Is the sale of a Ribawi item mixed with a non-Ribawi item permissible when the mixture is insignificant?

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The sale is permissible if the non-Ribawi admixture is minor and does not affect the measurement by volume or weight, such as salt in a substance requiring it, or barley grains in wheat. This is because the small amount does not violate the requirement of parity. Similarly, if the admixture is present in only one of the two exchanged items, it does not invalidate the sale for that reason. Furthermore, selling such an item for the non-intended component itself, like selling bread for salt, is valid because the presence of the minor admixture is treated as non-existence.