Items kept in an equipment rack will not deteriorate, even if outside.
The storage tab above the inspect pane can be configured to set what items are allowed to be stored.
The command icons (Copy settings, Paste settings) can be used to copy storage settings between equipment racks. Settings can also be copied to other containers like stockpile zones and dumping stockpile zones; however, settings that an equipment rack doesn't have (i.e. food) will be copied as disallowed. The copy function can take settings from one container and apply them to many containers, when shift-click is used to select multiple.