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Heavy Metal Testing Info

BuildASoil Policy Regarding Heavy Metals:

1. We will not carry products that test higher than 50% of the maximum allowable heavy metals according to the Oregon Department of Agriculture. 

Here is the link to the rules: OREGON HEAVY METAL RULES

In Short: 

(a) When the product has a guaranteed analysis of available phosphate (P2O5), for each percent of P2O5 guaranteed, the maximum allowed level of a metal, expressed in parts per million (ppm), must not exceed: 9 ppm arsenic, 7.5 ppm cadmium, 43 ppm lead, 0.7 ppm mercury, 175 ppm nickel.

BuildASoil Maximum Per Percentage of P: 

4.5 ppm Arsenic

3.75 ppm Cadmium

21.5 ppm Lead

.35 ppm Mercury

87.5 ppm Nickel

So Fish Bone Meal = 20% P so you would multiply the above numbers  x 20 to get the maximum acceptable limits in a manner that is allowing for half of what Oregon would allow. Our products are usually less than 5% of maximum allowable because all organic material will have some metals it's important to note the maximum allowable. No organic material will be 100% free of metals and that is not the goal. 

(A) To determine the maximum allowed concentration of each metal in a product, multiply the percent guaranteed P2O5 for the product by the maximum allowed level of the metal.

(B) For the purpose of calculating the maximum allowed concentration of a metal in a product with a guaranteed analysis of less than six percent P2O5, the minimum percent of P2O5 utilized as a multiplier shall be 6.0.

An article from BuildASoil Blog regarding Heavy Metals:


Some general info from OSU:


What do we know about cadmium and arsenic in soils?

  • Cadmium and arsenic are naturally occurring elements widely distributed in the earth's crust.
  • Exposure to cadmium can come through foods, cigarette smoke, water or air.
  • All foods contain a low level of cadmium.
  • Leafy vegetables, grains, legumes and kidney meat have the highest levels.
  • You can reduce your risk by eating a balanced diet.
  • For adults, most exposure to arsenic occurs through the diet and inhalation.
  • For young children, hand-to-mouth activity is an important exposure route.
  • Most arsenic consumed in foods is excreted unchanged in the urine.