The BE-10BR Hood is designed to provide respiratory protection against certain particulates like dust, fumes, mists, radionuclide, asbestos, organic vapors, and inorganic gases. The butyl rubber hood offers resistance to certain chemical warfare agents. It meets Military Standard MIL-C-51251A for butyl. In September 2016, 3M issued a User Advisory Notice regarding the Breathe Easy BE-10BR Rubber Butyl Hood, the purpose of which was to communicate the valve replacement requirement and the use and storage limitations that were defined by 3M while redesigning the hood. 3M established a 10-year maximum life for this product. When used beyond the 10-year shelf life or stored outside of the recommended temperature range, these hoods may not work properly because they are more likely to deteriorate. In this case, hoods must be replaced immediately. For details, download the pdf version of this document: User Advisory Notice To answer all the inquiries, 3M provided more explanation about why hoods older than 10 years need to be replaced in their second notice in November 2016. The recommended 10-year period was determined to be necessary after 3M inspected several BE-10BR hoods that were in service for different periods of time. A number of hoods that had been in use for over 10 years experienced deterioration of various components. 3M recommended the following action plan for the customers who choose to use the hood past the 10-year recommended shelf life: 1. Ensure that the product is being stored in accordance with the conditions specified in the user instructions. 2. Replace the over-pressure valve and valve holder assembly in the hood. Call 1-855-317-4203 and request a complimentary replacement valve and valve seat. 3. Carefully inspect the condition of the hood and all the components for signs of degradation. To learn more, download the pdf: BE-10BR Notice If you have questions, please give us a call at 1-800-829-9580, or visit us online at www.pksafety.com.