NSF International determined in a recent retesting that Wedeco’s UV disinfection systems, M4 unit, was not performing in accordance with the requirements of certification. NSF/ANSI Standard 55, to which the product was certified, requires the treatment system to deliver an equivalent UV dose of 40 mJ/cm2 at the specified flow rate and either the manufacturer’s set point of the system’s performance alarm or at 70% transmittance, whichever yields less transmittance. Retesting by NSF indicated the system was not able to demonstrate this level of UV dose required by the Standard. As a result, NSF has removed this model from the NSF Official Listing. Because the model M7 was certified based on the testing of the model M4 at the original time of certification this model has also been removed from the NSF Official Listing is being included in this notice.
The requirement of 40 mJ/cm2 is established under NSF/ANSI Standard 55 based on the scientific evidence that correlates this performance level with adequate treatment of water that contains potential contamination from microorganisms. In the absence of performing at this level there is a concern that model M4 and M7 may not be performing as required by the standard in actual use conditions.
Please contact Wedeco at (704) 716-7602 or by e-mail at firstname.lastname@example.org to make arrangements for the recall of your unit.