WP is a traditional dry formulation type where the active ingredient is adsorbed onto a solid carrier with wetting and dispersing agents. Agrospear produces WP formulations with wettability <60 sec and suspension rate >70%.
Specifications verified: 2026-08-01
Wettable Powder (WP) is one of the oldest and most established agrochemical formulation types. The active ingredient is adsorbed or blended onto an inert solid carrier — typically a clay or silica — together with wetting agents and dispersants, producing a fine powder that wets rapidly and disperses uniformly when added to water in the spray tank.
How WP formulation works
The active ingredient is mixed with an inert carrier (attapulgite, kaolin, diatomaceous earth or synthetic silica), wetting agents (to ensure the powder is wetted rather than floating on the water surface), and dispersants (to keep the suspended particles from agglomerating). The blend is micronized through an air mill or hammer mill to achieve the required fineness, and the finished powder is tested for wettability, suspensibility and flowability before packaging.
Benefits of WP formulations
WP formulations remain relevant in many markets for practical and economic reasons:
- Low cost — simpler production equipment and lower energy consumption than SC (wet milling) or WDG (granulation) make WP the most cost-effective formulation type per kilogram of active ingredient
- Stable storage — dry powder is inherently resistant to microbial growth and hydrolysis, giving excellent shelf stability even in hot and humid climates without the cold-chain requirements of some liquid formulations
- Simple production — blending and micronizing require less specialized equipment than SC or WDG lines, enabling faster setup and lower capital investment for new products
- High active loading for solids — some active ingredients that are insoluble in common solvents and difficult to mill to SC-grade fineness are more practically formulated as WP
- Wide registration base — many older active ingredients have long-standing WP registrations in key markets, and switching to a new formulation type can require new field data
Agrospear WP specifications
Every WP batch produced at Agrospear meets or exceeds these validated specifications:
| Parameter | Specification | |-----------|--------------| | Wettability | < 60 sec | | Suspension rate (30 min) | > 70% | | Fineness (75 μm sieve) | > 98% pass | | Moisture content | < 3% | | pH (1% suspension) | 5.0–9.0 | | Accelerated stability | Pass at 54°C / 14 days | | Shelf life | 2 years at ambient storage |
Wettability below 60 seconds ensures the powder enters the water rather than floating on the surface — a common failure mode in poorly formulated WP products. The >70% suspension rate keeps the active ingredient distributed in the spray tank during application, and >98% fineness through the 75 μm sieve prevents nozzle blockage.
Limitations and market positioning
WP formulations carry a dust hazard that limits their appeal in markets with strict operator safety regulations. Agrospear recommends WP for cost-sensitive markets and active ingredients where the price premium of WDG or SC is not justified by the target crop and application volume. For regulated markets, WDG provides the same dry-product advantages without the dust exposure.
Production at Agrospear
WP production runs on a dedicated blending and micronizing line equipped with high-speed mixers, air mills and automated packaging with dust containment. Each batch is tested for wettability, fineness, suspension rate and moisture content before release.
Ready to spec a WP product for your brand? See our <a href="/oem-manufacturing">OEM/ODM manufacturing program</a> or walk the <a href="/factory">production line</a> where WP formulations are blended and packed.
Read the full formulation walkthrough: <a href="/technology/wettable-powder-wp">Wettable Powder deep dive</a>.
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