The aerosol trigger sprayers that are common on dusters, freeze sprays, and flux removers, have two ways to store the straw when not in use. The hole at the back of the body of the sprayer is just the right size for the straw to slide into place for storage. The slot below the trigger is also the right size for the straw to snap into place, which also has the advantage of locking the trigger.
The shelf life of a product can be found on either the technical data sheet (TDS), available on the product page or by looking on the certificate on conformance (COC). The COC can be downloaded by going to https://www.techsprayeu.com/coc. Once you have the shelf life, you will need to add it to the manufacture date for a use-by date. The manufacture date can be identified by the batch number. The batch code used on most of our products are manufacture dates in the Julian Date format. The format is YYDDD, where YY = year, DDD = day. For example, 19200 translates to the 200th day of 2019, or July 19, 2019. This webpage explains and provides charts to help interpret our batch numbers: https://www.techsprayeu.com/batch-codes.