The number of pesticides newly registered in China has plummeted from 4326 in 2018 to 294 in 2019 and one of the main causes is the elevated data requirements newly enforced. As an essential component of a dossier, product chemistry data is usually firstly reviewed by the competent authorities. In a training course organized by the Chinese Crop Protection Industry Association in June, Ms. Nancy Shen, technical supervisor of REACH24H, concluded the similarity and differences in the data requirements and exchanged her long years of experience in registering pesticides in China, EU and the United States.
Generally, Product chemistry data consists of component analysis, Physico-chemical properties, physic-chemical hazard properties and product technical indicators related to its formulation types.
Component analysis refers to the qualitative and quantitative analysis on active ingredient and impurities in TGAI (technical grade active ingredients) sampled from 5 representative batches, mainly aimed to determine the relevant impurities with toxicological and environmental significance.
China, EU and the United State have developed technical guidelines for component analysis and their similarity and differences are summarized as follows:
Name of Data
Analytical profile of batches
Representative batched sampled from a proven and stable process
Discontinuously produced in recent 5 years at large scale
AI: UV/IR/NMR/MS spectrums
Impurity: 1 spectrum (Qualitative)
Depending on the specificity of the method used
Refer to EU
Contents of active ingredients, relevant impurity and significant impurity and mass balance (98-102%)
In addition to support component/product identification, the physic-chemical properties can help to determine the possible changes in production process and whether additional tests/assessment are required, the utilization of an appropriate container and signal words as well as other measures for first-aid and agricultural practice(re-entry interval). As shown in below table, the EU has comparatively fewer requirements on TGAIs while the US has the most complicated requirements on stability study. For formulated products.
Both pure AI and TGAI
Only required for pure ai (below 360℃) or decomposition/ sublimation temperature
Melting point will be required for solid sample and boiling point for liquid sample
At 20-25℃(normal substance);
If the VP is less than 10-5Pa 20-25℃, an extrapolated data after testing at a higher temperature will be acceptable;
Henry's constant will also be required
With no need for salt compound
Performed at 20 ℃ and the structure of the dissociated substances should be provided;
For salt compound, pKa will be required for function group
Only required for substance containing acidic/ alkali or alcohol groups
Tested at 20-25℃. For substance with pKa between 2 and 12, the impact of different pH values to the coefficient should be additionally tested.
Only required for nonpolar organic substance
In organic solvents(polar, nonpolar and aromatic)
Water: in a neutral condition. For substance with pKa between 2 and 12, the solubility in acidic(pH 4 to 5) and alkali(pH 9 to 10) conditions should be provided;
Organic solvent: for substance with solubility below 250g/L at 15-25 ℃, the applicant should provide the solubility in aliphatic hydrocarbons, aromatic hydrocarbons, halohydrocarbon, alcohols, ketones and esters.
With no need for organic solvents
Hydrolysis/photolysis in water
pH and acidity
For liquid formulation, test the substance directly.
For non-liquid formulation, the pH value of a 1% solution.
For substances with pH value greater than 10 or less than 4, the acidity will be additionally required.
Only pH value will suffice
2 shear rates obtained at 20 ℃ and 40℃.
To predict and prevent possible explosion and combustion during the transportation, storage and handling of pesticide, the 3 economies have explicit requirements on hazard identification for both TGAI and formulated pesticides, but the EU and the US have offered considerable flexibility.
Deducible from structure theory following the CLP rules
Only required for substance with oxidizing or reducible group
Only required for flammable liquid
Only required for possible explosive substance
Technical indicators are a series of specific requirements relevant to pesticide formulation type. Only the US has not yet required the testing of these indicators. China and the EU have established the requirements similar to the FAO specification. China developed the agricultural standard “NY 2989-2016: Guidelines on Developing the specifications of pesticide for registration” and multiple standards for each formulation type and the applicant only needs to complete the tests of indicators already established. In EU the tests are more conducted on a case-by-case basis and FAO specification is the most frequently referred guideline.
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