OPL vs. GML

The OMRI Products List©, OMRI Canada Products List© and OMRI Mexico Products List© consist of individual brand name products that have been reviewed by OMRI and confirmed to be compliant with the National Organic Program, Canada Organic Regime, or Mexican Organic Products Law standards, respectively. 

OMRI has specific standards manuals that describe general review criteria for each standard. For example, the OMRI Generic Materials List© (GML) describes whether different generic substances, such as mined minerals and synthetic micronutrients, comply with the USDA's National Organic Program regulations. Brand name products on the OMRI Products List(s) are listed with a specific Use Class and Category corresponding to the Generic Materials List (or Permitted Substances Categories for Canada or Mexico).