Paraquat procurement is not decided by a concentration number alone. A paraquat formulation comparison for importers must connect the declared concentration with the active-ingredient basis, soluble concentrate (SL) design, registration dossier, packaging system, analytical release and destination-market label. The two commercial descriptions considered in this guide—paraquat 200 g/L SL and paraquat 276 g/L SL—can represent different declaration conventions and different formulation objectives. The number therefore requires technical interpretation before a purchase order is issued.
FAO/WHO Specification 56.302/SL describes paraquat dichloride SL as an aqueous solution made with compliant technical material and necessary formulants. It also states that FAO specifications are international reference points rather than product endorsements or exemptions from national law. An importer can use the specification as a quality framework, while the importing country remains responsible for registration, labelling, transport, storage and use requirements.
A formulation label may state paraquat as the cation, paraquat dichloride salt, or another locally accepted expression. These expressions are not interchangeable on a commercial document. FAO records paraquat dichloride and paraquat dication separately and notes a conversion relationship between ion content and dichloride content. A comparison that does not identify the declared basis can make two different products appear equivalent or make equivalent products appear different.
Check | 200 g/L SL | 276 g/L SL | Procurement implication |
Declared concentration | Lower nominal concentration on the stated basis | Higher nominal concentration on the stated basis | Compare like-for-like units and chemical basis before pricing |
Formulation type | Soluble concentrate; aqueous solution when correctly formulated | Solution clarity, sediment, pH, foam and storage stability remain release controls | |
Container demand | Potentially higher product volume for an equivalent declared amount | Potentially lower product volume for an equivalent declared amount | Freight, warehouse space and dangerous-goods handling need landed-cost modelling |
Registration fit | Dependent on local label, concentration range, salt/ion declaration and dossier | Neither concentration is universally acceptable across markets |
The table is a procurement framework, not an application-rate recommendation. A lower pack volume does not automatically create a lower environmental or occupational risk, and a higher concentration does not automatically create better field performance. Those conclusions require the registered label, exposure assessment and product-specific data.
The purchase specification should state the common name, salt form, CAS or CIPAC identity where applicable, declared concentration, unit basis, reference temperature, and analytical method. FAO 56.302/SL allows the paraquat dichloride content to be declared in g/kg and/or g/L at 20 ± 2°C. Density becomes important whenever a mass declaration is compared with a volume declaration. A CoA that reports “276 g/L” without the chemical basis, temperature or method is incomplete for a technical-commercial comparison.
Identity testing should be separated from assay testing. The FAO specification refers to identity tests for the paraquat and chloride components and identifies chromatographic or other confirmation approaches. The assay result confirms the quantity found under the stated method; it does not, by itself, establish the salt form, impurity profile, formulation stability or registration identity.
· Identity: paraquat component and chloride component confirmed against the agreed specification.
· Assay: declared concentration reported in the agreed unit and basis.
· Impurities: free 4,4'-bipyridyl and total terpyridines assessed where required by the specification or dossier.
· Physical properties: pH, solution appearance, sediment and persistent foam checked against agreed limits.
· Stability: low-temperature and elevated-temperature records retained with sample identity and test dates.
Red Sun’s paraquat formulation comparison for importers can support an initial supplier discussion. It should be followed by a batch-specific CoA, specification sheet, SDS, packaging declaration and regulatory data package.
Commercial comparison should use the cost per unit of declared active ingredient, not only the price per drum. The calculation requires the concentration basis, net volume, density where relevant, drum count, freight classification, insurance, port handling, storage and any local relabelling or registration cost. A 276 g/L offer may reduce the number of containers, while a 200 g/L offer may fit an existing label or local registration. The economic result depends on the complete supply chain.
1. Convert both offers to the same declared chemical basis.
2. Calculate declared active ingredient per saleable unit.
3. Compare price per kilogram of declared active ingredient.
4. Add freight, dangerous-goods, packaging, inspection and storage costs.
5. Test whether the concentration and pack size match the registered label and customer market.
Unit conversion must not be used to infer a legal use rate. The registered label controls the permitted concentration, crop, use pattern, personal protective equipment and other instructions in the destination market. U.S. EPA materials, for example, place paraquat dichloride within a restricted-use and certified-applicator training framework. That U.S. framework cannot be transferred automatically to another jurisdiction.
Soluble concentrate quality is demonstrated after manufacture, storage and dilution—not only by the initial assay. FAO 56.302/SL specifies a pH range of 4.0 to 8.0, solution stability after elevated-temperature testing and dilution with specified CIPAC standard water, a limit for persistent foam, and separation limits after low-temperature storage. The document also requires the average active content after elevated-temperature storage to remain at least 97% relative to the pre-test determined content, alongside continued compliance with the pH clause.
For an importer, the release protocol should connect each test to a risk. Visible particles or sediment can affect filtration and spray preparation. Excessive foam can interrupt filling, transfer or mixing operations. Phase separation can create non-uniform sampling and uncertain dose delivery. pH drift can indicate formulant interaction, contamination or degradation. These observations do not prove field failure, but they are practical indicators that a batch needs investigation before release.
· Signed CoA showing batch number, manufacture date, net content and declared basis.
· Identity and assay methods, including method version or CIPAC reference where applicable.
· Impurity results for the agreed critical impurities.
· pH and appearance results before and after the agreed storage challenge.
· Solution-stability, low-temperature and elevated-temperature records.
· Packaging compatibility statement for the proposed container and closure.
· SDS and dangerous-goods transport information appropriate to the shipment route.
FAO notes that paraquat formulations must not come into direct contact with unsuitable metal surfaces and that containers must comply with national and international transport and safety requirements. The packaging decision therefore includes polymer compatibility, liner or treatment requirements, closure integrity, tamper evidence, label durability and handling conditions. Higher concentration may change the mass of active material per package and the consequences of leakage, but packaging suitability remains a product- and route-specific assessment.
Stewardship documentation should be checked before shipment. The destination-market label and SDS should agree on hazard classification, first-aid information, storage conditions, personal protective equipment and emergency measures. Any required emetic, colorant, or odour alerting component should be addressed in the agreed specification and registration dossier rather than assumed from a trade description. FAO’s paraquat specification includes an emetic requirement for the referenced SL framework, but the current applicable national rule and formulation registration remain controlling.
Supplier qualification is stronger when documents are reviewed as a connected package. The legal entity, manufacturing site, technical-material source, formulator, batch-release laboratory and export route should be identified. A product page can establish that a supplier handles the relevant category; it cannot establish that a particular 200 g/L or 276 g/L batch meets the buyer’s specification.
A practical audit sequence starts with a document review, continues with a retained-sample or pre-shipment test, and then moves to a controlled first shipment. The buyer can compare the supplier’s CoA with an independent laboratory report and reconcile any difference in salt/ion basis, density or test method. Repeated batches should be trended for assay, pH, impurity profile and stability rather than accepted solely on a single pass result.
Red Sun’s paraquat formulation guide and paraquat SL formulation products provide starting points for a commercial inquiry. A formal request should specify the destination country, intended formulation code, required concentration basis, pack size, registration status and evidence package. The paraquat importer supplier qualification route can then be used for current availability and documentation requests.
The 200 g/L SL option may be considered when the target market, existing label, customer equipment or formulation program is built around that declared concentration. The 276 g/L SL option may be considered when the registration dossier, pack-size economics, transport plan and customer specification support the higher declaration. Neither option should be selected solely because the number appears higher or because the drum price appears lower.
The final procurement decision should record five approvals: regulatory fit, chemical identity and assay basis, formulation stability, packaging and logistics, and supplier continuity. If one approval is missing, the commercial comparison remains provisional. This decision record also gives procurement, quality, regulatory and product-management teams a common basis for resolving price-versus-compliance trade-offs.
No. Interchangeability depends on the declared chemical basis, registered label, formulation specification and market authorization. A concentration conversion is not a permission to change the use rate or relabel a product.
A batch-specific CoA supported by the agreed specification, analytical methods, SDS, stability evidence and registration documentation has greater release value than a brochure. Independent testing may be required by the quality agreement.
No. Higher concentration can reduce container volume, but freight classification, packaging, inspection, storage, registration and customer requirements can change the result.
No. FAO describes its specifications as quality reference points and states that national or provincial authorities decide suitability, labelling and applicable legal provisions.
A defensible paraquat formulation decision begins with a like-for-like declaration and ends with documented release controls. Importers comparing 200 g/L SL with 276 g/L SL should confirm the salt or ion basis, use the current applicable specification, test identity and assay, review impurities and stability, validate packaging, and check the destination-market registration before shipment. A supplier that can provide a coherent technical, regulatory and logistics package offers a stronger basis for long-term procurement than a quotation based on concentration alone.
