Using “Off the Shelf” Bleach Quick Guide to Maintain Consistency By: Matthew Demers 3/20/2020 While we are in the midst of the COVID 19 crisis and we are all looking at supply chain stresses and struggles you as operators may find yourselves in a situation where you may need to use a bleach product that you may not usually use. The following information is to help you determine what and how much of a different bleach product to use, while maintaining the safety of your water for you and your users. Find and Use Approved Products It is important use chemicals that are approved by the Maine Drinking Water Program and meets the NSF 60 requirements. The following is the list of currently approved “Off the shelf” bleach that can be used for disinfection in drinking water. Be sure to check MEDWP for updates https://www.maine.gov/dhhs/mecdc/environmental- health/dwp/fit/documents/ApprovedBleachProductsForDisinfection.pdf Maine Drinking Water Approved "Off the Shelf" Chlorination products As of March 20, 2020 Clorox Regular Bleach (6%) EPA Registration # 5813-100 Clorox Germicidal Bleach EPA Registration number 5813-100-67619-32 Clorox Ultra Bleach (8.5%) EPA Registration # 5813-50 Clorox Regular Bleach2 (with Cloromax) (6%) EPA Registration # 5813-111 Clorox Germicidal Bleach (7.5%) EPA Registration # 67619-32 Pure Bright Disinfectant Bleach NSF 60 Pure Bright Disinfectant Bleach 5.25% Sodium Hypochlorite NSF 60 Pure Bright Disinfectant Bleach 6.00% Sodium Hypochlorite NSF 60 Information You Need: Verify Product is on the list and the Determine your “Normal” Bleach and EPA Registration No./NSF rating match “New” Bleach concentration (%) Determine how much you need: • Divide the normal bleach concentration by the new bleach concentration to get a conversion factor. Now simply multiply the conversion factor by the amount of bleach used in your mix recipe to determine how much new bleach to use. For example: If your normal bleach is Clorox Regular at 6%, you get Clorox Ultra at 8.5% and your normal mix is 3 cups of bleach to 15 gallons of water: 6% 8.5% = 0.71 then 3 cups X 0.71 = 2.13 cups of new bleach to 15 gallons of water. It is important to make additional checks of your system chlorine residual after you start using a new bleach to make sure you are still in your normal range. 0.2 to 0.7 mg/L is usually the desired range and at no time should the residual go over 4.0 mg/L .