EMULSIFIABLE CONCENTRATES (EC)
Emulsifiable Concentrates (EC), despite the evolution of other up to date formulations, are
still used worldwide because of their simple manufacturing process and lower cost. For application in the field, such formulations are diluted in water, forming oil-in-water emulsion which allow a homogeneous distribution of active ingredients on crops.
Emulsifiable concentrates have some advantages when compared to other formulations :
• Low cost of production
• Very simple technology
• Often better biological activity
Despite some disadvantages such as :
• high amount of solvents
• often low flash point
• low flash point
• high dermal toxicity
• packaging disposal
These disadvantages can be partially overcome by choosing high flash point solvents and a by
new packaging technology such as " gel in water soluble bag", however the formulations
will always contain solvents.
Emulsifiable Concentrates generally contain :
• Active Ingredients
• Solvents - co-solvents
• Stabilizers, stickers, antifoam.
Active ingredients have to be chemically stable and soluble within the solvents to obtain a suitable active content.
Solvent - co-solvents
Aromatic paraffin, solvents such as Xylene and Solvesso are still widely used in EC.
To ease the storage, handling and transportation high flash point solvents such as Solvesso 150 , and Solvesso 200 are used along with new solvents with a more favorable eco-toxicological profile.
When the solubility of actives in aromatic solvents is not sufficient to obtain a suitable active
content, it is necessary to add a polar solvent. In the past the most common co-solvents used were cyclohexanone, isophoron and N-methylpyrrolidone, nowadays they have been replaced by a new generation of solvents with a very favorable eco-toxicological profile.
In particular Solvay has recently developed Rhodiasolv Polarclean. It is an ester amide powerful polar, water soluble solvent with outstanding solvency properties.
The below diagrams show the solubility of various agricultural actives in Rhodiasolv® PolarClean compared to other:
a) harmful but performant agrochemical solvent such as N-M Pyrrolidone
b) other amide commonly used in agrochemicals (Rhodiasolv ADMA 10 and ADMA 810)
c) other ester such as 2 ethyl hexyl lactate.
One or more hydrophilic nonionics surfactants will have to be balanced with lipophilic anionic
one, in the formulation.
These are single surfactants of Hydrophilic (nonionic) or Lipophylic (anionic) activity to be balanced in the formulation to achieve suitable HLB and optimum emulsifiability. Their balancing is sometimes critical and the proper ratio of emulsifiers must be strictly applied.
These are blends of anionic and nonionic surfactants used as pairs.
Because of their compositions the balance is easier and consequently they offer a wide
range of application reducing the number of emulsifiers required. Normally formulations are
less sensitive to variations in water temperature and hardness. Blended emulsifiers
are also used for some specific formulations which could be difficult to achieve with