5*» 0/09- 90-08?
DIETARY EXPOSURE BRANCH
STANDARD EVALUATION PROCEDURE
Residues in Meat, Milk, Poultry and Eggs:
Feeding Studies/Feed-throughs
Prepared by:
Richard A. Loranger, Ph.D.
United States Environmental Protection Agency
Office of Pesticide Programs
Washington, DC 20460
ENVIRONMENTAL PROTECTION AGENCY
WSHWGTON.D.C. 20460
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TABLE OF CONTENTS
Section
Paa* No.
I. INTRODUCTION 1
(A) Purpose of the Standard Evaluation Procedure 1
(B) Background Information 1
(C) Objective of Feeding Studies 1
II. INFORMATION TO BE SUPPLIED 2
III. THE DATA EVALUATION PROCESS 2
(A) Determine Need for Study and Dietary Burdens 2
(B) Read Report and Identify Data Gaps 4
(C) Assess the Appropriateness and Adequacy of the Data 4
(D) Make a Regulatory Determination 5
IV. REVIEWER AIDS 7
Appendix 1: Information Requested of Petitioner
for Livestock Feeding Studies 8
Appendix 2: Points to Consider in Evaluating
Feeding Studies 10
Appendix 3: Reviewer Aids Materials 14
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DIETARY EXPOSURE BRANCH
STANDARD EVALUATION PROCEDURE
Residues in Meat, Milk, Poultry and Eggs:
Feeding Studies/Feed-throughs*1'
I. INTRODUCTION
(A) Purpose of theStandard Evaluation Procedure
This Standard Evaluation Procedure is designed to
aid Dietary Exposure Branch reviewers in their evaluations
of livestock pesticide feeding studies submitted by
petitioners/registrants. The document also informs
pesticide manufacturers and the public of the considerations
involved in review of such data.
(B) Background information
Livestock feeding studies are required under 40
CFR 158.240 when residues of a pesticide requested for
registration under the amended Federal Insecticide,
Fungicide, and Rodenticide Act appear in livestock feed.
Such residues could be due to treatment of agricultural
crops or to intentional addition of the pesticide to the
livestock feed (a feed-through). Usually one feeding study
can be used to cover both of these situations. The section
of the Residue Chemistry Guidelines (Subdivision O) dealing
with such studies is 17l-4(c){3).
These animal studies are also needed to set toler-
ances for residues of pesticides in meat, milk, poultry and
eggs under Section 408 of the Federal Food, Drug and
Cosmetic Act. Exposure of the public to pesticide residues
from ingestion of these raw agricultural commodities can
then be estimated.
(C) Objective of Feeding studies
As noted in 40 CFR 180.6, a conclusion must be
made whether finite residues of a pesticide or its
"conversion products" will be found in meat, milk, poultry
and eggs when animals are "fed agricultural products bearing
(1) Dermal treatment of livestock is addressed in a
separate Standard Evaluation Procedure.
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... pesticide residues," when pesticides are used "directly
on the animal," or when pesticides are "administered
purposely in the feed or drinking water." To make this
conclusion livestock feeding studies and/or direct animal
treatments, (discussed in separate Standard Evaluation
Procedure) are required to determine the extent to which the
pesticide transfers to meat, milk, poultry and eggs. Such
experiments should measure the "total toxic residue" (parent
pesticide plus its degradation products, metabolites and
impurities of toxicological significance) in these
commodities following oral ingestion and/or dermal treatment
depending on the proposed uses of the chemical. If the data
then show that finite residues are expected from such uses,
the studies will be used to determine the appropriate
tolerances.
II. INFORMATION TO BE SUPPLIED
The submitted study should include all the information
needed to describe completely the actual administration of
the pesticide to the animals (i.e., the feeding portion of
the study), the analyses of the tissues, milk, and eggs for
the residue of concern, and the handling/storage of samples
between those two procedures. Appendix 1 lists the basic
information required for review of livestock feeding
studies. This list represents a shortened version of the
Data Reporting Guideline for this type of study (available
from NTIS as #PB 89-124606).
Useful Standard Evaluation Procedures and Data
Reporting Guidelines related to this document include those
on Analytical Methods, Storage Stability, and Qualitative
Nature of Residue: Metabolism in Food Animals.
III. THE DATA EVALUATION PROCESS
(A) Determine Need for Study and Dietary Burdens
Ruminant and poultry feeding studies are usually
required whenever detectable residues of a pesticide are
found on plant parts (such as grain, forage) or byproducts
(meals, pomaces) consumed by livestock. [The last two
paragraphs of this section describe a situation wherein the
feeding study may not be needed when low residues are
present on feed items.] Table II of the Residue Chemistry
Guidelines (Subdivision 0 of EPA Pesticide Assessment
Guidelines) lists the feed items associated with each crop.
Hog feeding studies may also be required if accumulation of
residues in tissues is likely.
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If detectable residues are observed in feed items,
the maximum dietary burdens for cattle, poultry and swine
are then determined with the aid of the aforementioned Table
II. The latter lists the maximum percentage of various feed
items in the diet on a dry weight basis. This percentage is
then multiplied by the level of pesticide residue (tolerance
in ppm) on the feed item. For example, alfalfa hay bearing
50 ppm of a pesticide would contribute 12.5 ppm to the beef
cattle diet (50 ppm X 25% of diet). The reviewer should
keep in mind that some feed items can be eliminated due to
feeding restrictions on the pesticide labels. Table II of
the Guidelines lists which feeds can be so restricted.
Reviewers are reminded that the percent of
livestock diet figures in Table II of the Guidelines are
expressed on a dry weight basis. Therefore, for feed items
with a high moisture content such as fresh grass, the
residue levels should be corrected to a dry weight basis
before utilizing the % of the diet figure.
If tolerances exist for several feed items that
could be fed in combination, the contributions from the
various feeds must be added. The reviewer should consider
various combinations of the feeds to arrive at a "sensible"
diet having the maximum dietary burden of pesticide. In
doing so, the sum of the % contributions must of course be
<100%. Also, the term "sensible" means that the mixture of
feeds should be practical. For example, although apple
pomace and corn silage each may comprise up to 50% of the
lamb diet, they would not be fed in combination as 100% of
the diet since both are roughages. About 30-50% of the lamb
diet usually consists of grain. Some guidance for livestock
diets is provided in Morrison's "Feeds and Feeding"
(Reference 17 in Appendix 3) and Section 4 (Feed
Substitution Tables) of the "Guide for Estimating Toxic
Residues in Animal Feeds or Diets" (Reference 16 in Appendix
3). The reviewer could also contact USDA and/or workers at
State Agricultural Experiment Stations for additional infor-
mation on feed composition for livestock (see Reference 20
in Appendix 3).
Having arrived at the maximum dietary burden
associated with a sensible combination of feed items, the
reviewer has determined the IX feeding level, a "worst case
estimate of the potential livestock exposure." As noted in
the Guidelines, the feeding study should include the IX
level as well as exaggerated levels (preferably 3X and 10X).
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When low residues are detected on feed items, the
reviewer should consider the anticipated dietary burdens and
the results of the radiolabeled metabolism study when
determining whether feeding studies are necessary. For
example, if the dietary burden (IX) is expected to be 0.01
ppm and the ingestion of 10 ppm radiolabeled compound
resulted in <0.1 ppm total radioactivity in all edible
tissues/milk/eggs, a feeding study would not be necessary.
The metabolism study in this case indicates that maximum
expected residues in animal commodities will be on the order
of 0.1 ppb (assuming linear relationship between dose and
residues). In this case the metabolism study also serves as
a feeding study and indicates that tolerances are not needed
for meat/milk/poultry/eggs [Category 3 of 40 CFR 180.6(a)].
Reviewers should use caution when making the above
extrapolations from results of metabolism studies to
expected residues in tissues. The waiving of feeding
studies should be limited to cases where the extrapolation
involves total radioactivity in tissues and milk/eggs in the
range of 0.1-0.2 ppm or less. When total radioactivity in
tissues, milk, or eggs in metabolism studies is in the range
of 1 ppro or higher, feeding studies will usually be
necessary regardless of the residue level determined by the
extrapolation. This is to take into account the fact that
metabolism studies are generally run with a goat for only
three days, while feeding studies typically use cattle and
last 28-30 days.
(B) Read Report and Identify Data Gaps
Next, the reviewer reads the study to determine
whether the information listed in Appendix 1 has been
submitted. Any omissions which are significant enough to
prevent a complete examination of the study should be noted
in the review. Such data gaps must be clearly identified so
the registrant can be informed by the Product Manager of the
need for additional data and/or details on the conduct of
the study.
(C) Assess the Appropriateness and Adequacy of the Data
The reviewer then considers the adequacy of the
supplied data/information. In doing so, the reviewer should
keep in mind the following major points:
Was the proper material (parent and/or
metabolites) fed at sufficient levels?
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* Were feeds analyzed and consumption monitored to
ensure ingestion of the claimed levels in the
diet?
Was the duration of dosing adequate (i.e., did
residues plateau in milk and/or eggs) and
•sacrifice accomplished within 24 hours of the
final dose?
Were the proper tissues and r.a.c.'s (milk/eggs)
sampled for both control and treated animals?
Did the registrant provide storage stability data
to show residues would not degrade between sample
collection and analysis?
Was the total toxic residue determined in tissues,
milk and eggs using a validated analytical method?
For a more detailed list of points the reviewer
should consider, refer to Appendix 2. In addition to the
latter, the technical guidance available in reviewer aid
materials such as the Residue Chemistry Guidelines and
sources listed in Appendix 3 should be utilized.
Having considered all the points involved
(Appendix 2) the reviewer writes a summary of the study
clearly outlining any (1) significant data gaps/omissions
[as noted above in (B)] and (2) deficiencies in the reported
data (such as insufficient levels fed; toxic metabolites not
measured; feeding terminated before residues plateaued in
milk or eggs).
(D) Make a Regulatory Determination
As noted under the Introduction, a determination
must be made as to whether finite residues of the pesticide
and its "conversion products" will be found in tissues/milk/
eggs and, if found, what tolerances are appropriate to cover
such residues.
If data gaps/deficiencies prevent such a deter-
mination, the reviewer so indicates and outlines what
corrective steps need to be taken. If the study is
adequate, the reviewer categorizes the proposed use of the
pesticide under 40 CFR 180.6(a).
For the use to be placed under Category 3 of
180.6(a) (i.e., no reasonable expectation of finite
residues), no detectable residues should be incurred after
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feeding the pesticide at 10X or more the expected dietary
burden. In that case no tolerances are required for the
pesticide in animal products (meat, milk, eggs, etc.).
The presence of detectable residues from the 10X
or lower feeding levels means the use falls under Categories
1 or 2 of .180.6(a) ("finite residues will actually be
incurred" or "there is a reasonable expectation of finite
residues"). In that case the reviewer must determine what
tolerance levels are appropriate. This generally involves
using the maximum residues found from the IX feeding level
(method sensitivity used when no detectable residues found
in the IX study). If no animals were fed at the IX level,
the results from the feeding level closest to the maximum
anticipated dietary burden are utilized. In that case the
calculation assumes residues are proportional to dietary
burden. For example, if cows ingesting 4.0 ppm of a
pesticide produce milk containing 0.2 ppm residues, the
appropriate tolerance for a 2.0 ppm dietary burden would be
0.1 ppm. If the anticipated burden falls roughly in between
two levels employed in the study, calculations are made with
both levels and the tolerances based on the higher of the
two calculated or extrapolated values. It should be noted
that the tolerances are almost always set to one significant
figure (e.g., 0.01, 0.2, 0.5 ppm) for those <1 ppm. On
occasion, fractional values greater than 1 ppm may be
acceptable, although whole numbers are still preferred.
If dermal uses of the pesticide are registered,
the tolerances must cover both the feed and dermal exposure.
For this purpose it is generally assumed that residues from
oral ingestion and dermal treatments are additive.
Although separate tolerances are established for
meat, fat and meat byproducts (latter include liver and
kidney), they are often set at the same numerical value.
However, if residues concentrate in fat, the latter may
receive a higher tolerance. Likewise, when milk residues
are found to partition mostly into the milk fat, the
tolerance is generally set on the latter with the equivalent
whole milk value (1/25X milk fat tolerance) expressed
parenthetically (e.g., "milk fat [reflecting 0.02 ppm in
whole milk] 0.5 ppm"). If liver or kidney contains
significantly higher levels than other tissues, a separate
tolerance is established for that organ. The meat byproduct
tolerance is then qualified to show the separation of that
tissue as in the following example: meat byproducts (except
kidney) 0.1 ppm; kidney 2 ppm.
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In most cases tolerances are also established for
the meat, fat and meat byproducts of goats, horses and sheep
at the same levels as cattle. (Note that Table II of the
Residue Chemistry Guidelines does not describe diets for
these animals. For tolerance purposes their diets are
assumed tq be the same as cattle.) Unless a separate swine
study has been conducted, the cattle data are also utilized
to set tolerances on hog meat, fat and meat byproducts.
However, the hog diet is based on the swine information in
Table II (i.e., not assumed to be the same as the cattle
diet).
Having completed the various calculations
discussed above, the reviewer states whether the
meat/milk/egg tolerances (existing or proposed depending on
the type of registration action) are appropriate. If they
are not, the proper ones are listed so the Product Manager
can inform the registrant of the requirements for revised
tolerances (i.e., a new tolerance petition or a revised
Section F in a pending petition).
IV. REVIEWER AIDS
There are a large number and variety of source
materials that are available to assist the data reviewer in
the evaluation process. A listing of some of the more
useful references that reside within the Branch is provided
in Appendix 3 to this document.
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-APPENDIX 1-
INFORMATION REQUESTED OF PETITIONER
FOR LIVESTOCK FEEDING STUDIES
1. Identity, source, and purity of material (pesticide and/or
metabolites) fed to animals.
2. Identity of animals and number per feeding level.
3. Housing and health of animals and feeding/milking schedules
during acclimation and dosing periods.
4. Composition of diet (feeds, concentrates, water/liquids,
etc.) and feed consumption prior to and during dosing.
5. Mode of administration of pesticide/metabolites (gelatin
capsule, spiked feed, etc.).
6. Dosage levels in parts per million in the total ration (dry
weight basis).
7. Frequency of dosing and dates of initial and final doses.
8. Dates of dose preparation, storage conditions until
administration, and analyses of spiked feeds to determine
actual feeding levels.
9. Sampling dates for milk and eggs and compositing techniques
(if applicable).
10. Body weights and egg/milk production prior to and during
dosing period.
11. Mode and date of sacrifice (time in hours from final dose of
pesticide) and organs sampled (compositing of latter if
applicable).
12. Conditions and length of sample storage (including shipping
if applicable) prior to extraction/analysis.
13. Detailed description of analytical method and chemical
species determined.
14. Recovery data demonstrating validity of analytical method.
15. Dates of sample extraction and analysis of extract (also
storage conditions of extract if applicable).
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16. Data demonstrating stability of residues under observed
storage of samples and extracts (if applicable).
17. Measured residue levels in muscle, fat, liver, kidney
(except poultry), milk, and eggs.
18. Representative raw data and chromatograms of control,
spiked, and treated samples supporting reported residues and
recoveries.
19. Names/addresses of organizations/personnel involved in the
feeding and analytical portions of the study.
20. Quality assurance procedures - measures/precautions to
ensure fidelity of feeding study and analyses (such as
animal identification, proper labeling/coding of samples,
record keeping procedures, high quality equipment and
reagents, etc.).
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- APPENDIX 2 -
POINTS TO CONSIDER IN EVALUATING FEEDING STUDIES
Administration of Pesticide to Animals
Was the material fed clearly identified as to its chemical
structure(s) and purity? Is there any impurity of concern
(such as hexachlorobenzene)?
* Was the proper mixture (parent pesticide and/or metabolites)
fed? The material fed should resemble the composition of
aged residues in feed items. However, as long as plant and
animal metabolites of the pesticide are the same, we usually
accept administration of only parent compound. In some
cases where the identification of parts of the plant residue
is not known or a large number of metabolites is formed, the
registrant may feed plants bearing weathered residues of the
pesticide.
Were the proper animals administered the pesticide? For
ruminants and poultry the preferred species are cattle and
chickens. Healthy animals should be chosen with dairy cows
in mid-lactation (producing average milk yields) and
chickens in full lay (producing eggs on most days). A swine
study may be required if there is a likelihood for
accumulation in tissues or if the pig (or other non-ruminant
such as the rat) metabolism is significantly different from
cattle and poultry.
Did each feeding level have an adequate number of animals?
For cattle and poultry there should be at least 3 and 10
animals per feeding level, respectively. (Ten birds allow
compositing 3-4 tissues/eggs to produce 3 unique samples.)
We also prefer that cattle and poultry feeding studies
employ 3 and 10 control animals, respectively.
Did feed consumption, body weights, and milk/egg production
decrease drastically after dosing started? If so, animals
did not receive an adequate acclimation period or the
pesticide is producing deleterious effects. If the effects
continue for the entire study, TOX should be alerted as to
the possible hazard of residues in feed to livestock.
How was the pesticide dosage expressed? Dosages should be
given as concentration (ppm) in the total ration (dry weight
basis) . Expression as mg/kg body weight is acceptable
provided enough information (total mg dose or body weight;
feed consumption) is available to enable calculation of the
ppm in the total ration.
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* Were adequate levels administered? The study should include
the IX level (max dietary burden) and 3 and 10 tiroes that
level. The higher levels allow a determination of whether
residues are proportional to intake.
What modes of administering the pesticide were employed?
For cattle the pesticide may be mixed with a concentrate
ration or administered in a gelatin capsule. For chickens
it is convenient to fortify the entire feed at the
appropriate ppm.
Were spiked feeds analyzed to check for proper mixing and to
confirm the intended dose?
If not used on the day of preparation, was spiked feed
stored properly? Were data provided to show the level of
pesticide was not affected by such storage?
If the total diet was not spiked with pesticide (i.e., dose
in gelatin capsule or in concentrate ration), was total feed
consumption data provided to calculate ppm in diet?
Were animals administered the chemical daily and until
residues plateaued in milk or eggs for for 28 days if no
detectable residues in milk/eggs)? Note that Branch policy
was clarified on 4/13/89 to state that dosing should
continue at least four weeks even if residues plateau
earlier in milk or eggs.
Sample Collection andAnalysis
what sampling procedure was utilized for milk and eggs?
Milk and eggs should be collected twice daily and analyzed
frequently enough (preferably at least twice weekly) to
determine trends in total residues with time. Milk samples
from different cows should not be pooled, although up to 3
eggs per composite sample is acceptable. Analyses should be
conducted on whole milk and eggs (yolk + white). Several
milk samples should also be analyzed to determine how
residues partition into milk fat. However, information on
the latter may be available in the metabolism study.
Were animals sacrificed within 24 hours of ingestion of the
final dose? Waiting periods longer than this are usually
not acceptable for setting tolerances to cover residues
incurred by ingestion of pesticide treated feeds. (Note:
This may not be the case for determining tolerances to cover
dermal treatment of livestock. We allow pre-slaughter
intervals of up to three days for such uses. Refer to the
separate SEP for details.)
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Which organs were analyzed? Were samples composited? For
cattle and swine, analyses should be conducted on muscle,
fat, liver and kidney. For poultry, samples should include
muscle (leg and breast), liver and fat. Tissues from
different cows or hogs should not be combined. Pooling of
poultry tissues and eggs is acceptable provided that at
least three unique samples are analyzed per feed level
(i.e., composites of 3-4 tissues if 10 hens per level).
Were all samples frozen as soon as possible after
collection/sacrifice? Is storage stability data available
reflecting intervals from collection to extraction and from
extraction to residue quantitation? Refer to separate
Standard Evaluation Procedure on Storage Stability for more
details.
Was the total toxic residue measured by a validated method?
Has the method been tested by EPA and published in the FDA
Pesticide Analytical Manual? Parent compound plus all
metabolites and impurities of toxicological concern should
be determined in milk/eggs/tissues. Recoveries should be >
70%. For more details on analytical methodology refer to
the Standard Evaluation Procedure (SEP) on that topic. For
background on how we determine what comprises the "total
toxic residue" refer to the SEP on Qualitative Nature of
Residue: Metabolism in Food Animals.
Was the method sufficiently sensitive? The sensitivity
should be 0.01-0.05 ppm or less.
Were control values less than the method sensitivity? If
samples from untreated animals are found to contain apparent
residues, the validity of the study is questionable.
Did the submitter provide raw data and chromatograms to
support the reported residue levels? Representative
chromatograms should be presented for control, fortified and
treated samples of each commodity. Actual values should be
reported for each sample rather than an average for an
entire group.
Was there reasonable agreement between samples from the same
feeding level? If one value is considerably higher than the
others, can it be discarded as an outlier?
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Other Considerations
Are the results of the cold feeding study consistent with
the radiolabeled metabolism study? The levels of the
residue of concern should be similar provided comparable
doses and pre-slaughter intervals were employed. However,
variations may occur due to the shorter dosing period
usually employed in the metabolism study.
Does the proposed feed through use involve a formulation
designed to change absorption characteristics within the
digestive system? If so, a separate study for the feed
through will be required.
Has a Registration Standard been issued for this chemical
and, if so, is it being used in evaluation of the feeding
study?
Is the pesticide undergoing Special Review? If so, has any
relevant information been submitted under that process?
Is there any other unpublished (such as data submitted in
earlier petitions, Section 18 and 24(c) requests) or
published information (such as Codex/FAO Monographs) known
to us about feeding of this pesticide to livestock? If so,
this information should be consistent with the results of
the new study.
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- APPENDIX 3 -
REVIEWER AIDS MATERIALS
Following is a listing of some of the more useful source
materials withi-n the Dietary Exposure Branch that could prove
helpful in reviewing livestock feeding studies:
(1) Federal Food, Drug, and Cosmetic Act, as amended,
§ 408-409.
(2) Federal Insecticide, Fungicide, and Rodenticide Act, as
amended.
(3) Subdivision O [Residue Chemistry] of the Pesticide
Assessment Guidelines, § 171-3 and § 171-4, prepared by OPTS/EPA,
1982.
(4) Subdivision D [Product Chemistry] of the Pesticide
Assessment Guidelines, prepared by OPTS/EPA, 1982.
(5) Code of Federal Regulations [40 CFR 158, 180, 185, and
186], General Services Administration, Washington, D.C., updated
annually.
(6) Pesticide Chemical News Guide. R. E. Duggan, editor,
Food Chemical News, Inc., Washington, D.C., 1982, updated
monthly.
(7) "Guidelines for Data Acquisition and Data Quality
Evaluation in Environmental Chemistry," Anal. Chem. 52. 2242-2248
(1980} .
(8) Acceptable Common Names and Chemical Names for the
Ingredient Statement on Pesticide Labels. 4th ed., C.R. Blalock,
et al., editors, OPP/EPA, 1979, available from National Technical
Information Service, Springfield, VA.
(9) Farm Chemicals Handbook. Meister Publishing Co.,
willoughby, OH, updated annually.
(10) Nanoqen Index: A Dictionary of Pesticides and Chemical
Pollutants. K. Packer, editor, Nanogens International, Freedom,
CA, 1975 (updated periodically by supplements).
(11) F.D.A. Pesticide Analytical Manual. Volumes I and II,
available from the National Technical Information Service,
Springfield, VA.
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(12) Guidelines on Supervised Studies to Provide Data on the
Nature and Amount of Pesticide Residues in Products of Animal
Origin. Codex Committee on Pesticide Residues, draft dated Nov.
5, 1984.
(13) Foods and Food Production Encyclopedia. D. M. Considine
and G. D. Considine, editors, Van Nostrand Reinhold Company, NY
(1982).
(14) Food and Feed Crops of the United States. J. R.
Magness, G. M. Markle, and C. C. Compton, Rutgers University,
N.J., 1971.
(15) McGraw-Hill Encyclopedia of Food. Agriculture &
Nutrition. D. N. Lapedes, editor-in-chief, McGraw-Hill Book
Company, N.Y., 1977.
(16) "Guide for Estimating Toxic Residues in Animal Feeds or
Diets" prepared for the E.P.A. by Lorin E. Harris, available from
National Technical Information Service, Springfield, VA.
(17) Feeds and Feeding. Abridged: The Essentials of the
Feeding, Care, and Management of Farm Animals, Including Poultry,
F. B. Morrison, 9th ed., The Morrison Publishing Co., Ithaca, NY,
1958.
(18) StatisticalMethods Applied to Experiments in
Agriculture and Biology. 7th ed., G. W. Snedecor, Iowa State
College Press, 1980.
(19) Registration Standards on various individual
pesticides, prepared by OPTS/EPA, (several issued each fiscal
year).
(20) Directory of Professional Workers in State Agricultural
Experiment Stations and Other ^opperatingestate Institutions.
published by U.S. Dept. of Agriculture.
(21) Various reference texts and journal publications of a
scientific or agricultural nature, including FAO/Codex
Monographs; Residue Reviews; Analytical Chemistry; Journal of
Agricultural and Food Chemistry; Journal of the Association of
Official Analytical Chemists.
(22) Dietary Exposure Branch files: petition and
registration files; reviewer aids; policies; subject files;
reading files; cultural practices files (livestock feeds, cattle,
poultry, swine); et al.
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