Expiration date for solid and liquid reagents

Hi all,
Can someone give me a reference for determining expiration date’s for solid and liquid form reagents, if in the certificates of reagents there isn’t any expiration date.
For example methanol hasn’t expiration date on it’s certificate.

USFDA States :

If the purchased laboratory reagent or solution includes a manufacturer’s suggested “use by” or expiry date, that date should be followed. For purchased laboratory reagents and solutions without a “use by” or expiry date, FDA would expect that an assessment be conducted (literature review may be acceptable) of that specific chemical’s or chemical family’s stability and that an appropriate “use by” or expiry date be determined.

Most of the industries follows :2 years expiry for methanol.

Bujji Reddy Kanchi.