Lab results
Each lot we pack carries a lot number stamped on the bag. Look up that number here and you are reading the independent lab results for the exact material in your hand.
Testing references: CFIA Trade Memorandum T-4-93 (heavy-metal limits) · declared minimum analysis per T-4-130. Independent analysis is commissioned from the Agriculture & Food Laboratory (AFL), Laboratory Services Division, University of Guelph.
| Batch / Lot | Date | Carbon % | Ash % | Heavy metals | Feedstock | Certificate |
|---|---|---|---|---|---|---|
| 2600000387 | Jul 27, 2026 | 86.96 % (dry basis) | 5 % max. (label declaration) | Pass (T-4-93) | Ontario hardwood — 100 % maple, untreated | On request |
Lot 2600000387 — launch lot
This is the lot behind the bags shipping now. One lot number means one supplier bag: we never fill a single lot across two, so the number stamped on your bag points at exactly the material tested below.
Analysis was commissioned by Charged Earth from the Agriculture & Food Laboratory (AFL) at the University of Guelph — an independent laboratory, not our supplier. Submission 26-062084, reported 27 July 2026.
Total carbon — 86.96 % (dry basis)
Measured by LECO combustion. The bag declares a guaranteed minimum of 75 % as sold — the floor we hold ourselves to on all future lots, not a description of this one. This lot came in well above it. The two numbers sit on different bases: the lab result is dry, while the guarantee is as-sold, which includes the moisture biochar picks up from the air in storage.
Heavy metals — full panel, all eleven pass
By ICP-MS, against CFIA Trade Memorandum T-4-93. Results in mg/kg:
| Metal | Result | Metal | Result |
|---|---|---|---|
| Arsenic | < 0.03 | Molybdenum | 0.079 |
| Cadmium | 0.44 | Nickel | 0.51 |
| Chromium | 0.81 | Selenium | < 0.05 |
| Cobalt | 0.16 | Zinc | 160 |
| Copper | 5.5 | Lead | 1.2 |
| Mercury | < 0.02 |
Every metal cleared its T-4-93 ceiling with room to spare. Even at a heavy 20 % by-volume application worked into the top 15 cm, the highest single result uses only about 3 % of the forty-five-year cumulative soil-loading allowance. Arsenic, mercury and selenium were not detectable at all.
The certificate
The full AFL report is available to wholesale accounts and on request.
What we test for
On the launch lot:
- Total carbon, by LECO combustion
- Heavy metals vs. T-4-93 limits — full eleven-metal panel by ICP-MS (As, Cd, Cr, Co, Cu, Pb, Hg, Mo, Ni, Se, Zn)
- Feedstock declaration in writing from the supplier
The panel expands with the next submission: ash by ASTM D1762-84, moisture, and pH — published here against the lot number when they land.
Who tests it
Analysis is commissioned from the Agriculture & Food Laboratory (AFL) at the University of Guelph — an independent laboratory, not our supplier.
A full panel runs at launch, then heavy metals every six months or roughly every ten incoming super sacks, whichever comes first, and again on any visible product change, customer complaint, or new feedstock lot.
How long we keep it
Retention: 5 years minimum on all batch records, certificates, and test results. Records are kept in the Charged Earth Inc. compliance system.