ASTM E1673-96(2017)

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it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: E1673 − 96 (Reapproved 2012) E1673 − 96 (Reapproved 2017)
Standard Test Method for
Percent Suspensibility
This standard is issued under the fixed designation E1673; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope
1.1 This test method is used to determine the percent suspensibility of dry pesticide formulations.
1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility
of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory
limitations prior to use. For specific precautionary statements see Section 7.
1.4 This international standard was developed in accordance with internationally recognized principles on standardization
established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued
by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
2. Referenced Documents
2.1 ASTM Standards:
D1126 Test Method for Hardness in Water
D1193 Specification for Reagent Water
3. Summary of Test Method
3.1 A known quantity of dry pesticide is slurried into 50 mL of test water in a 100-mL beaker. The slurry is quantitatively
transferred to a 250-mL mixing cylinder using additional test water to rinse the beaker. The 250-mL mixing cylinder is then filled
to volume with test water. The mixing cylinder is stoppered and inverted 15 complete cycles. The mixing cylinder is allowed to
stand for 30 min. After 30 min the top 225 mL is drawn off and the remaining suspension is dried. The residue weight will
determine the percent suspensibility.
4. Significance and Use
4.1 This test method is designed specifically for dry formulations, but need not be restricted to these materials.
4.2 Either option of this test method (see Section 8) may be used to determine the percent suspensibility.
4.3 This test method may not be applicable to all dry formulations such as those containing either liquids or ingredients that
rise to the top upon separation.
4.4 This test method may not be applicable to formulations containing ingredients that decompose under the test conditions.
4.5 This test method may not give reproducible results if flocculation occurs.
4.6 This test method should be run in duplicate.
4.7 Products containing water soluble or volatile components may result in errors.
5. Apparatus
5.1 Balance, top loading, with an accuracy of 60.01 g or better.
5.2 Beaker, 100 mL.
This test method is under the jurisdiction of ASTM Committee E35 on Pesticides, Antimicrobials, and Alternative Control Agents and is the direct responsibility of
Subcommittee E35.22 on Pesticide Formulations and Delivery Systems.
Current edition approved Oct. 1, 2012April 1, 2017. Published October 2012April 2017. Originally approved in 1995. Last previous edition approved in 20062012 as
E1673 – 96 (2006).(2012). DOI: 10.1520/E1673-96R12.10.1520/E1673-96R17.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
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E1673 − 96 (2017)
5.3 Mixing Cylinder, stoppered, 250 mL, flat bottom, KIMAX series 20039 or equivalent.
5.4 Timer, adjustable, with an accuracy of 6 min.
5.5 Magnetic Stirrer, 120 to 1200 rpm, or equivalent.
5.6 Stir Bar, magnetic 1 in. in length and ⁄8 in. in diameter (2.5 cm × 1 cm).
5.7 Weighing Dish, aluminum (57 × 18 mm) or petri dish, or equivalent.
5.8 Vacuum Apparatus, see Fig. 1, equipped with a vented stopper to prevent the formation of a vacuum.
5.9 Filtering Flask, heavy wall, 500 mL, KIMAX Series 27060 or equivalent.
5.10 Gravity Oven.
5.11 Centrifuge, any centrifuge capable of holding a 50 mL or larger tube and maintaining a minimum speed of 1500 rpm.
5.12 Centrifuge Tube, plastic or glass, 50 mL or larger.
6. Reagents (Test Water)
6.1 Purity of Reagents—Reagent grade chemicals shall be used in all tests. Unless otherwise indicated, it is intended that all
reagents shall conform to the specifications of the Committee on Analytical Reagents of the American Chemical Society where
such specifications are available.
6.2 Purity of Water—Unless otherwise indicated, reference to water shall be understood to mean reagent water, Type IV, as
defined by Specification D1193.
NOTE 1—Type IV grade reagent water may be prepared by distillation, ion exchange, reverse osmosis, electrodialysis, or a combination thereof.
Reagent Chemicals, American Chemical Society Specifications, American Chemical Society, Washington, DC. For Suggestions on the testing of reagents not listed by
the American Chemical Society, see Annual Standards for Laboratory Chemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeia and National
Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville, MD.
FIG. 1 Vacuum Apparatus
E1673 − 96 (2017)
6.3 Synthetic Hard Water Stock—Transfer 12.14 g of anhydrous calcium chloride (CaCl ) and 5.55 g of magnesium chloride
hexahydrate (MgCl ·6H O) to a 1000-mL volumetric flask. Dissolve the reagents with approximately 750 mL of water and
2 2
equilibrate to 20°C. Dilute the solution to 1000 mL total volume with water at 20°C, stopper the flask and mix the solution
thoroughly. This mixture is equivalent to 13 680 ppm as calcium carbonate (CaCO ) and is based on a compositional ratio of 4:1
calcium carbonate to magnesium carbonate.
6.3.1 Soft Water—Equivalent to a total hardness of 34.2 ppm as calcium carbonate (CaCO ). Transfer 2.50 mL of synthetic hard
water stock by pipet to a 1000-mL volumetric flask and dilute to volume with water at 20°C. Mix solution thoroughly.
NOTE 2—It is recommended that total hardness be checked in accordance with Test Method MT-73, CIPAC 1, EDTA titration. An alternate method
is provided in Test Method D1126 where the value is represented as CaCO . A value within 6% of the nominal hardness value is acceptable.
6.3.2 Hard Water—Equivalent to a total hardness of 342 ppm as calcium carbonate (CaCO ). Transfer 25 mL of synthetic hard
water stock by buret to a 1000-mL volumetric flask and dilute to volume with water at 20°C. Mix this solution thoroughly (see
Note 2).
6.3.3 Extra-Hard Water—Equivalent to a total hardn
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