Shelf life of Weedol weedkiller

Hi. Does anyone know the shelf life of Weedol weedkiller? Thanks.

 

I would have thought it was fairly indefinite, if not in direct sunlight and protected from extremes of temperature.

 

I would agree with Kristen. The active ingredient is Glyphosate (N-(phosphonomethyl)glycine), which is a pretty simple chemical - inspite of its complicated name.

 

My experience is that Roundup weakens with age. The active ingredient is glyphosate, but perhaps it is not that that decays, but the surfactants that stick it down? Or, as glyphosate is reduced to harmless starches by soil microbes, if those soil microbes were airborne (as many soil microbes are), and they got into the container, could they not break down the glyphosate?