ASTM E2686-09(2021)

Standard Test Method for Volatile Organic Compound (VOC) Solvents Absorbed/Adsorbed By Simulated Soil Impacted by Pesticide Emulsifiable Concentrate (EC) Applications

SIGNIFICANCE AND USE
5.1 This test method is designed specifically for emulsions of pesticide emulsifiable concentrates.  
5.2 This test method provides information on the absorption/adsorption of solvents by simulated organic soil and inorganic soil impacted by pesticide EC emulsion applications.  
5.3 The amount of solvent lost by volatilization at 40 °C as determined by this method is an indirect measure of the atmospheric availability of the solvent to potentially react with nitrogen oxides to form tropospheric ozone, a major air pollutant.
SCOPE
1.1 This test method simulates the application of an emulsion of a pesticide emulsifiable concentrate (EC) to soil with high organic matter (corn cob granules) and to soil with high inorganic matter (clay granules) and determines the amount of solvent retained by the granules, and withheld from the atmosphere, before and after exposure to 40 ºC in a vented oven. The granules simulate two extremes of soil composition, and the 40 ºC exposure simulates high temperature weathering. Solvent loss from organic substrates other than corn cob may also be determined by repeating the 40 °C exposure tests with the chosen substrate replacing corn cob. The results with corn cob, however, are a reference that must be reported with the alternate substrate results. The difference in solvent content of the granules before and after weathering is an indication of the emission of the solvent from soil impacted by emulsions or solutions during pesticide applications using common practices such as spraying and drip irrigating. Analysis of the granules for solvent content is by high pressure liquid chromatography (HPLC), gas chromatography (GC), or other methods tested and proven to be accurate and reproducible.
Note 1: Since it evaluates soil surface sorption, this test method will underestimate soil sorption from pesticide applications made below the soil surface. Sub-soil surface treatments may include, but are not limited to, mechanical soil injection and soil incorporation applications. In these cases, the increased depth of the sub-soil treatments reduce the soil surface exposure and facilitate increased levels of soil sorption.  
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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
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.

General Information

• Status: Published
• Publication Date: 31-Oct-2021
• ICS: 13.080.10 - Chemical characteristics of soils
• Technical Committee: E35 - Pesticides, Antimicrobials, and Alternative Control Agents
• Drafting Committee: E35.22 - Pesticide Formulations and Delivery Systems

Standards Content (Sample)

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.
Designation:E2686 −09 (Reapproved 2021)
Standard Test Method for
Volatile Organic Compound (VOC) Solvents Absorbed/
Adsorbed By Simulated Soil Impacted by Pesticide
Emulsifiable Concentrate (EC) Applications
This standard is issued under the fixed designation E2686; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope priate safety, health, and environmental practices and deter-
mine the applicability of regulatory limitations prior to use.
1.1 This test method simulates the application of an emul-
1.4 This international standard was developed in accor-
sion of a pesticide emulsifiable concentrate (EC) to soil with
dance with internationally recognized principles on standard-
high organic matter (corn cob granules) and to soil with high
ization established in the Decision on Principles for the
inorganic matter (clay granules) and determines the amount of
Development of International Standards, Guides and Recom-
solvent retained by the granules, and withheld from the
mendations issued by the World Trade Organization Technical
atmosphere, before and after exposure to 40ºC in a vented
Barriers to Trade (TBT) Committee.
oven.The granules simulate two extremes of soil composition,
andthe40ºCexposuresimulateshightemperatureweathering.
2. Referenced Documents
Solvent loss from organic substrates other than corn cob may
also be determined by repeating the 40°C exposure tests with 2.1 Other Standards:
40 CFR 51.100(s) Protection of Environment—
the chosen substrate replacing corn cob. The results with corn
cob, however, are a reference that must be reported with the Requirements for Preparation,Adoption, and Submittal of
Implentation Plans—Definitions
alternate substrate results. The difference in solvent content of
the granules before and after weathering is an indication of the
3. Terminology
emission of the solvent from soil impacted by emulsions or
solutionsduringpesticideapplicationsusingcommonpractices
3.1 Definitions:
such as spraying and drip irrigating. Analysis of the granules
3.1.1 absorb, v—a process in which one material (the
for solvent content is by high pressure liquid chromatography
absorbent) takes in, and retains, through its pores and inter-
(HPLC), gas chromatography (GC), or other methods tested
stices the molecules of another material (the absorbate).
and proven to be accurate and reproducible.
3.1.2 adsorb, v—a process in which one material (the
NOTE 1—Since it evaluates soil surface sorption, this test method will
adsorbent) attracts to, and retains on, its surface the molecules
underestimate soil sorption from pesticide applications made below the
of another material (the adsorbate).
soil surface. Sub-soil surface treatments may include, but are not limited
to, mechanical soil injection and soil incorporation applications. In these
3.1.3 emulsifiable concentrate, n—asingle-phaseliquidsys-
cases,theincreaseddepthofthesub-soiltreatmentsreducethesoilsurface
tem having the property of forming an emulsion when mixed
exposure and facilitate increased levels of soil sorption.
with water.
1.2 The values stated in SI units are to be regarded as
3.1.4 emulsifying agent, n—a surfactant that promotes the
standard. No other units of measurement are included in this
suspension of one liquid in another.
standard.
3.1.5 gas or liquid chromatography, n—a process in which
1.3 This standard does not purport to address all of the
a chemical mixture carried by a mobile liquid or gas is
safety concerns, if any, associated with its use. It is the
separated into components as a result of different affinities of
responsibility of the user of this standard to establish appro-
thecomponentsfortheliquidorgasandtheadsorbingmedium
through which they pass.
3.1.6 inorganic matter, n—substances of mineral origin that
This test method is under the jurisdiction of ASTM Committee E35 on
are not characterized by primarily carbon-based structures.
Pesticides, Antimicrobials, and Alternative Control Agents and is the direct
responsibility of Subcommittee E35.22 on Pesticide Formulations and Delivery
Systems.
Current edition approved Nov. 1, 2021. Published December 2021. Originally AvailablefromU.S.GovernmentPrintingOfficeSuperintendentofDocuments,
approvedin2009.Lastpreviouseditionapprovedin2015asE2686–09(2015).DOI: 732 N. Capitol St., NW, Mail Stop: SDE, Washington, DC 20401, http://
10.1520/E2686-09R21. www.access.gpo.gov.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
E2686−09 (2021)
3.1.7 organic matter, n—in soil, organic matter consists of 6. Apparatus
plant and animal material that is in the process of decompos-
6.1 Balance, sensitivity of 0.01 g.
ing.
6.2 Roller System, two or more rollers with a drive bed,
3.1.8 tropospheric ozone, n—an air pollutant formed by the
capable of rotating a glass bottle or jar, about 1 to 4 L in size,
sunlightcatalyzedreactionbetweenhydrocarbonsandnitrogen
at 20 to 60 r/min.
oxides present in the troposphere, the layer of the atmosphere
6.3 Glass bottle or jar,round,withscrew-threadcap,foruse
closest to the earth’s surface.
with roller system. Typical size is 1 to 4 L.
3.1.9 volatile organic compound (VOC), n— any compound
6.4 Oven,vented,mechanicalconvection,40ºC 62ºC,2.0
of carbon, excluding carbon monoxide, carbon dioxide, car-
ft minimum inside capacity, 50 to 90 air exchanges per hour.
bonic acid, metallic carbides or carbonates, and ammonium
carbonate, which participates in atmospheric photochemical
6.5 125 mL laboratory media bottles, glass, round, outside
reactions; excluded is a list of organic compounds which have
diameter about 55 mm, height about 123 mm, inside diameter
been determined to have negligible photochemical reactivity
opening about 30 mm, with screw-thread caps.An example is
(40 CFR 51.100(s)).
Wheaton brand, available from many laboratory supply com-
panies.
3.1.10 volatilize, v—to pass off as vapor; to evaporate.
6.6 Apparatus required by the analytical test method.
4. Summary of Test Method
7. Reagents and Materials
4.1 A pesticide EC (emulsifiable concentrate) is simulated
7.1 Corn cob granules, 20/40 Mesh
with a concentrate consisting only of solvent plus emulsifying
7.2 Montmorillonite clay granules, LVM, 12/24 Mesh.
agent(s). The concentrate is then mixed with water, and the
emulsion is applied to corn cob granules (organic substrate)
7.3 Solvent to be tested.
andmontmorilloniteclaygranules(inorganicsubstrate),which
7.4 Emulsifying agent(s) suitable for emulsifying the sol-
absorb/adsorb the liquid.
vent.
4.2 Other organic substrates, like corn stover, straw, or
7.5 Reagents and materials required by the analytical test
sphagnum peat, for example, may simulate the harvest debris
method.
from some crops better than corn cob, and the test method can
beusedwithanyofthistypesubstratereplacingcorncob.Care 8. Hazards
must be taken to select a substrate appropriate for the crop of
8.1 Before testing, read the precautionary statements on
concern,andtheresultswithcorncobareareferencethatmust
product labels and the Material Safety Data Sheets (MSDS).
be reported with the alternate substrate results. The treated
Take proper precautions to prevent skin contact and inhalation
granules are placed in a vented 40ºC oven in uncapped bottles.
of fumes or dust. Take care to prevent contamination of the
The uncapped bottles allow for loss of the solvent by volatil-
surrounding area. Always wear the appropriate safety equip-
ization. Each bottle is left in the oven for a different, and ever
ment and, where indicated, wear respiratory devices approved
increasing,timeperiod.Thetimeperiodforthefirstbottlemay
by the National Institute of Occupational Safety and Health
be as little as two hours, and that for the last bottle may be as
(NIOSH) for the product being tested.
much as one-hundred twenty hours or longer. After the 40ºC
8.2 Store, handle, and dispose of test materials with consid-
exposure,thegranulesareanalyzedtodeterminetheamountof
eration for health and environmental safety, and in accordance
solvent still retained. Successive time periods continue until
with federal, state, and local regulations.
theamountofsolventfoundintwoormoresuccessivesamples
indicates more exposure time is not expected to cause signifi-
9. Sampling, Test Specimens, and Test Units
cantly more loss of solvent.Analysis is by high pressure liquid
9.1 The uniform mixing of the roller system procedure
chromatography (HPLC), gas chromatography (GC), or other
ensures any size sample taken from the roller system jar is a
methods tested and proven to give accurate and reproducible
representative sample. Do not use riffling to reduce a gross
results.
sampleofthetreatedgranulestoarepresentative,suitablesize.
Significant volatilization of the solvent may occur during
5. Significance and Use
riffling or any other time the granules are not in a sealed
5.1 This test method is designed specifically for emulsions
container.
of pesticide emulsifiable concentrates.
10. Preparation of Apparatus
5.2 This test method provides information on the
10.1 For all apparatus, see the manufacturers’ instructions
absorption/adsorptionofsolventsbysimulatedorganicsoiland
for proper operation and maintenance.
inorganicsoilimpactedbypesticideECemulsionapplications.
11. Calibration and Standardization
5.3 The amount of solvent lost by volatilization at 40°C as
determined by this method is an indirect measure of the 11.1 See the analytical test method to be used for determin-
atmospheric availability of the solvent to potentially react with ing solvent content for information relative to calibration and
nitrogen oxides to form tropospheric ozone, a major air adjustment of the apparatus necessary for the use of the
pollutant. method.
E2686−09 (2021)
11.2 See the analytical test method for the standardization 12.8 Add the first emulsion increment, promptly cap the
and use of reference standards and blanks used in the method. container, and place it on the roller system at, typically, 30
r/min to 50 r/min for a good cascading motion that gives good
12. Procedure mixing of the granules inside. Rotate 10 min. Repeat the
increment additions of emulsion and 10 min rotating two more
12.1 Prepare an emulsifiable concentrate consisting only of
times.
solvent plus emulsifying agent(s).Atypical formula is 90% to
92%solventand8%to10%emulsifyingagent(s).Checkthe
12.9 Use an analytical method tested and proven to give
emulsion performance by adding 1 part concentrate to 14 parts
accurateandreproducibleresults.HPLCandGCmethodshave
water. Stir the mixture to form the emulsion. The emulsion
been used successfully.
should form easily, remain free of separation for 15 min, and
12.10 Determinebytrialanderrorthenumberofsuccessive
re-emulsifyeasilyaftersitting24h.Iftheconcentratedoesnot
time periods needed for tracking the loss of solvent from the
meet these performance limits, reformulate using a different
granules by volatilization at 40°C to a plateau indicating
emulsifyingagent(s).Keeptheconcentrateandtheemulsionin
furtherlossisnotexpectedtobesignificant.Aminimumoffive
closed containers, regardless of the ambient temperature, to
successive time periods is needed to conclude the plateau
prevent loss of solvent by volatilization. Open the containers
occurs; two of those periods must be 0 h and 72 h. Tracking is
only for the time needed to perform a necessary task.
completed when the results from any two of three successive
12.2 Analyze the concentrate for weight % solvent, using
time periods do not differ from each other by more than the
the same analytical method to be used for the treated granules.
accuracy of the test method. See 15.2 for repeatability and
Repeat the analysis. The two analyses must not differ more
reproducibility standard deviation and the 95% repeatability
than 4% from each other. Use the average to calculate the
and reproducibility limits on the difference between test
makeup of the emulsion to be used for treating the granules.
results.
In the rare event it is concluded that a plateau for loss by
12.3 Prepare one batch of emulsion treated corn cob gran-
ules and one batch of emulsion treated clay granules as vaporization will not be seen, the half-life for biodegradation
described below. These are the primary sampling units. Test of the solvent in soil can be used as a second tier end-point.
Stop the testing after exposure time at 40°C equals 3× the
unit samples are sub-units taken from these primary units.
biodegradation half-life.The determination of soil biodegrada-
12.4 Keep all treated granules in closed containers, regard-
tion half-life, itself, is beyond the scope of this test.
less of the ambient temperature, to prevent loss of solvent by
volatilization. Open the containers only for the time needed to
12.11 A suggested sequence of successive time periods at
perform a necessary task.
40°Cforstartingtrialanderrortestsis:0h,8h,24h,48h,72
h, 96 h, and 120 h.
12.5 Typically,thedesiredweight%solventingranulesfor
analysis by HPLC or GC is about 1%%.Asuggested protocol
12.12 A suggested testing protocol is as follows: Prepare
for the preparation of granules with 1% solvent is as follows:
threesetsofseven125mLmediabottlescontainingthetreated
Prepare a concentrate of 90% solvent plus 10% surfactant(s).
granules. Trial and error results may reduce or increase the
Add 1.1 parts concentrate to 14 parts water. Add the resulting
number of samples actually needed.
emulsion to 85 parts granules and mix to uniformity. Deter-
12.13 Weigh the empty bottle and cap to the nearest 0.01 g.
mine the initial solvent content of the granules by extracting a
Add a test unit (nominal weight) of granules to the bottle.
sample with a suitable analytical solvent followed by analysis
Typically,thenominalweightofgranulesforHPLCanalysisis
of the extract. The weight of the sample, or test unit, for 40°C
5g,andthenominalweightforGCanalysisis5gto20g.Use
exposure and subsequent analysis is the weight determined to
the nominal weight specified by the analytical method for all
be nominal for the analytical method.
40ºC exposures and solvent extractions.
12.6 Begin preparation of the two batches of treated gran-
12.14 Weigh the bottle and granules and cap to the nearest
ulesbyaddinguntreatedgranulestotheglassbottleorjartobe
0.01 g.
...