and food processors worldwide use Ultraviolet (UV) light systems to disinfect water, and these numbers are growing due to improved technology, lower cost of operation, and greater interest in environmental sustainability. On October 14, 2009, the U.S. Food and Drug Administration issued the IMS-a-47, finalizing changes to the 2009 Pasteurized Milk Ordinance (PMO), which includes provisions for the use of UV in dairy processing, both to pasteurize and disinfect water. By concurring with the proposals adopted by the National Conference of Interstate Milk Shippers (NCIMS), the FDA is helping pave the way for the expanded use of UV in the U.S. dairy industry. WHAT IS UV? Ultraviolet (UV) light combines wavelengths that are shorter than that of visible light, but longer than x-rays. It is so named because the spectrum consists of electromagnetic waves with frequencies higher than those that humans identify as the color violet. Among its many applications, UV is used to inactivate all kinds of microbes including viruses, spores and bacteria. UV disinfection is commonly used where disinfection in needed and chemicals are undesirable. IS UV REALLY EFFECTIVE? UV is extremely effective for inactivating a wide variety of pathogens including those that are resistant to traditional chemical disinfectants. UV systems can use either low pressure or medium pressure UV lamps. Recent research has shown that medium pressure lamps, which deliver broader spectrum UV, can inactivate even the most resistant viruses at reasonable doses and disable repair mechanisms. IS UV RELIABLE? Yes. New technologies and better designs have made UV highly reliable. The effectiveness of chemical disinfection varies with pH and temperature; but ph and temperature have no impact on the effectiveness of medium pressure UV, which inactivates microorganisms Questions & Answers within milliseconds. To ensure that the accurate UV dose is reliably delivered to the water, a UV system should automatically measure water quality and intensity of the UV lamps, and then respond by adjusting the dose in real time. HOW DO YOU KNOW THAT IT IS WORKING? New standards from both the EPA and FDA require that units sold for treatment of water have a control system designed to track when the unit is providing the required dose and when it is not. The PMO does not permit any water not disinfected or pasteurized properly to enter into the dairy’s pasteurized milk handling system. Sensor calibration is critical – if the sensor is not working properly, chances are the water is not getting the prescribed dose. The Atlantium system has an accessible sensor and computer-assisted calibration routine to ensure the system readily complies with EPA and FDA rules. Particles can absorb UV thereby lowering the water’s UV transmission. Depending on the particles, they could block UV light or hide microbes. Depending on the quality and transmission of the water, as well as the type of UV technology, filtration may or may not be necessary. Some units have the UV light coming from a central source and may need prior filtration if the water quality fluctuates. Atlantium has UV photons attacking microbes from all directions and can self-adjust as the water quality fluctuates and in this case, filtration may not be necessary. HOW IMPORTANT IS SENSOR CALIBRATION? HOW DO PARTICLES IN THE WATER AFFECT THE TREATMENT OF WATER? SO, IS THERE A NEED TO FILTER WATER PRIOR TO TREATING WITH UV? HOW WERE THE UV DOSES IN THE PMO DETERMINED? While the European standard dose of 40 is recognized by the EPA's rigorous protocols as the equivalent of a 3-log cryptosporidium disinfection credit (i.e., enough of a dose to inactivate cryptosporidium),EPA standards require UV to provide a 186 LP equivalent dose for a 4-log virus disinfection credit, benchmarked on adenovirus. This dose is enough to inactivate the most resistant pathogens to an equivalent standard of chlorine and other chemical disinfectants – but without ph or temperature dependency or disinfection by-products as well as the equivalent to time/temperature pasteurization. In practice, medium pressure (MP) technology can achieve the 186 LP equivalent for adenovirus at significantly lesson – recently proven with an Atlantium unit during an EPA validation at the UV Disinfection Center in Johnstown, New York. This is because MP polychromatic light damages both the DNA and the cell’s repair mechanisms and has more modes of microbial attack and more wavelengths to use against viruses compared to low pressure UV . Any system currently using UV that is approved by the Regulatory Authority can continue to operate under the originally validated conditions. New systems can be used if they meet all WHAT IMPACT DOES THE 2009 PMO HAVE ON UV SYSTEMS CURRENTLY INSTALLED IN DAIRY PROCESSING PLANTS? Questions & Answers the criteria in the IMS-a-47 of October 14, 2009, or they can be separately validated through side by side testing and the full protocol introduced in the 2007 PMO. IS UV MORE COST-EFFECTIVE THAN HEAT PASTEURIZATION FOR WATER? Yes, UV is much more cost-effective than thermal pasteurization. The electrical, steam and labor costs involved in traditional thermal water pasteurization add up. Heat pasteurization at one dairy, for example, can cost as much as 175 Kw/hour plus labor. After switching to Atlantium’s UV system, pasteurization never costs more than 13 Kw/hour, including the pumps, controls and accessories and runs automatically, requiring no labor. WILL UV SYSTEMS PASTEURIZE MILK? No, UV systems that treat drinking water are optimized for water with a high level of transmission; as milk is opaque, the UV units will not be effective. In addition, research at Cornell University showed that the doses required impacted the flavor of the milk over time. WHAT ABOUT OTHER LIQUIDS? UV can treat water and clear liquids with reasonable levels of UVT. ARE ALL THE UV REQUIREMENTS LAID OUT IN THE NEW 2009 PMO NECESSARY? Yes. The PMO focuses on the performance that will achieve the desired disinfection results and only includes requirements that contribute directly to that goal. ARE SOME OF THESE REQUIREMENTS SPECIFIC TO ATLANTIUM? No, while we believe that the Atlantium UV units provide the best operational reliability, performance and value, other UV companies can provide technology that satisfies the criteria. CONVERSELY, ARE THERE ENOUGH REQUIREMENTS IN THE 2009 PMO TO ENSURE SAFE WATER IN THE DAIRY? There are fewer UV requirements in the 2009 PMO than stipulated by the EPA, especially around validation protocols and reporting, but there are sufficient requirements to assure that units that fulfill the stated PMO criteria will reliably provide the required performance. INSTEAD OF CREATING NEW REQUIREMENTS FOR DAIRY, WHY NOT FOLLOW NSF OR EPA REQUIREMENTS FOR UV? NSF standards are currently in transition, and it is unclear today what they will provide. In addition they are focused on small installation use (under 40 gpm) and designed to provide water for home point of use/point of entry systems. EPA requirements are many and stringent as they aim to cover the broadest possible set of circumstances. As pasteurization equivalent water using UV is a specific instance, a customized set of proposals was developed in concert with the FDA, state regulators and several dairies. These proposals, reviewed by the Technical Engineering Committee and the Scientific Advisory Committee of the NCIMS, unanimously adopted by the all of the states voting in the General Assembly of the NCIMS and concurred to by the FDA, were issued on October 14, 2009.