ASTM E1518-05 Physical compatibility with other products
The method is aimed to evaluate the physical compatibility and stability of pesticide tank mixtures diluted for aqueous application and it can be also adapted to use with liquid fertlizers. Compatibility is measured in terms of dispersion stability and wet sieve residues. Formulation is added into a wide-mouth jar containing 100 mL of synthetic hard water, the jar is swirled to ensure a good dispersion. A specific amount of the additional pesticide is added into the jar which is capped and swirled. After an appropriate shaking time, the jar content is poured  through a 50-mesh sieve. 50 mL of synthetic hard water are transferred into jar and poured through a 50-mesh sieve for 2 times and the residue remaining both on the jar and 50-mesh sieve are observed.

STUDY DESIGN
On case by case basis, the following experimental conditions are set: number of application doses of test formulation, number of pesticides to be mixed with the test formulation and number of binary mixing and individual (as controls) samples to be evaluated.

The results are expressed, in terms of evaluation of dispersion stability and residue %, according to the following definitions:
Compatible Formulation:
Mixture of pesticides in water is well-dispersed and no nonrinsable residue are found on the 50-mesh sieve or remaining on jar walls.
Incompatible Formulation:
There is a separation of the mixture of pesticides in water and/or presence of flocculation, coagulation, gel or curd during or at the end of the test that not re-disperse nor pass through the 50-mesh sieve or remaining on the jar.
Study includes GLP management and reporting.

REFERENCES AND GUIDELINES
ASTM E1518-05 – Standard practice for evaluation of physical compatibility  of pesticides in aqueous tank mixtures by dynamic shaker method.