DMSO is used as a solvent for NBPT, N-(n-butyl)thiophosphoric triamide, in selected liquid fertilizer-stabilizer formulations. Its immediate job is to dissolve the inhibitor and help produce a liquid that can be handled and applied. DMSO is not itself the urease-inhibitor active ingredient.
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Solvent use is documented, but the blend matters
US11198653B2 describes liquid NBPT formulations using DMSO among the solvent systems. Other patents describe DMSO-containing compositions with stabilizers or co-solvents. These disclosures place DMSO in the formulation step; they do not show that pure DMSO alone gives the best shelf life for every NBPT material.
NBPT is used to inhibit urease-mediated urea breakdown. Its solubility in a formulation and its retained activity after storage are different questions. A clear freshly prepared concentrate answers only part of the formulation problem.
Check physical and chemical stability separately
For physical stability, assess low-temperature crystallization, phase separation, viscosity and recovery after temperature cycling. Test the intended blend at its actual inhibitor loading. A result for another solvent ratio or a purified laboratory material may not represent the proposed commercial concentrate.
For chemical stability, measure NBPT content and relevant degradation products over the intended storage conditions. Where other inhibitors are present, measure each relevant active separately. Appearance alone cannot distinguish a stable active ingredient from a solution that has begun to degrade.
Water enters through DMSO, other raw materials and handling. Include it in the blend balance and stability trials. The appropriate incoming DMSO water limit should follow the evaluated formulation, not a universal ultra-dry requirement.
Investigate color, odor and gas evolution
WO2026017687A1 discusses storage problems in some DMSO/NBPT systems, including discoloration, inhibitor degradation and possible sulfur-containing volatile emissions. It is a reason to examine the proposed formulation rather than assume that good initial solubility proves long-term stability.
Where the formulation assessment identifies possible gas generation, evaluate storage temperature, headspace and packaging compatibility with appropriate analytical and process-safety support. Do not identify a gas or accept a batch by deliberately smelling an open container.
Evaluate the finished fertilizer application
Check dosing, mixing and distribution in the intended fertilizer process after establishing concentrate stability. Solvent screening cannot by itself establish agronomic efficacy, crop tolerance or permission for a destination market. Those assessments belong to the finished product and its intended use.
Keep the approved concentrate composition and solvent specification linked. When changing a DMSO source or raw-material composition, use the stability and application tests that demonstrated the formulation’s suitability.
For formulation sourcing, share the evaluated DMSO specification, formulation type and packaging requirement with YUJI.