ASTM E1945-98

Standard Test Method for Percent Dispersibility

SCOPE
1.1 This test method is used to determine the percent dispersibility of dry pesticide formulations.  
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.

General Information

• Status: Historical
• Publication Date: 09-Mar-1998
• ICS: 13.080.01 - Soil quality and pedology in general
• Technical Committee: E35 - Pesticides, Antimicrobials, and Alternative Control Agents
• Drafting Committee: E35.22 - Pesticide Formulations and Delivery Systems

Relations

• Replaced By: ASTM E1945-02 - Standard Test Method for Percent Dispersibility
• Effective Date: 10-Nov-2002

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or
withdrawn. Contact ASTM International (www.astm.org) for the latest information.
Designation: E 1945 – 98
AMERICAN SOCIETY FOR TESTING AND MATERIALS
100 Barr Harbor Dr., West Conshohocken, PA 19428
Reprinted from the Annual Book of ASTM Standards. Copyright ASTM
Standard Test Method for
1
Percent Dispersibility
This standard is issued under the fixed designation E 1945; 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 (e) indicates an editorial change since the last revision or reapproval.
1. Scope 5. Apparatus
1.1 This test method is used to determine the percent 5.1 Balance, top loading, with an accuracy of 60.01 g or
dispersibility of dry pesticide formulations. better.
1.2 This standard does not purport to address all of the 5.2 Gravity Oven.
safety concerns, if any, associated with its use. It is the 5.3 Weighing Dish, 150 mL capacity or greater.
responsibility of the user of this standard to establish appro- 5.4 Vacuum Apparatus, see Fig. 1, equipped with a vented
priate safety and health practices and determine the applica- stopper.
bility of regulatory limitations prior to use. For specific 5.5 Mixing Cylinder, stoppered, 250 mL, flat bottom, KI-
precautionary statements see Section 7. MAX series 20 039 or equivalent.
5.6 Timer, adjustable, with an accuracy of 61 second.
2. Referenced Documents
5.7 Weighing Dish, aluminum (57 3 18 mm) or petri dish or
2.1 ASTM Standards: equivalent.
2
D 1126 Test Method for Hardness in Water
5.8 Filtering Flask, heavy wall, 500 mL, Kimax Series 27
2
D 1193 Specification for Reagent Water 060 or equivalent.
3. Summary of Test Method
6. Reagents (Test Water)
3.1 A known amount of dry pesticide formulation is added 6.1 Purity of Reagents—Reagent grade chemicals shall be
to a 250-mL mixing cylinder that has been filled to volume
used in all tests. Unless otherwise indicated, it is intended that
with standard water. The mixing cylinder is then stoppered and all reagents shall conform to the specifications of the Commit-
inverted 30 times in two minutes. The mixing cylinder is
tee on Analytical Reagents of the American Chemical Society
3
allowed to stand for 1 min. After 1 min the top 225 mL is where such specifications are available.
drawn off and the remaining suspension is dried. The residue
6.2 Purity of Water—Unless otherwise indicated, reference
weight will determine percent dispersibility. to water shall be understood to mean reagent water, Type IV, as
defined by Specification D 1193.
4. Significance and Use
NOTE 1—Type IV grade reagent water may be prepared by distillation,
4.1 This test method is designed specifically for dry formu-
ion exchange, reverse osmosis, electrodialysis, or a combination thereof.
lations.
6.3 Synthetic Hard Water Stock, transfer 12.14 g of anhy-
4.2 This test method may not be applicable to all dry
drous calcium chloride (CaCl ) and 5.55 g of magnesium
2
formulations such as those containing either liquid technicals
chloride hexahydrate (MgCl •6H O) to a 1000-mL volumetric
2 2
or ingredients that rise to the top upon separation.
flask. Dissolve the reagents with approximately 750 mL of
4.3 This test method may not be applicable to those tech-
water and equilibrate to 20°C. Dilute the solution to 1000 mL
nicals that decompose below the drying temperature.
total volume with water at 20°C, stopper the flask, and mix the
4.4 This test method should be run in duplicate.
solution thoroughly. This mixture is equivalent to 13 680 ppm
4.5 Products containing water soluble or volatile compo-
as calcium carbonate (CaCO ) and is based on a compositional
3
nents may result in errors.
ratio of 4:1 calcium carbonate to magnesium carbonate.
6.3.1 Soft Water, equivalent to a total hardness of 34.2 ppm
3
Reagent Chemicals, American Chemical Society Specifications, American
1
This practice is under the jurisdiction of ASTM Committee E-35 on Pesticides Chemical Society, Washington, DC. For suggestions on the testing of reagents not
and is direct responsibility of Subcommittee E35.22 on Pesticide Formulation and listed by the American Chemical Society, see Analar Standards for Laboratory
Application Systems. Chemicals, BDF Ltd., Poole, Dorset, U.K., and the United States Pharmacopoeia
Current edition approved March 10, 1998. Published May 1998. and National Formulary, U.S. Pharmaceutical Convention, Inc., (USPC), Rockville,
2
Annual Book of ASTM Standards, Vol 11.01. MD.
1

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NOTICE:¬This¬standard¬has¬either¬been¬superseded¬and¬replaced¬by¬a¬new¬version¬or
discontinued.¬Contact¬ASTM¬International¬(www.astm.org)¬for¬the¬latest¬information.¬
E 1945
hard water stock at 20°Ctobe
diluted volumetrically to 1000 mL
with water at 20°C#. (1)
6.4 Other Carriers—Carrie
...