United States Prevention, Pesticides EPA712-C-96-213
Environmental Protection and Toxic Substances February 1996
Agency (7101)
&EPA Occupational and
Residential Exposure
Test Guidelines
OPPTS 875.1400
nhalation Exposure—
ndoor
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INTRODUCTION
This guideline is one of a series of test guidelines that have been
developed by the Office of Prevention, Pesticides and Toxic Substances,
United States Environmental Protection Agency for use in the testing of
pesticides and toxic substances, and the development of test data that must
be submitted to the Agency for review under Federal regulations.
The Office of Prevention, Pesticides and Toxic Substances (OPPTS)
has developed this guideline through a process of harmonization that
blended the testing guidance and requirements that existed in the Office
of Pollution Prevention and Toxics (OPPT) and appeared in Title 40,
Chapter I, Subchapter R of the Code of Federal Regulations (CFR), the
Office of Pesticide Programs (OPP) which appeared in publications of the
National Technical Information Service (NTIS) and the guidelines pub-
lished by the Organization for Economic Cooperation and Development
(OECD).
The purpose of harmonizing these guidelines into a single set of
OPPTS guidelines is to minimize variations among the testing procedures
that must be performed to meet the data requirements of the U. S. Environ-
mental Protection Agency under the Toxic Substances Control Act (15
U.S.C. 2601) and the Federal Insecticide, Fungicide and Rodenticide Act
(7U.S.C. I36,etseq.).
Final Guideline Release: This guideline is available from the U.S.
Government Printing Office, Washington, DC 20402 on The Federal Bul-
letin Board. By modem dial 202-512-1387, telnet and ftp:
fedbbs.access.gpo.gov (IP 162.140.64.19), internet: http://
fedbbs.access.gpo.gov, or call 202-512-0132 for disks or paper copies.
This guideline is also available electronically in ASCII and PDF (portable
document format) from the EPA Public Access Gopher (gopher.epa.gov)
under the heading "Environmental Test Methods and Guidelines."
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OPPTS 875.1400 Inhalation exposure—indoor.
(a) Scope—(1) Applicability. This guideline is intended to meet test-
ing requirements of the Federal Insecticide, Fungicide, and Rodenticide
Act (FIFRA) (7 U.S.C. 136, et seq.).
(2) Background. The source material used in developing this har-
monized OPPTS test guideline are OPP guidelines 230 and 234. This
guideline should be used with OPPTS 875.1000.
(b) Estimation of respiratory exposure by passive dosimetry. Be-
cause of the wide differences in chemical and physical properties of the
many pesticides that will be investigated, this guideline will necessarily
be more general than the guideline on dermal exposure (OPPTS 875.1200).
The specific sampling method, appropriate sampling medium, conditions
for storage of samples, and appropriate analytical procedure will largely
be dependent on the material being studied. Personal air monitoring will
be required and procedures using battery-operated pumps or modified res-
pirators developed by Durham and Wolfe (see paragraph (f)(2) of this
guideline) will be described.
(1) Laboratory studies necessary before field studies are initi-
ated—(i) Analytical procedure. The choice of analytical procedures will
depend on the material being studied and is, therefore, left to the discretion
of the investigator. The method must be sufficiently sensitive so that, cou-
pled with the trapping and extraction procedures chosen, it is capable of
measuring exposure to 1 (ig/h (or less, if the toxicity of the material under
study warrants greater sensitivity).
(ii) Choice of personal monitors—(A) Trapping efficiency testing.
(7) A trapping efficiency test must be documented for the medium chosen.
The procedure described by Melcher et al. under paragraph (f)(6) of this
guideline is preferred since it can be performed at approximately the rel-
ative humidity expected during field studies. The investigator can adapt
this procedure, which was designed for solid sorbents, to all types of sam-
pling media by appropriate modification. Gauze pads can be tested by
eliminating the solid sorbent and placing a pad holder between the glass
tube containing the front glass wool plug (described under paragraph (f)(6)
of this guideline) and a pump. A filter support assembly such as that avail-
able from Ace Glass, Inc. (catalog no. 7519) may be used to support the
pad in the air stream. The gauze pad may have to be trimmed to fit the
support, but should be large enough so that all flow is through the pad
and no leakage occurs around the periphery. The apparatus used by Mel-
cher will have to be further modified to accommodate the large airflow
of this procedure.
(2) If a liquid medium is to be tested, the glass tube containing the
front glass wool plug is connected directly to the impinger. In all cases,
the residue remaining in the front glass wool plug and that trapped in
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the medium must be determined to find the trapping and extraction effi-
ciency:
(quantity recovered from medium)
percent efficiency = x 100
(quantity added to plug) - (quantity left in plug)
Efficiency testing for gauze pads should be conducted using an
airflow near the mean minute ventilation of a man doing light work
(29 L/min). If a medium to be used with a personal sampling pump is
being tested, the airflow must be equal to the maximum that will be used
in the field. Tests are to be be conducted with the relative humidity of
the airflow through the collection medium held at a level based on a rea-
sonable estimate of what the relative humidity might be during the field
study. Each test should be run for a period of time at least as long as
the longest exposure time anticipated during field studies. Seven or more
separate determinations constitute a test.
(4) While it would be desirable to know the trapping efficiency of
media using aerosols or particulates, no completely satisfactory procedure
is currently available for this type of testing. Registrants are strongly urged
to develop an appropriate procedure. Unless aerosols or particulates can
be introduced to test the collecting medium when pesticides having very
low vapor pressures are used, the investigator will have to determine the
retention efficiency of fortified media rather than the trapping efficiency.
(5) To ensure that collected material is not lost from the medium
during sampling, the investigator should also test for breakthrough. This
can be done by analyzing for any residue that is collected by a trap placed
downstream to the medium being tested. This is exemplified by the ' 'back
section'' of packing in the sampling train described by Melcher et al. under
paragraph (f)(6) of this guideline. Tests must be performed at high enough
residue levels to determine the percentage of breakthrough that will occur
if high air concentrations of pesticide are encountered in the field. It is
recommended that at least one test be carried out where the initial trap
contains lOx the highest amount of residue expected in the field.
(B) Criteria of acceptability. (7) The extraction efficiency of labora-
tory fortified controls will be considered acceptable if the lower limit of
the 95 percentile interval is greater than 75 percent, unless otherwise speci-
fied by the Agency. At a minimum, seven determinations should be made
at each fortification to calculate the mean and standard deviation for re-
covery. Total recovery from field-fortified samples must be above 50 per-
cent for the study.
(iii) Exposed media and extract storage—(A) Storage of exposed
media. If trapping media are to be stored after exposure, a test for the
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stability of the compound of interest must be documented. Media are to
be charged with a pesticide by the same procedure as was specified under
paragraph (b)(l)(ii)(A) of this guideline for efficiency testing. Fortified
media must be stored under the same conditions that will be used for field
samples. The storage stability samples are to be extracted and analyzed
by the same methods that will be employed for field samples. Replicate
samples should be extracted and analyzed immediately before and at ap-
propriate periods during storage. The time periods for storage are to be
be chosen so that the longest corresponds to the longest projected storage
period for field samples. A decay curve can then be constructed to deter-
mine the appropriate length of storage to meet total recovery criteria.
(B) Storage of extracts. If extracts from field samples are to be
stored prior to analysis, a documented study of stability is to be be made.
Portions of appropriate solvent are to be fortified with levels of authentic
concentrate of the same formulation that was used in the field studies and
at approximately the same concentration that is expected in extracts from
field studies. The fortified samples are to be stored under the conditions
to be used for storing extracts from field samples. Each sample should
be analyzed immediately before and at appropriate times during storage.
The periods of storage are to be chosen so that the longest corresponds
to the longest projected storage period for extracts from field samples.
A decay curve can then be constructed to determine the length of time
to store extract analysis to meet recovery criteria.
(2) Personal monitoring using battery-powered pumps—(i)
Pumps. Several brands of battery-powered personal monitoring pumps are
satisfactory for use in estimating an applicator's respiratory exposure to
pesticides. However, a pump which is capable of producing an airflow
of at least 2 L/min should be used and its batteries should be capable
of sustaining maximum airflow for at leat 4 h without recharging.
(ii) Media containers. Many devices are available for containing the
different types of media that may be used for entrapping pesticides during
personal air monitoring. These range from elegant spill-proof
microimpingers equipped with membrane filters for separate collection of
large particulates to simple tubes used to contain solid sorbents. Most of
these devices and their uses have been described by Linch under paragraph
(f)(5) of this guideline. Polyurethane foam plugs have become popular for
monitoring pesticide exposure and several types of devices to hold these
plugs have been described under paragraphs (f)(l) and (f)(4) of this guide-
line.
(iii) Sampling media. A host of different media are also available
for trapping pesticides in air. The most suitable medium for a particular
investigation will depend on the chemicals being studied. The medium
should entrap a high percentage of the chemical passing through it, and
should allow the elution of a high percentage of the entrapped chemical
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for analysis. The chemical should be recovered without any conversion
to other reaction products, and the medium should not produce a signifi-
cant restriction of airflow. Various media that have proved effective for
trapping pesticides have been reviewed by Van Dyck and Visweswariah
under paragraph (f)(8) of this guideline, and by Lewis under paragraph
(f)(3) of this guideline.
(3) Personal monitoring using modified respirators—(i) Sup-
plies—(A) Respirators. A tight-fitting dust respirator with a removable
filter is used. The Willson Dustite (Model CP-2D), produced by Willson
Safety Products Division of WGM Safety Corp., Reading, PA 19603, has
been used with good results. However, this model is no longer in produc-
tion. If a similar respirator is not available, a cartridge-type respirator, such
as the Willson Paint Spray and Pesticide Respirator (Model C-122115),
may be used.
(B) Funnels. Any polyethylene funnel large enough in diameter to
cover the dust pad retaining ring of the respirator is satisfactory.
(C) Respirator filters. Commercially available dust filters often con-
tain materials that will interfere with chemical analyses, so they should
be discarded. Discs the same diameter as the discarded dust filters are
cut from a coarse filter paper, such as Whatman No. 4, to serve as backing
for the construction of the monitoring pads.
(D) Gauze. Any 4-inch (10.2 cm) square gauze surgical sponges that
do not contain material that will interfere with analysis are satisfactory.
Interfering materials must be preextracted.
(E) Storage envelopes to contain exposed pads. If exposed pads
are to be stored prior to extraction, envelopes cut from heavy filter paper
may be used. The same white crepe filter paper that is used for backing
the dust exposure pads is suitable for this use. It is also necessary to check
the envelope for material that will interfere with analysis, since that portion
of the envelope that will be in contact with a stored exposure part must
also be extracted to obtain any residues that may have been transferred
from the pad. A 5x10 inch (12.6x25.2 cm) rectangle cut from the large
sheet of filter paper is folded once across the long dimension so that ap-
proximately 0.75 inch (2.2 cm) of the lower portion projects above the
upper portion. This projection provides a convenient space to record the
sample number of the exposed pad contained in the envelope. The filter
paper envelopes are to be kept in individual unwaxed sandwich bags ap-
proximately 6.5x8x1 inch (16.5x20.3x2.5 cm). The sandwich bags keep
the exposed pads within the protective envelopes and help protect against
contamination.
(ii) Construction details—(A) Respiratory exposure pads. A disc
of filter paper backing is overlaid with 32 plies of gauze, and this combina-
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tion is stapled around the periphery of the filter. Excess gauze is trimmed
away to conform to the original filter circumference.
(B) Respirator modification. The ordinary dust filter is replaced by
the gauze fronted filter described under paragraph (b)(3)(iii)(A) of this
guideline, and the respirator is fitted with an inverted funnel to eliminate
direct drift onto the gauze filter. The spout of a plastic funnel is cut off
above the intersection of the spout with the beginning of the conical por-
tion so that a 17 mm hole is produced (if using a single-unit respirator)
or a 12 mm hole (if using a double-unit respirator). Durham and Wolfe,
under paragraph (f)(2) of this guideline, plugged the hole and drilled simu-
lated nares in the bottom side of the cone. Their original design presented
some problem in attaching the funnel because the holes must point down-
ward. Satisfactory results are obtained using a single hole in the end of
the funnel.
(4) Field operations—(i) Use of personal monitors. The intake tube
of any pump-powered sampler unit should be positioned so that the open-
ing is downward, to avoid collection of large droplets, which are not nor-
mally drawn into the nostrils, via direct drift. The intake tube should be
placed as near as possible to the nose level of the test subject. The height
of the intake tube is especially important when taking samples indoors
where walls or ceilings are being sprayed. For the study subject's comfort
and safety, it is necessary to ensure that the pumps, hoses, and samplers
are secured to minimize movement and the potential for snagging.
(ii) Field calibration of personal monitors. When personal sampler
pumps are used, it is necessary to check the flow at the beginning and
the end of the exposure period. A convenient flow meter for this operation
is battery-operated and will measure flow without disturbance (Model 541
or 543 portable flow calibrators, fitting this criterion, are available from
Kurt Instruments, Inc., Carmel Valley, CA 93940). If the flow has been
found to change, the mean flow should be used for all calculations.
(iii) Use of respirators. The gauze side of the pad must face out,
and the mask should be snug. It is advisable to observe workers periodi-
cally. Workers may remove the mask to wipe off sweat and inadvertently
contaminate the exposure pad by wiping the inside of the mask with a
contaminated rag. They may pull the mask down around the neck if it
becomes uncomfortable, thus allowing direct drift onto the inside of the
exposure pad. Since respiratory exposure is normally quite low, even slight
contamination will lead to the introduction of large errors.
(iv) Field-fortified samples and blanks. (A) Inclusion of field-for-
tified samples in a study is vital because it will allow data to be corrected
for any residue losses that may occur during the exposure period, during
storage in the field, and during transportation to the laboratory. The need
for a study of the stability of residues on damp stored pads is eliminated
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if field-fortified samples are extracted on the same day as are the samples
which have been collected.
(B) Because a standard procedure to assess losses from field-fortified
samples has not been developed, it is left to the investigator to propose
such a procedure. However, the Agency recommends the following as a
guide:
(7) Pads should be fortified at approximately the levels expected for
actual exposure samples. The fortified pads should be exposed to the
weather concurrently with the pads being worn by the workers. A member
of the monitoring team who is careful to position him or herself where
inadvertent exposure cannot occur may wear the fortified pads, or they
may be placed in a fixed location that is upwind and a sufficient distance
from the application site to avoid contamination. However, investigators
are cautioned that upwind locations can quickly become downwind loca-
tions, and such occurrences will ruin a set of fortified samples.
(2) Field-fortified samples will be needed to ascertain total recovery
of residues under conditions of the studies. These samples should be for-
tified at the expected residue levels of actual field samples prior to the
start of the monitoring period. Field-fortified samples should be subjected
to the same conditions as actual field samples. There should be at least
one field-fortified sample per worker per monitoring period for each for-
tification level. These samples should be stored and analyzed along with
the exposure samples collected on the same day. Field blanks of exposure
collection media such as pads are also required in order to account for
any possible contamination which may occur while collecting, transport-
ing, or handling field samples prior to extraction in the laboratory. Field
blanks should be handled in the same manner as exposed pads.
(v) Handling exposed monitoring media. Respirator pads are to be
removed using clean tweezers and placed in protective white crepe filter
paper envelopes inside sandwich bags. They are to be stored in a chest
containing ice or an appropriate plastic-encapsulated frozen gel coolant
until they are returned to the laboratory, where they should be stored in
a freezer prior to extraction. It is usually convenient to detach the media
container from personal monitors and to store the intact container inside
a Mason jar in the ice chest until it is returned to the laboratory, whereupon
the unit can be disassembled to recover the exposed media.
(vi) Field data collection. The type of field data that must be reported
will vary with the operation being studied. A set of data must be compiled
for each set of exposure pads. These data must be indexed so that they
can easily be related to any particular exposure value. Two examples of
the type of data needed in a particular exposure situation are presented
as a general guide.
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(A) Agricultural applications, yards, and gardens (7) Pesticide
identification — chemical name, formulation, EPA registration number, lot
number, and type of concentrate container.
(2) Investigator's name.
(3) Description of the area — crop, plot size, and row spacing.
(4) Application data — rate, tank capacity, type of carrier, final mix
concentration, total pounds applied or mixed.
(5) Equipment data — type, model.
(6) Weather data — relative humidity, wind speed, wind direction, and
temperature.
(7) Work activity monitored.
Location of exposure pads on the subject and sample numbers
corresponding to these pads.
Exposure observations — direction of travel of applicator in rela-
tion to wind direction, and any special situation observed that might alter
normal exposure, such as splashing concentrate directly on a particular
pad while filling tank.
(10) Exposure time — presented in such a way that total exposure can
be calculated per amount of pesticide (or other chemical) handled for the
time interval of each work activity.
(B) Structural pest control, greenhouse, indoor residential appli-
cations (7) Pesticide identification — chemical name, formulation, EPA
registration number, lot number, and type of concentrate container.
(2) Investigator's name.
(3) Description of area — linear feet of baseboard treated, size of
rooms.
(4) Indoor environmental conditions — ventilation, air exchange rate,
if known.
(5) Application data — rate, tank capacity, type of carrier, final mix
concentration, total pounds applied or mixed.
(6) Equipment data — type, model.
(7) Weather data — relative humidity and temperature.
(8) Work activity monitored.
Location of pads on the subject and sample numbers correspond-
ing to these pads.
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(10) Exposure observations—special situations observed that might
alter normal exposure, such as adjusting nozzle or rinsing hands after fill-
ing tank.
(11) Exposure time—presented in such a way that total exposure can
be calculated per amount of pesticide (or other chemical) handled for the
time interval of each work activity.
(vii) If personal monitoring pumps are being used, the airflow must
also be recorded at the beginning and end of the exposure period. A sample
form which can be adapted for use in recording these data in the field
is provided.
(5) Laboratory operations subsequent to exposure. As soon as the
investigator returns to the laboratory from the field, all samples held in
ice chests must be stored in a freezer pending further treatment. A sample
history sheet should be prepared to document laboratory operations. A con-
venient sheet of this type contains columns labeled: Sample number, date
sample was collected, date of extraction, date of analysis, names of those
responsible for the task. The lower portion of the sheet should contain
spaces for recording the condition of storage for pads, other media, ex-
tracts, andthe extraction and analytical procedures used. A suggested form
for a sample history sheet is included.
(i) Extraction of residues from exposed media. Samples are to be
extracted according to the procedure that was determined as appropriate
by earlier laboratory studies under paragraph (b)(l)(ii)(B) of this guideline.
The date and method of extraction are to be entered on the sample history
sheet and the extracts whether analyzed immediately or stored under ap-
propriate conditions (under paragraph (b)(l)(iii) of this guideline) for later
analysis. If stored, the method of storage must be specified on the sample
history sheet.
(ii) Analysis of samples. All samples must be analyzed by methods
meeting the criteria specified under paragraph (b)(l)(i) of this guideline.
The date and method of analysis are to be noted on the sample history
sheet.
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DATA REPORT FORM
Exposure Sample History
Sample Series
Sample num-
ber
Date
Col-
lected
By
Date
Ex-
tracted
By
Date
Ana-
lyzed
By
Preextraction storage:
Extraction procedures:
Analysis:
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(6) Presentation of results—(i) Standard breathing rates. For the
sake of standardization in order that results collected by different investiga-
tors will be comparable, the Agency will use the values in the following
Table 1. for minute ventilation (refer to paragraph (f)(7) of this guideline):
Table 1. Standard Breathing Rates
Rest
Light work
Heaw work
Ventilatio
Male
74
29
60
i (L/min)
Female
45
16
24
(ii) Information for inhalation exposure calculations. (A) The final
results for respiratory exposure are to be reported in the text of the report
submitted to the Agency as the mean residue per liter of air drawn through
the sampling media (if sampling pumps are used). These results must be
corrected for losses due to trapping, extraction, and storage. The number
of separate exposures giving rise to the mean and the range of the expo-
sures must also be specified. If any exposures are below the quantitative
limit of the method used for analysis, the number of such exposures must
also be specified. For the purposes of calculating mean residue per liter
of air sampled, any samples that contained residues below the limit of
quantification should be considered to have contained half this limit. Also,
samples should not be considered as valid if the final airflow through the
sampling medium was found to be less than 25 percent of the initial air-
flow. The total time worked and the total quantity of active ingredient
handled during the sampling period must be reported. The residue and
the total quantity of air drawn through each individual sample are to also
be included in the report.
(B) The final results must also include pertinent field data such as
type of application, equipment, formulation, tank mix, application rate,
crop, and range of weather conditions. Information pertaining to nozzle
type and droplet size produced must also be provided. All assumptions
used in calculations must be specified. Refer to OPPTS 875.1600 for com-
plete instructions for reporting.
(c) Number of replicates—respiratory exposure. For the purposes
of these guidelines, a replicate is defined as measuring potential inhalation
exposure during application, using a personal monitoring device for an
individual over the course of one work cycle or portion thereof.For expo-
sure during application, a minimum of five replicates each at a minimum
of three representative indoor sites shall be employed.
(d) Postapplication measurements. The monitor may be fixed at a
location in the room at a height representative of the breathing zone of
the individual. Potential respiratory exposure should be monitored for ap-
10
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propriate periods of time on a schedule of days such that the pattern of
decline of potential respiratory exposure as a function of time can be de-
fined for the persons typically present at the indoor site. Postapplication
exposure shall be monitored at each site. One replicate per time point is
required. It is recommended that as many individuals as practicable be
monitored.
(e) Combined testing. When both dermal and inhalation monitoring
are required, field studies designed to measure exposure by both routes
on the same subjects may be used.
(f) References. The following references should be consulted for ad-
ditional background material on this test guideline.
(1) Davis, J.E. et al., Potential exposure of apple thinners to
phosalone. Bulletin of Environmental Contamination Toxicology 29:592-
598 (1982).
(2) Durham, W.F. and H.R. Wolfe, Measurement of the exposure of
workers to pesticides. Bulletin of the World Health Organization 26:75-
91 (1962).
(3) Lewis, R.G., Sampling and analysis of airborne pesticides. Pp.
51-94 in Air Pollution from Pesticides and Agricultural Processes. R.E.
Lee, Jr., ed. CRC Press, Cleveland, OH (1976).
(4) Lewis, R.G. et al., Protocol for Assessment of Human Exposure
to Airborne Pesticides. Health Effects Research Laboratory, Office of Re-
search and Development, US EPA. NTIS EPA-600/2-80-180, 46 pp.
(1980).
(5) Linch, A.L., Evaluation of Ambient Air Quality by Personnel
Monitoring. CRC Press, Cleveland, OH (1974).
(6) Melcher, R.G. et al., Collection of chlorpyrifos and other pes-
ticides in air on chemically bonded sorbents. Analytical Chemistry 50:251-
255 (1978).
(7) Spector, W.S., Handbook of Biological Data. W.B. Saunders Co.,
Philadelphia, PA (1956).
(8) Van Dyk, L.P. and K. Visweswariah, Pesticides in air: sampling
methods. Residue Reviews 55:91-134 (1975).
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