The EC formulation type refers to a liquid, homogeneous formulation intended for use as an emulsion after dilution in water. Typically, the emulsion droplets in the spray liquid range from 1 to 10 microns in size.
The most important parameter describing the EC formulation is emulsion stability, which refers to the ability to form a uniform and stable emulsion in the spray liquid. Good emulsion stability ensures that the correct and consistent dose of active substance is delivered to the protected crops throughout the spraying process.
EC formulations have been used for many years, although they have undergone numerous changes and modifications – especially in terms of using safer solvents and emulsifiers. In recent years, they have become less popular, mainly because many active ingredients previously formulated as EC have been withdrawn from use, and newer active substances often lack the solubility required for this type of formulation.
Definition of EC Formulation Type According to FAO/WHO
An EC formulation consists of an active ingredient dissolved in suitable solvents along with any other necessary formulants. It shall in the form of a stable homogeneous liquid to be applied as an emulsion after dilution in water.
Typical Composition of EC Formulation Type
The EC formulation is relatively simple in composition, although more complex recipes may be used to prevent degradation or crystallization of the active ingredient. A typical plant protection product in EC formulation contains:
– Active substance: 5–50%
– Emulsifiers: 5–15%
– Solvent(s): up to 100%
Solvents are most commonly petroleum-derived products such as aromatic solvents or cyclohexanone, but renewable or biotechnological solvents are also used, such as dimethyldecanamides, methyl esters of vegetable oils and lactic acid derivatives.
Advantages and Disadvantages of EC Formulation
Advantages:
– Easy to produce
– Easy to mix
– Suitable for formulating active ingredients with low melting point and poor water solubility
– High biological efficacy
Disadvantages:
– Expensive to package and transport
– Increased risk of crystallization at low temperatures
– May increase dermal toxicity of active ingredients
– May cause phytotoxicity
– May contain volatile organic compounds (VOCs)
– May be sensitive to water hardness
Quality Testing of EC Formulation Plant Protection Products
1. Active Ingredient
– Identification
– Content
2. Physical Properties
– Acidity and/or alkalinity (MT 191) or pH range (MT 75.3)
– Emulsion stability (MT 36.3)
– Persistent foam (MT 47.3)
3. Storage Stability
– Stability at low temperature (0 °C for 7 days) (MT 39.3)
– Stability at elevated temperatures (MT 46.3):
a) 54 °C for 2 weeks
b) 40 °C for 8 weeks
c) 30 °C for 18 weeks
Image: EC formulation’s ability to form an emulsion
Author: Piotr Paleń – R&D Director
