ASTM E939-94(2005)

Standard Test Method of Field Testing Topical Applications of Compounds as Repellents for Medically Important and Pest Arthropods (Including Insects, Ticks, and Mites):I Mosquitoes

SCOPE
1.1 This test method is used to evaluate the repellency of promising compounds that have undergone primary laboratory studies and have been approved for skin application for secondary testing.  
1.2 This test method is designed for the study of mosquito repellents, but with some modifications this test method can be used to determine the repellency of candidate compounds for other flying insects that attack humans.  
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.

General Information

• Status: Historical
• Publication Date: 31-Oct-2005
• ICS: 71.100.99 - Other products of the chemical industry
• Technical Committee: E35 - Pesticides, Antimicrobials, and Alternative Control Agents

Relations

• Replaces: ASTM E939-94(2000) - Standard Test Method of Field Testing Topical Applications of Compounds as Repellents for Medically Important and Pest Arthropods (Including Insects, Ticks, and Mites):I Mosquitoes
• Effective Date: 01-Nov-2005
• Replaced By: ASTM E939-94(2006) - Standard Test Method of Field Testing Topical Applications of Compounds as Repellents for Medically Important and Pest Arthropods (Including Insects, Ticks, and Mites):I Mosquitoes
• Effective Date: 01-Apr-2006

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NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.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:E939–94(Reapproved 2005)
Standard Test Method of
Field Testing Topical Applications of Compounds as
Repellents for Medically Important and Pest Arthropods
(Including Insects, Ticks, and Mites):I Mosquitoes
This standard is issued under the fixed designation E 939; 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 4.2 This test method is primarily designed to simulate a
situation in which a person treated with a repellent is exposed
1.1 This test method is used to evaluate the repellency of
to natural populations of attacking mosquitoes.
promising compounds that have undergone primary laboratory
4.3 The simplicity of the test offers flexibility under a
studies and have been approved for skin application for
relatively wide range of circumstances and geographical loca-
secondary testing.
tions. By following this test method, international testing with
1.2 This test method is designed for the study of mosquito
a variety of vector mosquito populations is no more difficult to
repellents, but with some modifications this test method can be
accomplish than tests with various domestic species.
used to determine the repellency of candidate compounds for
4.4 A number of people test topical applications of a
other flying insects that attack humans.
repellent for the following reasons:
1.3 This standard does not purport to address all of the
4.4.1 To determine how long the repellent is effective;
safety concerns, if any, associated with its use. It is the
4.4.2 To establish the effective dosage range;
responsibility of the user of this standard to establish appro-
4.4.3 To establish the range of effectiveness on several
priate safety and health practices and determine the applica-
mosquito genera and species in a number of geographical
bility of regulatory limitations prior to use.
areas; and
2. Terminology 4.4.4 To identify the material in terms of odor, staining
capability, plasticizing effect, and oiliness or greasiness.
2.1 Description of Term Specific to This Standard:
4.5 No repellent should be tested on humans without the
2.1.1 complete protection time (CPT)—the time from appli-
written consent of the test volunteers (hereafter referred to as
cation of the repellent to the time of the first confirmed bite (a
test subjects) and prior approval of competent authority, as
secondbitebythesamespecieswithin30minofthefirst).This
designated in applicable laws and regulations governing ex-
permits any number of unconfirmed bites during the CPT.
perimentation on humans.
3. Summary of Test Method
5. Apparatus
3.1 Ameasured amount of the candidate material is applied
5.1 Insect collection vials.
totheforearmorsometimesthelowerleg.Theseareasarethen
5.2 Aspirator.
protected from rubbing and are continuously exposed to
5.3 Stereoscope (optional).
mosquitoes in the field to determine the length of time the
5.4 Standard References for Mosquito Identification, for
treatment provides either complete protection or a high level of
determining species present in the field (optional).
protection.
5.5 Temperature and Humidity Reading Equipment—
4. Significance and Use
Ideally, a continuous recording device such as a hygrothermo-
graph should be used to record conditions during tests. If such
4.1 This test method is an important part of the final phase
equipment is not available, readings should be made immedi-
ofstudyinthedevelopmentofmosquitorepellentsforpersonal
ately before, midway during, and immediately after the tests
use.
are made, using a sling psychrometer.
5.6 Air Speed Indicator and Light Meter, optional but
This test method is under the jurisdiction of ASTM Committee E35 on
preferred if equipment is available.
Pesticides and Alternative Control Agents and is the direct responsibility of
5.7 Watch.
Subcommittee E35.12 on Insect Control Agents.
5.8 Headnets.
Current edition approved Nov. 1, 2005. Published November 2005. Originally
approved in 1983. Last previous edition approved in 2000 as E 939 – 94 (2000). 5.9 Cotton Gloves.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
E939–94 (2005)
5.10 Battery-Operated Head Lamps,withredfiltersfortests sitates the use of the legs instead of the arms as treatment sites.
with nocturnally active species. This can be determined by observation before the tests begin.
5.11 Notebook, Test Sheets, and Pencils, for recording
NOTE 4—The concentration of a compound being tested is not as
species, test data, date, and locality of the test.Asample work
important as the assurance that it is paired with another compound of
sheet is attached with recorded results (see Annex A1.).
equal concentration.
5.12 Water Supply, Mild Soap, and Paper Towels, for
8.4 If legs are used as treatment sites, apply 1.5 mL on the
washing treated skin.
skin between the ankle and knee.
5.13 Clothing, should be appropriate to the season and
8.5 Determine the surface area of the limbs of each test
geographical area.
subject so that treatment rates of candidate repellents and the
NOTE 1—There are differences of opinion as to whether the clothing
standard are uniformly applied.Adjust the application rates for
worn should be uniform in color and type, however, data available do not
differences in arm or leg size of different subjects.
reject or confirm this contention.
8.6 Expose the treated arms or legs continuously to natural
5.14 List of Chemical Names, identifying the compounds or
populations of the mosquito species being tested.
mixtures, or both, to be tested.
8.7 The duration of effectiveness of the repellent is indi-
cated by the CPT.
NOTE 2—In the event of a medical emergency, the chemical list along
8.8 Employ a balanced incomplete block (BIB) experimen-
with pertinent toxicological data may be required.
tal design (round robin) when three to five chemicals are to be
6. Reagents and Materials
tested. With this design, test each repellent in the series on
6.1 All test solutions are formulated on a weight to volume opposite arms of a given number of subjects.
basis (usually with 95% ethanol).
NOTE 5—Ideally, the number of subjects should equal the number of
6.2 Test chemicals in 25% ethanol solutions.
candidate compounds, excluding the standard. Thus, if four compounds
6.3 Test standard deet (N,N-diethyl-meta-toluamide) in a
are to be tested, including the standard, three test subjects would be
25% ethanol solution.
required. To illustrate, the pairings would be: AB, AC, AD, BC, BD, and
CD. Subject 1 would testAB and CD; Subject 2,AC and BD, and Subject
6.4 For final development studies, formulations of lotion,
3, AD and BC.
liquids, creams, solids, or pressurized aerosols containing
ingredients for field evaluation are included.
8.9 Because of their variability in attractiveness, assign
repellentstotestsubjectsinarandomizedandbalancedfashion
7. Sampling
so that each subject does not wear the same combination of
materials more than once in a single BIB test series. For
7.1 Each candidate repellent is paired with each other
example, if compounds A, B, C, D, and E are tested with a
repellent or a standard on the arms of a subject and exposed
standard F, then Subject 1 will testAB, CD, and EF; Subject 2
simultaneously to the same insect population (SeeAnnex A1).
will testAC, BE, and DF; Subject 3 will testAD, BF, and CE;
7.2 A round-robin or paired test is used in the experiments,
usually based on the number of experimental materials being Subject 4 will testAE, BC, and CF; and Subject 5 will testAF,
BC, and DE.
evaluated.
7.3 Treatments are exposed to the mosquito population for
NOTE 6—If four or five compounds, excluding the standard, are tested
as long as the repellents are effective, and the biting activity
in a BIB series, one replication of the BIB is sufficient for a statistical
continues.
analysis. If three compounds are to be tested in this fashion, two
replications of the round robin will be necessary.
8. Procedure
8.10 A direct comparison of the candidate versus the stan-
8.1 Determine the identity of species of mosquito in the test
dardrepellentdeetisusedwhenfewerthanthree chemicalsare
area prior to the test. Determine the time to begin and end tests
to be tested. For these tests, four or more replications of tests
each day by the activity of the species to be tested. Diurnal
with each chemical on at least three different subjects are
nocturnal or other patterns of mosquito behavior will govern
necessary.
the scheduling of tests.
8.11 Express the results obtained by paired tests or BIB
8.2 For field tests, make the initial studies with a 25%
comparisons at CPT in minutes or hours.
ethanol solution of the candidate repellents (250 mgAI/mL).A
8.12 During the experiment, subjects shall avoid contact
compound or formulation may be retested at reduced or
with the treated skin surfaces. Touching, rubbing, or abrasive
increased concentrations, or at full strength, if warranted.
action on the treated skin can affect the results. Avoid undue
sweating or wetting of the treated skin except in special tests
NOTE 3—If the complete protection times (CPTs) of repellents are too
long for the available testing period or if the CPTs are too short for designed to study the durability of repellents under adverse
evaluation, adjust the concentrations accordingly. The termination of an
conditions. Loss due to evaporation and absorption is, of
evaluation before a confirmed bite occurs is termed a “plus out” and
course, unavoidable but should be the only known reason for
should be avoided.
loss in these tests, if the above precautions are taken.
8.3 Spread 1 mL of the repellent formulation or repellent 8.13 Test each species with its biting behavior in mind. For
solution evenly over the forearm of the subject and compare example, if a test subject remains immobile, some diurnally
directlywithanotherrepellentofthesameconcentrationonthe active mosquito species become less aggressive and biting
other arm (see Note 4). The behavior of some species neces- pressure on the repellent treated skin will be reduced.
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