Organic Materials Review Institute
(OMRI) Listed® Products

U.S. Borax produces refined boron fertilizer that supports organic farming.
We have specific products that are OMRI® Listed.

OMRI Certificates: Granubor, Fertibor, Solubor, and Optibor TG

Need to prove that your fertilizer ingredients are appropriate for organic
farming? Download the OMRI Listed certificates below.


What Is OMRI?

OMRI is an international nonprofit organization that determines which crop fertilizer and soil amendment products are acceptable for use on certified organic crops under the USDA National Organic Program, and the Canadian Organic Standards OMRI is ISO 17605 accredited as a material review organization, meaning certifiers can accept the OMRI Listed seal anywhere in the world.

Currently, U.S. Borax offers four OMRI Listed products: Granubor®, Fertibor®, Solubor®, and Optibor® TG. All U.S. Borax products, including our OMRI Listed products, come from a clean, reliable, and fully traceable boron source that is further refined to ensure quality.

More registration certificates

Three other organic industry organizations have certified U.S. Borax refined boron fertilizer products:

Supporting resources

What Does “Sustainable Farming” Really Mean?
Agricultural industrialization in the mid-1900s led to increased output but took a harmful toll on precious resources. Today, farmers big and small across the... Learn More
Celebrating the heart of American agriculture: Family farms
In the vast and ever-evolving landscape of American agriculture, one steadfast presence remains the backbone of rural communities and the source of our nation... Read More
Arsenic in fertilizers
Arsenic (As) is a naturally occurring, toxic heavy metal dispersed in the environment through a variety of industrial, mining, and agricultural activities. Hi... Read More

U.S. Borax, part of Rio Tinto, is a global leader in the supply and science of borates—naturally-occurring minerals containing boron and other elements. We are 1,000 people serving 650 customers with more than 1,800 delivery locations globally. We supply around 30% of the world’s need for refined borates from our world-class mine in Boron, California, about 100 miles northeast of Los Angeles. Learn more about Rio Tinto.

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