Familiar with/have used both of these. As long as they haven't taken on a gross amount of moisture, they should be just fine to use for quite some time. The only time I'm leery with fertilizers is when/if they have gotten wet or taken on an inordinate amount of moisture - and while I won't use them "as directed" with my plants then, I will use them up in whole in an open plot or a new area that I am prepping, or will further dilute with more moisture/water and go around using it on trees, the lawn, etc. - depending on the type of fertilizer (usually aim to check the numbers to see what it would be best for or if it is designed for a specific group of plants).

I've had bags tear, get punctured, outside when a surprise rain came on, etc. so I try to safeguard any "dry" gardening products - especially those in bags or thin plastic (bags or containers) by doubling up and putting them into glass containers - or if too big, into relatively airtight buckets with lids or tote boxes that I can tape around the seal for out-of-season storage.

Hope this helps!

Thanks for the info, you've saved me money!