Recently the State of Colorado released a new limit for heavy metals in certain vegetative plant material. The metal of most concern to most people is arsenic. Unfortunately the State did not release a limit or even a guideline for soil or soil mixes so we’ll do our best here to help customers understand where Paonia Soil Co. stands.
There is an existing Federal standard for arsenic set by the EPA (EPA 503) of 41 parts per million in compost so that’s a good place to start. The most recent tests we have received have been from customers doing random sampling from our product without our knowledge through labs that we have no affiliation with and as such are completely independent. We also do our own heavy metals testing to insure product safety in addition.
The results from the most recent tests are .79 and .687 (less than 1) parts per million of arsenic in Bomb 50/50. This is more than 51 times lower than the EPA standard and lower than the 1 ppm lowest testable amount for many labs. Natural soil can often contain 30 – 50 ppm or more. In a recent poll of our customers well over 90% are passing the .2 mark with plenty of room to spare.
For those that aren’t passing we are here to help you figure out where it’s coming from. All inputs will need to be tested. This includes water, fertilizer or anything you add to your soil or spray on your plants. Other culprits include pressure treated lumber, plastic containers and even dust from native soil blown onto the plants. Some confusion has been seen in the .2 ppm number which is for plant tissue, not the soil. With an absolute maximum of 10% possible uptake of a metal and a real world number closer to 1% in most conditions you can see why Paonia Soil Co. is one of the best choices for a high mineral soil with very low arsenic.
*independent lab tests of PSC Bomb 50/50 submitted by our customers (their names have been removed)