Here is the U.S. National Institute of Standards and Technology Standard Reference Materials Catalog [PDF]. This 2018 edition appears to be the last glossy catalogue they published. The current list is available through the NIST Store, which is much more difficult to navigate. Here are some choice items:
Interesting - all this with the unspoken assumption that years elapsed have zero effect on the composition of say, the peanut butter. Several times, it was asserted that they took years to accurately characterize the composition. It seems to me this is a significant systematic problem.
I do note that the peanut butter sample material is listed with:
NIST Storage Temperature: Freezer (−20° C)
while peanut butter is usually considered to have a short shelf life (6–9 months without refrigeration, another 6–9 months refrigerated after opening), I don’t know the extent to which freezing at −20° C slows the reactions that cause the oils to go rancid (and presumably alters their chemical composition in analysis).
They list the expiration date of the frozen peanut butter currently in stock as 2029-12-31, so they must be assuming it degrades pretty slowly.