Look at their ingredients:
White Rice, Rice Bran Oil (Contains Antioxidant (307b)), Maltodextrin, Salt, Emulsifier (322 (Soy)), Sugar, Soy Sauce Powder, Yeast Extract, Flavour Enhancer (635).
These are an example of an ultra-processed food, with ingredients coming out of a laboratory. Yeast extract is a manufactured free glutamate, like MSG. The flavour enhancer 635 is added to manufactured free glutamates to enhance their effects, make them taste better than they actually are. Many may react to this flavour enhancer ('ribo rash') and to MSG, especially those who are young with an underdeveloped blood-brain barrier, and the elderly with a porous one. MSG, like aspartame, is an excitotoxin, overstimulating brain cells to death, depending on the dose.
If you want rice crackers without suspect additives, look for organic rice crackers.
Read more about The truth, the whole truth, and nothing but the truth about MSG.
Read stories about ribo rash from the fedup website.