OMRI Status Lookup.
OMRI Status Lookup
Quick reference for USDA NOP organic compliance. Check whether common compounds and product classes are OMRI-listed.
How OMRI works
The Organic Materials Review Institute (OMRI) is an independent nonprofit that reviews input products for compliance with the USDA National Organic Program (NOP) standards. Products that pass review get listed on the OMRI Products List and can carry the OMRI Listed seal.
OMRI listings are per-product, not per-compound. A specific brand's "Calcium Nitrate" might be OMRI-listed while a different brand's chemically equivalent product isn't (often because the latter brand didn't pay for the OMRI review). Both can be NOP-compliant if the underlying compound is on the National List of Allowed Substances — but only the OMRI-listed one comes with the third-party verification stamp that organic certifiers rely on.
Two related authorities to know:
- USDA NOP National List — the federal regulation listing allowed and prohibited substances for organic agriculture. Check the official list.
- WSDA / CDFA OIM — Washington State Department of Agriculture and California Department of Food and Agriculture Organic Input Materials lists. State-specific equivalents to OMRI; some states require their own listing.
Compound classes commonly OMRI-allowed
The lookup above covers specific products and active ingredients. At a higher level, these classes are typically OMRI-allowed (with caveats):
| Class | Status | Notes |
|---|---|---|
| Plant-derived organic fertilizers | Generally allowed | Kelp, alfalfa meal, soybean meal, cottonseed meal — non-GMO source required |
| Animal-derived organic fertilizers | Generally allowed | Blood meal, bone meal, feather meal, fish emulsion — source documentation required |
| Mined minerals (untreated) | Generally allowed | Rock phosphate, sul-po-mag (langbeinite), gypsum, lime, basalt rock dust |
| Synthetic fertilizers | Generally prohibited | Urea, ammonium nitrate, etc. — not allowed in NOP |
| Calcium nitrate, potassium nitrate | Conditional | Only specific OMRI-listed mined sources allowed (Chile saltpeter); synthetic is prohibited |
| Mycorrhizae, Trichoderma, Bacillus | Generally allowed | Microbial inoculants — non-GMO required |
| Compost, vermicompost | Generally allowed | Source-documented, properly composted |
| Humic / fulvic acid | Generally allowed | Specific extraction methods restricted |
| Kelp / seaweed | Generally allowed | Most extracts allowed; chemical extraction methods restricted |
| Pyrethrins (botanical) | Allowed with restriction | Botanical pyrethrins yes; synthetic pyrethroids no |
| Neem (azadirachtin) | Allowed | Cold-pressed neem oil + extracted azadirachtin both allowed |
| Bt (Bacillus thuringiensis) | Allowed | Various Bt strains for caterpillars, mosquitoes, beetles |
| Spinosad | Allowed | Soil-microbe-derived; very effective |
| Copper sulfate | Allowed with restriction | Conditional — some uses restricted by NOP |
| Sulfur (elemental) | Allowed | Both fungicide and pesticide use |
| Phosphoric acid (food grade) | Allowed for pH | OMRI-listed food-grade phosphoric acid for pH-down |
| Citric acid | Allowed for pH | Organic-source citric acid |
| Potassium hydroxide | Allowed with restriction | Some uses restricted |
| Synthetic pesticides | Prohibited | Pyrethroids, neonicotinoids, glyphosate, etc. |
| Synthetic chelates (EDTA, DTPA) | Conditional | Most EDTA chelates prohibited; some DTPA forms allowed; check per product |
| GMO-derived products | Prohibited | Even if technically equivalent compound; sourcing matters |
Why this matters
Organic certification under USDA NOP requires that every input applied during the certified period be NOP-allowed. Inspectors verify:
- Application records (what was applied, when, where, how much)
- Allowed-substance documentation per input (OMRI listing, source documentation, COAs)
- Substrate / soil history (3 years of compliant management for organic land)
If you can't prove that an input was NOP-allowed at the time of application, that input — and potentially the cycle it touched — disqualifies that crop from being sold as certified organic. This isn't theoretical: organic certifications are revoked over input documentation gaps regularly.
The OMRI seal is the easiest path to documentation: a third party already verified the product. For non-OMRI products, the burden of demonstrating NOP-compliance falls on the grower.
Free under CC BY 4.0. Cite as "OAT OMRI Status Lookup (openagriculturetechnology.com)". Listings curated; verify against omri.org for certification audits.