The following is an edited excerpt.
In seeking to understand the relevancy of the issue of labeling foods in halakhah (Jewish law), it would seem that a good place to start would be g’neivat da’at – literally, “theft of consciousness,” and in practice prohibits offering misleading information in business practices and personal relations.
In the Shulhan Arukh, an authoritative code of Jewish law written by Rav Yosef Karo in the 16th century, we learn: “It is forbidden to deceive a person in purchasing or selling, or engage in g’neivat da’at, for example: if there is some type of deficiency in the purchase, this information needs to be provided to the purchaser.”
A very limited application of this law would seem to only apply to GMO foods if, in fact, there is something unsafe in their consumption and they are marketed as safe.
Read the full article here: A Consumer’s Right To Know: Business Ethics, Halakhah and GMOs