Pot is not a food additive whose health hazards need to be tested on rodents.
Once a food additive is approved, any manufacturer of food or food packaging may use the food additive.
The children diagnosed with hyperactivity reacted to the food additive challenge but the other children did not.
It is already widely used as a gelling agent and a food additive.
British Dictionary definitions for food additive
any of various natural or synthetic substances, such as salt, monosodium glutamate, or citric acid, used in the commercial processing of food as preservatives, antioxidants, emulsifiers, etc, in order to preserve or add flavour, colour, or texture to processed food