This product is not assigned an expiration date. It is assigned a recommended retest date of 5 years after the quality release date. It will be stable at 2 - 8 °C during this period if not contaminated and securely closed.
A recommended retest date is the period during which the product is expected to remain within established stability specifications, provided that it has been stored under defined conditions. After the Retest Date, product samples should be examined to ensure that the product is still in compliance with the established specifications.
For more information, you may access the "Product Dating Information" document under "ADDITIONAL USEFUL DOCUMENTS ABOUT OUR PRODUCTS" at the bottom of the Quality Services page with this link: https://www.sigmaaldrich.com/US/en/life-science/quality-and-regulatory-management/quality-services.