ETHYLENE DIBROMIDE (EDB)
Scientific Support and Decision Document for Grain
and Grain Milling Fumigation Uses
OFFICE OF PESTICIDE PROGRAMS
UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
FEBRUARY 8, 1984
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ETHYLENE DIBROMIDE (EDB)
Scientific Support and Decision Document for Grain
and Grain Milling Fumigation Uses
OFFICE OF PESTICIDE PROGRAMS
UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
FEBRUARY 8, 1984
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EXECUTIVE SUMMARY
Agency has determined that further Federal regulatory actions for
pesticide uses of ethylene dibronide (EDB) are necessary to reduce the
risks to human healthTj These actions include:
"linniediate emergency suspension of all uses of EDB to fumigate stored
grains and grain milling equipment?]
0 guidelines for maximum permissible levels of EDB in raw grains and
consumer products made fron grains;
0 initiation of the rulemaking process to revoke the exemption from
the tolerance requirements for EDB on grain products which is
currently applicable; and
0 establishment of appropriate federally enforceable maximum residue
levels for EDB.
exposure can pose risks to human health which include cancer,
reproductive disorders and heritable genetic damage?) Consequently,
residues of EDB occurring in consumer products raise public health
concerns. The actions the Agency is taking will reasonably reduce the
present risks to human health from the uses of EDB to fumigate stored
grains and to fumigate grain-milling equipment.
In September 1983 EPA announced a series of regulatory decisions for each
of the pesticide uses of EDB. The Agency issued a Notice of Intent to
Cancel registrations for the uses of EDB to fumigate grains and milling
equipment. Pursuant to §6(b) of FIFRA, the cancellation of pesticide
products which are the subject of a Notice of Intent to Cancel does not
become effective when adversely affected persons file a request for a
hearing for particular registrations and uses. Hearing requests were
submitted. Subsequently two hearing requests have been withdrawn.
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ii
As a result of these challenges, the sale and distribution of several
EDB-containing pesticides for use on stored grain and grain-milling
equipment have continued to be legal under FIFRA. Historically,
adjudicatory cancellation hearings have lasted about two years and may
extend for longer periods. The Agency has concluded that this extended
period of time is unacceptable in light of the additional risks to human
health which would be expected to result as use of EDB continues. In
its 1983 decision, the Agency stated that it would consider emergency
suspension of the grain registrations of EDB if additional monitoring
data confirmed widespread dietary residues in consumer grain products.
Recent results fron numerous testing programs of consumer products
confirm that there are residues of EDB in the nation's grain-based food
supplies. EPA's monitoring efforts were aided by collaborative efforts by
the Food and Drug Administration and the United States Department of
Agriculture. Several states have supplied the results of significant
numbers of samples of grain products analyzed for EDB. In addition, the
American Bakers Association and the Grocery Manufacturer's Association
and certain of its member companies have conducted extensive EDB analyses
and submitted those results to EPA. The Agency has evaluated the results
which have been provided by these public and private organizations, and has
concluded that it would be appropriate to recommend EDB residue guidelines
below which grain products should pose no extraordinary risks to public
health. These recommendations are being made available to the public as
well as to state governments and to the various sectors of the grain
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iii
products industry. The Agency will initiate the rulemaking process
necessary to revoke the current exemption of grain products containing EDB
from the tolerance requirements of the Federal Food, Drug, and Cosmetic
Act, and will seek the establishment of federally enforceable maximum
residue levels.
The Agency has further concluded that the uses of EDB to fumigate grains
and milling equipment are responsible for residues of EDB in the nation's
grain-based foods and such use must be stopped immediately to eliminate
continued contamination of grain-based consumer products.
The Agency has evaluated the economic impact of these actions and
reconnendations and has determined that there could be sane economic
disruptions, but that they are not unreasonable in light of the reduction
in the hazards to human health which are expected to result.
This document summarizes the Agency Staff evaluation of exposure, risk and
economic consequences of implementing alternative maximum permissible
residue levels of EDB in grain and grain products and, at the same time,
placing an immediate emergency suspension upon further use of EDB for
fumigation of grain and grain milling equipment. The consequences of a
number of optional levels of maxium permissible EDB residues were
evaluated, for raw grain, cooked/ready-to-eat grain products and uncooked
grain products. The results of the analysis are summarized in Table 1,
including the option selected, which was to recommend against human
consumption of products with EDB residues above 30 ppb (parts per billion)
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Hsnrussicde
[to.
1
2
3
4
5
6
7
a
9
level
FEBa/
N3 Oaair^p
Limit
9U/250/
5,000
30/150/
3,000
30A50/
1,000
JU/L50/900
24/100
2,000
10/50/
1,U»
5/25/500
Witt)
(Estimated Actual
Intake)
HB in
Oain Diet
2.9
2.1
1.8
1.8
1.8
1.6
1.1
0.8
0.5
Kj^/t&y
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1.3xlO-^/
6x10-"
9x10^
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3xlO-°
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2x10-6
3K10-6/
2x10^
2X10-6/
9x10-''
10 ^ SlldlTtJ ar-alo 1.2 SxlfMV
a/ Permissible residua levels
Vo
h/ L*a
if we
:rt.ct to the
alCLc .IcVeL
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d/ Aoretant exD
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UUU IULU-MHU Ly (J
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Ifew Grain
P&lXEXt.
ftOK
Level
(pet)
NA
0.2
0.2
0.6
0.7
0.2
0.6
1.4
6.3
0.2/0.6
value
Arrve
Level
(ma.)
S ryfc
26
3S
73
97
26
73
193
858
13/86
a 5-fold increase from the finished
JIB a 6-7- told increase fron uncooked predict to grain) .
in the ED 2/J and SO 4.
EXnosjce is nred
ictsd to cbclire after the susuens
ion is in effect
f
antes: See TfebLes VT-1, VIII-B, 9, 15 and 18.
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in ready-to-eat products, 150 ppb in prepared/uncooked grain products and
900 ppb in raw grain. Enforcement of this option would mean that generally
1 to 2 percent of grain and related products would exceed these levels,
with such stocks having a value of nearly 5150 million. Economic impacts
would be most significant in the immediate future, and would dissipate
as EDB-contaminated stocks of grain and related products are eliminated
from the food system in a period to three to five years.
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ACKNOWLEDGEMENTS
Arnold Aspelin, Economist
Gary Ballard, Economist
Anne Barton, Statistician
Gary Burin, lexicologist
Jim Cogliano, Statistician
Roger Holtorf, Economist
Cara Jablon, Attorney
Richard Johnson, Team Leader
Robert Lenahan, Economist
Robert Mclaughlin, Attorney
Sami Malak, Residue Chemist
Marcia Mulkey, Attorney
Richard Schmitt, Residue Chemist
Linda Stallard, Secretary
Peggy Stuart, Secretary
Edward Zager, Residue Chemist
Consultants
S.B. White, Statistician (Research Triangle Institute)
Andy Clayton, Statistician (Research Triangle Institute)
Barbara Petersen, Nutritionist
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TABLE OF CONTENTS
Executive Summary
I. Introduction 1
II. Background 4
III. Use and Usage 7
IV. Residue Data 10
V. Consumption Pattern and Dietary Burdens 33
VI. Cancer Risks 51
VII. Toxicity of Likely Chemical Alternatives 57
VIII. Economic Impacts 63
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I. Introduction
On September 28, 1983, EPA issued a Notice of Intent to Cancel
registrations for the pesticidal uses of EDB which were determined to be
responsible for residues occurring in consumer grain products. These uses
include spot fumigation of grain milling equipment, and fumigation of
stored grains. These cancellation notices were the result of an evaluation
of the long-term risks to public health and the economic consequences of
cancellation.
FIFRA §6(b) provides that adversely affected parties may challenge these
cancellation actions through requests for adjudicatory hearings. For the
specific products for which hearings nave been requested, registrations
remain unaffected by the cancellation actions until the cancellation
proceeding is concluded for these products. The products subject to the
cancellation hearing, therefore, can continue to be sold, distributed, and
used until the hearings end and the Agency announces its final regulatory
decision. Historically, adjudicatory hearings average 2 to 3 years or
more.
In announcing its decisions to cancel registrations of EDB for fumigation
of stored grain and milling machinery, the Agency stated that further
federal action might be necessary if the cancellation was delayed by a
hearing request and additional residue data increased the Agency's concern
for human health risks. At the time the notice of cancellation was issued,
there was very little data on the actual residues of EDB occurring in
grain-based consumer products. The cancellation action was instead based
primarily on residue levels which the Agency predicted would result from
these two uses of EDB.
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The information now available on residues occurring in consumer products
is greatly expanded, and clearly demonstrates the need for additional
federal actions. These actions include:
1. Emergency suspension of the uses of EDB for spot fumigation of
milling equipment and fumigation of stored grain;
2. Revocation of the exemption from tolerances of residues of ECB in
fumigated grains, and;
3. Steps to establish appropriate federally enforceable maximum
permissible residue levels.
Claims that this contamination is the result of other sources of EDB such
as gasoline or a naturally occurring source of EDB have been rejected. The
Agency knows of no scientifically sound studies which can reasonably
explain that these or other possible sources are responsible for this
extensive contamination of the nation's food supply.
The comprehensive scientific and technical analyses and extensive data
discussed in this document and the PD 2/3 and PD 4 provide the basis for
the Agency's decision to emergency suspend the stored grain and milling
uses of EDB. Additional analyses provided are the basis for the Agency's
reconnendation of the maximum permissible residue levels during the period
of time required for treated grains to clear the food supply. Included in
this document are:
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1. a survey of the extent of use of EDB to fumigate grains and to
fumigate grain milling equipment;
2. a detailed evaluation of all available data on residues of EDB
occurring in grains, and grain-based consumer products before and
after cooking;
3. an evaluation of dietary consumption patterns to determine
"typical" consumption of grain-based products and levels of intake
for subgroups of the population with high grain consumption;
4. dietary burdens or residue consumption levels for dietary patterns
developed in 3 above, both for best judgement estimates of EDB
contamination levels, and also for hypothetical maxmimum permitted
residue standards;
5. estimated human health risks for dietary burden levels developed
in 4 above;
6. economic impacts expected to occur for hypothetical maximum
permitted residue levels and impacts of the use of alternative
fumigation methods;
7. economic impacts of immediate suspension of the grain and milling
registrations during the next six months and two years; and
8. summaries of readily available information on the toxicity of
alternative chemicals.
This document reflects the information upon which the Adminsitrator's
February 3, 1984 Suspension Order and recommended maximum residue levels
were based. A final February 3, 1984 version of this document has been
maintained by EPA. This February, 1984 document reflects additional
explanatory material and some additional analyses, but does not materially
differ from the February 3 document.
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II. Background
On September 28, 1983, the Administrator signed a Notice of Intent to
Cancel the registrations of pesticide products containing EDB and labeled
for use as a fumigant of grain stored in bulk, and as a spot treatment of
grain milling equipment. The cancellations of 16 registrations for the
stored grain uses, and 4 registrations for spot treatment of milling
equipment did not go into effect because requests for a hearing on the
proposed cancellation action were filed by 9 parties. One registrant has
since withdrawn and voluntarily cancelled 2 registrations for the stored
grain use. A second registrant has voluntarily cancelled a registration
for grain fumigation and spot treatment of milling equipment.
The Agency's notice of cancellation concluded an extensive analysis of the
risks and benefits of the use of EDB as a pesticide under the Agency's
Rebuttable Presumption Against Registration (RPAR) process.
The Environmental Protection Agency issued a Notice of Rebuttable
Presumption Against Registration and a Position Document 1 (EDB PD 1)
concerning the pesticide products containing ethylene dibrcmide (EDB) in
the FEDERAL REGISTER of December 14, 1977 (42 FR 63134). The Agency took
this action in response to test results which showed that EDB induced
cancer, mutations, and adverse reproductive effects in test animals. The
EDB PD 1 discussed the relevant test data and the Agency's concerns with
the continued use of EDB as a pesticide. The document also solicited
public comments and additional data.
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Comments and data in response to the BOB PD 1 were submitted to the Agency
by registrants, user groups, and other members of the public. The Agency
carefully evaluated the comments and additional data vihich were submitted,
and in the FEDERAL REGISTER of December 10, 1980 (45 FR 81516), the Agency
announced the preliminary notice of determination for EDB and the
availability of the EDB PD 2/3.
In the EDB PD 2/3, the Agency concluded that EDB poses a significant risk
of oncogenic, mutagenic, and adverse reproductive effects in the human
population. In addition, the EDB PD 2/3 contained analyses of the risks
and benefits of continuing the various uses of EDB and presented the
Agency's proposed regulatory decisions.
The EDB PD 2/3 was submitted to the Scientific Advisory Panel (SAP) and the
U.S. Department of Agriculture (USDA) for review and ccmment. The SAP held
public hearings concerning the EDB PD 2/3 on March 25-26, 1981, and heard
presentations by the Agency, registrants and other interested members of
the public. Both SAP and USDA submitted comments on the EDB PD 2/3 to
EPA on April 22, 1981 and April 8, 1981, respectively.
The Agency again received numerous comments fron registrants, user groups,
and other members of the public. All comments were reviewed and evaluated
by EPA in arriving at the final regulatory positions concerning the uses of
EDB as a pesticide. Comments which included significant information were
analyzed and discussed in the EDB PD 4. The Notice of Cancellation was
published in the FEDERAL REGISTER on October 11, 1983 (48 FR 42668).
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Since the Notice of Cancellation was issued, an administrative hearing has
commenced to consider, among other things, the cancellation of pesticide
products containing EDB for use as a fumigant of stored grain and a spot
treatment for milling equipment. The first prehearing conference was held
on December 1, 1983. A second prehearing conference is scheduled to be
held on March 5, 1983. The date of commencement of the testimony in the
hearing is not yet set, but it is estimated that least 2 years may elapse
before a cancellation order could be issued at the close of the hearing.
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7
III. EDB Usage Estimates
An estimated 452,000 gallons of formulated products containing 471,000
pounds of EDB active ingredient are used annually for insect control in
grain stored in bulk and flour milling machinery (Table III-l).
For grain storage uses, 425,000 gallons of formulated products were
applied to an estimated 202 million bushels of grain in 1983. Usage on
wheat is believed to comprise about 75% of annual usage; corn 10%; oats,
rye, rice, and barley 10%, and grain sorghum 5%. In total, the
estimated bushels treated comprise about 2.4 percent of 1983 production
of these commodities, and 1.4 percent of the total supply of these
commodities. It should be noted that these estimates do not include
mixing or blending of grain as it moves through conmerce.
The estimated 159.4 million bushels of wheat treated in 1983, represent
about 6.6 percent of the 1983 production and about 4 percent of total
wheat supply for 1983 (beginning stocks, plus production and imports).
Corn is the other major grain crop treated with EDB; with about 10% of
EDB usage in 1983 on about 14.2 million bushels. Com treated comprises
about 0.3 percent of 1983 production, and about 0.2 percent of 1983
supply. Stored grain treatments with EDB are most canton in the late
summer and early fall. EDB usage during the year on stored grain is
believed to be distributed on a quarterly basis as follows: 10% First
Quarter; 15% Second Quarter; 25% Third Quarter; and 50% Fourth Quarter.
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8
Table III-l. Estimated Annual Usage of Formulated EDB as a Fumigant of Grain
Stored in Bulk and for Spot-Treatment of Flour Milling Equipment
GrainFlour
Item Storage Milling a/ Total
Gallons of
formulated product
applied: 425,000 27,277 452,277
Pounds A.I.
Applied: 170,400 300,600 471,000
Units treated: 202 million bu. 243 mills
a/ Usage of EDB by the majority of flour milling firms was apparently
~ voluntarily halted in August/September 1983. Estimates are for a typical
recent year of usage.
Sources: Centaur, 1983; Douglas Chemical Co., 1984; and EPA Estimates.
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9
States leading in EDB usage to fumigate stored grain include Minnesota,
North Dakota, Iowa, South Dakota, Nebraska, Oregon and Indiana.
EDB usage to spot treat flour milling machinery was apparently
voluntarily discontinued in August and September, 1983, by the major
producers in the milling industry. Prior to that time, typical annual
usage was about 300,600 Ibs. active ingredient. The majority (75-80%)
of the industry employed EDB to combat insect infestations in milling
machinery. The frequency of usage varies widely but averaged 10-11
annual treatments in 231 to 243 flour mills during recent years.
Approximately 10.5 gallons are used (range 2-45 gallons) per mill
fumigation.
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10
IV. Residues of EDB in Grain and Grain Products
This section contains a summary and discussion of the available data on EDB
residues in grain and grain products throughout the United States.
A. Raw Grain
The available data indicate a large variation in the EDB residues in
fumigated grain. This is due to several variables including the use patterns,
temperature, amount of aeration, and time in storage. Length of time in storage
appears to be the predominant factor in determining the level of EDB in treated
grains.
Table IV-1 contains estimates of the maximum likely EDB levels at various
post-fumigation intervals.
Table IV-1. Estimated EDB residue (ppb) in fumigated grain at various
intervals post-treatment
Grain
Barley,
Oats,
Popcorn,
Rice, Kye
and Wheat
Corn
Sorghum
Maximum
Application
Rate/1000 bu
1.2 Ibs.
9.0 Ibs.
11.0 Ibs.
Calculated
Initial
Residues
120,000
140,000
183,000
Post-Fumigation Time
1 wk. 2 wk.
60,000 47,000
75,000 58,000
92,000 72,000
30 days 60 days
-ppb
27,000 10,000
33,000 11,000
41,000 14,000
90 days
3,400
4,200
5,100
Source: Worthington, 1978
The calculated initial residues in Table IV-1 are derived assuming that the
maximum registered application rates are used. If lower application rates
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11
are used, the calculated values would be reduced proportionately.
Moreover, these calculations assume there is no mixing of treated grains
with untreated grains and therefore no reduction of residues through
dilution.
A large volume of monitoring data for grains has been received by the
Agency. These data are summarized in Table IV-2. The data indicate a wide
variation in residue levels, which would be expected from the use of EDB on
a small percentage of the grain (5%). Surprisingly, however, the extent of
EDB contamination of raw grain is much greater than 5%. About 60% of all
tested raw grain samples contained detectable residues of EDB. This is
likely attributable to mixing during storage and transit of treated grain
with grain which has not been treated or that the estimate of the percent
of grain treated was wrong.
The monitoring data described in the previous paragraph were combined to
give an estimate of the distribution of EDB in raw grains. The combined
results of all of these studies are presented in Table IV-3. In this
table, the total number of samples, the average residue and the standard
deviation of the average residue are given in the last three columns
entitled "no regulatory restriction level." Values are given for wheat,
corn and other grains (rice, barley, oats, rye and sorghum). Table IV-3
also includes the effect of setting various maximum permissible residue
levels. This calculation assumes that enforcement results in removal from
commerce of 100% of all grains containing residues above the maximum
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12
Table IV-2. Residue Data for EDB in Raw Grain
Study
FDA-1
NC
USDA-1
USDA-2
GMA
Texas
Reference Grain
IV 3 Wheat
Other
IV 9 Wheat
Corn
Other
IV 14 Wheat
Corn
Other
IV 12 Wheat
Corn
Other
IV 1, 2 Wheat
Corn
Other
IV 5 Corn
Other
Number
of
Samples
31
6
2
3
3
10
10
10
197
202
1
622
69
90
6
2
Average
Residue (ppb)
33
2000
27
N.D.
N.D.
4.9
0.9
2.1
36
5.6
N.D.
43
220
5.7
1.4
N.D.
Standard
Deviation
85
4000
__
7
0.5
2.4
61
26
150
1200
20
1.6
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Table IV-3 Effect of Proposed Maximum Permissible Residue
Levels (MPL) on Average (mean) EDB Residues In Raw Grains
Guideline
Level In
ppb
Product
Wheat
Corn
Other
100
No.
Samples
below mpl
No. (I)
783 (90.8)
279 (96.2)
108 (96.4)
Ave rage
Residue
12
5
3.7
500
No.
Samples
below mpl
No. (Z)
8SO (98.6)
286 (98.6)
110 (98.2)
Ave rage
Residue
27
13
7.0
900/1000
No.
Samples
below mpl
Ho. (2)
858 (99.5)
289 (99.7)
110 (98.2)
Average
Residue
34
21
7.0
2000
No.
Samples
below mpl
No. (*)
862 (100)
289 (99.7)
111 (99.1)
Average
Residue
40
21
21
3000
No.
SampJ es
below mpl
No. (Z)
862 (100)
289 (99.7)
111 (99.1)
Average
Residue
40
21
21
5000
No.
Samples
below mpl
No. (Z)
862 (100)
290 (100)
111 (99.1)
Average
Residue
40
21
21
No
Restriction Level
All
Samples
862
290
112
Average
Residue
40
56
110
Standard
Deviation
130
590
950
Osl
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14
permissible residue level. The extent of reduction will depend on the
effectiveness of enforcement. Thus, the averages given in Table IV-3
should be taken as the maximum possible reduction in average residues,
which may not be achieved in reality.
B. Effect of Milling on Residues in Grain
Residues in processed grain products can result from residues in the bulk
grain and also from residues resulting fron spot fumigation of mills and
milling equipment. While the milling process may reduce levels (i.e.
produce lower levels in flour than in bulk treated grain), spot fumigation
of mills will contribute additional residues during milling.
1. Effect of Milling on Residues in Grain
In a controlled study by Wit et. al. (IV-16) (1969), treated wheat
containing an average of 9,500 ppb EDB was milled. After milling,
residues in the flour averaged 3,000 ppb (68% reduction) and residues in
shorts/bran averaged 14,600 ppb (a concentration factor of 1.5x). In a
similar experiment by Berk (IV-15), treated wheat grain containing an
average of 376 ppb EDB was milled. After milling, residues in the flour
averaged 98 ppb (74%, reduction), residues in the shorts/bran averaged 106
ppb (0.3x) and residues in middlings averaged 78 ppb (0.2x).
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15
Recently (1983), in a controlled experiment by the USDA (IV-18), fumigated
wheat grain containing an average of 3,690 ppb EDB was milled. After
milling the average residues in the flour was 520 ppb (after subtracting
contribution from spot treatment), a reduction of 86%.
In a study carried out by the Grocery Manufacturers of America (IV-1),
fumigated wheat containing 17,816 ppb EEB was milled. After milling,
residues in the flour were an average of 967 ppb (95% reduction).
It is concluded from these studies that residues in the treated grain are
retained in the processed fractions. Residues in the flour are generally
lower than the residues in the grain. EDB residues may concentrate in
selected milled fractions other than flour.
The studies reported above are all controlled experiments and are presumed
to be broadly indicative of the changes in residue levels that would occur
during commercial milling, tto data on the effect of processing on
residues in milled products are available for grains other than wheat.
2. Contribution from Spot Fumigation
In a study conducted by Litton Bionetics (IV-17), it was shown that spot
fumigation with EDB resulted in residues in flour that generally follow a
loy-linear curve. Initial EDB residues in the wheat-flour in the first
half hour after start-up of the milling process was determined at 2,750
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16
ppb. This level declined to 900, 170 and 30 ppb after 1.5 hrs., 3 hrs.,
and 1 week, respectively. A time-weighted average contribution to the
wheat flour from spot treatment was estimated in 'the Agency's PD-4
(September 27, 1983) at 34-68 ppb (based on a 4-week time weighted
average). Actual levels in flour ranged from 54 to 2,750 ppb, some of
which may have been attributable to bulk grain fumigation.
In a controlled study conducted by the USDA (IV-18), it was shown that
contribution to the initial wheat flour from spot fumigation averaged 240
ppb. Because the wheat was treated and processed in a laboratory study,
contribution frcm spot treatment in this test may not be representative of
grain in commerce that received multiple applications. It is also noted
that this study was run for only a short time after fumigation, commercial
mills are normally treated only once every 2-4 weeks, and residues in flour
fall to lower levels with time. Thus the 240 ppb average residue observed
in this study is higher than the average residue expected in a conmercial
mill.
C. Intermediate (Uncooked Grain Products)
Monitoring data for uncooked grain products were reported by the Grocery
Manufacturers of Anerica, Inc., FDA, Midwest Research Institute, the States
of Florida, Georgia, North Carolina, California and Texas. The data for
each of these studies are summarized in Table IV-4. The data on uncooked
grain products were analyzed as described previously for the raw grains.
The results of this analysis are presented in Table IV-5. This table
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17
Table IV-4. Residue Data for EDB In Uncooked Grain Products
Study
FDA-1
FDA-2
Georgia
Florida
Texas
N.C.
GMA
MRI
Reference Grain
IV 3 Wheat
Other
IV 3 Wheat
IV 8 Wheat
Corn
Other
IV 6 Wheat
Corn
IV 5 Wheat
Corn
Other
IV 9 Wheat
Corn
Other
IV 1, IV 2 Wheat
Corn
Other
IV 10 Wheat
Corn
Numbe r
of
Sample
13
3
10
4
9
1
39
107
40
50
32
51
43
1
473
74
9
8
20
Average
Residue (ppb)
4.0
1.2
1.8
3.7
3.2
0.75
2.9
19
21
8.5
5.4
19
4.3
2.3
15
140
0.87
22
16
Standard
Deviation
4
2.8
5.5
7.4
86
20
26
23
38
7.4
46
250
0.35
37
25
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Table IV-5. Effect of Proposed Maximum Permissible Residue Levels
MPL on Average (mean) EDB Residues in Uncooked Products
Guideline
Level In
ppb
Product
Wheat
Uncooked
Products
Corn-
Uncooked
Products
Other
Grains-
Uncooked
Products
5
No.
Samples
below mpl
No. (Z)
425 (66.6)
193 (63.7)
43 (93.5)
Average
Residue
1.6
1.3
0.89
25
No.
Samples
below mpl
No. (Z)
S58 (87.5)
257 (84.8)
45 (97.8)
Average
Residue
3.8
3.7
1.3
50
No.
Samples
below inpl
No. (Z)
598 (93.7)
267 (88.1)
45 (97.8)
Average
Residue
6.1
5.0
1.3
100
No.
Samples
below npl
No. (Z)
623 (97.6)
279 (92.1)
45 (97.8)
Average
Residue
9.2
7.6
1.3
150
No.
Samples
below npl
No. (Z)
628 (98.4)
281 (92.7)
46 (100)
Average
Residue
10.0
8.4
4.0
250
No.
Samples
below mpl
No. (Z)
632 (99.1)
286 (94.4)
46 (100)
Averag"
Residue
11.0
12.0
4.0
No Restriction
Level
All
Samples
638
303
46
Average
Residue
14.4
44.0
4.0
Standard
Deviation
42
140
19
00
-------
19
includes the total number of samples, the average residue and the effect of
various maximum permissible residue levels on the average residues in
wheat, corn and other grains. The data generated by Pains and Holder in
1980 (IV-19) on school lunch flour were not included in this data analysis.
These results were significantly higher than the current monitoring data
and thus are not considered reflective of current residue levels.
D. Cooking Studies
Several studies have been carried out to determine the extent of reduction
of EDB residues upon cooking. In this section only data on the cooking of
commercial products are included. Studies involving spiked products are
not included.
In a study by the Midwest Research Institute (IV-10), 32 samples of corn
meal, hushpuppy mix, instant and regular grits, cake mixes, pancake and
cornbread mixes containing from <0.5-110 ppb EDB were prepared, as
ready-to-eat products, following the label instructions. Residues of EDB
in the cooked products were reduced by 67-99% and ranged fron ND «0.75
ppb) to 36 ppb in the final product.
In a study by FDA (IV-11), 7 samples of cornmeal, cornmeal mix, quick grits
and hushpuppy mix obtained from Florida and containing from 1.9-586 ppb EDB
were prepared as ready-to-eat products following standard recipes.
Residues of EDB were reduced by 47-97% and ranged frcm <1 ppb-92 ppb in the
ready-to-eat products.
-------
2C
In a study conducted by the Grocery Manufacturers of America, Inc. (IV-1),
95 samples of wheat flour, wheat yerm, pasta, mixes, corn meal, hushpuppy
and grits obtained fron GMA member companies containing EDB residues frcm
-------
21
Table IV-6. Data on the Effect of Cooking on EDB Residues*
Study Reference
Florida IV 6
FDA IV 11
GMA IV 2
MRI IV 10
Number
of
Experiments
32
8
100
13
Average
Reduction
88.4%
84.0%
80.2%
79.0%
82.0% weighted
average
*Not counting those experiments in which the uncooked product contained
<3 ppb EDB.
-------
22
E. Ready-to-Eat Grain Products
Monitoring data for ready-to-eat products derived from grains were
reported by the Midwest Research Institute, and the States of Florida,
Georgia, North Carolina, California, and Texas and the Grocery Manufacturers
of America, Inc. The data from each of these studies are summarized in
Table IV-7.
The data on ready-to-eat grain products was analyzed as described for raw
grains. The results of this analysis are given in Table IV-8. This table
shows the total number of samples analyzed, the average residue levels and
the effects of various maximum permissible residue levels on the average
residues found in ready-to-eat wheat, corn and other grain products.
The data on residues in uncooked and cooked grain products in Tables IV-5 and
IV-8 were used to estimate the average residue level for EDB in ready-to-eat
grain products. In this calculation the Agency assumed an 80% reduction of
residue on cooking. Thus, the average residue levels shown in Table IV-5 for
uncooked grain products were reduced by 80% and averaged with the residue data
for cooked commodities given in Table IV-8. The average residue level was
calculated by weighting the average residue by the number of cooked and
uncooked samples. Samples with no detectable residues were treated as having
0.75 ppb. The Agency utilized the uncooked sample data in addition to the
cooked sample data because of the much larger number of uncooked samples
analyzed. The Agency did not use the data from Table IV-3 for raw grains
because of the larger error involved in extrapolating from raw grains to
cooked ready-to-eat residues. The results of the weighted average
-------
23
Table IV-7. Residue Data for EDB in Cooked Grain Products
Study
FDA-2
Georgia
Florida
Texas
N.C.
GMA
MRI
Reference
IV 3
IV 8
IV 6
IV 5
IV 9
IV 1, IV 2
IV 10
Grain
Wheat
Other
Wheat
Corn
Other
Wheat
Corn
Other
Wheat
Corn
Wheat
Wheat
Corn
Other
Wheat
Corn
Number
of
Sample
10
12
3
6
3
2
29
9
3
6
5
243
31
65
6
20
Average
Residue (ppb)
N.D
N.D
N.D.
4.5
N.D.
N.D.
4.7
N.D.
N.D.
1.1
7.7
2.2
2.9
0.84
6.8
4.7
Standard
Deviation
_
__
5.3
__
10.0
«
0.76
9.5
4.9
4.5
0.41
14
7.5
-------
Table IV-8. Effect of Proposed Maximum Permissible Residue Levels (HPL) on
Average (mean) EDB Residues In Ready~to-Eat-Producta
Guideline
Leve 1 In
ppb
Product
Wheat
Ready-
to-Eat
Product s
Corn-
Ready-
to-Eat
Products
Other
Grains-
Ready-
to- Eat
1
No.
Samples
below tnpl
No. (Z)
217 (79.8)
55 (64.0)
95 (95.0)
Average
Residue
0.72
0.76
0.66
5
Ho.
Samples
below rapl
No. U)
248 (91.2)
66 (76.7)
100 (100)
Average
Residue
0.91
0.96
0.73
10
No.
Sanples
below mpl
No. (*>
255 (93.8)
73 (84.0)
100 (100)
Ave rage
Residue
1.1
1.6
0.73
20
No.
Samples
below opl
No. (Z)
267 (98.2)
84 (97.7)
100 (100)
Average
Residue
1.7
3.3
0.73
30
No
Samples
below mpl
No. (Z)
269 (98.9)
85 (98.8)
100 (100)
Average
Residue
1.8
3.5
0.73
50
No
Samples
below tnpl
No. (Z)
272 (100)
85 (98.8)
100 (100)
Average
Residue
2.3
3.5
0.73
No Restriction
Level
All
Samples
272
86
100
Average
Residue
2.3
4.1
0.73
Standard
Deviation
5.3
7.4
0.46
ro
-fa.
-------
25
calculations are given in Table IV-10. The results given in Table IV-10 are
skewed due to overrepresentation of seme portions of the diet. The averages
are based on the samples analyzed and not corrected for the percent of the
diet of each product type.
F. Limitations of the Residue Data
While a large volume of residue data are available, there are several
limitations that must be considered in evaluating these data. The maximum
permissible residue levels discussed in this paper should be accepted with the
caveats as discussed below.
The estimates are based mostly on residue data from monitoring studies and
only a few controlled experiments. The data cones from a variety of sources
which possibly followed different sampling and testing protocols.
In most of the submitted residue studies there is no significant information
available concerning application rates; methods of application; whether bulk
or spot fumigation was used; length of exposure, aeration intervals,
temperatures during treatment and storage or the interval from treatment to
sampling. Without treatment histories for the monitoring samples, the Agency
cannot ensure that the maximum residue level that may result from the
registered uses are found. On the other hand, some of the values reported in
the monitoring studies may be the result of misuse and may, therefore, be
higher than the maximum residue level that would likely result fron the
registered uses. Further, residue levels may vary seasonally due to
temperature variations during treatment and shipping.
-------
26
The tollowing caveats are of somewhat lesser importance and are not expected to
significantly affect the overall results. The available studies do not usually
specify whether standardized sample collection procedures were followed; e.g.,
.whether grain tiers were uses for taking core samples of commodities in bulk
quantities; whether samples were composited by quartering; whether the quantity
sampled was adequate; and whether the samples shipped and stored were frozen or
in cold storage.
In general, various modifications of the Rains/Holder method (J.ADAC 64(5)
1252-54, 1981) were used to quantify the residue levels. For some of the data
submitters, the analytical methodology used was not given. In only a few
instances were the data cross-checked by analysis at different laboratories.
In no study is the sample representative of all products on the market.
Indeed, some studies purposely chose samples that concentrated on products
where high residues were expected; this practice extended to looking for
particular lots. Many variables which are likely to be related to contamination
are either unknown or known to be nonrepresentative of the U.S. as a whole.
Sane of these variables are:
The state data analyzed to date are primarily from Southern States and
California. However, new data being submitted to the Agency by various states
appears to be consistent with the data already analyzed. All data indicate that
cake mix and corn products, especially hushpuppy mix, are often contaminated.
-------
27
But many other products have never been sampled, an samples of other than
wheat and corn products are very limited. Thus, an important source of
exposure to EDB may have been overlooked. There is no way to ensure that
all samples taken have been reported to the Agency.
The following limitations apply to the data on reduction of residue in
processing. The data are not directly comparable because they core from
different sources. Even within a single study, different facilities and
procedures may have been used. In no study is the sample of cooked goods
representative of dietary patterns. Because the reduction apparently
increases with the initial residue, the selection of which products to cook
can bias the results. Some studies cooked only high-residue products,
increasing the reported reduction. Some studies may not be representative
of consumer baking practices. The reduction in residue may depend on
whether the product was baked, boiled, or fried; at what temperature; and
for how long. These differences cannot be estimated with the available
data. The observed reduction in residue levels is a combination of loss of
EDB by volatilization, decomposition and dilution with unoontaminated
ingredients. EDB residues below 1 ppb cannot be measured accurately, thus
for the cooked samples in which cooking reduced residues below 1 ppb, the
percentage reductions cannot be computed accurately. The Agency
conservatively treated levels below 1 ppb as .75 ppb which should tend to
underestimate the actual reduction in cooking. However, all monitoring data
and data on cooking are subject to the limitations discussed above. The
data being submitted to the Agency on a daily basis by various states
support the residue estimates discussed in this section.
-------
28
G. Residues in Baby Food
fable IV-9 summarizes the available data on baby foods. Only two of 89
samples contained detectable residues of EDB and these samples were <1.5
ppb.
H. Residues in Meat, Milk, Poultry and Eggs
No controlled livestock feeding studies have been conducted for EDB and
the Agency is unable to conclusively evaluate the potential for transfer of
residues from grain-based feed to meat and milk. It is reassuring,
however, that the monitoring to date has not shown significant residues in
any of the meat, milk, poultry and eggs tested to date.
I. Additional Data
This report includes all monitoring data available to the Agency during
preparation of this report. Additional data is being received daily and
will be included in all future analyses. The Federal agencies, State
agencies, and trade associations response to the Administrator's letter of
January 13, 1984 requesting data on EDB shows an outstanding level of
cooperation. Those data are being scanned as received to determine if
patterns contrary to those established by the statistically analyzed data
are observed. In general, the new data have served to confirm previous
analyses.
-------
29
Table IV-9. Baby Foods - Data on EDB up to 1/28/84
Source
FDA
GMA (IV-1)
GMA (IV-2)
Florida
Texas (IV-5)
Georgia
(IV-8)
North
Carolina
(IV-9)
FDA (IV-3)
Ibtal
Type
infant cereal
wheat cereal
wheat cereal
rice cereal
oat meal
wheat cereal
corn cereal
barley cereal
oat cereal
multigrain
cereal
Rice cereal
multigrain
cereal
wheat cereal
rice cereal
oat cereal
wheat cereal
1 of
Samples
12
12
16
15
1
7
5
1
1
2
2
1
4
1
1
6
86
*
(+)
0
0
1
1
0
0
0
0
0
0
0
0
0
0
0
2
2
Average
Range Residues
(ppb) (ppb)
<1
<1
<1-1.3 <1
<1-1.5 <1
-------
Table IV-10. Effect of Proposed Haulmum Permissible Residue Levels (HPL) on Weighted Average
(mean)
Residue
Levels of Ready
Co Eat
Products (Table
I) and Uncooked Products
Proposed
HPL
Product
Wheat
Corn
Other Grains
1
N.D.
N.D.
N.D.
5
0.81
0.79
N.D.
10
1.2
1.1
N.D.
20
1.8
1.9
N.D.
30 SO No Regulatory Restriction
2.0 2.2 2.7
2.1 2.6 7.8
N.D. N.D. N.D.
a/*After adjusting for 80Z reduction of residues by cooking.
N.D. - non-detectable (< 0.75 ppm).
Usl
-------
31
J. References
IV(1) Grocery Manufacturers of America, Inc., tranamittal letter of 1/20/84
Sherwin Gardner to Edwin L. Johnson.
IV{2) Grocery Manufacturers of America, Inc., Supplemental submission of
1/28/84.
IV(3) FDA, EDB data in grain fron Dr. Sanford Miller, Delivered to John A.
Moore, D.V.M., November 2, 1983.
IV(4) USDA, January 23, 1984; Letter from John W. Marshall to Dr. John A.
Moore. R(5)Texas Department of Health, Tranamittal letter from Robert
Bernstein, MD.D., F.A.CI.P., post marked January 13, 1984 to Dr. R.D.
Schmitt.
IV(5) Texas Department of Health, transmittal letter from Robert Berstein,
postmarked January 13, 1984 to Dr. R.D. Schmitt.
IV(6) Florida Department of Agriculture, transmittal letter to Dr. Richard D.
Schmitt from Doyle Conner, 1/19/84.
IV(7) California Department of Food and Agriculture, Letter from Clare
Broyhill to Dr. Richard D. Schmitt, January 20, 1984.
IV(8) Georgia Department of Agriculture, Letter from J.R. Conley to Dr.
Richard D. Schmitt, January 23, 1984 and supplemental submission of
1/27/84.
IV(9) North Carolina Department of Agriculture, Letter from Leonard P.
Blanton to Mr. Richard J. Johnson, January 10, 1984 and supplemental
submission of 1/27/84.
IV(10) Midwest Research Institute (MRI), EPA Contract #68-02-3938, Sampling
and Analysis for Ethylene Dibromide. Preliminary data submitted January
20, 1984.
IV(ll) FDA Cooking Study, Data verbally transmitted to Dr. R. D. Schmitt,
1/20/84 and a letter from Jerry A. Burke, FDA to Dr. R.D. Schmitt dated
1/26/84.
IV(12) USDA, Janurary 31, 1984, Letter from Kenneth A. Giles to Dr. R. D.
Schmitt.
IV(13) USDA, January 30, 1984 letter from Ronald E. Engel, Deputy
Administrator for Science to Donald L. Houston, Administrator.
IV(14) USDA, January 23, 1984 letter from John W. Marshall to Dr. John A.
Moore, D.V.M.
-------
32
IV{15) Berk, B. 1974. Fumigant residues of carbon tetrachloride, ethylene
dichloride and ethylene dibromide in wheat, flour, bran, middlings and
bread. J. Agri. Fd. Chem. 6:977-984.
IV(16) Wit, S., A. Besemer, H. Das, W. Goedkoop, F. Loosjes, ad E. Meppeling.
1969. Results of an investigation on the regression of three fumigants
(carbon tetrachloride, ethylene dibronide and ethylene dichloride) in
wheat during processing to bread. Report No. 36/39 Tbx., National
Institute of Public Health. Bilthoven, Netherlands.
IV(17) Litton Bionetics, Inc. 1978. Determination of residues of ethylene
dibromide in wheat and wheat products: Final Report, Project No.
20927, May, 1978. In: Rebuttal Submission #22 & 22E (3000/25), of
unpublished report, by Ferguson Fumigants, Inc. June 1, 1978 and Sept.
22, 1978.
IV(18) Getz, M.E. and K. R. Hill. 1983. Ethylene dibrcmide residues in wheat,
flour, bread, and grapefruit - An analytical method evaluation and
results. A report to the Administrator, ARS, transmitted to R.
Johnson, September 15, 1983. 10 pp.
IV(19) Rains, D.M. and Holder, J.W.; J. Association of Official Analytical
Chemists, Vol. 64, No. 64, Vol. 5, 1981).
-------
33
V. Dietary Patterns/Dietary Burdens
A. Dietary Patterns
The food consumption estimates were prepared using The EPA
Tolerance Assessment System (Chaisson et al., 1984) and dietary
estimates derived from the most recent nationwide survey of
individuals. This survey of three day dietary records for
30,770 individuals was conducted by the U.S. Department
of Agriculture in 1977-78. The USDA survey design is
summarized in section V-D-1. The methods which were used to
adapt the USDA data to a form comparable to the residue data
described in chapter IV are summarized in section V-D-2.
Briefly, the data file used to estimate EDB dietary
burdens contains the quantity and form of each Raw Agricultural
Commodity (RAC) eaten per unit of body weight/day. The
record is on an individual basis, and is accompanied by
demographic and soci©economic information for that individual
(age, sex, ethnic origin, region of the country, season
surveyed, pregnant or nursing, etc). Therefore, subgroups
of the U.S. population can be analyzed for differences in
their dietary profiles, allowing the calculation of differences
in dietary burdens of EDB. Subgroups analyzed for exposure
to EDB were the U.S. population (48 states, all seasons), 4
regions (northeast, north central, southern, and western), 4
seasons (spring, summer, fall and winter), ethnic (hispanics,
non-hispanic whites, non-hispanic blacks, and-other), infants
-------
34
(nursing and non-nursing), children {1-6 and 7-12 yrs),
teenagers 13-19 (male & female), 20+ (male and female), and
females who were pregnant or nursing.
Two analytical procedures are available for estimating exposure
to EDB. The first procedure uses values for mean consumption
of products to estimate the average exposure for the U.S.
population and for subgroups of the population. These exposure
estimates were then used to estimate risks.
The second procedure generates a set of of exposure
estimates - one for each respondent in the USDA survey -
that is, the estimated exposure to EDB for that day for that
individual. Individual exposures are then analyzed by subgroup
to estimate the mean (weighted) exposure and to estimate the
percentage of the subgroup who exceeded predetermined
daily intake levels. This procedure generates a curve which
describes the distribution of exposure over the population,
and allows other regulatory options to be compared for their
impact upon exposure.
This approach provides a mechanism to examine differences in
eating patterns among subgroups of the U.S. population.
Subpopulations were examined for differences in either
quantities or patterns of grain consumption. Consumption of
-------
35
the three major grains is summarized in Table V-l for subgroups
who consumed more grains than the national average or who
had different patterns of consumption. Infants and children
under the age of 12 consume almost twice the national average
grain consumption - when consumption is expressed per unit
body weight. Certain ethnic groups also consume more grains
than the national average. The contribution of each grain
to the diet varies for different subgroups. Grain consumed
by the U.S. population is 74% wheat, 10% corn, 8% rice and 8%
"other" grains. Hispanics have different patterns, reporting
56% of their grain consumed as wheat, 17% as rice and 21% as
corn. Non-nursing infants (less than 1 yr) have very different
patterns with grain consumption distributed as 4% barley, 8%
corn, 21% oats, 37% milled rice and 29% wheat. Patterns for
other subgroups are summarized in Table V-l.
B. Dietary Burdens
Exposure is a function of the residue level in each grain
at the time it is consumed and the quantity of that
food consumed. Dietary burden is the sum of the EDB consumed
in each grain. Using the second procedure, described above,
it is possible to analyze each individual's dietary burden.
For example, non-nursing infants consume more rice than
other grains. Therefore, the fact that monitoring data has
found lower levels of EDB in rice than in other grains will
have a greater impact on the dietary burden for non-nursing
infants than it will for the U.S. population. This is
illustrated by two hypothetical examples: 10 ppb on all grains
-------
36
Table V-l. Patterns of Grain Consumption
SUBGROUP WHEAT RICE CORN OTHER ALL GRAINS
g food/kg body weight/day{% of grain consumption)
US. population 1.4(73) 0.16(8) 0.19(10) 0.15(8) 1.9
(48 states)
Ethnic groups
Hispanics
Non-hispanic
whites
Non-hispanic
blacks
Other
1.35(56)
1.44(78)
1.26(65)
1.34(55)
0
0
0
0
.41(
.IK
.25(
.78(
17)
6)
13)
32)
0
0
0
0
.49
.14
.35
.18
(21)
(8)
(18)
(7)
0
0
0
0
.14(
.16(
,09(
.15(
6)
9)
5)
6)
2.4
1.9
2.0
2.5
Infants & Children
Non-nursing
infants
1-6 yr.
7-12 yr
Regions
Northeast
North Central
Southern
Western
1.03(29)
b/
b/
1.47(74)
1.45(76)
1.35(71)
1.36(72)
1
0
0
0
0
.32(
b/
b/
.20(
.IK
. 16(
.17(
37)
10)
6)
8)
9)
a/
0
0
0
0
0
.29(8)
b/
b/
.09
.14
.26
.23
(5)
(7)
(13)
(12)
0
0
0
0
0
.90(
b/
b/
.19(
.16(
.IK
.17(
25)
10)
9)
6)
9)
3.5
4.3
3.0
2.0
1.9
1.9
1.9
a/ All milled rice.
b/ Not presently available
-------
37
except 1 ppb on rice is:
DIETARY BURDEN
Residue levels U.S. population Non-nursing infants
(ppb EDB) rag EDB/KG body weight/day
10 ppb, all grains
0 ppb other foods 1.9 X 1Q-5 3.5 X KT*
10 ppb all grains except 1.8 X 10~5 1.3 X 10~5
1 ppb rice, 0 ppb
other foods
The second analysis procedure, described above, also allows
analysis of the distribution of exposure across individuals in
a subgroup, and it is then possible to answer the question,
"Is the average dietary burden due to a few individuals with a
large exposure or is it due to a large number of individuals
with a low exposure?" The results of monitoring data, summarized
in Section IV of this document were used to assess the potential
dietary burden for the U.S. population and for subgroups.
The mean dietary burden for the U.S. population from consumption
of EDB-contaminated grain is 0.55 x 10~5 mg EDB/KG body
weight/day. Generally dietary burdens parallel grain consumption.
That is, subgroups, such as 1-6 year olds who had higher grain
consumption also had higher dietary burdens of EDB. However,
the dietary burden is not directly proportional to grain
consumption since different residue levels were estimated for
corn, wheat, rice and other grains (Table IV-10). Children
(1-6) and hispanics have mean exposures which are greater than
the U.S. population (Table V-2).
Fig. V-l shows the percent of individuals whose dietary
burden is currently greater than the levels of EDB shown on the
-------
38
V-l Effects of sets of proposed action levels on the percent of
individuals who exceed each level of EDB: U.S. POPULATION
c
0)
a
EH
cfl
-P
^ 60
? c
vH
CO T3
H OJ
Cd 0)
3 o
T3 X
H a
T3
H
current residue levels
Circles numbers from Table VII-1
ermissible residue options
X - mg EDB x IcrVKG body weight/day
-------
39
Table V-2.
Dietary Burdens for the U.S. population and
selected subgroups
Mean Exposure DISTRIBTUION
(mg EDB/kg B.W./day) {Percent of Individuals
in Group exceeding
0.00001 mg/KG B.W./day)b/
Current Under
Recommended
Current Under
Recommended
U.S. Population
Hispanics
Non-hispanic
white
Non-hispanic
blacks
Other
Nursing infants
Non-nursing infants
Children(l- yr)
Children(7-12 yr)
Males(13-19 yr)
Females (13-19 yr)
Males<20+ yr)
Females (20+ yr)
Pregnant (13+ yr)
Nursing (13+ yr)
Spring
Summer
Fall
Winter
Northeast
Northcentral
Southern
Western
.55x10-5
.79x10-5
.52x10-5
.63x10-5
.57x10-5
.26x10-5
.67x10-5
1.28x10-5
.92x10-5
.63x10-5
.50x10-5
.42x10-5
.34x10-5
.40x10-5
.44x10-5
.53x10-5
.54x10-5
.57x10-5
.56x10-5
.51x10-5
.52x10-5
.59x10-5
.52x10-5
Action a/
.34x10-5
.43x10-5
.34x10-5
.36x10-5
.39x10-5
.19x10-5
.45x10-5
.77x10-5
.57x10-5
.40x10-5
.31x10-5
.28x10-5
.22x10-5
.25x10-5
.30x10-5
.34x10-5
.34x10-5
.36x10-5
.36x10-5
.35x10-5
.35x10-5
.35x10-5
.35x10-5
12
25
11
18
12
5
23
62
34
12
5
3
2
3
4
11
12
13
12
10
11
14
14
Action a/
3
3
3
3
5
1
8
21
6
1
_
-
1
3
3
3
4
3
3
3
3
3
a/ Recommended action levels of 900 ppb in whole grains, 150 ppb in
milled products, and 30 ppb in ready-to-eat products. Calculations
assume 100% compliance with recommended levels.
b/ 0.00001 mg/kg B.W./day (approximately 2 times the mean exposure of
the U.S. population) was arbitrarily selected as an index value
for examining the proportion of individuals in each group with
potentially high exposure.
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40
X-axis. Fig. V-l also shows the distribution of exposure
which could be expected to result from 6 possible
sets of permissible residue levels. Based on the residue
data, currently, 15% of individuals in the U.S. population
exceed 0.00001 mg/kg body weight/day. Hispanics have higher
exposure with a mean of 0.0000080 mg/kg body weight/day and
29% of the hispanics surveyed exceeded 0.00001 mg/kg body
weight; 52% of the hispanics exceeded the U.S. population's
average dietary burden. Children (1-6) have a mean dietary
burden of 0.000013 mg/kg body weight and 70% exceeded 0.00001
mg/kg body weight; 94% exceed the U.S. population's national
average dietary burden. As average EDB consumption levels
rise, there is a rapid decline in the percent of individuals
with exposures above that EDB level because the general
population has relatively uniform exposures - i.e. a large
number of individuals with similar consumption patterns.
However, it must be noted that each individual was surveyed
for only 3 days.
EPA has considered 11 possible sets of permissible residue
levels. It is assumed that as a result of regulatory actions,
all commodities above these levels would be removed from the
food supply and that the average residue level for each type
of grain would decline (Table IV-10).
The proposed regulatory action, assuming complete compliance,
will lower mean exposure for each population subgroup and
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41
the percent of individuals within each subgroup who exceed
specified levels of EDB (See Figures V-l, V-2, and Table V-2)
In all subgroups, the lower the permissible residue levels,
the lower the dietary burden.
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42
FigV-2 Effect of sets of proposed action levels on the percent of
individuals who exceed each level of EDB: CHILDREN (1-6 YRS)
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C. Summary of Procedures Used to Estimate Risk
The average levels of residues in cooked and uncooked
grain products was determined using all available residue
data. Estimates of average residue levels were calculated
separately for corn, wheat and "other grains". The category
"other grains" includes rice, barley, oats, rye, buckwheat
and sorghum. In the determination of average residue levels,
all samples with nondetectable levels of EDB (less than 1
ppb)were conservatively treated as 0.75 ppb. The mean residue
level of each product at the uncooked stage was reduced by a
factor of 80% to reflect an assumed reduction in residues
during cooking. The average residue for both stages (cooked
and uncooked) were then combined to yield an overall average
which uses all of the available residue data from both cooked
and uncooked samples. In combining this data, the means for
cooked and uncooked grains were weighted by the number of
samples in each data set. Mean residues estimated for each
set of maximum permissible residue levels are summarized in
Table IV-10. Average residue levels at each level were
determined by deleting from the data set those samples above
the level. Samples were not gathered in proportion to their
diet. For example, bread, rolls and biscuits represent 30%
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44
and cakes about 10% of the grain consumed by adults (Table
V-3), yet sampling was not proportional. Also, the proportion
of each of these food eaten by different subgroups varies.
For example, ready-to-eat cereals represent from 3-6% of the
grain consumed by individuals over the age of 15, but 60% of
the grain consumed by infants. Residue has been detected in
only 2 (of 86) baby cereals and both positive samples were
near the limit of detection (1.5 ppb).
In spite of these observations, the monitoring data was
not weighted to account for the nonproportional sampling since
there was a wide variation in the residue levels reported within
product lines as well as across product types.
The estimated mean levels of EDB for each grain type at each
set of maximum permissible residue levels were then entered
into the dietary consumption models (described in Chapter V)
and an estimate of the daily dietary burden was determined
for the U.S. population and for each subgroup.
The estimates of dietary burden were then used in the appropriate
equations (Chapter VI) in order to predict risk. Dietary
burdens were assumed to be constant over the 2-3 year exposure
period for which risk has been estimated.
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45
Table V-3. Distribution of consumption among grain
products.
Age
Male & Female
Less
than 1 yr
1-2
3-5
6-8
Males
15-18,
23-24,
Females
15-18
23-34
Breads,
Rolls,
Biscuits
10
17
25
26
30
32
29
30
Other
Baked
Goods
Percent of
12
15
20
27
25
23
22
23
CEREALS
Cooked
Cereals
Pastas
Total Grain
11
19
21
20
11
13
16
16
, PASTAS
Ready
to Eat
Cereals
Consumed
60
9
9
9
6
3
5
4
MIXTURES
(mainly
grains}
!/
7
40
25
18
27
29
28
27
a/ Include dry infant cereals.
Adapted from Table 1.3a, Grain Products, Fats, Oils; (USDA,
1980).
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46
The procedure used to generate risk estimates for children
(1-6) and to the U.S. population is summarized below:
MEAN EDB RESIDUE
uncooked
corn
wheat
"other"
80%
Reduction
)
cooked
corn
wheat
"other"
->
DIETARY
MODEL
Individual
Consumption
of each
grain
-?
DIETARY
BURDENS
Mean
Dietary
Burden by
subgroups
& Distri-
bution of
Exposures
-*
RISK
Cancer
risks
due to
dietary
exposure
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47
D. Technical Notes
A detailed description follows of the USDA Food Consumption
Survey and procedures used to convert that survey to equivalent
quantities of raw agricultural commodities.
1. USDA Survey Design.
Briefly, the USDA 48-state sample survey design consisted of
three levels of stratification. First, all housing units in
the United States (based on the 1970 Census) were grouped
according to the nine census divisions. Within each division
housing units were then grouped into three zones central
cities, remaining metropolitan areas, and non-metropolitan
counties. A third level of stratification was carried out
within each of the 27 Census division/zone combinations.
This was accomplished by forming groups containing approximately
600,000 households based on political/economic similarities
and geographical proximity. Overall, the three levels of
stratification resulted in a total of 114 strata. Each
stratum was divided into primary sampling units (PSU) and
one PSU was selected from each stratum with probability
proportional to size. Each selected PSU was divided into
clusters of 100 or more housing units called "area segments".
A total of 2550 segments were selected with the number of
segments in a PSU being proportional to the size of the
stratum in which the PSU was located. The selection probability
of an individual segment in a PSU was proportional to the
ratio of the number of units in the segment to the total
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48
number of units in the PSU. Finally, housing units were
selected from area segments with the sampling ratio determined
by: the total number of interviews desired; the estimated
occupancy rate; the estimated completion rate; and the increase
in the number of housing units from 1970 to 1977.
To provide seasonal information, four samples, independently
selected from the same set of PSUs, were implemented in
consecutive calendar quarters beginning in April 1977. The
sampling ratio for each quarterly sample was determined so as
to yield approximately 3750 completed household interviews in
each quarter.
A subsample of household members was selected to complete
a 3-day record (24-hour recall and a 2-day diary) of individual
food items consumed. For the Spring survey, every household
member was eligible to complete this record. In the remaining
three quarterly samples, all persons younger than 19 and one-
half of all persons 19 years and older were eligible.
2. EPA's Food Composition Data.
A computer search of the USDA data revealed that 3734 individual
food items pizza, chocolate cake, etc. had been
consumed on at least one occasion. Bach food item was then
examined and a determination made as to the:
(1) raw agricultural commodities (RACs) milk, wheat,
carrots, etc which make up the food item,
(2) percentage of each RAC, by weight, and
(3) form of each RAC "as eaten" (cooked, raw, fried, etc)
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49
(4) water used in cooking is not included in the estimate
of the consumption of each RAC, but is retained as a
separate entry - that is 100 g of cooked rice, would
be coded as 30 g rice and 70 g water.
Information on how the formulations were derived is given
in White, et al. (1983). The food composition data was then
merged with the USDA food consumption files to estimate each
individual's RAC consumption which was then adjusted for that
person's self-reported body weight - that is, all consumption
is expressed as g RAC per kg body weight/day.
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50
B. References
Chaisson, et al. Tolerance Assessment I. A new approach for
estimating public risk due to pesticide residues in food. In
press, 1984.
White, S.B., et al. The construction of a raw agricultural
commodity consumption data base. Interim Report No. 1. RTP,
April 27, 1983.
USDA, Science and education Admin. Food and nutrient intakes
of individuals in 1 day in the U.S., Spring, 1977 (Preliminary
Report No. 2).
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51
VI. Cancer Risks
As noted in previous position documents (PD 2/3 and PD 4), the Agency has
concluded that BOB is a potent animal oncogen and a likely human oncogen.
At dietary levels of exposure that have been, estimated for grain-based
products, cancer risk must be of primary concern. Although potential
reproductive hazards can result from exposure to EDB, the inhalation dose
levels which have been associated with gonadal toxicity are much greater
than the observed and estimated dietary levels. Although EDB may pose a
risk with respect to heritable mutations, it is not yet possible to
quantify this risk.
The evidence supporting the Agency conclusion that EDB is an animal oncogen
results from studies conducted in two species and several routes of
exposure. The initial studies that triggered the RPAR were the NCI gavage
studies (Hazelton, 1973). Both the MCI rat and mouse bioassays showed
significant increases in several tumor types. The most common tumor type
observed was a gastric carcinoma. By the end of the first year of the
test, 90% of low dose male rats were diagnosed as having this malignant
tumor.
Other studies, conducted via the inhalation route of administration, also
found EDB to be a potent animal oncogen. The Midwest Research Institute
under contract to NIOSH found significant increases in the incidence of
tuners of the spleen, manniary gland, adrenals and subcutaneous tissues at
an exposure level of 20 ppm (Wbng, 1979). NCI found EDB to be oncogenic to
rats or mice exposed to dose levels of 10 or 40 ppm via inhalation (NCI,
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52
I960). An increased incidence of hemangiosarconas (a cancer of the
circulatory system) was found in both rats and mice. In addition, a highly
significant increase in tumors of the respiratory system (nasal cavity
tumors in rats and lung tumors in mice) were observed. Finally, a skin
painting study (Van Duuren, 1979) found that repeated painting of EDB on
the skin of mice induced not only skin tumors but lung tumors as well.
In summary, EDB has shown to be oncogenic in two species (rats and mice)
in both sexes and via three routes of administration (gavage, inhalation
and skin painting).
Quantitative risk estimates in general contain a great deal of uncertainty
because they must extrapolate from laboratory animals to humans and fron
the very high exposures used in the laboratory studies to the much lower
human exposures. The estimates of risk from dietary exposure to EDB
require yet another extrapolationfrom partial to full lifetime
riskbecause the exposed animals in the laboratory study did not live for
more than about half their normal lifespan. This additional extrapolation
step introduces yet more uncertainty into the process. In addition, the
only oral studies available administered EDB by gavage rather than through
the diet. The use of gavage data required another step to correct for
gavage vs dietary routes, utilizing data fron a different chemical.
Much care and effort has been put into the quantitative extrapolation
procedure to ensure that all the assumptions and extrapolations are handled
in the most appropriate way. Nonetheless, there is unavoidable uncertainty
remaining in the estimates and they are appropriately taken as only rough
indications of potential risk.
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53
The cancer model used in the PD 4 to extrapolate risk from the NCI
bioassays, has been developed by the EPA Carcinogen Assessment Group
(GAG). The risk model used in the PD 4 to estimate risks fron dietary
exposure incorporated a tine parameter which allowed the differential
risks for less than lifetime exposure for different age groups to be
estimated fron the data in the oral (gavage) study. This was possible
because of the extraordinary rate of unscheduled deaths with tumor which
occurred in the study. CAG has concluded that "the model fits the data
well, it is consistent with the biological hypothesis of direct acting
genotoxic agents and it permits a direct estimate of the effect of partial
lifetime exposure to be made."
The model takes the form:
P(t,d) = l-e~x
where: x = (1.02 x 1013) x d x fy,1/3 [(t-s)7'6-(t-f)7-6]
W = average weight of the individual from age
f to s (in kg)
s = age at start of exposure (years)
f - age at end of exposure (years)
d - mg/kg/day exposure fran age s to f
t = age at end of observation period (years).
For a lifetime exposure, V^ = 60 kg., s = 0, f = t = 70 yrs. of
age, and the above equation has the form p(d) = 1 -e41d.
Earlier, before the PD 4 model was developed, the Agency used a simpler model
which did not utilize this time-to-death-with tumor information. Instead,
this model made the simplistic assumption that risks from less-than-lifetline
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54
exposures are directly proportional to the length of the exposure, regardless
of the aye at which exposure occurs. This model takes the form:
P(d) = i-e-18.71d
where: d = average ing/kg/day exposure over a 70-year lifespan
Both of these models were used to generate the range of risks in Table VI-1.
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55
Table VE-1. Career Risks of Alternative Permissible Reside Options
fa: HB in Grain Products
Permissible
Residue
E"
EBa/
Exposure
(EstinetBd A±ual
Intake)
HB in
Grain Diet
Mg/Kg/tay
Child. Mult
Canoer Risk c/
(2 to 3-Years Bqpbsure) d/
Child
(lyr.)
ASults
(30 yr.)
1
2
3
4
5
6
7
8
9
10
lit/
Current
Bqposure
50/250/
5,000
30/150/
3,000
30/150A003
30/150/900
20/100/2,000
10/50/1,000
5/25/500
1/5/100
<1/1/LOO
SlldlTQ 9ucQj6
*
2.9
2.1
1.8
1.8
1.8
1.6
1.1
.8
.5
«
1.2
ftwerage
a/ RarmissibLe residue options
1.3x106 iOH*-icr* ^(pv-icn
6x10-6
9x10-6 IQ-S-ICT4 MT6
4x10-6
8x10-6 10^-10^ 10T^
3x10-6
8x10-6 10-^rlOr^ 10"^
3x10-6
8x10-6 lQr6-10r4 10"^
3x10-6
Txio-6 lor6rior^ icrT-icr^
3x10-6
5x10-6 lO^slQ-^ 10"7-10~^
2x10-6
3x10-6 lQ"*MLQr5 10~7-icr^
2x10-6
2x10-6 KT^lCrS lD-7
9x10-7
<2xlO-6 aO"5 <10~7
0x10-7
5x10-6 ]0~^rlOT^ 10~7-1CI~6
2x10-6
lighBri are Br ready-tb^eat corisunEr products, milled
c/
d/
fton the finished pxxJuct 'to the inoooted prriict and a 20-fbld increase fran
unctxjked cmtrt to grain (with tha esoepticns of .#4, #5, vhidi assure a 6-7-fiald
increase fcon inoooted pxxiuct to grain) .
JermissitQe residue optioi 11 assures 6 norths enftxosnent at 20/100/2,000 followed
ty peonanent enfeEoamat of 10/50/1 f 000 ppb.
f&vp in canoer risk using dietary career models presented in the H> 2/3 and ED 4.
A constant apoajre ves assured 'fir calculation purposes. It is predicted that
exposure will actually decline after the suspension is in effect.
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56
References
1. Hazelton Laboratories. 1978. Technical Background Information Report
on Carcinogenesis Bioassay of 1, 2-Dibronoethane (EDB). US-DHEW, NIM,
NCI. 11-14-78.
2. National Cancer Institute. 1978. Bioassay of 1, 2-Dibroraoethane for
Possible Carcinogenicity. TR-86 (CAS No. 106-93-4). Carcinogenesis
Testing Program. DHEW Publication No. 78:1336
3. Van Duuren, B.L. et al. 1979. Carcinogenicity of Halogenated
Olefinic and Aliphatic Hydrocarbons in Mice. J. Nat. Cancer Institute
63(6):1433-39.
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57
VII. Toxicity of Likely Chemical Alternatives
A. Aluminum Phosphide
Aluminum phosphide is formulated as tablets or pellets which liberate
highly toxic phosphine gas when the aluminum phosphide reacts with moisture
in the commodity or surrounding air. Because of the highly toxic nature of
the phosphine which is liberated, formulations of aluminum phosphide have
also been considered as highly toxic materials (EPA, 1981).
A two-year rat feeding study examined the effects of feeding diets
fumigated with phosphine gas to rats (Hackenberg, 1972). Analytically
determined levels of phosphine in the diet ranged from 0.2 ppm to 7.5 ppm
and averaged approximately 1 ppm. Ho differences were found between
control animals and those animals receiving treated diet with respect to
growth, food consumption, survival, morbidity, hematology, blood chemistry,
gross and microscopic pathology.
B. Ethylene Bichloride
Ethylene dichloride (1,2-dichloroethane) has a relatively low toxicity to
mammals on an acute basis (LC5Q = 12,000 ppm. or 48 mg/L for 0.53 hour
of exposure). The primary effects of human exposure to ethylene dichloride
were reported to be central nervous system (CNS) depression and
gastrointestinal upset. Liver, kidney and adrenal injuries occurred in a
dose-related fashion.
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58
This chemical is rapidly metabolized and eliminated in mammals. The
metabolic pathway of EEC is not adequately delineated, but very likely
occurs via a dechlorination reaction. The metabolism of EDC may be
catalyzed by the glutathione system in the soluble fraction of the liver.
EDC metabolities include monochloroethanol and monochloroacetic acid which
are more toxic than EDC.
The chemical was shown to be mutagenic in the reverse mutation assay in
Salmonella typhimurium TA1535 and TA100 with and without metabolic
activiation (McCann, 1975). Metabolities of EDC are also known to be
mutagenic (McCann, 1975).
There is evidence that exposure to ethylene dichloride poses a carcinogenic
risk to man. An NCI study showed statistically significant increase of
tumors in both rats and mice after long-term oral intubation (Dhew, 1974).
A statistically significant positive association between the dosage and the
incidence of squamous cell carinomas of the forestomach and
hemangiosarccnias of the circulatory system occurred in male rats but not in
females. There was also a significantly increased incidence of
adenocarcinonas of the mammary glands in female rats. The incidence of
mammary adenocarcinoma in female mice were statistically significant. The
EPA Carcinogen Assessment Group concluded that EDC was 50 times less potent
as an oncogen than EDB (Albert, 1978).
C. Carbon Tetrachloride
CC14 was found to be cncogenic (liver tumors) in rats, mice, and hamsters
after oral administration. Other chronic effects observed in laboratory
animals included cirrhosis of the liver after oral, subcutaneous, or
inhalation exposure of rabbits, rats, mice, and hamsters; severe liver
-------
59
damage observed in humans after chronic exposure; kidney damage in humans
and rats (nephrosis and degenerative changes).
Fetotoxic effects have been observed by Schwetz, et al (1974) in rats
exposed bo CC14 vapor. Bhattacharyya (1963) also reported fetal as well
as neonatal effects in rats exposed via inhalation. Testiticular atrophy
and impaired spermatogenesis have also been observed in male rats which
were given intraperitoneal doses of CC14 (Chatterjee, 1966: and Kalla and
Bansal, 1975).
No genotoxic activity has been reported in bacteria (McCann et al, 1975),
yeast (Callen et al, 1980), or rat liver cells ir\ vitro (Dean and
Hudson-Walker, 1979). In vitro experiments indicate (£14 may also bind
to other macronolecules which could be the reason many microbial or jri
vitro assays vgere negative (Rocchi, 1973, Uenlejce, 1976).
D. Methyl Bromide
Methyl bromide has not been well studied toxicologically. It is currently
being tested for oncogenicity by the Dutch government and the National
Toxicology Program. Three in vitro mutagenicity studies indicated a
mutagenic potential for methyl bromide with mutagenic effects shown in a
dose dependent manner. Test systems used were Salmonella, the yeast
Saccharomyes cerevisiae and Chinese hamster ovary cells. A 3-generation
reproduction study via the inhalation route is being sponsored by several
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60
manufacturers of methyl bromide. Teratogenicity studies of methyl bromide
(in the rat and mouse) have been submitted to the Agency. Although they
have not yet been evaluated, the authors of the study report no teratogenic
effect at the highest dose level administered.
E. Carbon Disulfide
Carbon disulfide is a volatile and extremely flamable liquid.
Chronic exposure to carbon disulfide at airborne concentrations greater
than 30 mg/m^ has been associated with diseases of the cardiovascular and
nervous system. Acute exposure to carbon disulfide at airborne
concentrations greater than 60 mg/m^ has been associated with
physiological and behavioral abnormalities. The chemical was also reported
to cause a marked decrease in visual acuity as a result of an effect on the
optic nerve (Potts, 1980).
In experimental animals, subchronic exposure to concentrations greater than
50 ppn caused brain weight depression accompanied by histopatholgoical
changes in the nervous system in rats. In addition, compound-related renal
lesions and pigmentation of the spleen were also reported in mice.
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61
F. REFERENCES
1. Albert, R.E. The Carcinogen Assessment Group's Preliminary Report on
Ethylene Dichloride. April 7, 1978.
2. Bhattacharyya, K. Fetal and Neonatal Responses to Hepatotoxic Agents.
J. Pathol. Bact. 90:151-161.
3. Chatterjee, A. Testicular Degeneration in Rats by Carbon Tetrachloride
Intoxication. Experimentation. 22:395-396, 1966.
4. Dean, B. J., and G. Hudson-Walker. 1979. An in virto Chromosome assay
using cultured rat-liver cells. Mutat. Res. 64:329.
5. Department of Health, Education and Welfare. Bioassay of 1,
2-Dichloroethane for Possible Carcinogenicity. Public Health Service
National Institute of Health, National Cancer Institute DHEW
Publication No. 78-1305 (1974).
6. Environmental Protection Agency. 1981. Pesticide Registration
Standard. Aluminum Phosphide.
7. Hazelton Laboratories. 1978. Technical Background Information Report
on Carcinogenesis Bioassay of 1, 2-Dibromoethane (EDB). US-DHEW, NIM,
NCI. 11-14-78.
8. Hackenberg, U. (1972). Chronic Ingestion by Rats of Standard Diet
Treated with Aluminum Phosphide. Tox. App. Pharm. 23(1): 147-158.
9. Kalla, N. R., and M. P. Bansal. 1975. Effect of carbon tetrachloride
on gonadal physiology in male rats. Acta Anta. 91:380-385.
10. MeCann, J., E. Choi., E. Yamasaki, and B. N. Anes. 1975. Detection of
carcinogens as mutagens in the Salmonella/microsome test: Assay of 300
chemicals. Proc. Natl. Acad. Sci. 72:5135-5139.
11. McCann, J., Siimion, V., Stretiwieser, D., and Ames, B.N. "Mutagenicity
of Chloroacetaldeyde. A Possible Metabolic Product of 1,
2-Dichloroethane (Ethylene Dichloride), Chloroethanol, Vinyl Chloride
and Cyclophosphomide" Proceedings of the National Academy of Science,
U.S.A. 72: 3190-3193, (1975).
12. National Cancer Institute. 1978. Bioassay of 1, 2-Dibrcmoethane for
Possible Carcinogenicity. TR-86 (CAS No. 106-93-4). Carcinogenesis
Testing Program. DHEW Publication No. 78:1336
13. Potts, A.M., Gonasun, L.M. 1980. Toxic Responses of the Eye. In
Casarett and Doull's Toxicology, Second Edition, Macmillan Publishing
Co., Inc., New York, p. 301.
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62
14. Rocchi, P., G. Pordi, S. Grilli, and A. M. Ferreri. 1973. In vitro
and in vivo binding of 0014 with nucleic acids and proteins in rat
and mouse liver. Int. J. Can. 11:419-425.
15. Rosenkran, S., Carr, H.S., and Rosenkranz, H.S. 2-Haloethanols:
Mutagenicity and Reactivity with DNA. Mutation Research, 26 367-370
(1974).
16. Schwetz, B. A., B. K. J. Leong, and P. J. Gehring. 1974. Embryo- and
fetotoxicity of inhaled carbon tetrachloride, 1, 1-dichloroetnane, and
methyl ethyl ketone in rats. Tbxicol. Appl. Pharmacol. 28:452-464.
17. Uenleke, H., H. Greim, M. Kramer, and T. Werner. 1976. Covalent
binding of haloalkanes to liver constituents but absence of
mutagenicity on bacteria in a metabolizing test system. Mutat. Res.
38:114.
18. Van Duuren, B.L. et al. 1979. Carcinogenicity of Halcgenated Olefinic
and Aliphatic Hydrocarbons in Mice. J. Nat. Cancer Institute
63(6):1433-39.
19. Wong, L.C.K. 1979. Study of Carcinogenicity and Toxicity of Inhaled
1, 2-Dibronoethane in Rats Treated with Disulfiram. Midwest Research
Institute Final Report, NIOSH Contract No. 210-76-0131. 2-8-79.
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63
VIII. Economic Impacts
A. Introduction
The purpose of this section is to provide information on economic
impacts and implications of implementation of national maximum
permissible residue levels for EDB in grain, flour and related finished
or consumer products and economic impacts of emergency suspension of
grain fumigation and spot-treatment uses of EDB. Specifically, this
section focuses ugpn alternative sets of maximum residue levels for
grain and related products which may contain EDB residues from either
treatment of grain or spotrfumigation of milling machinery. Economic
impacts of emergency suspension are evaluated for 6 months and for the
remainder of the cancellation proceedings already in process. The
cancellation hearings are expected to require about two years for
completion.
This report is intended to meet the requirements for Regulatory Impact
Analysis as established by Executive Order 12291, the Regulatory
Flexibility Act and Sectiqn 25 of FIFRA. It also serves as an input for
preparing any analysis required under the Paperwork Reduction Act of
1980.
Executive Order 12291 require^ that Adequate information concerning the
need for, and consequences of, a proposed action be presented. The
Order requires that j finding of potential benefits to society will
outweigh the potential cost for any reccranended action. Executive Order
12291 also recognizes that legal constraints may play a role in
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64
selecting among alternative approaches to achieving regulatory goals.
The Regulatory Flexibility Act requires that regulations take special
note of the impact of proposed regulations on small entities. The
Regulatory Flexibility Act requirements can and should be combined with
Executive Order 12291 requirements. FIFRA, Section 25, requires that
the Administrator of EPA consider such factors as the effects of
regulation on production and prices of agricultural ooranodities, retail
food prices and otherwise on the agricultural economy when issuing
regulations affecting pesticides. These three mandates for
consideration of economic aspects of pesticide regulatory matters are
applicable to the revocation of the present exemption and tolerances
governing EDB under the Federal Food, Drug and Cosmetic Act, but not to
the emergency suspension, which is not rulemaking.
As noted above, this analysis focuses on alternative options for
issuance of maximum permissible levels for EDB in food/feed grain
products. The specific options range frcm less than one part per
billion (ppb) to 100 ppb in final consumer products (Table VTII-1). For
each option at the final consumer product level (ready-to-eat breads,
cereals, etc.), there are corresponding levels identified for
processed/uncooked foods (e.g., milled flour) and for raw grain. The
alternatives were selected at the final consumer product level to
reflect a range of levels which have differing exposure/risk
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65
implications for human health. Given those values, the other
permissible residue levels for processed/uncooked foods and raw grain
were assumed to have fixed relationships with the ready-to-eat products.
Obviously, actual levels of EDB residues at the three stages of the
marketing system would vary considerably. However, those contained in
Table VIII-1 are internally consistent within options and are thought to
be reasonable approximations. A separate option for raw grain of 900
ppb was also considered but is not shown in-Table VIII-1.
This analysis is not highly quantitative due to the complex nature of
the problem and also due to the short time available for preparing this
analysis. Quantitative estimates of usage and economic impacts are
included whenever possible. However, in many cases only qualitative
estimates are presented'. The quantitative estimates- should best be
considered as illustrative of. possible economic effects rather than
values with any known probability of occurrence.
B. Economic Impacts of Setting Maximum Permissible EDB Levels for Raw
Grain
1. Usage of EDB and Other Fumigants
EDB is used as a liquid grain fumigant in mixtures whose major
constituents are carbon tetrachloride/carbon disulfide and carbon
tetrachloride/ethyl-ene dichloride. These funigants are used as remedial
treatments to control insects in stored grain. EDB is also used in
combination with chloroform and carbon disulfide, but the overall volume
of this product is small in comparison to the carbon tetrachloride-based
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66
Table VIII-1. Maximum Permissible Levels of EDB in Grain
Option
1
2
3
4
5
6
7
8
9
10
Ready- to-Eat
100
50
30
20
10
5
2
1
C
20AO
and Related Products
Prepared/Uncooked
500
250
150
100
50
25
10
5
1
100/50
Raw Grain
10,000
5,000
3,000
2,000
1,000
500
200
100
100
2,000/1,000
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67
products. An estimated 425,000 gallons of formulated products
containing 170,400 pounds of EDB active ingredient were used for insect
control in grain storage facilities in 1983 (Table VIII-2). At typical
application rates, approximately 202 million bushels of grain stored in
1983 were treated with fumigants containing EDB (Table VIII-2).
The majority of EDB usage in the U.S. is to control stored product
insects of wheat. Using an application rate of 2 gal. per 1,000 bu., an
estimated 159.4 million bushels of wheat were treated in 1983. This
quantity of wheat treated with EDB represents about 5.4 percent (Table
VIII-3) of the wheat in storage on October 1, 1983 (USDA, Crop Reporting
Board, SRS., 1983. pp. 3). In 1983, approximately 14 million bushels of
corn were treated with 42,500 gallons of EDB-containing liquid grain
fumigants assuming an application rate of 3 gallons per 1,000 bushels.
This amount of corn treated with EDB-containing liquid grain fumigants
represents about 0.5 percent of the corn in storage on October 1, 1983.
The usage on oats, barley, rye and rice comprised approximately 10
percent of the EDB usage in 1983. Crop-specific data for these
canned ities are not available, but overall, approximately 21 million
bushels were estimated to have been treated in 1983. The remaining
usage of EDB was to treat approximately 7 million bushels of grain
sorghum, which would equal 1.8 percent of that commodity in storage on
October 1, 1983.
While actual usage statistics are not available to indicate the precise
locations of EDB usage, it is believed that approximately 65 percent of
the annual EDB usage is on farms and the remaining 35 percent used in
all off-farm positions. According to Douglas Chemical Co. data,
Minnesota, North Dakota, Iowa, South Dakota, Nebraska, Oregon and
Indiana were states which received the bulk (60.8 percent) of Douglas1
1983 distribution of EDB containing products (Table VIII-4).
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68
Table VIII-2. Estimated Usage of EPS-Containing
Liquid Grain Fumigants by Crop, 1983
Stored Commodity
Wheat
Corn
Oats, Barley, Rye, Rice
Grain Sorghum
Total
Percent of
EDB
Usage
75
10
10
5
100.0
Pounds
A.I.
Applied
127,800
17,040
17,040
8,520
170,400
Gallons
Applied
318,750
42,500
42,500
21,250
425,000
Application
Rate
(gal/1,000 bu)
2
3
2
3
N/A
Bushels
Treated
(000)
159,375
14,167
21,250
7,083
201,875
Source: EPA Estimates; Douglas Chemical Co., 1984.; Harein and Sumner, 1982.
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69
Table VIII-3. Estimated BOB Treated Grain as a Percentae of Grain Stocks
On-Farms and All Stock Positions, Various Dates, 1983
Commodity Bu. Treated
Wheat 159,375,000
Corn 14,167,000
Sorghum 7,023,000
On-Farm
.Jan 1
Apr 1
Jun 1
Opt 1
Jan 1
Apr 1
Jun 1
Oct 1
Jan 1
Apr 1
Jun 1
Oct 1
Treated
Storage
13.7
18.0
22.9
12.9
6.23
0.3
.0,4
0,9
2.6
4.7
7>.4
12.0
as Percentage of
All Positions
'Percent
6.3
8.5
10.3
5.4
0.2
0.2
0.3
0.5
0.9
1.1
1.3
1.8
Sources: USDA. Grain stocks, .October 1983; and Table VI11-2.
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70
Table VIII-4. Distribution of Douglas Chemical Co.
Liquid Grain
Fumigants Containing
BOB by State, 1983
State
MN
ND
IA
SD
NE
OR
IN
IL
MT
AR
OH
MO
CO
PA
VA
GA
MI
NY
WI
NC
AL
KS
WY
TX
Subtotal
Misc. Dealer Sales
Total
Gallons
55,602
27,240
27,098
25,660
24,235
21,996
20,555
15,164
14,859
12,219
11,535
8,141
5,610
5,082
3,635
3,414
2,755
2,312
2,247
1,938
965
335
251
106
292,954
20,046
313,000
Percent of Total
17.8
8.7
8.2
7.7
7.0
6.6
4.8
4.7
3.9
3.7
2.6
1.8
1.6
1.2
1.1
0.9
0.7
0.7
0.6
0.3
0.1
0.1
0.1
<.l
93.6
6.4
100.0
NOTES: Total Ibs. of EDB = 78,953 (Douglas products only).
Lbs. of EDB per gal. = 0.252 (Douglas products only).
Estimated total Ibs. EDB on all formulations = 170,383.
Source: W.P. Conrath, Vice President, Douglas Chemical Company. January 18,
1984.
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71
According to USDA, the most commonly used fumigation method in small
farm-type bins is the application of liquid fumigants in a coarse spray
over the grain surface (USDA, 1979). This method relies on gravity to
distribute the fumigant down through the grain mass as the
heavier-than-air vapors change from the liquid form. Pre-application
procedures include leveling the grain surface and sealing the juncture
between the sidewall and roof with masking tape. Fumigants are usually
applied using a bucket pump or garden sprayer adapted to produce a
coarse spray. Fumigants are normally applied from outside the bin.
After treatment, the access door and fillhole lid are sealed with
masking tape or plastic sheeting to prevent fumigant vapors fron
escaping to the outside.
2. Profile
Grain production is one of the major agricultural sectors in the U.S.
In 1983, a total of 8.281 billion bushels of major grain crops were
produced. The total supply (production, beginning inventory and
imports) for the 1983/84 crop year was 14.006 billion bushels (Table
VIII-5 ). Several hundred thousand farms are engaged in production of
major grain crops. Nearly 900,000 farms produce corn and more than
380,000 produce wheat. Other crops involve fewer farms.
There were a total of more than 1 million grain farms in the U.S. in
1978; 589,480 had sales exceeding $20,000 (U.S. Dept. of Commerce,
1981). While actual data are not available, the average quantity of
commodities stored on farms in bulk on January 1, 1980-1982 could range
between 7,576 and 13,497 bushels per farm (Table VIII-6). The estimated
average storage capacity per farm could range between 10,956 and 19,518
bushels.
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72
Table VIII-5. Economic Profile Information on U.S. Grain Production
Grain
Wheat
Corn
Oats
Barley
Rye
Rice
Sorghum
Total
Sources:
Total Production
1983
2,425
4,121
473
532
28
220
482
8,281
Grain Stocks, USDA, Jan. 23
Feed Outlook and Situation
U.S. Census of Agriculture,
Total Supply
1983/84
3,970
7,262
715
765
35
378
881
14,006
, 1984
Report, USDA, Nov., 1983
1978, Census Bureau
Stocks
1A/84
2,325
4,928
378
378
20
123
651
8,803
No. Farms
(Harvesting)
1978
tnnn\
\\f
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73
Table VIII-6. Estimated Quantity of Commodity Stored on Farms
January 1,
Stock Position
Date
January 1
April 1
June 1
October 1
April 1, June 1,
Quantity
Stored
7,956,000
5,242,000
3,575,000
3,071,000
and October 1, 1980-8:
Estimated. I
Grain Stored
"ATI "Farms b/ ~
* -Busfiels^ =-
7,576
4,992
3,404
2,924
I Average a/
\ye.rage
Pec Farm
"Farms "with
sales >$ 2 0,000 c/
13,497
8,893
6,065
5,210
a/ Includes corn, sorghum, oats, barley, wheat, rye, flax seed, soybeans,
and rice.
b/ Quantity stored divided by the 1,050,178 grain farms in the U.S. (1978
Census of Agriculture). Assumes all farms have equal storage capacity.
c/ Quantity stored divided by the 589,480 grain farms in fche U,S. with
sales greater than $20,000. Assumes .all grain .storage capacity is
concentrated on larger farms.
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74
Circular steel bins are the most caramon structures used for on-farm
storage. While precise data are not available, it is estimated that
steel bins comprise 90-95 percent of long-term on-farm grain storage.
There are still seme structures built of wood which are generally used
for storage of bumper crops. Newer structures (i.e., circular steel
bins) usually have aeration systems while older structures (wooden
construction) are often not so equipped. Most modern structures can be
treated with any of the common grain fumigants. The exception would be
crib-type structures.
Off-farm storage includes all forms of grain containers used to hold,
handle, or transport grain frcm the time the grain leaves the fam until
it is either sold to processors or is exported. This definition
includes, but is not necessarily limited to, country elevators, terminal
elevators, port facilities, railroad cars, barges, trucks, and so forth.
There are over 15,000 off-farm grain handling and storage facilities in
the U.S. with nearly 7.5 billion bushels of capacity. Commercial
facilities in the Corn Belt, Northern and Southern Plains comprise about
two-thirds of this capacity. The Lake, Delta and Pacific States
ccroprise an additional 20 percent of capacity. The remaining capacity
is nearly uniformly distributed throughout the remaining production
regions. January 1 grain storage stocks (1979-81) averaged 4.3 billion
bushels or 57 percent of capacity. Corn and wheat doninate grain
storage with 43 and 26 percent of total volume, respectively. Soybeans
account for an additional 19 percent of total storage volume.
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75
3. Quantities Exceeding Maximum Permissible Residue Levels
A key aspect of evaluating economic impacts of maximum permissible
residue levels is estimation of the quantities of grain that would
exceed such specified levels. In this case, the quantities have been
estimated, as a percentage of stocks as of February 1, 1984 that would be
used for human food consumption or export. The procedure used was as
follows:
a. Adjust 1/1/84 stocks for pro-rata share which would not
be used for U.S. human consumption or export, i.e. feed/seed uses. A
percentage was estimated to be used for feed/seed and was subtracted
fron the total 1/1/84 stocks, based upon projected 1982/83 usage
(1983/84 not available).
b. Stocks for food/export use as of 1/1/84 were reduced by
8.3 percent to approximate stocks as of 2/1/84, due to assumed dispersal
during January, 1984.
c. Grain stocks estimated to exceed maximum permissible
levels of EDB were based upon a statistical analysis of grain residues
submitted by GMA/states/USDA. This statistical analyses was performed
by EPA staff (OPPE).
d. Qiantities exceeding maximum permissible levels were
computed by multiplying the percentages of grain samples exceeding
permissible residue levels by food/export stocks as of 2/1/84.
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76
The results of the estimation process are presented in Tables VIII-7 and
VIII-8 for each maximum permissible residue level. The grain stocks
estimated to exceed the maximum permissible residue levels ranged frcm a
low of 0.2 percent exceeding 5,000 ppb (9.5 million bushels) to a high of
6.3 percent at 100 ppb (250 million bushels).
4. Impact Analysis
a. Direct Impacts
One of the potential economic impacts from enforcing maximum permisssible
residue levels is that grain could be withdrawn fron the market. Such
withdrawals could be made of grain from storage at the farm level or from
storage in ccmnercial channels following marketing frcm the farm. In this
analysis, estimates are made of the aggregate value of bushels that may be
lost from such eventualities. The overall aggregate value of all types of
grain exceeding permissible residue levels is shown in Table VIII-9.
Also, the approximate dollar values of typical sized lots of grain that
might be involved are summarized in Table VIII-10. A typical lot of grain
at the farm level could range from 6,000 to 13,000 bushels compared with
50,000 to 500,000 bushels or more in commercial channels. (Some shipments
of grain are in the millions of bushels.) The value of a 10,000 bushel
lot of grain at the farm level ranges frcm about $17,000 to nearly $40,000
(Table VIII-10). The values for comercial lots of grain would range from
about $427,000 for oats to nearly a million dollars for rice.
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77
Table VIII-7. Estimated Quantities, of Grain. Stocks- Available
Grain
Wheat
Corn
Oats
Barley
Rye
Rice
Sorghum.
Total
Stocks:
mi J. - oil'*
2*325-
4,928;
3:7.8^
3,78;
20?
123;
652
8',.803,
for Food, or Export
Peizsent. for-
Eood^Export
01983/8*):
rv*l-
»
3:7?
8
43=
15
9»
30;
50i
,. February 1,.
Stocks:
15/1/841 f or:
Eood/Export:
W
i^a
»
163!
3'
L20)
MS
41.3&7?
1984:
Stocks^
Used!
Janx 84
169
152
3
14
-
10
16
364
Stocks 2/1/84
for Food/
Export
1,855
1,671
27
149
3
110
179
3,993
Source: See* Table VIII-5
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78
Table VIII-8. Quantities of Grain Estimated to Exceed Maximum Permissible Residue
Levels for EDB, U.S., February 1, 1984
Permissible Residue
Level
No.
1
2
3
4
5
6
7
8
9
10
11
1
2
3
4
5
6
7
8
9
10
11 2
Base
PPB
None
5,000
3,000
2,000
1,000
900
500
200
100
100
2,000/1,000
None
5,000
3,000
2,000
1,000
900
500
200
100
100
,000/1,000
( food/export
stocks 2A/84)
Wheat
Corn
Oats
Barley
Rye
Rice
Sorghum
Total
_
0
0
0
0.5
0.5
1.4
NA
9.2
9.2
0/.5
0
0
0
0
9
9
26
NA
171
171
0/9
1,855
_
0.3
0.3
0.3
0.3
0.7
1.4
NA
3.8
3.8
.3/.3
0
5
5
5
5
12
23
NA
63
63
3/7
1.671
_
0.9
0.9
0.9
1.8
1.8
1.8
NA
3.6
3.6
.9/1.8
0
0.2
0.2
0.2
0.5
0.5
0.5
NA
1.0
1.0
0.1/0.6
27
_
0.9
0.9
0.9
1.8
1.8
1.8
NA
3.6
3.6
.9/1.8
- -Mil.
0
1.3
1.3
1.3
2.6
2.6
2.6
NA
5.1
5.1
0.7/3.2
149
_
0.9
0.9
0.9
1.8
1.8
1.8
NA
3.6
3.6
.9/1.8
bushels-
0
-
-
-
-
-
-
NA
0.1
0.1
-
3
_
0.9
0.9
0.9
1.8
1.8
1.8
NA
3.6
3.6
.9/1.8
0
1
1
1
2
2
2
NA
4
4
0.5/2.5
110
_
0.9
0.9
0.9
1.8
1.8
1.8
NA
3.6
3.6
.9A-8
0
2
2
2
3
3
3
NA
6
6
1/4
179
_
0.2
0.2
0.2
0.6
0.7
1.4
NA
6.3
6.3
,2/.6
0
9.5
9.5
9.5
22.1
29.1
57.1
NA
250.0
250.0
5.3/17.3
3,993
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79
Table VI11-9. Value of Grain Exceeding EPS Maximum Permissible
Residue Levels,
February 1, 1984
Action Level
No.
1
2
3
4
5
6
7
8
9
10
11
PPB
None
5,000
3,000
2,000
1,000
900
500
200
100
100
2,000/1,000
Price/bushel
Wheat
$ 0
0
0
0
32
32
92
NA
602
602
32
$3.52
Corn
§ 0
16
16
16
16
40
76
NA
208
208
16/24
3.30
Oats
$ 0
0.3
0.3
0.3
0.9
0.9
0.9
NA
1.7
1.7
0.2/1.1
1.71
Barley
Rye
$ 0 $ 0
3
3
3
7
7
7
NA
13
13
2/9
2.57
-
-
-
-
-
-
NA
0.3
0.3
0/0
2.75
Rice
$ 0
4
4
4
8
8
8
NA
16
16
2/10
3.99
Sorghum
$ 0
6
6
6
9
9
9
NA
17
17
4/12
2.85
Total
$ 0
26.3
26,3
26.3
72.9
96.9
192.9
NA
858.0
858.0
13/86
-
Source: Ag. Prices, USDA, Dec., 1983.
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80
Table VIII-10. Prices and Market Value of Grain, at Farm and
Non-Farm Levels,
Estimated Average
Lot Sizes, November, 1983 Prices
Item
Lot size
Wheat
Corn
Barley
Oats
Rye
Rice
Grain Soryhura
Price/bu.
11/83 a/
1,000 bu
§3.52
3.30
2.57
1.71
2.75
3.99
2.85
Value
Farm
10
(6-13)
$35,200
33,000
25,700
17,100
27,500
39,900
28,500
of Grain/Lot
Non-Farm
250
(50-500+)
$880,000
825,000
642,500
427,500
687,500
997,500
712,500
a/ Prices received by farmers, Nov. 1983, except for rye, which is
preliminary estimate.
Source: USDA: Ag. Prices, Dec. 1983.
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81
These aggregate dollar values'and values for a typical lot are obviously
very significant if they were to reflect the value of losses to operators
at either level in the market as described earlier in this section.
The fanner or other owner of grain with EDB at higher than permissible
levels realistically would face a number of options short of losing the.
entire value of the grain. Such options would include delay of marketing,
which would tend to reduce EDB residues due to the natural dissipation of
the chemical; turning or moving the grain; and aerating the grain. All of
these options have attendant costs of one type or another. Also, the
owner of the grain may need to sample amd test for residues which would
generate additional cost. These types of costs are addressed below in
this section of the report.
Turning the grain is one of the methods that farmers and grain merchants
may employ to help speed residue dissipation. This turning cost is
generally estimated to be between one-fourth and one-half of a cent per
bushel with seme estimates going as high as one cent per bushel. The
major obstacle to overcome when turning grain is breakage. It has been
estimated that grain is reduced one grade due to breakage with each
turning. For this reason, turning costs for corn would be prohibitive.
As noted above, the owner of grain may wish to have his product analyzed
chemically for residues of EDB. Agency staff has recently contacted a
number of vendors and found that the cost of analyzing grain or related
food products for EDB is approximately $100 to $110 per sample at
commercial laboratories. If a large number of samples (i.e., hundreds)
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82
are to be analyzed, lower unit cost may be obtained. There are additional
costs to be incurred in obtaining and transporting the sample to the
laboratory in a manner in which allows for accurate laboratory measurement
of actual residues. In instances where statistically valid estimates must
be taken of very large lots of grain or a number of lots from a particular
geographic area or source, a survey design and randan sample must be
developed, all of which is an added expense.
Agency staff estimated that approximately 150 to 300 commercial residue
chemistry laboratories are available for residue analysis of foodstuffs in
the U.S. at the present time. The capacity of these laboratories for EDB
testing is not known. If nothing else, there would be a relatively large
physical transportation problem in getting all of the samples that could
be taken nationwide to the relatively few laboratories nationwide. The
extent to which the testing sites might be geographically dispersed has
not been evaluated.
The amount of grain required to do chemical residue analysis of grain is
likely to be relatively small such as possibly a quart i.e., up to 3 Ibs.
of grain. The market value of corn is only about 6 or 7 cents a pound and
rice. The most expensive grain, about 9 or 10 cents per pound.
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83
b. Indirect Impacts
Implementing EDB residue guidance at the raw grain level in the industry
could have indirect effects on other sectors in the economy. Products for
which grain is a raw product could be affected as well as substitutes for
such products at the intermediate and consumer levels. Also, the
livestock sector could be affected if there were significant disruptions
in the supply of feedgrains. In view of the relatively small maximum
percentages of the grain sector that would be likely to be affected, the
potential for such indirect economic effects is quite limited. To the
extent they do occur, they would be temporary.
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84
C. Economic Intact of Setting Maximum Permissible EDB,Levels for Uncooked
Grain Products
1. Usage, of EDB and Other Fumigants.
This section analyzes the potential economic effects of a.range of proposed
maximum permissible EDB,.residue levels for grain-based products which require
further cooking. Products included as processed/uncooked are typified by
wheat flour, corn-based products, blended and prepared flour mixes (e.g., cake
mixes, muffin mixes, etc.) and milled rice. Other product sectors, such as
wet corn milling (producing corn starch and corn syrup) and brewing, were not
included. Only those industries in the GMA/states/USDA data bases which
produce processed/uncooked grain-based products with known residues are
considered in this analysis.
BOB finds its way into the human food chain in grain in a variety of ways. As
discussed in the previous section, the first route of entry is the direct
application to grain stored in bulk. Treated grain goes into the market,
becomes mixed with untreated and other treated grain and "disappears" as
exports and feed and food components of domestic consumption. The grain
containing EDB residues which "disappears" into the domestic diet becomes the
initial source of the dietary burden. The second major route of entry is
fumigation within the industries which utilize raw grain in milling and
processing.
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85
EDB can be used as a spot treatment of cereal processing and flour milling
machinery to rid the internal portions of the machines (which are virtually
inaccessable) of insect infestations. The major use of the so called "spot"
materials containing EDB are wheat and corn-milling facilities. EDB was also
used to a very minor extent in a variety of other cereal grain processing
industries (e.g., brewing). Virtually every firm utilizing U.S. grain as a
feed stock or a basic input item could potentially produce products with
detectable EDB residues.
EDB in combination with methyl bromide was the most conmonly used fumigant
mixture to spot-treat insect infestations in flour milling machinery.
Approximately 300,600 pounds of EDB active ingredient were used annually by
the flour milling industry (Table VIII-11). While actual data are not
available for 1983, the overall usage of EDB for spot-treating flour milling
equipment was probably less than typical usage in most recent years. The
major companies in the milling industry apparently discontinued usage of EDB
in their mills in August and September, 1983. Since that time, the usage of
EDB in the milling industry appears to be very limited. Moreover, the largest
distributor of spot-funigant materials (with about 60% of the market) is not a
party to the on-going cancellation hearings and registrations for these
products are cancelled. Other suppliers are parties to the cancellation
hearings, but are no longer producing EDB-containing products for usage in
spot-treating milling machinery.
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86
Table VIII-11. Estimated Annual U.S. Usage of EDB as a Spot Fumigant, 1978-1983
"Annual U.S. Usage of EDB
Source Date
Ferguson Fumigants, Inc.
Research Products Go.
Millers' National Federation
Millers' National Federation
Millers' National Federation
Environmental Protection Agency
U.S. Department of Agriculture
Ferguson Fumigants, Inc.
Douglas Chemical Co.
Centaur Associates
Centaur Associates
1978
1978
1978
1979
1980
1980
1981
1981
1982
1983
1983
290 ,000
600 ,000
323 ,087
323 ,235
285,759
465,000
162 ,000
230,518
164 ,000
300,000
300 ,591
Source: Adapted from Centaur Associates, 1983.
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87
Centaur (1983) estimated that 79 percent of flour mills in the U.S. used EDB
as a spot fimigant. Centaur estimated that 231 to 243 flour mills used EDB
spot fumigants an average of 10.0 to 10.69 times per year. Respondents to
Centaur case studies indicated average usage of EDB-containing fumigants
approximated 10.5 gallons per mill fumigation. Obviously, larger mills use
more and smaller mills use less. The range in reported usage was 2 to 45
gallons per treatment.
2. industry Profile
The major raw grain materials for the milling and processing industry include
wheat, corn, oats, barley and rice. Of these raw materials, wheat is by far
predominant in terms of U.S. consumer importance, and is the most frequently
treated with EDB.
The flour milling industry is widely dispersed throughout the U.S. Wheat
flour mills tend to be geographically dispersed due to the bulky nature of the
input. Transportation costs encourage producers to locate wheat flour mills
over a wide geographic range (Table VIII-12). The Corn Belt, Northern Plains
and Northeast states comprise over half of total average daily milling
capacity. Ownership in the wheat flour milling industry is concentrated in
relatively few firms. The leading 5 firms comprise about 72 percent of the
wheat flour milling capacity (Table VIII-13).
The production of flour and other grain-mill products from raw grains involves
an intricate process of many grindings and sittings. While the details of the
entire process will not be given here, in general, about 72 percent of the
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Table VIII-12. Daily Milling Capacity of vheat Flour Mills by Region
Region
Northeast
Southeast
Appalachian
Lake States
Corn Belt
Northern Plains
Delta States
Southern Plains
Mountain
Pacific
Puerto Rico
Total
Source: Milling
Nunber of
Mills
45
12
50
20
37
26
2
10
19
18
2
241
and Baking News.
in the U.S., 1983
Active Daily
Capacity
(cwt)
146,962
37,390
96 ,691
116,350
254,673
156,170
11 ,300
69,440
68,450
103 ,025
9,000
1,069,451
Average
Daily Capacity
Per Mill
(cwt)
3,266
3,116
1,934
5,818
6,883
6,007
5,650
6,944
3,603
5,724
4,500
4,438
Pet. of
Total
Capacity
13.7
3.5
9.0
10.9
23.8
14.6
1.1
6.5
6.4
9.6
0.8
100.0
1983 Milling Directory Buyers' Guide. Kansas
City, MO. Sosland Publishing Company, 1982, 120pp. As cited in Centaur
Associates, October 13, 1983.
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89
Table VIII-13. Top Ten Wheat-Durun-Rye Milling
Conpanies and Their Daily Capacities
Wheat
Company
Con Agra, Inc.
ATM Hilling Co.
Cargill, Inc.
The Pillsbury Co.
International Multifoods
General Mills, Inc.
Dixie-Portland Flour Mills
Nabisco Brands, Inc.
General Food Processors, Inc.
Bay State Milling Co.
Total
Total U.S. 1
Flour Capacities
(cwt)
186,300
135 ,700
130,500
114 ,900
60,000
55,000
51,000
43,000
31 ,300
30 ,000
837 ,000
,069,451
Source: Milling and Baking News. 1983 Milling
No. of
Wheat Flour
Mills
25
17
13
8
9
8
5
5
4
5
99
241
Directory Buyers1 Guide.
Kansas City, MO. Sosland Publishing Company, 1982, 120 pp. As
cited in Centaur Associates, October 13, 1983.
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90
Wheat kernal is extracted as flour with the remainder as raillfeed. The
majority of millfeeds are used in a wide variety of animal feeds. The value
of flour and other mill products approximated $5.7 billion in 1983 (Table
VIII-14).
Flour can be treated in a number of different ways to improve some particular
property. Such additives as maturing agents, bleaching agents and self-rising
ingredients are blended into the flour at the mill. Other additives such as
vitamins and iron are added at the bakery. Blended and prepared flour
products were valued at about $1.5 billion in 1983 (Table VIII-14}. Two other
industry components of this sector are rice milling and wet corn milling. The
value of shipments from rice milling and wet-corn milling industries were $1.5
and $4.6 billion, respectively in 1983.
3. Application Practices and Rates
The primary registered uses of EDB as a spot fumigant are in cereal processing
equipment, flour elevators, empty flour bins, flour-milling equipment, grain-
mill equipment and grain-milling machinery. EDB is particularly effective in
flour mills against most caramon stored product insect pests that infest
milling machinery and equipment. There are many ledges and obstructions in
milling machinery and equipment that form "dead spots" where product can
accumulate. These areas are particularly susceptible to infestation with
insects and proper "spot" treatment of these critical locations prevents
insect growth and reproduction.
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Table VIII-14. Value of Shipments for Selected Industries and Years
Industry 1972 1977 1979 1980 1981 1982 1983 a/
Flour and other
grain mill
products 2,380 3,683 4,218 4,835 5,103 5,494 5,685
Rice milling 681 1,263 1,397 1,818 1,884 2,040 2,111
Blended and prepared
flour 705 1,012 1,172 1,289 1,369 1,460 1,511
Wet corn milling 832 2,015 2,442 3,239 3,378 4,479 4,634
Total 4,598 7,973 9,229 11,181 11,734 13,473 13,941
~aj Estimated. ~
Source: U.S. Department of GCranerce: 1983 U.S. Industrial Outlook. Washington,
D.C. 1983. pg. 37-2.
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92
In typical spot fumigation, a -70% EDB and 30% methyl .bromide formulation
is applied by mill employees or by ccnmercial applicators. The actual
application of the EDB product is to only certain parts or "spots" in the
milliny machinery. Fumigators move from the bottom of the mill to the top of
the mill fumigating individual pieces of equipment as they go.
Generally when a mill is fumigated, it is shut down. The milling equipment is
allowed to run dry to remove as much grain and flour from the milling machinery
as possible. Doors and windows are closed and locked except for the exit door
for the fumigators. Typically, the fumigatoral/ enter the mill wearing
appropriate full-face respirators applying the fumigant to the predetermined
spots, working floor-by-floor.
In most cases the applicator uses an application gun, which can be adjusted to
allow predetermined amounts of fumigant to be applied. Usually 1 to 4 ounces
of EDB-containing fumigant is used per "spot." As each spot is fumigated, the
applicator will close up the equipment so that the EDB will volatilize and
remain within the equipment for as long as possible.
When the application is complete, a process taking no more than a few hours,
the mill is locked and posted with warning signs. The "hold" time within the
mill is usually 24 hours, the time needed to kill the insects. Centaur (1983)
in case studies indicated that a hold time of 41 hours is cannon. In several
cases, Centaur reported that the applicators complete the fumigation by
Saturday noon and the mill remains closed and locked until Monday when it is
T/ Fumigation is always done by a minimum of two-person teams.
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93
aired out. Some time prior to the resumption of the milling operations, the
mill is aerated as much as possible by opening windows and doors and turning on
fans and milling equipment blowers. Start-up of mill operations occurs
anywhere from zero to several hours after reopening. In Centaur case studies,
the average time for reopening to start-up was 3.89 hours, but the range in
time varied from zero to 15 hours.
4. Projected Quantities Exceeding Maximum Permissible Residue
Levels
The eventual economic impacts of choosing a maximum permissible residue level
for EEB in flour will depend on the actual profile of residues existing in
flour and grain mill products. A variety of data on EDB residues have been
received from GMA, several states, and USEft. It is not known how
representative these data may be of actual residues across the nation but for
now, these data will be used in analyzing the economic impacts of the proposed
permissible residue levels. Quantities of stocks at mills, bakeries and retail
outlets with violative residues could not be estimated with available data.
Hie value of stocks potentially violative of each given level were derived
using the following methodology and assumptions.
a. All residue data from GMA/states/USDA were assembled into one
data base by statisticians in the ^ency's Office of Policy, Planning and
Evaluation. The percentage of samples of uncooked grain-based products
exceeding each level were derived fron OPPE printouts.
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94
b. The individual inventory values for wheat, corn, rice and
other uncooked grain-based product stocks were not immediately available. The
percentages of wheat, corn, and other grain-based products which exceed each
permissible residue level, were combined to form a single percentage. This was
accomplished by multiplying each percentage that exceeds the level by the food
factor coefficients utilized in the Tolerance Assessment System model. The TAS
model is the model utilized in determining dietary intake and risks from these
intakes elsewhere in the document.
c. About 2/3 of the flour, milled products and blended and
prepared mixes are baked within one month of milling. The remaining 1/3 of
these products are packaged in consumer-sized units and may remain on retail
shelves for an average of 4 months (but usually no longer than 8 months).
Milled-rice products were assumed to remain in inventory for 6 months.
5. Economic Impacts
a. Aggregate
Using the asssumptions and data previously discussed, the value of stocks
potentially violative were calculated. Table VIII-15 provides the percentage
of uncooked products projected to exceed permissible residue levels being
considered. For corn and other grain-based products, setting permissible
residue levels at 250 ppb or lower could threaten a considerable portion of
existing stocks. Only a small portion of wheat products (the major component)
would be affected until more restrictive action levels of 50 and 25 ppb are
enforced. Because wheat products are dominant, values of products exceeding
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95
Table VIII-15. Estimated Percentage of Samples and Value of Uncooked Products
Maximum
Permissible
Option Residue
Level
(PPB)
1 No Action
2 250
3 150
4 100
5 50
6 25
7 10
8 5
9 1
10 50/100
Above Maximum Permissible
Percent of Samples Above
Maximum Permissible
Residue Level
Wheat Corn Other
Percent -
N/A N/A N/A
0.9 5.6 0
1.6 7.3 0
2.4 7.9 2.2
6.3 11.9 2.2
12.5 15.2 2.2
22.3 23.8 4.3
33.4 36.3 6.5
N/A N/A N/A
1.6 7.3 0
Residue Level
Weighted
Average a/
N/A
1.2
1.9
2.9
6.2
11.0
19.4
29.1
N/A
2.9
Value of Products b/
Exceeding
Maximum
Permissible
Residue Level
$ million
N/A
22.4
35.5
54.2
115.9
205.7
362.8
544.2
N/A
54.2
a/ Samples were weighted using the following food factors: wheat = .73; corn = .1; and
other = .17
b/ Based on inventory value of $1.87 billion.
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96
permissible residue levels are relatively nominal at levels 100, 150 and 250
ppb. At 50 ppb, a significant percentage of wheat products were found to
exceed this residue level (6.3%). The value of products exceeding 50 ppb
approximates $120 million and would be expected to generate siynficant
economic disruptions. At the 5 ppb permissible residue level, severe
economic disruptions are likely for the short term (e.g. 6 months) as the
value of stocks exceeding this level is about $540 million.
b. Typical Firm
Although widely dispersed (Table VIII-12), the wheat flour milling industry
is dominated by a small number of large companies (Table VIII-13). The top
four companies have more than half the daily milling capacity of the
industry. For options 1 through 4 (Table VIII-15), producers of corn based
products face a much higher probability of having products in violation
than wheat cr other product manufacturers. The probabilities (measured in
percent) for corn and wheat products exceeding maximum permissible residue
levels began to converge at the more restrictive levels (50, 25 and 5 ppb}.
The probability at these levels of having products exceeding permissible
levels is about equal for corn and wheat products.
While large firms dominate, the impact of products exceeding any
permissible residue level may not accrue in proportion to production
capacity. As compared to anall firms, large firms may be able to mere
closely control the source of their grain input and be in a relatively
stronger position to produce below-permissible residue-level products.
Large firms would also be able to absorb product recall better. At this
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97
point, the distribution of the impacts on large and small firms cannot be
determined due to the anonymity of the sample origins. Under all but the
most restrictive residue levels, few firms would be expected to be
seriously affected. Some additional spot sampling of incoming grain for
EDB residues by millers can be anticipated at the cost of about $100 per
sample. Compared with other overall operational costs, costs at these
levels would be considered only incidental.
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98
D. Ready-to-Eat Grain Products
1. Profile
Grain for human consumption reaches the consumer in a variety of forms.
Major classes of grain-based food products include cereal breakfast foods,
bread and cake products, and cookies and cracker-type products. Table
VIII-16 provides recent data on the value of shipments for these groups of
food products. After accounting for inflation, these figures still reflect
slight real gains in shipments in recent years. Table VIII-17 provides a
profile of these same three industry segments.
2. Quantities Exceeding Allowable Levels
Estimation of economic impacts is dependent upon data submitted to the Agency
on EDB residues found in ready-to-eat products. Table VIII-18 provides the
percentages of products estimated to exceed the alternative residue levels
being considered. For those ready-to-eat products for which data on residues
are available, setting permissible residue levels as high as 50 ppb would
impact on only a small percentage of products in stock. Proceeding to lower
and lower permissible residue levels down to 1 ppb would place significantly
higher and higher portions of ready-to-eat product stocks in situations where
regulatory action might be taken.
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99
Table VTII-16. Value of Shipments for Selected Final
Grain-Based Products
Products
Value of Shipments
1980
1981
1982
Cereal Breakfast Foods
Bread, Cakes & Related Products
Cookies and Crackers
Total
3,476
11,703
4,036
19,215
-$ Millions
3,950 4,298
12 ,345 13,255
4,450 4,700
20,745
22,253
Source: U.S. Department of Conmerce, 1983.
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100
Table VI11-17. Industry Data for Segments of ReadyTo-Eat Grain-Based
Products Industry
No.
NO.
of establishments
of establishments
Cereal
Breakfast
Foods
48
13
Breads, Cakes
and Related
Products
3,062
1,945
Cookies
and
Crackers
324
152
with less than 20
employees
4 largest firm market
share 89%
Employment in
thousands 15.4
33%
178.0
59%
45.4
Source: U.S. Department of Commerce, 1983.
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101
Table VIII-18. Percent and Value of Existing Stocks of Ready-To-Eat
Grain- Based
Products Exceeding
Specified Maximum Residue
Levels for EDB
Option
1
2
3
4
5
6
7
3
y
10
Maximum
Permissible
Level
(ppb)
No action
50
30
20
10
5
2
1
<1
20/10 £/
Stocks Exceeding
Percent
N/A
0.1
0.9
1.5
6.1
8.7
N/A
19.2
N/A
1.5
Level
Value
($ mil.)
N/A
1.0
8.8
14.7
59.8
85.3
N/A
188.2
N/A
14.7
a/ Assumes 6 months enforcement at 20 ppb followed by permanent
enforcement at 10 ppb.
-------
The immediate initial effect of imposing a maximum permissible residue level
would depend on the volume and value of stock in inventory having EDB
residues from prior use of EDB as either a grain fumigant or a spot-fumigant
for milling equipment. Given the coincident imposition of an emergency
suspension of EDB use under FIFRA, the contamination of food products would
begin to decline from levels existing prior to the emergency suspension.
Hence, the volume and value of contaminated products having residues above a
given level would be limited to inventories of products at the time of the
emergency suspension and setting of maximum permissible residue levels.
Ready-to-eat baked goods have relatively short shelf lives and therefore
inventories must reflect this situation.
For bread and cake products, this analysis assumes that inventories would be
one week's sales. For other ready-to-eat products, an inventory of four
weeks1 sales is assumed. Using these factors and the sales fron Table
VII1-16, the value of inventories of ready-to-eat products are estimated to
be about $980 million in 1983 (assumes an inflation rate of 3.47% for
grain-based food products in 1983 over 1982). Using the percentages of
products exceeding the proposed permissible residue levels, the estimated
value of inventories potentially exceeding those levels can be calculated.
The results are shown in Table VIII-18. Clearly there could be major
economic dislocations depending on the option chosen. In this analysis, the
impact would range from less than $1 million to as much as nearly $190
million in value of ready-to-eat products that could be seized for exceeding
permissible levels for EDB residues.
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103
3. Economic Impacts
a. Aggregate
The wide range of impacts associated with the alternative permissible residue
levels need to be considered in the overall context of the ready-to-eat
grain-based product market. At the least strict or highest permissible
residue levels, the economic impacts would be relatively small, no more than
$10 million in an annual market of over $20 billion. At the more strict or
lower levels, the impacts would be significant at nearly $190 million, but
the value of commodities affected would still only account for less than 1
percent of annual sales of the affected product classes. The aggregate
impacts would likely result in short-term economic dislocations but would not
cause long-term industry disruptions.
b. Typical Firm
Referring back to Table VTII-17 which provides information on sane aspects of
the structure of the segments of the ready-to-eat grain-based industry, it
can be concluded that cereal breakfast foods is dominated by a small number
of large firms. On the other hand, the bread and cake industry is much more
atomistic with a much larger number of snail establishments. The cookies and
crackers segment fall in between the other two segments.
For several options considered, an individual firm would face a low
probability of having products in violation. For those firms that do have
such products, the impacts would generally be limited to the amount of
product in inventory. Both large and small firms would be potentially
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104
affected as there is nothing in these possible actions that is known to favor
one group over the other. Individual firms which happen to be small,
however, may be affected. The ability of such firms to absorb a recall of
its products must be questioned. At this point, it cannot be determined how
many small firms might be so adversely impacted as to cause business failure.
It can be concluded that under most optional permissible residue levels being
considered, that few firms would be expected to be impacted directly and in
a highly adverse fashion.
Individual firms oould also be affected if they felt it necessary to initiate
tests for EDB residues in the raw materials such as flour which they would
purchase in the future. Most major firms already use quality control
programs with respect to materials used to produce their outputs. The
addition of bests for EDB residues would cost an estimated $100 per sample.
For firms purchasing inputs in large volumes, the incremental costs would be
relatively minor. The cost of residue analysis would be much more
significant for firms that purchased materials in smaller lots but feel
compelled to test for such residues.
E. Value of All Grain and Related Products Exceeding Maximum Permissible
Levels
A summary of the value of all grain and related products that are estimated
to exceed maximum permissible residue levels is presented in Table VIII-19.
The values range from less than $50 million to near $1.6 billion with the
most restrictive option.
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105
Table VI11-19. Value of Grain Products Exceeding EDB Maximum Permissible Levels,
Maximum Permissible
Residue Level
No.
1
2
3
4
5
6
7
8
9'
10
11
ppb
None
50/250/5 ,000
30/150/3,000
20 A 00/2 ,000
10/50A ,000
5/25/500
2/10/200
1/5/100
<1A/100
2 ,OOOA ,000
30A 50/900
by Type of Product
Raw
Grain
$ 0
26
26
26
73
193
N/A
858
858
13/86
97
, February
Prepared/
Uncooked
$ N/A
22
36
54
116
206
363
544
N/A
54
36
1 , 1984
Ready- to- Eat
§ N/A
1
9
15
60
85
N/A
188
N/A
15
9
Total
N/A
49
71
95
249
484
N/A
1,590
N/A
82 A 55
142
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1C6
F. Summary of Agricultural and Food Industry impacts
FIFRA, Section 25, requires that the Administrator of EPA consider the
effects of a regulation upon production and prices of agricultural
commodities, retail food prices and otherwise on the agricultural economy.
In view of the projected aggregate effects from implementing the permissible
residue levels being evaluated in the options, there would probably be
notable temporary impacts with respect to the affected agricultural
commodities if certain of these levels were adopted as enforceable limits.
Most growers, grain dealers, milling firms, bakers, food processing
companies, and grocery related firms would be affected to seme degree.
Individuals and firms at each point in the chain from grain production to
consumer products may have to absorb losses totalling fron less than $50
million to as much as $1.6 billion depending on the residue levels chosen.
There would be the possibility of isolated and temporary dissruptions in
supplies of raw materials and final consumer commodities. The temporary
nature of the disruption, in some instances a matter of a few days, would
support the conclusion that overall supply and prices of agricultural
commodities would not be severely affected. In general, the dollar-value
impacts decline as one moves from the grain storage, through the grain
processing sector and finally into the retail sector. In no sector would
there be an expectation of any significant permanent structural or behavioral
changes.
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107
G. Summary of Small Business Impacts
The Regulatory Flexibility Act requires that agencies issuing regulations
take special note of the impacts of proposed regulations on small entities.
This analysis has focused upon the owners of grain which could be
contaminated by EDB residues, grain milling companies, and processors of
consumer readyto-eat products. The principal groups affected would be
farmers, grain storage companies, millers, and bakeries who might have raw
materials resulting in EDB residues above permissible levels as finished
products. In view of the projected overall aggregate impacts of implementing
the permissible residue levels, we conclude that, at certain levels, there is
a likelihood of an impact on the significant number of small businesses and
farms, many of which would be small entities. The number and profile of
those small entities could not be developed in detail with the data
available but is suggested in the foregoing analysis.
There is nothing in the proposals which would suggest that impacts would be
more likely to occur on small businesses than on larger ones. However, it
should be stated that in instances where residues would exceed permissible
residue levels and products would be taken from the market, there would be
significant economic impacts on those firms. Small firms would be less
financially capable of absorbing losses resulting from seizures of their
products. Countering arguments can be made that all adverse impacts from
this proposal should be temporary and henoe firms that can survive the
initial impacts would likely remain viable businesses.
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1C8
H. Economic Impacts of Emergency Suspension
1. Introduction
The Agency has evaluated the economic effects of an emergency suspension
of grain and flour milling uses of EDB. Economic impacts were separately
evaluated separately for a six-month period allocated for a suspension
proceeding and for two years which may be required to conduct the
cancellation hearings. The consideration of economic impacts stemming
from a suspension is limited to a two-year period because the maximum
projected length of a cancellation proceeding would be about two years. A
suspension order remains in effect only during a cancellation proceeding.
Thus, only the impact which would arise during this period would be at
issue in a suspension. Any impacts which would be caused by a suspension,
but which would be felt after this period, are also considered.
Economic impacts of suspending grain storage and milling/cereal processing
usage of EDB during the six-month period were estimated by assuming all
registered alternatives are available. The analysis generally provides
qualitative estimates of impacts since data are not available to support
precise quantitative estimates.
The Agency's analysis indicates that a six-month and two-year suspension
of grain and milling uses of EDB would not significantly affect U.S.
production or prices of any commodities or services in relevant sectors.
Economic impacts of the suspension would be minor in most cases, even at
the local/regional level.
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I U>
2. Grain Fumigants
a. Usage Profile
Details of the profile of the grain production industry have been
presented in Section VIII-B of this report and will not be repeated here.
EDB is used as a liquid grain fumigant in mixtures whose major
constitutients are carbon tetrachloride/carbon disulfide (CT/CD) and
carbon tetrachloride/ethylene dichloride (CT/EDC). EDB is also used in
combination with chloroform and CD, but the overall volume of this product
is small in comparison to the CT-based products. An estimated 425,000
gallons of formulated products containing 170,400 pounds of EDB active
ingredient were used for insect control in grain storage facilities in
1983. At typical application rates, approximately 202 million bushels of
grain stored in 1983 were treated with fumigants containing EDB (See Table
VTII-2). During the next 6 months, approximately 25%, or 51 million
bushels of grain would normally be treated with liquid grain fumigants
containing EDB. This is the approximate quantity that will need treatment
with other materials during the next six months if EDB is suspended.
The most likely alternatives to EDB-containing liquid grain fumigant
mixtures are the other mixtures of carbon tetrachloride/carbon disulfide
and carbon tetrachloride/ethylene dichloride at on-farm storage facilties.
At off-farm locations, either the CT/CD or the phosphine producing
products would be the major replacements. Both carbon tetrachloride-
containing products and the phosphine-producing products are currently in
widespread use and available in sufficient supplies to meet grain storage
treatment needs during either the six-month or two-year periods.
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110
Treatment costs with alternatives vary depending on many factors.
However, the available alternatives can be used at roughly the same (Table
VIII-20 and Table VII1-21) or less costs than the EDB-containing materials
without any significant loss in insect control. Moreover, the usage of
EDB-containing liquid grain fumigants during the first six months of the
year comprises only about 25% of annual usage. Thus, the demand for EOB
during the six-month anergency suspension period can be met by
alternatives.
b. Impact Analysis
If EEB-containing liquid grain fumigants are not available during a
six-month suspension period, treatment costs could decline slightly where
users shift from EDB to CT/CD containing products. Aggregate costs
(assuming all former BOB users shift to CI/CD products) for grain
fumigation could decline by $88,000 to $388,000. As for users who choose
to utilize the CT/EDC and phosphine products instead of EDB, the cost
increases experienced by CT/EDC users could be approximately offset by
cost decreases by phosphine users (Table VIII-22).
During a two-year period, treatment costs would decline by approximately
$348,000 to $1.5 million if former users of ED&-containing liquid grain
fumigants shift to the variety of available CT/CD products. Increased
costs that accrue to users who choose to use the CT/EDC product will be
offset by those users who can utilize the less costly phosphine producing
products.
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Ill
Table VIII-20. Prices for Selected Grain Fumigants a/, 1983-84
Product
%EDB
Unit
Price Per Unit
CT/CD/ECB/Sp2
Chlorofarm/EDB
CT/CD/EDB/SO^
CT/EDB/EDC/S02
CT/EDC/EDB
CT/CD (80-20)
CT/EDC (30-70)
CT/CD (85-15)
CT/CD/Sp2/Pentane
1.2
5.0
5.0
5.0
7.2
-0-
-0-
-0-
1 gal
53 gal
1 gal
5 gal
53 gal
5 gal
1 gal
53 gal
5 gal
54 gal
54 gal
5 gal
53 gal
5 gal
53 gal
5 gal
($)
7.95-9.75/gal
6.45/gal
6.45/gal
7.52/gal
5.20-6.30/gal
6.16-6.95/gal
6.65/gal
5.85/gal
6.50/gal
5.30/gal
5.15/gal
7.65/gal
5.30/gal
5.95/gal
5.30/gal
5.95/gal
Phosphine -0-
Flask
40/Flask
a/ EDB = ethyl ene dibrcraide
CT = carbon tetrachloride
CD = carbon disulfide
EDC = ethylene dichloride
S02 = sulfur dioxide
Phosphine = aluminum phosphide
Sources: J.M. Schultz Seed Company (November 14, 1983), Dieterich, IL.
Pueblo Chemical & Supply Co. (December 5, 1983), Hannibal, MO.
ADI Distributors Inc. (1983). Carmel, IN.
industrial Fumigant Co. (January 31, 1983). Olathe, KS.
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112
Table VI11-21. Comparative Treatment Costs for EDB and Alternative Liquid Grain
Fumigants, 1983-84
Product
CT/CD/EDB/S02
CT/CD/EDB/S02
CT/EDB/EDC/S02
CT/EDC/EDB
CT/CD/ (80-20)
CT/EDC
CT/CD (85-15)
CT/CD/S02/pentane
Phosphine
Unit
5 gal.
1 gal.
5 gal.
5 gal.
54 gal.
5 gal.
5 gal.
5 gal.
1,000 grams
Price Per
Gallon
(S)
6.45
7.95-9.75
6.16-6.95
6.50
5.30
7.65
5.95
5.95
$40/1,000 grams
Application
Rate a/
(gal ./I, 000 bu.)
2
2
2
2
2
3
2
2
150 grams
Material
Cost Per
1,000 Bu.
(S)
12.90
15.90-19
12.32-13
13.00
10.60
23.85
11.90
11.90
6.00
.50
.90
Note: Application costs were based on treatment rates for wheat stored in metal
bins. Treatment costs for shelled corn and crops stored in wooden bins are
higher for all liquid fumigants.
a/ Harein and Sumner, 1982.
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Table VIII-22. Estimated Treatment Costs Using EDB Alternatives for 6-Month
and 2-Year Periods
Product
EDB-oontaining
CT/CD-containing
CT/EDC-conta in ing
Phosphine
Range in
Treatment Cost
per 1000 bu.
(?)
12.31-19.50
10.60-11.90
23.85
8.00 £/
6-Month
Treatment
Costs a/
(? 000)
628-995
541-607
1,216
408
2-Year
Treatment
Costs b/
$ (000)
4,977-7,878
4,282-4,808
.9,635
3,232
Change in Treatment Costs
with Alternatives
6 months
($ 000)
-88 to -388
+221 to +588
-220 to -587
2 years
($ 000)
-348 to -1,535
+1,757 to +4,658
-1,745 to -4,646
a/ Assumes treatment of 51 million bushels of grain during the next 6 months.
b/ Assumes treatment of 202,000 bushels annually.
c/ Includes additional labor and materials charge of $2/1,000 bu.
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114
During either the six-month or the two-year time frames, users should not
experience any significant changes in the ability to control insects with
the CT/CD alternatives.
Overall for either time frame, the comparative costs of using other
registered and readily available materials, suggests that users should not
experience any sSrious economic impacts if EDB products are not
available.
3. Spot Treatment
EDB in combination with methyl bromide has been the most commonly used
funigant mixture to spot-treat for insect infestations in flour milling
machinery. There has been a significant decline in the use of the EDB/
methyl bromide mixture as concern has been raised with respect to the
safety of these products.
a. Usage/Profile
Details of the usage of EDB and the profile of the grain milling industry
have been presented in Section VIII.C.2 of this report. Major findings
are that up to 79% of all mills had been using EDB containing products
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115
prior to the summer of 1983. Spot treatment o£ milling equipment has been
done on a scheduled basis with treatments being applied about 10 to 11
times per year on average. Flour mills requiring treatment are dispersed
throughout the U.S. although there is increased concentration in the Corn
Belt, Northern Plains, and Northeast States.
b. Alternatives
Alternative means of insect control in grain milling equipment include the
use of other registered pesticides and increased diligence in cleaning and
sanitation of the mill machinery. The most likely chemical alternatives
to EEC-containing products would be methyl bromide and aluminum phosphide.
Other registered products containing ethylene dichloride and carbon
tetrachloride could also be used, but these products are less preferred as
the larger volume of liquid applied can leave residues that clog the
machinery when the mills are restarted following fumigation.
In addition to alternative chemical control measures, millers may need to
increase efforts in cleaning machinery. All grain product residues
should be removed when machinery is cleaned in order to remove food
sources and harborage for insects. The use of improved sanitation
practices and the available alternative chemicals will probably increase
the labor requirements for insect control in mills.
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1 16
c. Impact Analysis
Prior to the Agency's cancellation of EDB as a spot-furnigant to treat
cereal processing equipment, annual usage of EDB was approximately 300,600
pounds of active ingredient. Major millers stopped using EDB containing
fumigants in August/September of 1983, probably intending to await the
final outcome of the EDB cancellation hearing. There may currently be
usage of EDB by smaller mills, but this usage would have to cone frcm
existing stocks as none of the registered producers are currently
producing EDB containing products for spot-treating milling machinery. It
is estimated that usage has now declined to about 10 percent of its former
level. This situation is not likely to change over the next six months
since the milling industry no doubt is concerned with the public's concern
with respect to the wholesomeness of their products due to EDB residues.
Likewise, usage over the next two years would not be expected to be
significant.
The milling industry has the option of adopting the use of other
registered fumigants and strategies for insect control and apparently has
done so since the summer of 1983. Overall, the adoption of these
alternative control methods could increase insect control costs by $3.5 -
$4.0 million over the next six months and by $15.0 - $16.0 million over
the next two years. There remains seme uncertainty as to whether the mill
will be able to achieve insect control with the alternative chemical that
is comparable to control with EDB containing products.
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117
I. Economics References
1. ADI Distributors Inc. 1983. ADI 1983 Price Book. Carmel, IN.
2. Centaur Associates, Inc. 1983. Final Report. Analysis of Four
Industry Segments Vfaich Wbuld Be Affected By Proposed Standard
Contract J-9-F-2-0067. Prepared for the Occupational Safety and
Health Administration. October 13, 1983.
3. Conrath, W. P. Personal Communication with Roger C. Holtorf. 23
January 1984.
5. Data Resources, Inc. 1984. Agricultural Review. Lexington, MA.
6. Development Planning and Research Associates. 1979. Preliminary
Benefit Analysis. Cancellation of Ethylene Dibromide in Fumigants
for Stored Grain. Manhattan, KS.
7. Development Planning and Research Associates. 1979. Preliminary
Benefit Analysis of Cancellation of Ethylene Dibrcmide in Fumigants
for Flour Milling Equipment. Manhattan, KS.
8. E.P.A. 1983. Ethylene Dibromide (EDB) Position Document 4. Office
of Pesticide Programs. Washington, D.C.
9. Harein, P.K. and W. Sumner, 1982. A Report on the Use of CC14 on
Farm-Stored Drain. Draft. Univ. of Minnesota, St. Paul, MN.
10. Holtorf, R.C. and G. F. Ludvik. 1981. Grain Fumigants: An Overview
of Their Significance to U.S. Agriculture and Commerce and Their
Pesticide Regulatory Implications. Office of Pesticide Programs.
U.S. E.P.A. Washington, D.C.
11. Industrial Fumigant Co., 1983. Products and Services Price List.
Olathe, KS.
12. Inglett, G.E. 1974. Wieat: Production and Utilization. AVI
Publishing Co., Inc. Westport, CN.
13. , 1970 Corn: Culture, Processing, Products. AVI
Publishing Co., Inc. Westport, CN.
14. Pueblo Chemical & Supply Co. 1983. Price List. Hannibal, MO.
15. Roan, C.C. Senior Consultant, Hopes Consulting Inc. letter to
William D. Ruckelshaus. 17 January 1984.
16. J.M. Schultz Seed Company. 1983. Wholesale Price List. Dieterich,
IL.
17. Temple, Barker & Sloane, Inc. 1984. Economics of Immediate EDB
Removal. Lexington, MA.
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118
18. U.S. Department of Commerce. Bureau of the Census. 1981. 1978
Census of Agriculture. Summary of State Data. Vol. 1, Part 51.
Washington, D.C.
19. U.S. Dept. of Commerce. Bureau of Industrial Economics. 1983 U.S.
Industrial Outlook. Washington, D.C.
20. USDA EPS. 1983. Feed-Outlook and Situation Report. Washington,
D.C.
21. USDA SEA. 1979. Insect Control in Farm-Stored Grain, Fanners
Bulletin No. 2269. Washington, D.C.
22. USDA SRS Crop Reporting Board. 1984 Grain Stocks. January 23.
Washington/ D.C.
23. GSDA SRS. Crop Reporting Board., 1983. Agricultural Prices.
Washington, D.C. December.
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