Appendix C

NON-NUTRIENT METALS; PROHIBITED CONCENTRATIONS

Products Derived from Organic Sources

If a soil or plant additive is derived from materials that are at least 80% organic matter on a dry weight basis, the concentration of arsenic, cadmium, lead, mercury, nickel or selenium in that product may not exceed the maximum concentration specified for that metal in 40 CFR 503 .

Soil or Plant Additive Less than 80% Organic

If a soil or plant additive is derived from materials that are less than 80% organic matter on a dry weight basis, the product may not contain any metal shown in Table C-1 in a concentration that exceeds the maximum concentration shown in Table C-1:

Table C-1

METAL CONTAMINATION LIMITS FOR SOIL OR PLANT ADDITIVES

DERIVED FROM SOURCE LESS THAN 80% ORGANIC - See PDF for table