What is the ruling on buying and selling chicken that has been fed chemical feeds, and what is the ruling on feeding it chemically then naturally to remove the effects of the chemicals?

If chemical foods are toxins, then they may not be used except after consulting specialists to determine the possibility of removing the harm and the existence of an approved method for doing so. If such a method is found, it must be adhered to in quantity and quality to prevent harm. Specialists should be consulted regarding the feasibility of feeding the animal natural food to remove the harm of toxins, because the issue relates to the harm of toxins, not to impurity.