We manufacture our seaweed with utmost care. During the manufacturing process we check for any foreign materials three to four times before the final product is made, especially for any type of metals. Also, we regularly select random samples of the product and conduct several tests to make sure our seaweed is manufactured with the best quality. Such tests include: protein tests, color tests, moisture tests, microbiology tests, peroxide value tests, acid value tests, salinity test, texture test, and of course tests for any foreign material. You should not worry about any foreign materials on your seaweed.