USDA certified organic foods are grown and processed according to federal guidelines addressing, among many factors, soil quality, animal raising practices, pest and weed control, and use of additives. Organic producers rely on natural substances and physical, mechanical, or biologically based farming methods to the fullest extent possible. In this case, it meant that no herbicides, and pesticides has been used and all practices has processed according to federal guidelines. But to answer your question: If toxins such as heavy metals, herbicides, and pesticides are absorbed by the chlorella cell, either in their growth medium or while processing Chlorella, the toxin will remain bound in the fiber of the Chlorella, and that displays into the body. Dr. T. Nagano at Shizuoka College of Pharmacy in Japan did a study in which chlorella laced with cadmium was fed to rats.  Their growth rate was not affected and blood levels did not show an increase in cadmium levels, which demonstrated that the cadmium remained bound to the chlorella and was not released from it or absorbed into the rats’ tissue. This is just one example of chlorella may already contain toxins in its fiber and cell, it does not release them into the body. Instead they remain bound to the chlorella fiber. In addition, no pesticides are used in the growing process for this product.