In a container that waits closed, the moisture inside never dries, odour works into the surface, and the gasket stays compressed long enough to take a permanent set. One that waits open dries out, but dust, insects and rain get in. Where the container stands and for how long decides which risk counts more.
In a closed, clean and dry store, leaving the container open is no problem; a simple wedge under the lid or the first stage of the catch is enough. In a yard, on a dock or in a damp area, dry the container thoroughly first, then close and cover it. Off season the same rule holds: a dry place, lid ajar, covered against dust.
If the standing arrangement is written in the container record, the answer to ajar or closed does not vary from person to person. Before dispatch, check the interior, the gasket and the odour; if the smell persists, set the container aside, wash it again and dry it fully.
