we have never refrigerated a product. Brenda does the plant fats only because she thinks it taste better cold. We deal mostly with amish and they normaly don't have refrigerators.
It does not hurt the formulas to be kept cold if one desires to do so. My theory is all formulas are designed to be used daily, so the bottles will be used up. The bottles are not vacum packed or made sterile with radion, etc.....so opening the bottle really doesn't mean much, unless a person left the bottle set around with no lid on it or allowed some source of contamination to enter the solution.
The government standard probably would suggest every bottle be kept cold once opened, but they don't really understand herbal formulas. And hopefully they never do!