What lives in dry stock

Dry does not mean sterile and it does not mean inert. Two very different things colonize stored spice, and the dangerous one is invisible.

The hazard you cannot see

FDA identifies Salmonella as a hazard to be considered for all herbs, spices and seasonings, along with Bacillus cereus and pathogenic E. coli. Spice has been the vehicle in real outbreaks and real recalls.

Salmonella in a dry product

The intuition that a dry product is safe is exactly backwards, and the specifics are worth holding onto. Salmonella survives in dried spices for years. It is harder to kill in a dry environment than a wet one. And it takes only a small amount in a dry environment to make a person ill.

It will not grow in your jar, because there is no water for it to grow in. It does not need to. It simply persists at whatever level arrived, until it reaches food that is not cooked afterwards.

This is why treatment exists as a separate step, and why "we buy clean material" is not an answer to this question. Cleanliness and pathogen control are different controls.

Insects, which are the visible half

Stored product insects are the failure you will actually notice: they are in the bag, they are alive, and a customer can photograph them. ASTA cleanliness limits exist because insect fragments in an agricultural product are normal at some level, and those limits are written to sit inside the FDA defect levels.

Live infestation in your own store is a different matter from fragments in incoming material. The first is your housekeeping. The second is a specification.

Keeping both out

For the microbial hazard: buy treated material, know which method was used, and keep it documented per lot. There is nothing you can do downstream to fix it.

For insects: sealed containers rather than open bins, first in first out so nothing sits for years, a clean floor under the racking, and an actual look inside incoming bags rather than a signature on a delivery note.

References