Syngenta review the different insecticide concentrate formulation types available to professional pest managers, including their new ZC formulation, Demand Duo.
Formulations can play a vital role in determining the performance and use pattern of a product. Research and development companies aren’t haphazard in their formulation development; the formulation type and ingredients are specifically chosen to meet the performance requirements.
Product formulations are a mix of active constituent and inert ingredients including solvents, carriers, adjuvants, anti-settling agents, anti-foaming agents, heat and cold stabilisers, and other compounds.
While the active constituent (also known as an AI or active ingredient) controls the target, the inert components work to improve the product’s efficacy, stability and usability. They can suspend or hold the product’s components evenly in a mixture, ensuring an even distribution of the active and thus enhancing uptake and effectiveness. The inert components can also make the product easier to use by improving its ability to be handled, measured, mixed and applied to the target area.
It is the variations in these components that can result in two products with the same active ingredient and the same formulation type delivering very different results.Products come in a range of different formulations – some dry, others liquids, gels or pastes. The selection of formulation type by the manufacturer is often governed by the active constituent’s properties – such as its solubility in water and oil, and what the most effective formulation will be for the proposed use pattern of the product.
It’s worth taking the time to understand each formulation, so you can achieve the best performance. The following are some common formulations you may come across when selecting a spray product for general pest control.
Suspension Concentrate (SC): A stable suspension of active constituent(s) with water as the fluid, intended for dilution with water before use. An SC is a water-based liquid formulation that contains dispersed, finely milled solid particles of the active ingredient. The mark of a quality SC is how highly refined the product milling is compared to other SC formulations, which ensures improved product coverage and retention of the product. An SC usually comes with a wetting agent or surfactant that allows the active ingredient particles to ow easily in water. They do not require solvents, and have built-in adjuvants for improved efficacy.
Products with SC formulation often have a low odour due to not requiring solvents in the formulation.
Capsule Suspension (CS): A stable suspension of capsules in a fluid, normally intended for dilution with water before use.
When a CS formulation uses different sized microcapsules, the smaller ‘microcaps’ release the active ingredient swiftly for rapid knockdown of active pests, while larger microcaps remain intact and release the active ingredient slowly for long-lasting, residual control.
There is variety amongst different manufacturers’ microcaps and their resultant efficacy, as some will deteriorate prematurely from heat, UV light and/or pH extremes.
Multi-character liquid formulation: Contains a mixed formulation in a stable, homogeneous mix. One example is the combination of CS and SC technologies, which is known as a ZC formulation.
A ZC formulation is a stable suspension of fine particles of technical material (Suspension Concentrate), combined with a suspension of microcapsules of technical material (Capsule Suspension) in an aqueous phase together with suitable formulants.
After gentle agitation the material must appear homogeneous and be suitable for dilution in water. This formulation type is given the code ZC globally and by the Australian regulator. Other examples of mixed formulations can be found on the APVMA website.
Quality ZC formulations stay stable on surfaces. It is important that the milling of the SC component combined is of high quality and graded correctly. The encapsulation needs to be stable and robust to stay in shape and not be crushed or break, which makes it effective at maintaining control by ensuring a gradual diffusion over a long period of time.
Demand Duo is currently the only full form ZC formulation available in Australia. This general purpose spray benefits from the formulation being stable on a variety of surfaces – both porous and non-porous – as well as being stable in the treated environment. The product has a low odour, is non-staining and allows low use rates. It also provides high knockdown of difficult pests and up to 90 days longevity of control once you have left the job site.
Emulsifiable Concentrate (EC): A liquid, homogeneous formulation to be applied as an emulsion after dilution in water.
An EC is a blend of active ingredient, organic solvent and surfactants. When the transparent solution is diluted in the tank, spontaneous emulsification occurs to form a stable, milk-like emulsion that separates from the water
– much like olive oil mixed in salad dressing. EC products are generally simple to manufacture, have a relatively high biological activity and good stability. Depending on the solvent, they can emit a harsh smell.
Water-dispersible Granule (WG): A formulation consisting of granules, to be applied after disintegration and dispersion in water.
Products with a WG formulation come as easy-to-measure granules that do not dust like wettable powders. When you add the granules to water in a spray tank, the solution quickly disperses to form a fine particle suspension in the liquid. It’s important to note that with this formulation type, constant agitation is recommended to ensure best suspension in the tank.
In addition to these concentrate formulations frequently used to create dilutions for treatments, there are also a range of formulations that exist for specific job types, including many baiting formulations.
All formulations bring their own unique attributes, and there are a variety of reasons behind why they have been selected and developed. It could be to ensure the active ingredients stay stable in the formulation and do not break down, to provide longevity, or to manage the speed of uptake by pests or to be available on surfaces.
You can find the active constituent on the product label, and usually the formulation type as well.
More information on APVMA-recognised formulations can be found at on the APVMA website.
Mike de Luca, Technical Manager, Syngenta ANZ