DIBROMOCHLOROPROPANE (DBCP): FINAL POSITION DOCUMENT
SPECIAL PESTICIDE REVIEW DIVISION
OFFICE OF PESTICIDE PROGRAMS
U.S. ENVIRONENTAL PROTECTION AGENCY
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DIBROMOCHLOROPROPANE
Authors
Jeff Kempter, Project Manager, SPRD, OPP
Mitchell H. Bernstein, Attorney, OGC
Technical Support Team
Dr. David Severn, Chemist, CED, OPP
Dr. George Beusch, Chemist, CED, OPP
Dr. James Horst, Economist, CED, OPP
Mark Luttner, Economist, CED, OPP
Roger Holtorff, Economist, CED, OPP
Clara Roy, Economist, CED, OPP
Linda Zygadlo, Economist, CED, OPP
Roger Hogan, Aquatic Biologist, CED, OPP
Edward Fyte, Wildlife Biologist, CED, OPP
Willard Cummings, Plant Pathologist, C'ED, OPP
John Worthington, Chemist, CB, OPP
Roger Gardner, Toxicologist, CED, OPP
Dr. Chad Sandusky, Toxicologist, CED, OPP
Robert Heath, Statistician, TSD, OPP
Dr. Jack Griffith, Epidemiologist, TSD, OPP
Frank Davido, Biologist, TSD, OPP
Dr. Frederick Kutz, Biologist, TSD, OPP
Tom Dickson, Life Scientist ,TSD , OPP
Dr. Roy Albert, Chairman, Carcinogen Assesment Group
EPA Pesticide Chemical Review Committee (PCRC)
Dr. William A. Wel;s, Chairman, SPRD, OPP
David E. Menotti, OGC
Dr. Allen Jennings, SRD, 0PM
Mr. John J. Neylan, PED, OE
Dr. Donna Kuroda, OHEE, ORD
Dr. Richard N. Hill , OTS
Dr. Elizabeth Anderson, CAG, ORD
Special Acknowledgements
Geraldine Werdig, Branch Chief, SPRD, EPA
Paul N. Parsons, Writer/Editor, SPRD, EPA
Herman Delvo and Bob Torla, U.S. Department of Agriculture
U.S. Department of Agriculture Benefits Assessment Team
Jim Estep, Flo Ryer and David Welsh, Occupational, Safety
and Health Administration
Dr. Paul Corneliussen, Food and Drug Administration, HEW
Dr. Gene Kennedy, National Institute for Occupational
Safety and Health
Drs. Keith Maddy, Paul Kurtz and Jake MacKenzie, California
Department of Food and Agriculture
Drs. C.-H. Hall, R.A. Davis, W. Bontoyan, B.A. Schneider and
D. Hansen, CBIB, TSD, OPP.
Bob Kuykendall, Nancy Frost, Barbara Nellor and Sue Gallion
EPA Region 9
Dr. Elizabeth Weisburger, National Cancer Institute
Dr. Eric Sansone, Frederick Cancer Research .Center
Dr. Henry Enos, University of Miami School of Medicine
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Dibromochloropropane (DBCP): Final Position Document
TABLE OF CONTENTS
I. Introduction
A. The statute .1
B. The RPAR Process....." „ 2
C. Regulatory Actions Concerning DBCP ....3
D. Organization of Position Document 6
II. Risk Assessment
A. Toxicological Effects in Laboratory Animals
and Humans 8
(1) Cancer 8
(a) Laboratory animals studies 8
(b) CAG determination of carcinogenicity.12
(c) RPAR rebuttal comments 14
(d) Conclusions 16
(2) Adverse Reproductive Effects 16
(a) Laboratory animal studies 16
(b). Human epidemiol-ogical studies 19
(c) RPAR rebuttal comments 30
(d) Conclusions 30
(3) Other Toxicological Effects 31
B. Human Exposure to DBCP.. 31
(1) Ingestion of DBCP residues.-... ..34
(2) Inhalation of DBCP by applicators
during application 35
(3) Inhalation of DBCP during reentry into
treated areas. .37,
(4) Dermal exposure 1 ....37
C. Determination of Risk 38
(1) Cancer. 38
(a) General .38
(b) Rebuttal comments ." 39
{c) Final cancer estimates ........41
(2) Adverse reproductive effects 43
III. Benefits Analysis
A. Background. 44
B. The Cooperative Assessment 45
C. Benefits Analysis 48
D. Major Conclusions ....50
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IV. Development and Selection of Regulatory Options
of Action
A. Introduction 52
B. Rationale for Development of Options 52
C. Risk Reduction Methods 54
(1) Classification for restricted use 54
(2) Reduction of ingestion exposure..........55
(3) Reduction of dermal exposure .56
(4) Reduction of inhalation exposure by
use of respirators or closed systems.....58
(5) Reduction of inhalation exposure by
establishment of reentry intervals 60
(6) Reduction of inhalation exposure by
prohibiting irrigation method of
application 61
D. Regulatory Options Action Selected 63
V. Review of the Impacts of the Major Options
A. Citrus 70
B. Cotton 78
C. Grapes 83
D. Peaches and Nectarines 89
E. Peanuts .. .95
F. Pineapple.. .100
G. Soybeans '...... 104
H. Commercial Vegetables, Melons and Straw-
berries .109
I. Commercial Turf.. ....114
J. Strawberry Nursery Stock 119
K. Other Berries 124
L. Plums 129
M. Almonds 134
N. Home Gardens 139
O. Home Lawns . 143
P. Ornamentals ,.147
Q. Apricots, Cherries, Figs and Walnuts 152
R. Bananas .................156
VI. Summary of Proposed Course of Action 159
Bibliography
Tables
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.List of Tables
Table 1:
Table 2:
Table 3:
Table 4:
Table 5:
Table 6:
Table 7:
Table 8:
Table 9:
Table 10:
Table 11:
Table 12:
Table 13:
Table 14:
Table 15:
Table 16:
Table 17:
Table 18:
DBCP Sperm Count {1,000,000/ml) Data Adjusted
to Include Azoospermic Men.
Estimated Cancer Risks to U.S. Population from
Consuming Potential Food Residues of DBCP.
Estimated Cancer Risks.to Applicators From
Inhalation of DBCP
Estimated Cancer Risks Resulting From Poten-
tial Exposures to DBCP
Potential Human and Environmental Hazards
from Substitute Pesticides for DBCP.
DBCP Suspension Order.
Costs of and Risk Reduction Offered by Pro-
tective Clothing and Respirators.
Economic Impacts of Cancelling Registrations
of DBCP-
Substitute Pesticides Dsed if DBCP is Cancelled.
DBCP Use Patterns.
DBCP Applicator Exposure: Number of Persons
"Exposed and Duration of Exposure.
Estimated Food Residues of DBCP in Commercial
Crops.
Toxicological Test Results for DBCP.
DBCP Use Patterns.
Impacts of Regulatory Options for DBCP
for Citrus in California, Texas, Florida and
Arizona.
Impacts of Regulatory Options for DBCP
for Cotton.
Impacts of Regulatory Options for DBCP
for Grapes in California.
Impacts of Regulatory Options for DBCP
for Peaches and Nectarines in California .and
Eastern United States.
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Table 19:
Table 20:
Table 21:
Table 22:
Table 23:
Table 24:
Table 25:
Table 26:
Table 27:
Table 28:
Table 29:
Table 30:
Table 31:
Table 32:
Table 33:
Impacts of Regulatory Options for DBCP
for Peanuts in Texas, Oklahoma and the South-
eastern United States.
Impacts of Regulatory Options for DBCP
for Pineapples in Hawaii.
Impacts of Regulatory Options for DBCP
for Soybeans in the Southeastern United States
Impacts of Regulatory Options for DBCP
for Commercial Vegetables, Melons and
Strawberries Nationwide.
Impacts of Regulatory Options for DBCP
for Commercial Turf (Golf Courses in Florida,
Texas, South Carolina and Georgia).
Impacts of Regulatory Options for DBCP
for Strawberry Nursery Stock in Delaware and
Maryland.
Impacts of Regulatory Options for DBCP
for Other Vine Berries in Oregon, Washington
and California.
Impacts of.Regulatory Options for DBCP
for Plums in California.
Impacts of Regulatory Options for DBCP
for Almonds in California.
Impacts of Regulatory Options for DBCP
for Home Gardens in the South.
Impacts of Regulatory Options- for DBCP
for Home Lawns in Florida.
Impacts of Regulatory Options for DBCP
for Ornamentals in Florida, Georgia and South
Carolina.
Impacts of Regulatory Options for DBCP
for Apricots, Cherries, Figs and Walnuts in
California.
Impacts of Regulatory Options for DBCP
for Bananas in the United States.
Summary of Selected Courses of Action and
Their Impact.
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DIBROMOCHLOROPROPANE (DBCP): FINAL POSITION DOCUMENT
I, Introduction
A. The Statute
The Federal Insecticide, Fungicide/ and Rodenticide Act, as
amended ("FIFRA") (7 O.S.C. $136 et seq.) regulates all pesticide
products. Under S12(a)(l)(A) of FIFRA all pesticide products
must be registered before they may be sold or distributed.
Before the Administrator may register a pesticide, however,
he must determine that its use will not result in "unreasonable
adverse effects on the environment," defined by $2(bb) of
FIFRA to mean "any unreasonable risk to man or the environment,
taking into account the economic, social, and environmental
costs and benefits of the use of any pesticide." In other
words, any decision concerning registration must take into
account both the risks and the benefits from the 'use of the
pesticide.
Section 6(b) of FIFRA authorizes the Administrator to
issue a notice of intent to cancel the registration of a pesticide
or to change its classification if it appears to him'that the
pesticide or its labeling "does not comply with the provisions of
*
[FIFRA] or, when used in accordance with widespread and commonly
recognized practice, generally causes unreasonable adverse effects
on the environment-." Thus, the Administrator may cancel the
registration of a pesticide whenever he determines that it no
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longer satisfies the statutory standard for registration; that
standard requires, among other things/ that the pesticide not
cause "unreasonable adverse effects on the environment" (FIFRA
§3(c) (5)(C)). He may also cancel the registration of a pesticide
if its labeling does not comply with the misbranding provisions
of FIFRA which require-the labeling to contain language "adequate
to protect health and the environment" (FIFRA §2(q)).
B. The "RPAR" Process
The Agency has designed a process to gather
risk and benefit information about a problem pesticide and to
make a balanced decision concerning .it in an open manner allowing
maximum participation by all interested groups. This process is
known as the Rebuttable Presumption Against Registration process;
it is set out in 40 CFR S162.11.
In broad summary, these regulations describe various risk
criteria, and provide that a Rebuttable Presumption Against
Registration ("RPAR") shall arise if the Agency determines that
any of those criteria has been met. Once-a rebuttable pre-
sumption has arisen/ registrants, applicants and interested
persons are offered an opportunity to submit evidence in rebuttal
of the presumption. Those persons may also submit, evidence on the
economic, social and environmental benefits of any use of the
pesticide. If the presumptions of risk are not rebutted, the
benefits evidence submitted to or gathered by the Agency is
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evaluated and considered with the risk information. Various risk
reduction methods and their costs are then analyzed and it is
determined -whether the pesticide may be regulated by their use
so as to strike the.statutory balance between risks and benefits,
If the statutory balance cannot be achieved for any use, the
registrations of the pesticide for that use must be cancelled.
C. Regulatory Actions Concerning DBCP
.(!)• Issuance of the RPAR
On September 15, 1977, the Agency's Office of Pesticide
Programs ("OPP") issued a Notice of Rebuttable Presumption
Against Registration and Continued Registration of Pesticide
Products Containing Dibromochloropropane (DBCP) (42 FR 48026,
September 22,. 1977). That notice was supported by Position
Document 1 on DBCP, which described the physical and chemical
characteristics of DBCP, its registered uses arid existing
tolerances, and the toxicological test results then available
about it. Position Document 1 also described the evidence
supporting the conclusions that DBCP met two RPAR risk triggers:
the oncogenic trigger (§162.11(a)(3)(ii)(A)); and the "other
chronic or delayed toxic effects" trigger (§162.ll(a)(3)(ii)(B)),
based on evidence of its adverse reproductive effects in males.
(2) Suspension of DBCP
Based on the results of an intensive, expedited investi-
gation of the human health hazards of DBCP, the Administrator
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determined on September 8, 1977 that suspension of the regis-
trations of DBCP products was "necessary to prevent an imminent
hazard during the time required for cancellation or or change in
classification proceedings" (FIFRA S6(c}). Accordingly, the
Administrator issued on that date a Notice of Intent to Suspend
and Conditionally Suspend Registrations of Pesticide Products
Containing Dibromochloropropane (42 FR 48915, September 26, 1977)
*J
("Notice of Intent to Suspend").
On October 27, 1977, the Administrator issued a Suspension
Order which suspended the registrations of all pesticide
products containing DBCP (42 FR 57543, November 3, 1977). The
Suspension Order implemented two separate suspension actions: an
unconditional "specific food use" suspension of DBCP products
registered for use on any of nineteen (19) food crops, and a
conditional suspension of all DBCP products. Under the
conditional suspension, registrants were afforded an opportunity
for relief from the Suspension Order by obtaining an interim
registration amendment implementing certain classification and
labeling changes as set forth in the Suspension Order.
Section 6(c)(l) of FIFRA states that no suspension order
may be issued unless a notice of intent to cancel the registra-
tions or change the classifications of the pesticide products
Jy "Imminent hazard" is defined by FIFRA as "a situation which
exists when the continued use of a pesticide during the time
required for cancellation proceeding would be likely to result in
unreasonable adverse effects on the environment ..." (FIFRA
S2(1)J.
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concerned has already been issued, or is issued with the sus-
pension order. Accordingly, on October 27, 1977, the Adminis-
trator also issued a Notice of Intent to Cancel the Registrations
or Change the Classifications of Pesticide Products Containing
Dibromochloropropane (DBCP), and Statement of Reasons (42 FR
57545, November 3, 1977) ("Notice of Intent to Cancel").
As explained in the Notice of Intent to Cancel, the
information then available to the Agency on the issues relevant
to an ultimate cancellation decision, including information
on both the risks and benefits of DBCP, was incomplete. The
Administrator further noted that the RPAR process—which was
already initiated for DBCP—was designed precisely to permit
the Agency to gather the best available information about a
problem pesticide. Accordingly, the Administrator 'determined
•
that the decisions reached in the RPAR review, embodied in this
Final Position Document, could form the basis of an amendment
to the Notice of Intent to Cancel.
(3) pSHA Standard for Occupational Exposure
to DBCP
On Ma-'ch 17, 1978, the Occupational Safety and Health
Administration ("OSHA") published an occupational safety and
health standard for occupational exposures to DBCP. Among
other things, the standard limits employee exposure to DBCP in
the workplace to 1 part DBCP per billion parts of air (Ippb) as
an 8-hour time-weighted average and prohibits all eye and skin
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contact with DBCP (43 FR 11514).
The permanent standard was promulgated through notice-
and-comment rulemaking after an informal public hearing; it
superseded the emergency temporary standard ("ETS") issued by
OSBA on September 9, 1977 (42 FR 45536).
OSHA's issuance of the ETS was coordinated with the Agency's
issuance of the Notice of Intent to Suspend, and both agencies
have cooperated in the formulation of an overall regulatory
strategy designed to protect the public against the hazards of
DBCP. The permanent OSHA standard specifically states that it
does not apply to "exposure to DBCP which results soley from
the application and use of DBCP as a pesticide" (29 CFR 1910.
1044; 43 FR 11527, March 17, 1978). Those exposures are pre-
cisely the ones which the Agency reviewed in the RPAR process.
The Agency believes that the actions which it is proposing today
complement the permanent OSHA standard and provide comprehensive
protection to all members of the public against the risks from
all DBCP exposures.
D. Organization of This Final Position Document
This Final Position Document contains six parts. Part I is
this introductory section. Part II is an evaluation of the risks
associated with DBCP on which the RPAR action was based. It
includes descriptions of experimental and epidemiological data,
Agency responses to RPAR rebuttal comments, and the final Agency
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Agency responses to RPAR rebuttal comments, and the final Agency
assessment of those risks. Part III is a description of the
process which the Agency used to gather and analyze information
on the economic benefits of DBCP, on a use-by-use basis. Part
.IV describes the range of regulatory options available to the
•Agency for the reduction of unreasonable risks, and explains
/
the basis of the Agency's selection of six alternative courses
of action for each registered use of DBCP. Part V is the Agency's
evaluation of the risks and benefits associated with DBCP on a
use-by-use basis, including an evaluation of the risks from
substitute chemicals for DBCP, and the Agency's evaluation
of the viability of each available regulatory option. The
beneficial and adverse impacts of each option are* evaluated,
and the rationale for the final decision on each use is set
forth. Finally, Part VI summarizes the regulatory action which
the Agency proposes to take, in the aggrega-te, concerning
the registrations of pesticide products containing DBCP-
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II. Risk Assessment of DBCP
In its Notice Of Intent To Suspend, the Agency assessed the
potential human health risks to persons exposed to DBCP- This
assessment was performed in three parts. First, the toxicological
effects of DBCP, as demonstrated in laboratory animal tests or in
human epidemiological studies, were identified. Second, the
populations likely to be exposed to DBCP, and the routes of their
exposures, were identified, and the durations and levels of their
exposures were estimated. Third, based on these estimates and
using appropriate mathematical models, the degree of risk to each
.exposed, population was either quantified or qualitatively described.
This Final Position Document uses the same approach. The
scope of review, however, has been expanded to include new data
submitted in rebuttal comments to the RPAR, and new data obtained
or generated by the Agency during the RPAR review.
A. Toxicological Effects Of DBCP In Laboratory Animals
And In Humans
(1) Cancer
(a) Laboratory Animal Studies
i. Between 1972 and 1974, the National Cancer Institute
(NCI) sponsored a long-term bioassay of DBCP for possible
carcinogenicity, using Osborne-Mendel rats and B6C3F1 mice,
at Hazleton Laboratories. DBCP in corn oil was administered
by gavage (i.e., by a tube into the stomach) 5 days a week to
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groups of 50 males and females of each species, at two dose
levels per species. The time-weighted average doses of DBCP in
this chronic study were 29 mg/kg/day for the high dose rats
of both'sexes, and 15 mg/kg/ day for the low dose rats of
both sexes; the time-weighted average doses for the high dose
male and female mice were 219 and 209 mg/kg/day, respectively,
and for the low dose male and female mice were 114 and 110
mg/kg/day, respectively.
For each species, 20 animals of each sex were used as vehicle
controls, and were intubated with corn oil at the same time that
dosed animals were intubated with DBCP mixtures. In addition, 20
animals of each sex were placed on test as untreated controls
for each species, and did not received any gavage treatments.
DBCP was administered to the high dose male and female rats
for 64 weeks prior to sacrifice, and to the low dose female rats
for 73 weeks prior to sacrifice. The low dose male rats were
treated for 78 weeks, followed by an additional 5 weeks of
observation. The high dose male and female mice were treated
for 47 weeks prior to sacrifice? the low dose male mice were
treated for 59 or 60 weeks prior to sacrifice; and the low cose
female mice were treated for 60 weeks prior to sacrifice.
The results of that study have been published by the NCI
in "Bioassay of Dibromochloropropane for Possible Carcinogenicity"
(NCI, 1978) .
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The report concluded (at p.v):
"In rats and mice of both sexes, statisti-
cally significant incidences of squamous-cell
carcinomas of the forestomach occurred in each
dosed group and a significant positive association
existed between dosage level and tumor incidence.
The incidences of adenocarcinomas of the mammary
gland were statistically significant in female
rats when the treated groups were compared to the
controls. Tox.ic nephropathy was also observed
at elevated incidences in all of the treated rats
and mice.when compared to their respective un-
untreated or vehicle control groups.
"Under the conditions of this study, DBCP is a
stomach c?rcinogen in rats and mice of both sexes
and is carcinogenic to the mammary gland in female
rats."
ii. A bioassay on albino rats/ sponsored by Dow Chemical
Company, was also conducted at Hazleton Laboratories. DBCP
was administered in the diet at levels of 0.3, 1.0, and 3.0
mg/kg/day for 104 weeks, to groups of 60 female and 60 male
rats for each dose. An additional group of 60 female and 60
male rats served as the control group and received the
laboratory diet only.
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A 78-week progress week report received by the Agency on
July 21, 1977 indicated a statistically significant incidence
of "possible neoplasms" of the stomach, in both males and
females receiving 1.0 and 3.0 mg/kg/day (Piccirillo, 1977).
On November 8, 1977, Dow submitted its "Final Report, 104-
week Dietary Study in Rats, Project No. 174-122", dated October
28, 1977, to the Agency as part of Dow's rebuttal comments to
the RPAR (RPAR Comment No. 3A, [30000/19]). That report, as
well as the transmittal letter, indicated "a higher than control
incidence of raised areas or nodules in the stomachs of the
mid- and high-dose males and females," but did not include the
results of any histopathologic examinations. In July of 1978,
Dow submitted Hazleton's "Supplementary Histopathology Report
to Final Report dated October 20, 1977" (Hazleton Laboratories,
1978). Although its late submission precluded detailed Agency
review, the report did conclude that dietary administration of
DBCP "resulted in a tumorigenic effect in the kidneys and
nonglandular region of the stomach ...."
iii. Dow Chemical Company has sponsored another bioassay
at Hazel ton Laboratories, using groups of 50 male and 50 female
Hazleton Laboratories, albino mice which were administered DBCP
in the diet at levels of 0, 0.3, 1.0 and 3.0 mg/kg/day for 78
weeks. The Agency received a copy of a "52-Week Progress
Report" in August, 1977 (Schober, 1977). Although the study
was scheduled to be terminated in December of 1977, the Agency
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has not yet received any final report or histopathological
evaluations from the study.
iv. Another bioassay is currently in progress at the NCI,
in which, mice and rats are being exposed to 0.6 and 3.0 ppm
DBCP via inhalation. The results of that study will not be
available for several months.
v. The Agency has received a preliminary report from
Professor Van Duuren of New York University Medical Center
on a skin bioassay of DBCP in groups of 30 female Swiss mice.
Although the histopathology was still incomplete at the time
of the report, the report indicated a high incidence of tumors,
including squamous carcinomas of the forestomach, in the
treated animals (Van Duuren, 1978).
(b) CAG Determination Of Carcinogenicity
The Agency's Carcinogen Assessment Group ("CAG"), an
advisory body which analyzes of data related to the carcinoge-
nicity of test substances, makes judgments concerning the human
risk of suspected carcinogens. These analyses are performed in
accordance with the Agency's "Interim Procedures and Guidelines
for Health Risks and Economic Impact Assessment of Suspected
Carcinogens" (41 PR 21402, May 25, 1976) (The "Cancer Guide-
lines"). */
jy The Cancer Guidelines represent the Agency's accumulated
expertise concerning .the identification and assessment of
carcinogens. The approach taken in the Cancer Guidelines is
(CONTINUED)
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Although the final NCI report was not formally released
by NCI until 1978, at the time of issuance of the RPAR the CAG
had available to it, and reviewed, the final tabular data from
that study. The CAG determined that DBCP produces high levels of
squamous cell carcinomas of the stomach in rats and mice of
both sexes at both exposure levels. Among rats, gastric
carcimonas were observed in 47/50 (94%) of the high dose males,
47/50 (94%) of the low dose males, 29/49 (59%) of the high
dose females, and 38/50 (76%) of the low dose females. Among
mice, the gastric carcinomas were observed in 47/49 (96%) of
high dose males, 43/46 (93%) of the low dose males, 47/48 (98%)
of- the high dose females, and 50/50 (100%) of the low dose females
These incidences were highly significant (p less than .001) when
compared to both the vehicle and untreated controls for both
species, in which zero gastric carcinomas occurred.
In addition, both DBCP-treated groups of female rats showed
significant increases (p less than .005) in the incidence of
\
mammary adenocarcinomas. Mammary adenocarcinomas occurred in
31/50 (62%) of the high dose female rats, 24/50 (48%) of the low
dose female rats, and in 2/40 (5%) of both controls combined.
jV Continued from previous page
generally supported by the final report of the National Cancer
Institute's National Cancer Advisory Board Subcommittee on
Environmental Carcinogenesis, entitled "General Criteria for
Assessing the Evidence for Carcinogenicity of Chemical Sub-
stances" (also known as the "Shubik Committee Report").
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Th e CAG also observed that the times to tumor tended to be
very short, and that the tumors metastasized to a wide variety
of other organs. Accordingly, the CAG concluded that:
- "There is strong evidence that DBCP is likely to be
carcinogenic to man." (CAG, 1^77)
(c) RPAR Rebuttal Comments
The only comment submitted in rebuttal of the Agency's
determination of the carcinogenicity of DBCP was the statement
of Dr. Gehring, Director of the Toxicology Research Laboratory
of Dow Chemical USA (RPAR Comment No. 3A [30000/19]). Dr.
Gehring questioned whether the excess cancer observed in the NCI
study was in fact due to a primary carcinogenic effect of DBCP,
and argued that the doses used produced severe debilitation and
excessive mortality which may have contributed to the effects
observed.
In response, the CAG noted that there is no evidence that
nonspecific organ damage is the cause of cancer. Indeed, it
stated that excessive toxicity and mortality would be expected
to suppress carcinogenicity. (Albert, 1978). Moreover, Dr.
Gehring did admit that the NCI study indicated that cancer "may
be induced by ingestion of DBCP"; he further stated that that
conclusion "has been rendered more valid" by the interim
results of the Dow-Hazleton rat study, since the doses used in
that study "are unlikely to have caused irritation sufficient
to increase the induction of cancer and these doses do not
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appear to have affected dramatically the health status of the
rats on test" (RPAR Comment No.3A [30000/19]).
Similarly, Dr. Ge.hring suggested that the method of
administration (i.e., by gavage) may have contributed to the
induction of the observed neoplasms, since DBCP is a skin and
mucous membrane irritant and proliferative lesions of the
forestomach have been noted in other bioassays where chemical
irritants have been administered by gavage.
In response, the CAG.noted that most of the halogenated
aliphatic hydrocarbons, including DBCP, are known to be skin
and mucous membrane irritants. However, it also noted that the
NCI had tested thirteen aliphatic hydrocarbons for carcinogen-
icity; they were administered by oral intubation in 200 Osborne-
Mendel rats and 200 B(TC3F1 mice of both sexes. Of the thirteen
compounds tested, only three induced squamous-cell carcinomas of
the forestomach. (Albert, 1978). In addition, Dr. Gehring admitted
that the results of the Dow-Hazleton study validate the conclusion
that ingestion of DBCP causes cancer, since the doses used in that
experiment were unlikely to have caused irritation sufficient to
increase the induction of cancer (RPAR Comment No. 3A [30000/19]).
(d) Conclusions on the Carcinogenicity of DBCP
The Agency concludes that the presumption of risk arising
from the "oncogenic trigger" (§162.11(a)(3)(ii)(A)) has not been
rebutted for DBCP since no applicant or registrant has sustained
the affirmative burden of proof set forth in §162.11(a)(4).
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Since valid data demonstrate that DBCP is a strong carcinogen
in both sexes of two animal species, the Agency concludes that
DBCP presents a significant risk of cancer to human beings who
are exposed to the chemical.
(2) Adverse Reproductive Effects
(a) Laboratory Animal Studies
In the Notice of Intent to Suspend, the Agency summarized
several published reports which indicated that DBCP significantly
damages the testes of several animal species. In particular, the
studies published by Torkelson (1961) showed that groups of 15
rats exposed to DBCP vapors of 0, 5, 10, 20, or 40 ppm for a
total of 50 exposures over 7 weeks, developed gross lesions in
the testes ,at the 10 ppm and higher dosages. Testes atrophied
in treated rats at 20 and 40 ppm, while testicular'weight was
reduced in some males at as low as 5 ppm. In addition, three
male rabbits and 10 male guinea pigs exposed to 12 ppm DBCP
vapors 66 times showed severe testicular atrophy and degenera-
tion. The authors noted that "the most striking observation
at autopsy was severe atrophy and degeneration of the testes
of all species."
The Notice of Intent to Suspend also referred to several
Russian studies which indicated adverse reproductive effects in
rats resulting from exposures to DBCP. (Faidysh et al. 1974,
Faidysh et al. 1970, Rakhmatullayev 1971, Reznik and Sprinchan
1975).
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-17-
Bowever, Agency scientists have identified several factors
which preclude comparison of the Russian results with those
of Torkelson. For example, the chemical analysis of Russian
DBCP is not provided; the "index of spermatogenesis" is not
de.fined; and many of the studies wer'e performed with only
one dose with no description of how that dose was chosen.
Accordingly, the Agency can now only conclude that the results
and conclusions of the Russian studies are apparently similar
to those described above -
Three other sets of experimental data, not cited in the
Notice of Intent to Suspend, have also been found in the
course of the RPAR review. First, the NCI's "Bioassay of
Dibromochloropropane for Possible Carcinogenicity" (NCI, 1978)
referred to in Section II A (l)(a) earlier, includes a table
"Summary of the Incidence of Nonneoplastic Lesions in Male
Rats Treated with DBCP." The table indicates that atrophied
testicles were observed in 76% (38/50) of male rats receiving
15 mg/kg/day, 5 days/week, for 78 weeks, and in 96%(47/49) of
male rats receiving 29 mg/kg/day, 5.days/week, for 64 weeks.
Second, the Dow Chemical Company reports that in the
Hazleton Laboratories chronic ingestion study cited earlier in
Section II A (l)(a), no DBCP-related histomorphologic alterations
were revealed by examination of the testes of the high dose
(3 mg/kg/day) treated rats (RPAR Comment No. 3A [30000/19]).
-------
-18-
The Agency has not reviewed the raw data underlying these
histopathological conclusions.
.Third, Shell Oil Company submitted the results of a study
by the Department of Pharmacology and Experimental
Therapeutics, University of California, School of Medicine,
which were not reported by Torkelson (Bines et al., 1956) (RPAK
Comment No.20A [30000/19]). In that study, groups of 15 rats were
repeatedly exposed to 5, 10, 20 and 50 ppm DBCP for 7 hours/day,
5 days/week, for 77 days. According to Shell, the histopath-
#
©logical examination of all organs, including testes, revealed
pathologic changes only in the lungs. However, Shell admitted
in its rebuttal comment that these are "remarkedly different
results" from a second inhalation study performed at the same
facility, which was reported by Torkelson.
f
(b) Human Epidemiologic Studies
Medical evidence of adverse effects in humans resulting
from exposure to a pesticide is"significantly more valuable than
laboratory animal tests for judging the chemical's potential for
human harm. Accordingly, preliminary indications of depressed
sperm counts in workers at plants where DBCP was manufactured or
*
formulated, reported in the Notice of Intent to Suspend, gave
rise to intense investigations into adverse reproductive effects
in males resulting from exposure to DBCP by several other
chemical companies, by the National Institute of Occupational
-------
-19-
Safety and Health ("NIOSH"), and by the Agency.
As the result of those investigations^ the Agency has
received extensive epidemiologic information about males exposed
to DBCP. The data fall into three groups: data from manufac-
turers/ formulators of DBCP products; an in-depth study of the
Occidental Chemical Company workers exposed to DBCP, performed by
Dr. Who r.ton; and the results of a survey of agricultural workers
potentially exposed to DBCP/ conducted by the Human Effects
Monitoring Branch of OPP's .Technical Services Division.
The primary focus in the Agency's review and evaluation of -
these data was evidence of testicular toxicity, as might be mani-
fested by such clinical signs as decreased or depressed sperm
counts, low motility of sperm, abnormal sperm morphology, and
variations in sex hormone levels. Because sperm counts —
measured in terms of millions of sperm per milliliter of
semen (MM/ml)—provide objective data amenable to statistical
analysis, they were used by the Agency as the principal index
of testicular toxicity.
However, the Agency wishes to emphasize that statistical
analyses of sperm count levels are not attempts to-predict or
gauge the fertility or infertility of any male tested. Theo-
retically, as long as a male has a sperm count above zero, he
is capable of reproducing; the chances of successful conception
increase with increased sperm count, all other reproductive
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-20-
variables being constant and within normal limits. Accordingly,
an analysis of sperm 'count data indicating a depressed sperm
count in any exposed population does not mean that the affected
individuals (with the exception of azoospermics, persons with
zero sperm counts) are or will be incapable of fathering
children.
The threshold issue with respect to using sperm counts as
the index of testicular toxicity is the choice of a "normal"
sperm count for comparison. It is well established that the
sperm counts range from 0 sperm .to over 300 million sperm per
milliliter; the distribution of these sperm counts may be
s
described in increments of 10 MM/ml— i.e./ the percentage
of men with counts less than 10 MM/ml, the percentage from
10 MM/ml to 23 MM/ml, etc. At the informal public hearing
on the proposed OSHA standard for occupational exposure to
DBCP, expert witnesses testified to two factors:
(1) there is little disagreement among experts that a sperm
count of 40 MM/ml or more can be considered a normal value
(Whorton, 1977)? and
(2) any sperm count below 20 MM/ml would be considered ab-
normally low, or oligospermic (Marshall, 1977). An area of
limited controversy exists about how to best characterize
sperm counts in the range of 20-40 MM/ml, which Dr. Whorton
described as "mildly oligospermic".
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-21-
The Agency has determined that 40 million sperm per
railliliter is the appropriate upper limit of the range of
oligospermic sperm counts. The primary reason for this
decision is the Agency's concern for human health hazards
from DBCP; as a matter of policy, the Agency believes it
prudent to adopt a conservative approach in the assessment
of human risks, current scientific consensus. However, to
present a more complete picture of the available data, the
Agency has performed all of its statistical analyses with
both 20 MH/ml and 40 MM/ml as the upper limit of the range
of oligospermia.
The second issue concerning the use of sperm counts is
the choice of a "standard" distribution of sperm counts for
statistical comparison. For this purpose the Agency has used
the one compiled by McLeod (1977) , which was presented at the
NIOSH conference on DBCP held in Cincinnati on October 20 and
21, 1977. McLeod sampled 9,000 men examined over 11 years from
1966 to 1977, in conjunction with "infertile marriage" con-
sultations. Dr. Channing Meyer, chief of the medical section
.in the branch of NIOSH charged with investigating toxic
hazards in the workplace, discussed McLeod's data at the
informal public hearing on the proposed OSHA standard for
occupational exposures to DBCP; he explained that in any
sample of individuals seeking counseling because of infertility
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-22-
problems, the responsibility for the infertility will rest with
i
the male about half of the time and with the female about half
of the time. (Dr. Meyer, 1977). Accordingly, about half of the
men in McLeod's test population could be expected to have fer- .
tility problems, including low sperm counts, therefore, the
frequency distribution of "normal" sperm counts derived from
that test population would be biased downward relative to the
general population of non-vasectomized males.
This inference is supported by a comparison of McLeod's
"infertile marriage" data with other data collected by McLeod
(1951) in an earlier study of fertile males.. Sperm counts less
.. than 20 MM/ml comprise 15% of the "infertile" group (excluding
azoospermics) compared to only 5% of the fertile group; for
sperm counts less than 40 MM/ml, the. figures are 26.4% and
17%, respectively.
To the extent that the frequency.of sperm counts below
20 MM/ml or 40 MM/ral in any epidemiological study exceed at
a statistically significant level the frequency below 20 MM/ml
or 40 MM/ml, respectively, in McLeod's "infertility" data, the
Agency will be even more confident in concluding that the. results
demonstrate adverse human reproductive effects from DBCP exposure.
Finally, it should also be noted that for purposes of analysis,
non-vasectomized azoospermics were included in both the "less
than 20 MM/ml," and "less than 40 MM/ml" categories. McLeod's
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-23-
"infertile marriage" data were adjusted accordingly to reflect
the inclusion of azoospermics, so that the frequency of sperm
counts less than 20 MM/ml was 18.1% and of sperm counts less
than 40 MM/ml was 29.1%.
(1) The data received from manufacturers and formulators
are summarized in Table 1, together with the results of statis-
tical analyses performed by the Agency.
At the Occidental plant, 40 of 91 workers who were
exposed to DBCP (44%) had sperm counts below 40 MM/ml, compared
to only 4 of 35 workers who were not exposed to DBCP (11%).
This difference was highly statistically significant (p less
than 0.005). No data on sperm counts less than 20 MM/ml were
available.
At two other plants — the Dow (Magnolia) plant and the
Velsicol plant — no control data were available on workers not
exposed to DBCP, so that the McLeod "infertile marriage" data
were used for statistical analysis. At the Dow plant, 53 of
117 workers exposed to DBCP (4.5%) had counts below 20 MM/ml,
compared to 18.1% of McLeod's sample;-68 of 117 (58.1%) hed
counts below 40 MM/ml, compared to 29.1% of McLeod's sample-
Both comparisons indicated that the differences in frequencies
were highly statistically significant (p less than 0.005). At
the Velsicol plant, 12 of 24 workers exposed to DBCP (50%) had
counts below 20 MM/ml and 17 of 24 (70.8%) had counts below
-------
-24-
40 MM/ml. Again, these frequencies were highly significantly
different from the McLeod data (p less than 0.005).
The Agency believes that these data clearly indicate that
exposure to DBCP of workers in certain manufacturing or
formulating plants has resulted in depressed sperm counts in
those workers.
(2) A second epidemiologic study reviewed by the Agency
is the "Health Hazard Evaluation" ("HHE") conducted from August
to October, 1977 at the Occidental Chemical Company in Lathrop,
California by Drs. Whorton, Milby and Stubbs (Whorton et al.
19?7). A preliminary study at Occidental had found a clear
relationship between duration of exposure to DBCP and.sperm
"count; the HHE attempted to expand the data base to confirm that
relationship. A problem in the study was accurate measurement
of individual exposures to DBCP. For data analysis purposes,
exposure was first coded qualitatively on the basis of work
history either in the Agricultural Chemical Division ("ACD")
of Occidental, or in other areas of the plant in which DBCP was
formulated. Later in the study, a semiqualitative estimate of
exposure was devised, relying mainly upon individual memories,
to estimate length of exposure. Time in the ACD was considered
de facto exposure time, and total time of exposure was estimated
by months in the ACD or other relevant areas of Occidental. The
exposures were added cumultatively to provide a sum by months;
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-25-
exposure times were then divided into groups to allow meaningful
statistical analysis. Exposed workers for whom no reasonable
quantification could be determined were put in the category
"unquantifiable exposure".
The following table, based on data from the HHE, shows
V
the relationship between exposure to, DBCP and sperm counts.
^J The HHE used the value of 40 MM/ml as the upper limit of
range of sperm counts considered to be oligospermic.
-------
Sperm Count
Categories
less than or
• equal to
40 MM/ml
-26-
• Exposure Categories (Months)
None 1-6 7-24 25-42 43 +
Total
Exposed McLeod
(n) (4)
% 11.4
(11)
22.9
(7)
50.0
(8)
-66.7
(14)
82.4
(40)
44.0
29.1
greater than
40 MM/ml
(n)
%
totals
(n) •
%
(31)
88.6
(35)
100
(37)
77.1
(48)
100
(7)
50.0
(14)
:ioo
(4)
33.3
(12)
100
(3)
17.6
(17)
100
(51)
56.0
(91)
100
70.9
(9,000)
100
(number of individuals in parentheses)
A clear increase in incidence of oligospermia with
increased exposure to DBCP is evident from this table. The
-------
-27-
number of men in the "no exposure" group with counts greater
than 40 MM/ml was eight times the number of oligospermic men in
that same group. In the 1-6 month exposure category, however,
the ratio was about 3 to 1; in the 7-24 month exposure category,
the ratio was 1 to 1; and in the 25-42 month category, the
ratio reversed so that the number of oligospermic men was twice
the number of men in that category with counts greater than
40 MM/ml. An even more striking difference can be seen in the
43 month-plus exposure category, where the ratio of oligospermic
men to men with counts greater than 40 MM/ml increases to
almost 5 to 1.
The Agency believes the results and interpretations of the
HHE support a conclusion that in workers exposed to DBCP,
the'incidence of oligospermia increases with increased exposure.
(3) A third study, "Spermatogenesis In Agricultural
Workers Potentially Exposed to 1,2-dibromo-3-chloropropane
(DBCP)," was conducted by the Epidemiologic Studies Program
of OPP's Human Effects Monitoring Branch (HEMB, 1978). The
purpose of the study was to evaluate individuals potentially
exposed to DBCP in agricultural or related occupations to
determine whether the problem of depressed sperm counts
also .occurred among those individuals as it had among workers
who formulated the compound.
(i) The study's "South Carolina Cohort" consisted of partic-
ipants from South Carolina, Florida, Arkansas, Alabama, Tennessee
-------
-28-
and Mississippi; 'the,group of "users" included custom
applicators, farmers, farm workers, researchers, and sales
representatives. The study found that 16 of 45 users (35.6%)
had counts below 20 MM/ml as compared to only 18.1% of the
McLeod subjects (both counts include azoospermics). This difference
was highly statistically significant (p less than 0.01). Moreover,
the study indicates that an additional 6 users had sperm counts
in the range of 20.1-40 MM/ml, so that a total of 48.9% of the
users were below 40 MM/ml, as compared to only 29.1% of the
McLeod subjects. This difference was highly statistically
significant (p less than 0.01).
The study also developed a DBCP "use-index" for the user
group, calculated by dividing the total, estimated pounds of
DBCP used in each user's lifetime by the total estimated
number of days in which DBCP was used. The study demonstrated
a significant negative correlation between sperm count and
DBCP use-index— i.e., the higher the use-index value, the
lower the sperm count tended to be (Spearman rank correlation
coefficient -0.372; p less than 0.01). This finding supports
the relationship between sperm count and exposure time shown
by Whorton in the HHE.
(ii) The study's "California Cohort" consisted of agricul-
tural workers, including commercial injection applicators and
irrigation calibrators, farm hands and farm laborers, and
-------
-29-
researchers. Fifty of the workers had used DBCP for 15 to 2090
days during their lifetimes; ten had used it 1-10 days; and 23
controls had never been exposed to DBCP. Twelve -farm hands and
laborers, some of whom may have been incidentally exposed to DBCP,
were also examined .
When all persons in the California Cohort who had used
DBCP are considered, 21 of 60 (35.0%) had sperm counts less than
20 MM/ml and 31 of 60 (51.6%) had sperm counts less than 40
MM/ml, as compared to 1 of 23 controls (4.3%) and 6 of 23
controls (26.1%), respectively. These differences were statisti-
cally significant (p less than 0.005 and p less than 0.05,
respectively).
(iii) The study's "Texas Cohort" consisted of fourteen
citrus and vegetable farmers who had been exposed to DBCP. Six
of the individuals (42.9%) had sperm counts xess than 20 MM/ml,
as compared to 18.1% of McLeod's subjects (p less than 0.025).
Eight of the individuals (57.1%) had sperm counts less than
40 MM/ml> as compared to 29.1% of McLeod's subjects (p less
than 0.025).
(iv) The Agency believes that this study amply demonstrates
that exposure to DBCP in agricultural use situations poses a risk
of testicular toxicity (i.e., depressed sperm counts) to exposed
individuals, and that the risk increases with increased exposure.
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-30-
(c) RPAR Rebuttal Comments
Both Dow Chemical Company and Shell Oil Company submitted
RPAR rebuttal comments to the effect that laboratory animal
data indicate a 1 ppm "no effect" level for testicular atrophy
from subchronic inhalation of DBCP, the equivalent of an oral
dose of 1.6 mg/kg/day- They stated that this conclusion is
further supported by experimental data indicating that doses of
3 mg/kg/day of DBCP ingested for two years did not have an
anti-spennatogenic effect.
The Agency does not concur with the conclusion that a "no
observable effect level" (NOEL) has been established in laboratory
animals; further, it does not believe that it is necessary to
resolve that point since human epidemiologic evidence, discussed
above, especially the HEMB survey which indicates testicular
toxicity in workers exposed to.DBCP in agricultural use
situations. Moreover, the Agency submitted the data from the
HHE to Dr. D.W. Gaylor, the Chief of Biometry of the National
Center.for Toxicological Research. By plotting the data on
arithmetic scales, he concluded that "there is no indication
of a so calle-3 no effect exposure. A very short length of-
exposure to DBCP may in fact result in oligospermia in a small
proportion of workers" {Gaylor, 1978).
(d) Conclusions Regarding Adverse Reproductive Effects
of DBCP
The Agency concludes that the presumption of risk arising
-------
-31-
from the "other chronic .or delayed toxic effects "trigger (§162.11
(a)(3)(ii)(B)} has not been rebutted for DBCP since no applicant
or registrant has sustained the affirmative burden of proof set
forth in Sl62.11(a)(4) .
Based on epidemiologic evidence/ the Agency concludes that
DBCP poses a risk of testicular toxicity, as evidenced by an
increased incidence of reduced sperm counts, to males'who are
•exposed to the chemical. The Agency further concludes from that
: data that no "no observable effect level" may safely be estab-
lished for human exposure to DBCP with respect to testicular
toxicity, and further concludes that the risk of decreased sperm
counts increases with increased exposure.
. (3) Other Toxicplogical Effects
Other toxicological effects o.f DBCP which did not meet
the risk criteria of Sl62.11(a)(3) for issuance of an RPAR are
summarized in Table 13.
B. Human Exposure To DBCP
The next stage in the Agency's assessment of human risks
from exposure to DBCP was the identification of the populations
with actual or potential exposures to DBCP, and the identification
of their, routes of exposure. The levels and durations of those
exposures were then estimated, and the estimates were used to
calculate the potential lifetime exposures of the identified
populations.
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-32-
In the Notice of Intent to Suspend, the Agency used the
best data then-available to calculate the exposures from both
consumption of DBCP residues by the general United States popu-
lation, and from inhalation of DBCP vapors by DBCP applicators.
The Agency used residue data available from supervised field
trials approximating registered uses of DBCP- It also extrapolated
that data to predict DBCP residues in related crops (or crops
with common growing characteristics) for which there were
registered uses of DBCP and.for which residue data was absent
or inconclusive. No data were then available concerning potential
concentrations of DBCP in the air surrounding applicators.
However, there were such data for a similar chemical, ethylene
dibromide, which is also applied by soil injection. Accordingly,
the Agency used a ratio of the vapor pressures of the two
compounds to estimate a range of DEC? air concentrations which
could reasonably be expected from DBCP soil injection.
. The Agency has since received, both in RPAR rebuttal comments
and as the result of experiments by or under contract to the
Agency, substantial amounts of exposure data on DBCP itself.
These new data include: additional residue data from
registrants particularly Dow and Shell; inhalation exposure
data from agricultural applications of DBCP, from Shell and Dow;
air monitoring data of DBCP field applications submitted by the
Pineapple Growers Association of Hawaii ("PGAH") as well as a study
-------
-33-
conducted for PGAH by Dollar & Hertlein (1977) containing
additional air monitoring data; a study conducted by the OPP's
Chemical and Biological Investigations Branch, which gathered
data on the air contamination levels and disappearance rates
of DBCP from soil (Hansen, 1977); and a study conducted by Enos
j|t. ^1. (1978) at the University of Miami School of Medicine
reporting on the development and'application of a methodology for
environmental sampling to determine DSC? levels in ambient
air.
The information referred to above was analyzed by the
Chemistry Branch of OPP's Criteria and Evaluation Division,
and formed the basis of its "Analysis of Human Exposure to DBCP"
(the "Exposure Analysis"). The information in that document
. was used to estimate the exposures of all affected populations
from DBCP use, on a use-by-use basis. These estimates may best
be summarized by the four major routes .of exposure: ingestion
of DBC? residues in food, inhalation of DBCP by applicators
and mixers and loaders, inhalation of DBCP after reentry into
treated areas, and dermal absorption
%
of DBCP during application, mixing and loading, or spill cleanups.
Each of these categories will now be discussed in detail.
(1) Ingestion of DBCP Residues
Chemists in the OPP's Registration Division have reviewed all
of the available DBCP residue data.
-------
-34-
They have concluded that it is reasonable to hypothesize that
DBCP itself is not absorbed and translocated within growing
plants; rather, residues of DBCP in crops grown .in DBCP-trea-ted
soil are probably from the crops' contact with the treated
soil, from volatilization of DBCP from the treated soil and
condensation or absorption on crop surfaces, or from deposition
of. DBCP on the crop itself during application. They further
concluded that root crops, which bear the highest residues,
may be exceptions to this hypothesis, especially in light
of the demonstrated ability of carrots to absorb organochlorine
pesticides from the soil. Based on actual data from supervised
.trials, or extrapolation of that data to other related crops
or crops with similar growing characteristics, the chemists
estimated a range of residues that may result from registered
DBCP uses (Worthington, 1978a, 1978b; Cummings, 1978). Those
data are summarized in Table 12.
Those values are estimates of the range of residues
that might result from maximum registered application rates.
However, the chemists also noted that actual agricultural
practices currently in use are often more restrictive than the
registered recommendations (for example, with respect to
application rates and preharvest intervals), so that residues
which many treated crops may be expected to bear would fall
at the bottom of the estimated ranges. Nevertheless, for the
-------
-35-
purposes of calculating potential exposure to the general
population from ingestion of DBC? residues, the upper limits of
the estimates ranges have been utilized, and thus represent
a worst case situation.
Finally, to calculate an individual's average daily intake
of DBCP residues, the maximum residue for each crop was multiplied
by the average amount of that crop consumed daily on a per capita
basis. That figure was in turn multiplied by the percentage (by
acreage) of the national crop treated with DBCP, to get an
estimate of exposure potential reflecting actual use patterns.
Those factors also are tabulated in Table 12, together with the
.estimated maximum daily intake of DBCP (on a picogram/kilogram
bodyweight/day basis) for each food crop for which DBCP is
currently registered.
•
(2) Inhalation of DBCP By Applicators During Application
Applicator exposure to DBCP, by inhalation, calculated
on a use-by-use basis, is summarized in Table 3.
The first step in the calculation was the estimation of DBCP
t
air concentrations during application, on a technique-by-technique
b asis. The DECP Exposure Analysis estimated the inhalation exposure
on a milligram per hour basis for soil injection (other than
pineapple), soil injection (pineapple), irrigation, in-furrow,
granular, and drench.
The next step in the inhalation exposure analysis focused
on the individual use categories of DBCP. Thus, for each use
-------
-36-
pattern, the following information was identified or estimated:
the application technique(s); the number of applicators and
helpers exposed to DBCP; and the number of hours per year that
each expo-sed person might be expected to be exposed to DBCP.
This information is tabulated in Table 11, which is exhaustively
footnoted with the sources of the data and calculations. The
number of applicators exposed, the. duration of their exposure,
and their dose of DBCP per hour were then entered into the
appropriate columns in Table 3, estimates of yearly and lifetime
doses of DBCP, per exposed person, were then derived.
Finally, for each technique exposure was calculated
for two distinct phases of the overall application process:
during mixing and loading operations, and during the-actual
application. This was done to enable the Agency to evaluate
whether different restrictions to prevent or diminish inhalation
exposure would be appropriate for the different phases of
application. This subject is addressed in detail in Section IV.
(3) Inhalation of DBCP During Reentry Into Treated Areas
There may also be inhalation exposure to DBCP if people re-
enter treated areas after application of DBCP but before the
ambient air concentrations of DBCP have dissipated. Although
DBCP is a highly volatile compound, the Agency determined that
it was appropriate to measure DBCP disappearance rates in
treated soil and in air over treated soil at various intervals
-------
-37-
after DBCP application by various techniques. That data
was evaluated and analyzed in the DBCP Exposure Analysis, and is
presented in Table 4.
(4} Dermal Exposure to DBCP
Dermal exposure to DBCP may occur in a variety of situations
— for example, during mixing and loading operations, during spill
cleanups, during maintenance of application equipment, or during
different phases of actual application. Moreover, the subchronic
toxicity studies referred to in Section II A indicate that DEC?
is apparently readily absorbed through the skin. Indeed, Dow
Chemical Company states in its rebuttal comment, "it is reasonable
to expect that absorption through the skin may be as significant
or, indeed> more significant than inhalation unless precautions
to prevent skin contamination are adhered to strictly." (RPAR
Comment No. 3A [30000/19], p. 17)
Accordingly, Table 4 contains estimates of potential dermal
exposures to DBGP in various contexts. -The estimated doses
are calculated on a per drop basis, and assume that the entire
drop is absorbed through the s.kin. In fact, it is reasonable
to assume that a person will be dermally exposed to much more
than a single drop of DBCP in any of the exposure situations
described.
C. Determination of Risk
The final stage of the Agency's risk assessment of a pesticide
is a prediction of the human health hazards from exposure to the
-------
-38-
chemical. Based on the toxicological and epidemiological
evidence of adverse effects and human exposure estimates/ the
Agency used, where possible, appropriate mathematical models
to quantify the risk. In other circumstances, the Agency
was .only able to qualitatively describe the risk,
(1) Risk of Cancer
(a) General
The Agency's Cancer Guidelines state that when a chemical
is judged to be a potential human carcinogen, the Agency will make
estimates of its possible impac* on public health at current and
anticipated levels of exposure. The Cancer Guidelines also
recognize that the available techniques for assessing the magnitude
of cancer risk to human populations based on animal data are at
best very crude; this is due to uncertainties in the extrapolation
of dose-response data to very low dose levels and due to
differences in levels of susceptibility of animals and humans.
Accordingly, as the Administrator cautioned when he provided
preliminary risk estimates in the Notice of Intent to Suspend,
the risk estimates are neither scientific certainties nor
absolute upper limits on the risks of cancer from continued use
of DBCP. Rather, any estimates are used by the Agency as rough
approximations of the degree of human cancer risk which may be
expected from continued use of DBCP.
(b) Rebuttal Comments to the Risk Assessment
Dow Chemical Company has challenged the validity of the
-------
-39-
Agency's approach to quantification of the increased risks of
cancer from with exposure to DBCP. Dow asserted that the
Agency's risk assessment model is a very conservative one
which overestimates the risk, and claimed that application of
CAG's model to workmen exposed to 1 ppm DBCP for 10 years
would be expected to result in "such a horrendous increase of
cancer" among the workers that it would have been detected long
ago. Dow also claimed that by applying the model to the data
collected in the Dow-Hazleton bioassay (described in Section
II A), the model's prediction of risk is significantly greater
than the cancer rates actually observed. Finally, Dow asserted
that extrapolation of the incidence of stomach cancer incurred via
ingestion of DBCP to predict the incidence of cancer via inhalation
of DBCP is questionable, since the cancerous effect is likely to
be initiated locally (RPAR Comment No. 3A [30COO/19]}.
In response, the CAG acknowledged the difficulty of pre-
dicting the incidence of tumors which might be incurred via one
route of administration based on the incidence of tumors observed
via a different route of administration. However, the CAG also
noted that a target organ can often be affected via more than one
route of administration; it referred to a.recent skin painting
study on Swiss mice (See Section II A, supra) in which DBCP did
not induce skin cancer but did induce a high incidence of lung
adenoma and squamous cell carcinoma of the forestomach.
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Accordingly, the CAG concluded that in the absence of reliable
information on inhalation carcinogenesis of DBCP in animals, the
CAG's approach must be deemed reasonable and applicable.
(Albert, 1978).
With respect to Dow's assertions concerning epidemiologic
evide.nce which would have been uncovered if the CAG's mathe-
matical model were accurate, the CAG acknowledged that it was a
valid concern that any mathematical model used to estimate cancer
risk might seriously overestimate the true risk. However, the
CAG also noted that mere speculations as to what a validly
conducted epidemiologic study might reveal cannot be used to
invalidate a-mathematical model. Rather, for the assertion to
have any validity, a well-controlled epidemiologic study with
indications of lifetime exposures to DBCP would have to be
conducted and made available to the Agency' for analysis. (Id.)
Finally, the CAG expressed reservations about using the
Dow-Hazleton data as the basis for a risk assessment, because
the histopathology for that study had not yet been completed.
Nevertheless, a "non-conservative" model, based on the pre-
liminary results of the Dow-Hazleton study, was applied to the
exposure data available to the Agency at the time the Notice of
Intent to Suspend was issued. Although the estimated risks
were generally reduced by about one order of magnitude, the CAG
noted that the risks were still of considerable concern. (Id.)
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(c) Final Cancer Estimates
The CAG has used the exposure estimates described earlier
(See Tables 3/4 and 12) to estimate the risks of cancer from
those exposures to DBCP. The CAG has used the same mathematical
model as it used in the Notice of Intent to Suspend to estimate
the risk via ingestion (i.e., resulting from consumption of DBCP
residues in food crops). This was done because the final
histopathology for the Dow-Hazleton study has still not been
rece-ived by the Agency. The probabilities of the occurrence of
cancer due to consumption of DBCP residues are listed on a crop-
by-crop basis in Table 12.
With respect to the cancer risk from inhalation of DBCP,
the CAG noted that for a chemically related compound, EDB, the
estimated human risk based on a rat intubation study was higher
than the estimated risk based on a human epidemiology study.
Although the CAG did not have a human epidemiologic study for
DBCP, it used the relative potency of DBCP to EDB to construct
a model for estimating the risks from inhalation of DBCP which
took that relationship for EDB into account. The resulting
estimates are approximately 18.6 times lower than they would
have been if only the DBCP rat intubation study had been used.
Table 3 presents those estimates of risks for applicator inha-
lation exposure during application and during mixing and loading
operations; Table 4 presents estimates for inhalation exposures
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-42-
•
to persons reenter.ing treated areas and for inhalation exposure
during a .spill cleanup.
Finally, for potential dermal exposures to DBCP, the
CAG has estimated the risk of cancer from exposure to one drop
of DBCP in a lifetime (see Table 4), using a slightly modified
version of the mathematical model that was used for ingestion
exposure. Although this model may overestimate the risk of
cancer from dermal exposure, it must be strongly emphasized that
the-estimates are based on a lifetime exposure of only one drop
of DBCP. Since it may be anticipated that a person handling
DBCP carelessly is likely to be dermally exposed to more than
a single drop, these estimates must be given considerable weight
in terms of regulatory decisions as discussed in Section IV.
(2) Risks of Testicular Toxicity
The Agency has a significant amount of epidemiologic
evidence indicating that exposure to DBCP may result in testic-
ular toxicity, as manifested by depressed sperm counts. However,
the Agency does not have a model analogous to the CAG cancer
model for quantifying any dose-response relationship between
DBCP exposure and reductions in sperm counts.
Nevertheless/ as discussed earlier, the Agency determined
that the risk of a depressed sperm count from exposure to DBCP
increased with increased length of exposure to DBCP. This
relationship was clear notwithstanding that actual exposure
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levels could not be precisely quantified. Moreover, the Agency
concluded that the data would not support the establishment of
a level or length of exposure to DBCP that would not pose any
risk of a .depressed sperm count.
Accordingly, although the Agency will not now make
quantitative estimates of the risk of a depressed sperm count
from exposure to DBCP, the Agency does believe that there is
the risk of a depressed sperm count from
exposure to DBCP, and that the risk increases as the amount of
exposure increases. Based on this qualitative criterion and
the exposure figures in Tables 3 and 4, it is
apparent that: (1) the irrigation method of application presents
'a significantly greater risk of a depressed sperm count
than does the soil injection technique; (2) the drench technique
also presents a somevhat greater risk than does the soil injection
technique; and (3) all dermal exposures to DBCP
present significant risks of a depressed sperm count.
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III. Benefits Analysis of DSCP
A. Background
In the Notice of Intent to Cancel, the Administrator sum-
marized the conclusions of the preliminary benefits analysis of
DBCP. He noted that there are effective registered alternative
pesticides for most uses of DBCP, including most vegetable uses.
However, those alternatives are aloo generally more expensive.
Cancellation of DBCP for use on vegetables would thus probably
increase control costs by about $15-20 million per year, but
without any significant reduction in crop yields, and with only
a negligible impact at the consumer level. For use on grapes,
peaches and other stone fruits, and citrus, the Administrator
noted that although there are effective pre-plant alternatives
to DBCP, there are no registered post-plant alternatives. He
noted that this may be expected tc reduce the life expectancy
of affected vineyards, orchards and groves,'and to result in
short-term losses of about $67 million per year for the first
3 years after cancellation. At the time of issuance of the
Notice of Intent to Cancel, analyses of the long-term impacts
of cancellation on these and other affected crops were still
in progress.
For this Final Position Document, the Agency and the
United States Department of Agriculture (USDA) .have prepared
an economic analysis to quantify, on a use-by-use basis, the
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potential economic consequences of cancelling all registrations
of D3CP for all registered uses. (EAB/ARE3, 1978). In this
section of the Final Position Document, the Agency has summarized
in detail the methodology and process used to prepare the final
economic analysis. Since it was impossible to predict with
absolute certainty any economic or biological phenomenon/ the
Agency employed various economic assumptions and models in its
analyses, using the Agency's experience arid expertise in these
areas; they are outlined and explained in detail in the various
support documents which are discussed herein. Finally, this
section summarizes the major conclusions of the final economic
analysis, and provides a background for the specific dollar
figures, and the long and short term qualitative impacts, which
are discussed in detail in Section V.
B. The Cooperative Assessment
Following the publication of the Administrator's Notice of
Intent to Suspend, a DBCP Impact Assessment Team was appointed
by the National Pesticide Impact Assessment Steering Committee
pursuant to the Memorandum of Understanding between the Agency
and "USDA. The Assessment Team's membership included represent-
atives from both the Agency and USDA, as well as State Extension
Service and research personnel knowledgeable in the. field of
nematode damage and control. The Assessment Team met in Florida
on October 17-21, 1977, to assemble, organize and summarize the
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available biological data about the major agricultural uses
of DBCP.
The Assessment Team's deliberations and conclusions were
presented to the Agency in the "USDA/state and EPA Cooperative
Assessment of DBCP Uses in Agriculture," dated November 7, 1977,
and later designated as Rebuttal Comment No. 17. [30000/19]
. ("Cooperative Assessment"}. The Cooperative Assessment addressed
eleven different categories of uses of DBCP: peaches, citrus,
grapes, pineapples,•soybeans, cotton, peanuts, vegetables
(including melons and strawberries), home gardens and lawns,
commercial turf, and ornamentals.
For each category, the Cooperative Assessment first
identified the major nematode pests of the particular crop or
use.. It then discussed the DBCP application methods for that
crop or use.- the rate and frequency of applications, and the
availability of chemical alternatives to DBCP for pre-plant,
at-plant and post-plant application.
The Cooperative Assessment also examined the feasibility
of non-chemical alternative methods of nematode control for
each category. The alternatives ranged from crop rotation
to resistant varieties of root stock, biological control by
predators or natural enemies of the nematodes, and to other
cultural practices. Combinations of these methods were also
considered as part of an integrated pest management approach.
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The Cooperative Assessment then developed an estimate
of the economic consequences of a DBCP cancellation for each
category. It used available yield and efficacy data, the
results of actual use practice/ and other relevant published
data. When information was not available, Assessment Team
members/ relying on their collective experience and expertise
in the fields of nematology and agricultural practice, developed
consensus estimates of yield or quality impacts which would
result from the cancellation of DBCP.
The first factor addressed by the Cooperative Assessment
for each category was the impact on yield which would result if
DBCP were not available. Where there were no registered
alternatives for DBCP, as in the case of post-plant
applications for peaches, citrus and grapes, the dollar
impact of a loss in yield was mitigated to some extent by the
savings from not applying DBCP.
The second major element estimated by the Cooperative
Assessment for each category was the increased cost of
alternative nematicides, assuming that these alternatives would
be available. In determining both the allocation of present
DBCP usage to alternative cl.emicals and the usage rates of
those alternatives, the Cooperative Assessment relied on
such factors as the efficacy of the alternatives, the treatment
costs of the alternatives, State recommendations for nematode
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-48-
control, other product labels and Assessment Team members'
expertise -
Finally, the Cooperative Assessment predicted that there
would be a loss of quality in certain affected crops if DBCP
were not available. It also predicted that the longevity of
some perennial crops would be reduced if. DBCP were not
available, and it estimated the magnitude of those reductions.
C. Benefits Analysis
The Cooperative Assessment, and rebuttal comments on the
benefits of DBCP, were then reviewed by USDA and Agency
economists. Whenever appropriate, the economists also gathered
and evaluated additional information about the major crop
categories. The economists participated in further ccmmuni-
.cations communications and discussions directly with university,
Extension Service or user group personnel; they also conducted
additional research into previously published data and
agricultural statistics. In addition, the economists gathered
information and data on the minor use crops not addressed by
the Cooperative Assessment, through communications with
nematoiogists and other experts in the field. Specifically,
the economists estimated the impact c. f cancelling DBCP regis-
trations for use on almonds, apricots, cherries, figs., walnuts,
bananas, blackberries, blueberries, loganberries, dewberries,
boysenberries, plums, raspberries and eastern nursery stock
strawberries.
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That review and evaluation formed the basis of the Agency's
final analysis of the benefits of DBCP, "Economic and Social
Impacts of Cancelling Use of DBCP as a Pesticide for All
Registered Use Sites with Known Current Usage" ("Benefits
Analysis"). For each major use and for each class or category
of minor uses the Benefits Analysis summarizes: the geographical
area of use; the major pests controlled; major registered
alternative chemicals and -non-chemical controls, with comparative
evaluations of their efficacy/ performance, and cost; the extent
of use (in terms of both annual treated acres and quantity of
DBCP active ingredient applied annually); and a description o-f
the economic impacts of a DBCP cancellation.
Table 8 summarizes the potential economic impacts of
cancelling all registrations of DBCP. The impacts at the user
level/ expressed as increases in control costs or decreases
in yield or both/ are presented separately from the impacts
at the consumer level/ which are generally expressed
increased prices. The impacts are also broken down into
short-term (up to three years) and long-term (greater than
three years) impacts, these are qualitatively assessed (e.g.,
severe/ moderate/ negligible) for their overall significance
to the entire U.S. production of the crop.
The information and conclusions presented in Table 8 for
Benefits Analysis. Each chapter contains the assumptions and
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-50-
inethodologies used as well as supporting tables, calculations
of the estimates, sources of all data, and a bibliography of
references.
D. 'Major Conclusions
In summary/ the Benefits Analysis estimates that the
potential short-term impact of cancellation to DBCP users may
be as high as $400 million during the first 3 years after
cancellation; this is comprised of about $280 million in yield
reductions, and about $115 million in increased control costs.
Reductions in yield would be most severe in the perennial crops
for which there are no registered post-plant alternatives. Indeed,
five of these crops — citrus, grapes, peaches, plums and almonds
*
'.— account for about 80% of the projected dollar losses from yield
reductions. Increases in control costs, would be most severe for
soybeans, accounting for about 58% of the projected dollar increase
in control costs. However, only negligible decreases in soybean
yields would be expected from such a shift in control-chemicals.
The Benefits Analysis also estimates that the short-term
impact of cancellation at the consumer level would be increased
retail prices for certain commodities. Although the consumer
price impact for most commodities would be negligible, the most
seriously affected crops would be: peaches (up to 25% increase
in retail price); almonds and plums (up to 20%); pineapples
(up to 9%); and citrus (up to 5%).
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The Benefits Analysis also qualitatively described the
anticipated long-term impacts of a. DBCP cancellation for each
use or category of use- These impacts are difficult to assess
because of the large number of variables involved. Factors such
as the development, use and availability of new alternative
control methods or chemicals, and the potential for greater
productivity and increased planting in uninfested areas, are
almost impossible to predict. Moreover, price elasticity and
dema d curves for crops are not always available. Nevertheless,
for each major use and for each class or category of minor uses,
the Benefits Analysis predicted the long-term impacts of a DBCP
cancellation on users and consumers.
Finally, the Benefits Analysis concludes that the
macroeconomic (i.e., nationwide) impact on the agricultural
economy of a DBCP cancellation would be negligible—in terms
of both employment and inflation—notwithstanding the potential
severity of the impacts on certain sectors of the agricultural
economy. Similarly, it concludes that the average consumer's
food budget will not be measurably increased by a DBCP
cancellation.
Part V presents a more detailed discussion of the potential
impacts of a DBCP cancellation, on a use-by-use basis.
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52
IV. Development and Selection of Regulatory Options
A., Introduction
In Sections II and III, the Agency identified the risks
from exposure to DBCP and identified the benefits from each of
its uses. As explained in Section I, PIFRA mandates the Agency
to to achieve a balance between these competing considerations.
To accomplish that goal, the Agency has identified a number
of regulatory options, and has evaluated each option for its
• .
impacts on both sides of the risk/benefit equation.
This section of the Final Position Document describes how
the Agency developed possible regulatory options for evaluation,
and identifies six options which were ultimately selected for
in-depth evaluation. In Section V of this Final Position
Document, each option is evaluated for each registered use
of DBCP, and the rationale for final selection of an option
for each use is set forth.
B. Rationale for Development of Options
In its simplest terms, FIFRA contemplates two basic-
options concerning pesticide regulation — namely, to grant
or deny registration. For new pesticide products, these options
are approval or denial of an application for registration; for
previously registered pesticide products, they are a decision
to either cancel the registration or to allow the continued
registration of the product. Both denial and cancellation of
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registration represent absolute regulatory responses in
that they unqualifiedly prohibit the sale or distribution of the
pesticide for the uses at issue. Registration, on the other
hand, represents a whole range of regulatory options, since
the Administrator may specify the terms and conditions of the
registration, including label and labeling language and
classification for restricted use.
Cancellation and unrestricted registration fall at
opposite ends of the regulatory spectrum. The development of
intermediate regulatory options thus involves the formulation
of terms and conditions which may be imposed on a pesticide's
registration to reduce the risks from the use of the pesticide.
Reduction of risk is achieved by eliminating or
minimizing human exposure. Accordingly, after considering
the. routes of human exposure discussed in Section II, the
Agency has developed and considered six methods of reducing
both applicator and general population exposures to DBCP:
classification of DBCP for restricted use, for use only by
certified applicators; reduction of ingestion exposure by
elimination of residues of DBCP in food; reduction of dermal
•
exposure by use of protective clothing; reduction of
inhalation exposure by use of respirators; reduction of
inhalation exposure by establishment of reentry intervals; and
reduction of inhalation exposure by prohibition of the irrigation
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technique of application. Each of these methods will now be
discussed and evaluated.
: C. Risk Reduction Methods
• . (1) Classification For Restricted Use
Under FIFRA, hazardous pesticides may be classified for
restricted use and be limited to use only by or under the direct
supervision of certified applicators who have been determined
to be competent to use and handle pesticide products.
Certification programs are for t^e most part administered by
the states. These programs use various methods to certify
applicators, after a determination that they are competent to
use restricted use pesticides.
The Agency believes that the classification of DBCP for
restricted use would ensure that it would only'be available
to competent persons. By preventing untrained growers and
homeowners from using DBCP products, the risk of human exposure
to DBCP due to misuse or carelessness would be significantly
reduced. Moreover, the Administrator has already determined
in the Notice of Intent to Suspend that any marginal costs that
might result from restriction to certified applicators would
be minimal; state programs for the certification of applicators
are operational in almost all states, there is a large number
of certified applicators, and there is relatively llittle
difficulty in obtaining applicator certification.
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55
Accordingly, one regulatory option would be to classify
for restricted use all uses of DBCP that are not proposed to be
cancelled (or which are not cancelled).
(2) Reduction of Ingestion Exposure
As detailed in Section II, residues of DBCP per s_e may be
expected to occur in 19 food crops for which DBCP is presently
registered (See Table 12). As explained earlier, the Agency
has concluded that these residues probably result from the crops
coming into contact with the treated soil; from volatilization
of DBCP from the treated soil and condensation or absorption
on crop surfaces; or from deposition of DBCP on the crop during
application.
The Agency has explored ways to eliminate these residues
by controlling the time of application. Specifically, the
Agency believes that residues would be significantly reduced
(although not precluded) if application of DBCP were pro-
hibited when edible portions of the affected crops were present
or would be likely to be present before the DBCP has dissipated.
The Agency chemists who reviewed the residue data on DBCP
therefore recommended that all post-plant applications of" DBCP
to the affected food crops be prohibited.
The Agency then conducted a survey of Extension Service
and University nematologists. It determined that the impact
of post-plant prohibitions on residue reductions would be
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56
negligible, since it is already common agricultural practice to
use DBCP as a pre-plant or at-plant treatment. (Michell, 1978).
However, in light of existing data and scientific uncertainty
about the mechanism of formation of DBCP residues, the Agency
cannot conclude that prohibition of post-plant applications
of DBCP will preclude the possibility of residues occurring
in the affected crops.
The Agency must therefore conclude that there is no
regulatory restriction which it can reasonably impose that can
confidently be expected to eliminate the possibility of DBCP
residues.
(3) Reduction of Dermal Exposure
As discussed earlier., dermal exposure to DBCP is of con-
siderable concern to the Agency. It appears that DECP is
readily absorbed through the skin, and Dow Chemical Company has
commented that one drop of pure DBCP on the skin could result
in an exposure of 1.6 mg/kg body weight (RPAR Comment No. 3A
[300.00/19]). The CAG has determined that exposure to a single
drop of DBCP could result in an increased risk of cancer on
-4
the magnitude of 6.5 x 10' . Accordingly, it is necessary to
explore means for reducing or eliminating all possibility of
human dermal contact with DBCP.
Cleanup of DBCP spills and maintenance of application
equipment pose the greatest potentials for dermal exposure.
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At such times, the Agency believes 'that it is prudent and
necessary to protect all parts of the body from possible DBCP
exposures. To do this would require wearing of impermeable
gloves, boots or boot covers, helmet, face shield, coat and
pants of any of the materials described in Table 7. Since
the total cost of such a protective outfit is about one
hundred dollars, the Agency has determined that it would
be appropriate to require full-body protective clothing at
all times during cleanup of a spill and during maintenance
of any DBCP application equipment. This rationale is equally
applicable to all other exposure situations with high potentials
for dermal exposure, including all phases of mixing, loading
and transfer operations.
Another means of reducing such dermal exposures is use of
closed system equipment for mixing and transfer of DBCP. For
other pesticide products (see e.g., EPA Registration Nos.
2139-100 and 100-551), the Agency has defined a closed system
to include appropriate connections, meters, pumps and plumbing
which are designed to eliminate all human, contact with the
Ml
pesticide. Those registrations also preclude the use of open
mixing vats or tanks, or open pouring, and all plumbing con-
nections have to be sufficiently tight to prevent any leakage.
Moreover, hoses have to be constructed of chemically resistant,
heavy duty, reinforced materials, and transport and storage vessels
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md transfer equipment have to be equipped with dry-break valves.
Since the Agency believes that use of engineering controls to
reduce potential human exposures should be encouraged, it has
determined that if a closed system of mixing or transfer is
used, an impermeable apron may be worn instead of impermeable
0oat and pants. However, impermeable gloves and boots or
boot covers would still have to be worn.
Finally, the Agency has determined that there are moderate
to low risks of potential dermal contact with diluted DBCP during
application by irrigation, by drench, by in-furrow and by
granular formulations. The Agency believes that the potential
risks of dermal contact from these application techniques
would be significantly reduced or eliminated by a requirement
that applicators wear impermeable gloves and boots during the
application operations. Since the cost of this equipment is
about two dollars per pair of gloves and seven dollars per
pair of impermeable boot covers (see Table 7), this equipment
would be mandatory during application of DBCP by any of these
four techniques.
(4) Reduction of Inhalation Exposure by Use of
Respirators or Closed Systems
As detailed in Section II, the degree of exposure to DBCP
via inhalation varies significantly from one exposure situation
to another. Moreover, it appears that the risks from such exposure
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are roughly proportional to the overall degree of exposure—i.e.,
the higher the exposure, the greater the risk. The Agency has
therefore explored the feasibility of requiring respirators
when the potential for inhalation exposure is of concern.
Table 7 lists the three basic types of generally available
respirators (air-purifying, supplied-air, and self-contained
breathing apparatus (SCBA)) and their minimum protection factors
and approximate cost per item. In determining which type of
equipment to require, the Agency took into account the relative
costs of the different types of equipment, and also the feasibility
and enforceability of their use. Thus, although SCBA and other
supplied-air respirators provide much greater protection factors
than, do air-purifying respirators, they are considerably more
expensive than air-purifying respirators, are physically much more
limiting, and may require medical examination and monitoring
v
for their use. Moreover, the Agency would expect a much
higher degree of compliance with an air-purifying respirator
requirement—with which many applicators are experienced—than
with more burdensome and expensive equipment with which even
certified applicators are not likely to be familiar.
^J See, for example, subsection (m)(5)(c) of the permanent OSHA
standard for occupational exposure to DBCP (29 DBCP (29 CFR §
1910.1044) which requires physicians examining employees pursuant
to a medical surveillance program to recommend limitations
upon the employees' use of these types of respirators.
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Further, the Agency believes that the restriction of DBCP
products to certified applicators is likely to reduce the
incidence of the highest exposure situation, spill cleanups
(likely to be sporadic), and to avoid excessive and undue
exposure to a medical surveillance program to recommend limi-
tations upon the employees1 use of these types of respirators.
during other phases of mixing, loading, transfer, and actual
application of DBCP. Accordingly, whenever respirators would
be required—during, any phase of the mixing, loading and transfer
operations, during performance of maintenance upon application
equipment, or during application—the Agency has determined
that full-face air-purifying respirators would be appropriate.
Another means, of reducing inhalation exposure is use of
closed system equipment for mixing, transfer or application.
The Agency believes that the reduction of potential human
exposure through engineering controls should be encouraged.
Accordingly, the Agency has determined that if a closed system
of mixing,- transfer or application is used and results in an
airborne concentration of DBCP not exceeding 1 part DECP 'per
billion parts of air (1 ppb) as an 8-hour time-weighted average
— the OSHA standard for occupational exposure to DBCP — that
a respirator would not have to be worn during the operation of
the closed system. However, a respirator would have to be avail-
able for use in case of a leak, spill or other unexpected exposure.
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(5) Reduction of Inhalation Exposure by Establishment of
Reentry Intervals
As discussed in Section II, there may be- inhalation exposure
to DBCP v-apors during reentry into a treated areas. As seen from
the figures in Table 4, the potential for exposure decreases with
time for all of the application techniques for which data are
available. Thus, for the injection technique, DBCP concentrations
in the air decrease by a factor of 13 from time of application
to 1 day later and by a factor of 46 from time of application
to 7 days later. For irrigation, the one day decrease is by a
factor of 6; the Agency does not have data for longer periods
following application. For drench techniques, the reduction
in 1 day is by a factor of approximately 10,000, and the
reduction in 3 days is by a factor of approximately 30,000.
Finally, for the in-furrow method of application, the available
data indicates that there is no significant reduction in air
concentrations of DBCP 1 day after application, and a reduction
by a factor of 0.2 7 days after application. No data are
available to the Agency about application of the granular
formulation of DBCP.
The Agency recognizes that the available data on "fall-off"
curves for air concentrations of DBCP after application is
limited. Nevertheless, the Agency believes that it is prudent
and necessary to establish intervals after DBCP application
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during which reentry to treated areas without a full-face air-
purifying respirator would be prohibited. The Agency believes
that a 24 -hour interval would be reasonable and would signi-
ficantly reduce potential inhalation exposures. Therefore,
reentry into treated areas would be prohibited for 24 hours
after application, unless the person reentering the treated
area is wearing a full-face air-purifying respirator.
(6) Reduction of Inhalation Exposure by Prohibition
of Irrigation Method of Application
As seen in Table 3, the irrigation method of application
poses the highest estimated exposure per hour of all the
application techniques, both during mixing and loading and
during actual application. Indeed, the hourly exposure during
mixing and loading is approximately 25 times higher'than the
hourly exposure during mixing and loading for. the injection
technique; and the hourly exposure during actual application
is 100 times higher than the hourly exposure during actual
application by the injection technique. The Agency evaluated the
feasibility of prohibiting the irrigation method by determining
whether growers could switch to an alternative method .of appli-
cation, soil injection. Thery are three advantages to growers
I/
who are currently using the irrigation technique : the cost of
_/ The affected crops are peaches, plums, almonds and grapes
in California and citrus in California, Texas and Arizona.
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application is almost zero since DBCP treatment is performed
in conjunction with routine irrigation; unlike injection,
irrigation does not cause mechanical injury to tree or vine
roots; and unlike injection, irrigation does not disrupt
operations which have adopted no-till weed control systems
(Luttner, 1978).
The Agency also estimated that for those growers who
could change to soil injection using their own equipment
.(estimated to cost $200), the increased cost of application
would be from $6 to $10 per acre. For those growers who would
have to hire custom applicators, the cost could be .as high as
$35 per acre.
The Agency concluded that it is reasonable to assume that
many growers, especially citrus growers, would discontinue use
of DBCP if forced to use the injection technique, the increased
costs of DBCP treatment would decrease the margin of revenue
return from DBCP treatment, and there will be possible root
damage and disruptions in other operations. For these growers,
prohibiting the irrigation technique would be tantamount to
cancelling DBCP for those uses. However, many other growers
would be forced into absorbing higher applicator costs,
especially where post-plant DBCP application is essential to
maintain economic levels of production. Those growers may also
use reduced application rates and longer treatment intervals
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to decrease DBCP application costs, and may then also have
to accept lower production and revenues. However, the Agency
was not able to accurately project how many growers would
discontinue use of DBCP altogether.
In summary, the Agency has determined that prohibition of
the irrigation method of application would be an appropriate
'option, to be considered-on a use-by-use basis, to reduce
applicator inhalation exposure to DBCP.
D. Regulatory Options Selected
From the full range of available restrictions and regulatory
options discussed, the Agency has selected six options for the
ultimate .registration decision. In Part V, each options will be
considered and evaluated for each use of DBCP to determine whether
its adoption would achieve adequate risk reduction without signi-
ficant impacts on the benefits of the use.
In developing these options the Agency .started by choosing
both the least restrictive option — continued registration as a
general use pesticide without additional regulatory restrictions
— and the most restrictive option — cancellation. The Agency
then attempted to define' intermediate options. The first option
includes the minimum restrictions necessary to significantly
reduce at least some exposures to DBCP; the remaining three
options each cumulatively add additional restrictions to further
reduce exposure. In selecting these options, the Agency
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necessarily exercised its discretion in its choice and con-
sideration of options, since it is virtually impossible to
evaluate every conceivable option or combination of options.
In the aggregate, however/ the Agency believes that its choice
of options fully and adequately addresses all relevant exposure
concerns about the use of DBCP.
The options selected are:
• (1) Continue registrations without additional
restrictions
Under this option, a use of DBCP would be registered in the
same manner and with the same restrictions that existed before
the Notice of Intent to Suspend. In other words, no additional
regulatory action would be taken to reduce any risk"from DECP use.
(2) Classify for restricted use; require full-body protective
clothing and respirator during transfer, maintenance and clean-
up; require boots and gloves during application.
This option would reduce the potential for exposure,
especially dermal exposure, in several situations.
First, the use of DBCP would be limited to certified
applicators (or persons under their direct supervision) who have
been demonstrated to be competent to use and handle DBCP; this
would generally reduce the risks which may result from
carelessness or misuse.
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Next, full-body protective clothing and a full-face air-
purifying respirator would be required during all phases of
mixing and transfer operations, during maintenance (including
calibration) of application equipment, and during clean-up of
spills or accidents. The full-body protective clothing would
consist of impermeable gloves, boots or boot covers, coat
and pants; it would significantly reduce the high potential
for dermal exposure during these operations. Although it
would also be appropriate to require a helmet and face-shield
as part of the protective clothing, the Agency believes that
requiring the use of a full-face air-purifying respirator
would be even more appropriate; this would also reduce the
potentially high inhalation exposures during these operations
in addition to protecting against dermal exposure. If a closed
system for mixing or transfer is used, an impermeable apron,
gloves and boots or boot covers would be required. If a closed
system is used which results in an airborne concentration of
DBCP not exceeding 1 part DBCP per billion parts of air (1 ppb)
as an 8-hour time—weighted average, then a- respirator would -iot
have to be worn during the operation of the closed system, but
would have to be available for use in case of leaks, spills or
other emergencies.
Finally, to reduce potential dermal exposures during actual
application, impermeable gloves and boots or boot covers would
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be required during all phases of application using the irrigation,
drench/ granular and in-furrow techniques.
(3} Option (2) plus; require a respirator and
re-entry interval for irrigation applications
This option would include all of the restrictions and
conditions of option (2), and would also require the use of a
full-face air-purifying respirator during all phases of appli-
cation by irrigation. This would reduce the potential for inha-
lation exposure from the application technique posing the highest
hourly inhalation exposure. Further, this option would also
reduce the potential inhalation exposure of persons reentering
treated areas, by prohibiting reentry for 24 hours after the
completion of irrigation unless the persons reentering were to
wear a full-face air-purifying respirator and impermeable gloves
boots or boot covers.
(4) Option (2) plus: require a respirator _and
reentry interval for all application techniques
This option would also include all of the restrictions and
conditions of option (2)', and would further reduce the potential
for .inhalation exposure by requiring a full-fa'ce air-purifying
respirator during all phases of all applications by all
techniques. This option would also reduce the potential inha-
lation exposure of persons reentering treated areas, by
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prohibiting reentry for 24 hours after completion of application
unless the persons reentering were to wear a full-face air-purifying
respirator, and, in the case of irrigation or drench application,
impermeable gloves and boots or boot covers.
(5) Option (4) plus; prohibit application by
irrigation
This option is the most restrictive option short of
cancellation. It would incorporate all of the restrictions
and conditions of option (4) — which in turn incorporates the
restrictions and conditions of option (2) — and would also
prohibit all applications by the irrigation technique. This
option completely eliminates the high inhalation and dermal
exposure potentials of the irrigation technique, and the inhala-
tion and dermal exposure potentials of all other techniques would
be minimized.
(6) Cancel registrations
Under this option, a specific use of DBCP would be pro-
hibited and all risks from that use of DBCP would be completely
eliminated.
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Y. Review of;the Impacts of the Major Options
This section evaluates, on a use-by-use basis, the
impacts of each regulatory option developed in Section IV.
In assessing each option, the Agency determined the reductions
in risks which would be achieved and considered how the risk
reduction measures would affect the benefits of the use.
All information necessary for this evaluation has been
described in Sections.II and III, with the exception of one
important area--namely, information concerning the risks
from the use of pesticides which would be.used if DBCP were
unavailable. To provide these data, the Agency has generated
three support documents. A memorandum of human hazards,
"Toxicology Data on Alternative Pesticides to DBCP,"
details all published and proprietary data concerning those
alternatives (Dale, 1978b). The significant acute and chronic
toxic effects of each substitute chemical were derived from
this document and presented in another memorandum, "Summary
Tables for DBCP" (Sandusky, 1978).
A "Fish and Wildlife Risk Analysis" evaluated all
the potential effects on terrestrial and aquatic organisms
(Bushong, 1978). Sufficient data were not available to
perform a full, detailed risk assessment for any of the
substitute pesticides. However, the available acute and
chronic toxicity data, field studies and incidents, wildlife
label warnings and the rates of application were described
for most of the substitutes. In a few instances possible
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significant wildlife losses or dieoffs which could occur
from the use of a substitute at the recommended application
rates were pointed out.
All hazards of concern—both human and environmental--
frora potential use of the substitute pesticides are listed
in Table 5 and are discussed in detail for each use in this
section. "Table 9 contains estimates of the percent increased
use of the. substitutes to indicate the magnitude of the
potential hazards of concern.
For .each use a standard format is followed: (1) Usage
data—the total amount of DBCP applied, total acres treated,
the predominant techniques of application and any available
substitute methods of nematode control; (2) Risk-data—the
primary routes of human exposure, the number of people in-
volved and the risks to individuals; (3) Benefits data—the
advantages of DBCP over other methods of control and the
impacts that would- result if DBCP were not available;
(4) .Impacts Analysis — the adverse and beneficial impacts of the
options on human health, the environment and various economic
rectors; (5) Alternative Chosen—the final course of action
and the .rationale for choosing it.
A. Citrus
(1) Usage
DBCP is the only registered nematicide for postplant
control of neraatodes on all varieties of citrus trees.
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About 1,292,000 pounds are applied annually to 31,200 acres
in Texas, Florida, California and .Arizona (Benefits Analy-
sis). Since the material is applied once every 3 years, a
total of 93>600 acres or 7.9% of domestic citrus acreage are
treated. Soil injection and irrigation are the only applica-
tion methods. Their use varies by state (see Table 11).
(2) Risks
- . Since no residues of DBCP are expected in citrus, the
only risks are to 593 pesticide applicators. As summarized in
Table 3* the risks from inhalation during application vary
considerably by state and by application technique. For in-
jection, the risk of cancer ranges from a lifetime probabi-
lity 1.31 X 10~5 in California to a probability of 2.63 X }$**
in Florida; for irrigation, the cancer risk ranges from
5.11 X 10~3 in California and Arizona to 8.72 X 10~2 in
Texas. The risks from inhalation during mixing and loading
also vary by state and by application technique. For injection,
the risk of cancer ranges from a lifetime probability of
3.32 X 10~6 in California to a probability of 6.57 X 10~5
in Florida; for irrigation, the risk ranges from 3-07 X 10"
in California and Arizona to 5.M8 X 10 in Texas. A risk of
adverse reproductive effects for male applicators accompanies
the cancer risk.
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Table M summarizes risks from other potential
exposure situations.
(3) Benefits
The value of DBCP to citrus may be expressed in terms
of the adverse economic impacts of the unavailability of
DBCP. Fresh and process orange production would be reduced
by 4.60* and 0.17?., respectively, after 3 years. Fresh
grapefruit, lemon and tangerine reduction would be reduced
by 6.03J, 9.77% and 3-81J respectively per year at the end
of 3 years. The total value of reduced production on the
affected acreage would be $29,092,000. Subtracting the cost
of control with DBCP, the net grower level impact in reduced
revenues during the three-year period is $26,851,000
(Benefits Analysis).
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In the long term, the greatest impact would be reduced
tree longevity. With DBCP, grove life is about 60 years;
without DBCP, groves would remain productive only 30 to *4Q
years. This would-necessitate replanting and M years of un-
productive acreage at an earlier than normal time. These
production reductions would increase retail citrus'prices:
fresh oranges, 3-&3£'; process orange products, 0.23*; fresh
grapefruit, ^.9^; lemons and tangerines, an undetermined
but probable increase.
The long-term impacts would be severe for affected
growers and moderate for consumers and the citrus industry.
(M) Regulatory Options and Their Impacts
Option 1: Continue registrations without additional
restrictions.
(i) Adverse Impacts - The risks to 593 applicators
would continue.
(ii) Beneficial Impacts - The nematode control
advantages of DBCF would continue.
Option 2: Classify for restricted use; require full-
body protective clothing and respirator during transfer,
maintenance or cleanup operations: and require boots and gloves
during application.
(i) Adverse Impacts - The risks, frora inhalation
•exposure to DBCP during application would continue. The
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costs of requiring protective equipment, including respirator,
would be $110 per person in the affected operations.
: (ii) Beneficial Impacts - DBCP use by untrained
persons would be eliminated. The risks from dermal exposure
to DBCP by all applicators would be virtually eliminated by
the protective clothing. Risks to applicators from inhalation
exposure during mixing and loading, spill cleanups, etc.
would be reduced- at least fiftyfold. Applicators would have
to wear full protective clothing for only about 30 minutes
per day, a practice with which most persons may be expected
to comply. The nematode control advantages of DBCP would
continue.
Option 3: Option 2 plus require a respirator and reentry
interval for application by irrigation.
(i) Adverse Impacts - There would still be some
risks, one-fiftieth that described in the citrus risk discussion,
from inhalation exposure during irrigation. The risks from
inhalation exposure during soil injection would continue. The
costs of imposing these restrictions would be $110, the same
*
as in Option 2.
(ii) Beneficial Impacts - There would be the same
beneficial impacts as in Option 2, but the risks from inhal-
ation exposure during irrigation would be reduced at least
fiftyfold. The risks from inhalation exposure during reentry
into treated areas after irrigation would be reduced. The
nematode control advantages of DBCP woul.d,continue.
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Option 4: Option 2 plus require a respirator and reentry
Interval for all application techniques.
(i) Adverse Impacts - There would still be some
risks, at one-fiftieth the level described in the citrus
risks discussion, from inhalation exposure during application.
The costs of imposing these restrictions would be $110, as
in Option 2.
(ii) Benefici'al Impacts - These would be the same
as in Option 2, but in addition the risks to applicators
from inhalation exposure during all applications would.be
decreased at least fiftyfold. The risks from inhalation
exposure during reentry into treated areas after all appli-
cations would be reduced. The nematode control advantages
of DBCP would continue.
Option 5: Option 4 plus prohibit application by
irri gat i on..
(i) Adverse Impacts - Most of the 716 growers— in
California, Texas and Arizona who had been using irrigation
would probably not be willing to switch to soil injection;
they could minimally maintain economic production without
DBCP, since revenues and returns would be significantly reduced
and since there would be root damage and disruption of no-till
*/ 716 is the total number of farmers who grow citrus on
"acres that are treated with DBCP (See Table 11). The 593
persons cited previously are'those who actually apply DBCP.
In Texas, only 20 persons apply DBCP on the farms of 303
growers. This accounts for the difference between 716 and
593. • '
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weed control. If all growers stopped using DBCP, the total
impact would be $21,800,000. For the growers who continue
the use DBCP via soil injection, the cost of application
would be about $8 per acre if they applied it themselves, or
as high as $35 per acre if they hired a custom applicator.
If all growers switched to injection, the total impact would
be $190,000-$830,000 per 3 years on 23,700 acres, or $265-$1160
per grower per year cycle (Luttner, 1978) These growers or
custom applicators would also be subject to the same risks
described in Option 4.
(ii) Beneficial Impacts - The high risks from
inhalation and dermal exposures during and after irrigation
would be completely eliminated, and the risks from inhalation
during soil injection would be reduced at least fiftyfold.
The risks from inhalation exposure during reentry into treated
areas after soil injection would be reduced. The nematode
control advantages of DBCP would continue.
Option 6.: Cancel registrations.
(i) Adverse Impacts - Significant adverse economic
Impacts would occur as described in citrus benefits.discussion.
(ii) Beneficial Impacts - All risks associated with
the use of DBCP would be eliminated.
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(5) Regulatory Option Selected
Option 1 is rejected, because without further restric-
tions this use of DBCP will result in unreasonable adverse
effects on the environment. The Agency has selected Option
4, since it will adequately reduce risks without significant
.impacts on the benefits of this use- Options 2 and 3 will
not satisfactorily reduce risk and will result in unreasonable
adverse effects. Options 5 and 6 will reduce or eliminate the
risks of DBCP, but will result in unacceptable adverse impacts
on the economic benefits of this use. Thus, in order to conti-
nue a registration of DBCP on citrus, the conditions of registra-
tion must be modified as described in Option 4.
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B. Cotton
(1) Usage
Each year 2,700,000 pounds of DBCP are applied pre-,
at- or post-plant at a rate of 12.1 pounds per acre to
225,000 acres, or 2% of all planted acres (Benefits Analy-
sis). It is applied most commonly pre-plant by soil injec-
tion.
EDB, Telone II and D-D are ';ne most viable, registered
substitutes. Under ideal conditions they.control nematodes
on cotton. They cost more per acre and require a 10- to
14-day delay in planting in order to avoid phytotoxicity
(Benefits Analysis).
(2) Risks
The only risks from use on cotton are for 1,271 applica-
tors in the South.
The increased probability of cancer from inhalation during
application is 7.76 X 10 (Table 3). The increased probability
of cancer from inhalation during mixing and loading is 2.01 X
.10 , Simultaneously, there is an increased risk of decreased
sperm counts for exposed males.
Table 4 summarizes the risks from other potential ex-
posure situations.
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(3) Benefits
The value of DBCP to cotton growers is estimated at
$2,600,000 per year. This figure is based on the cost of substi-
tute chemicals and on the assumption that those pesticides are
as efficacious as DBCP. This impact is very small as compared
to the total farm value of cotton of $3,100,000,000 in 1976; con>
sequently, this impact would not be expected to significantly
affect total cotton production or consumer prices (Benefits
Analysis).
(4) Regulatory Options and Their Impacts
Option 1: Continue registrations without additional
restrictions.
(i) Adverse Impacts - The risks to 1,271 applica-
tors would continue.
(ii) Beneficial Impacts - The nematode
control advantages of DBCP would continue.
Option 2: Classify for restricted use; require
full-body protective clothing and respirator during transfer,
maintenance or cleanup operations; and require boots and
gloves during application.
(i) Adverse Impacts - The risks from inhalation
exposure to DBCP during application would continue- The
costs of requiring protective equipment, including respira-
tor, would be $175 per person in the affected operations.
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(ii) Beneficial Impacts - DBCP use by untrained
persons would be eliminated. The risks from dermal exposure
to DBCP by all applicators would be virtually eliminated by
the protective clothing. Risks to applicators from inhalation
exposure during mixing and loading, spill cleanups, etc.
would be reduced at least fiftyfold. Applicators would
have to wear full protective clothing for only about 30
minutes per day, a practice with which most persons may be
expected to comply. The nematode control -advantages of DBCP
would continue.
Option 3: Option 2 plus require a respirator and
reentry interval for application by irrigation.
(1) Adverse Impacts - These would be- the same as
in Option 2, since no DBCP is known to be applied by irrigation.
(ii) Beneficial Impacts - These would be the same as
in Option 2, since no DBCP is known to applied by irrigation.
However, if DBCP were applied by irrigation, the risks to
applicators from any inhalation exposure would be decreased
fiftyfold. Risks to persons reenterinc a treated area would
be reduced at least sixfold.
Option 4: Option 2 plus require a respirator and re-
entry interval for all application techniques.
(i) Adverse Impacts - There would still be some
risks, one-fiftieth of that described in the cotton risks dis-
cussion, from inhalation exposure during application. The
costs of imposing these restrictions would be $175 as in
Option 2. , '
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(ii) Beneficial Impacts - These would be the same
as in Option 2; in addition the risks to applicators from
inhalation exposure during all applications would be decreased
at 1-east fiftyfold. The risks from inhalation exposure during
reentry into treated areas after soil injection would be reduced,
The nematode control advantages of DBCP would continue.
Option 5: Option 4 plus prohibit application by
irrigation.
(i) Adverse Impacts - These would be the same as
in Option 4, since no DBCP is known to be applied by irrigation.
(ii) Beneficial Impacts - Same as for alterna-
tive 2, since no DBCP is known to applied by irrigation.
However, if DBCP v^are applied by irrigation, the risks
to applicators from any inhalation exposure would be eli-
minated. Risks to persons reentering a treated area would
also be eliminated.
Option 6: Cancel registrations.
(i) Adverse Impacts - There would be minor
long and short-term impacts for growers and consumers:
$3,300,000 per year in control cost increases for growers
and up to 0.1% price increases for consumers. There may be
some risks to applicator from the increased use of substitute
pesticides (see Tables 5 and 9).
There may be some chronic risks to a-ppl i cators from in-
creased use of the substitute pest.icides DO, EDB and Telone
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II.(see table 5). About 9,200,000 pounds of DD, 950,000 pounds
of EDB and 4,300,000 pounds of Telone II might be used annually
in place of DBCP- These amounts are 130%, 13% and' 62%, re-
spectively, of the amounts of these chemicals produced in
the United States in 1974 or 1.975. Thus, the. chronic risks
to applicators from use of these substitutes only on cotton
•might be substantial.
(ii) Beneficial Impacts - All risks from the use
of DBCP would be eliminated.
(5) Regulatory Option Chosen
Option 1 is rejected, because without further restric-
tions this use of DBCP will result in unreasonable adverse
effects on the environment. The Agency, has selected Option
4r since it will adequately reduce risks without significant
impacts on the benefits of this use. Options 2 and 3 will
not satisfactorily reduce risks and will result in unreason-
able adverse effects. Options 5 and 6 will eliminate the
risks of DBCP, but will result in unacceptable adverse
impacts on the economic benefits of this use and will create
significant potential risks from use of substitute nemati-
cides. Thus, in order to continue a registration of DBCP on
cotton, the terms and conditions of registration must be
modified as described in-Option 4.
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C. Grapes
(1) Usage
DBCP is an integral part of neraatode -control programs
for vineyards. Other fumigants are used for pre-plant
treatment; DBCP is applied post-plant 2 to 5 years later
'if nematode populations return to damaging levels. These
post-plant treatments are applied at 1 to 3 year intervals
thereafter, usually by flood irrigation, but sometimes by
injection. Rates of application range from 2.86 to 3«57
gallons of DBCP per acre (12.1 pounds a.i. per gallon)
(Benefits Analysis).
In California, where 9Q% of grapes in the U.S. are
grown, about 165,000 acres or 31 % of the total bearing acres
are treated subject to treatment. Based on an average
application rate of 39 1bs. a.i./acre, the total use of DBCP
is 3f200,000 pounds annually or 6,^400,000 pounds for a two-
year treatment cycle.
There are no effective Federally registered nemato-
cides that cciId substitute for DBCP postplant nematode
control in vineyards.
(2) Risks
Only 2,320 growers applying DBCP by irrigation and 258
growers applying it by soil injection.are at risk. For irri-
gation applicators, inhalation exposure during application
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o
poses 5.48 X 10 increased probability of cancer; during mix-
ing and loading, the cancer risk from inhalation is 3.54 X
10 (table 3). For soil injection applicators, inhalation of
DBCP 'during application poses 1.57 X 1(5 increased probability
of cancer; during mixing and loading their risks of cancer are
increased by 4.02 X 10 For males in both groups, there is a
risk of reduce.d sperm counts. The risks from other potential
exposure situations are summarized in Table 4.
(3) Benefits
Since there are no registered alternative nematicides
for grapes, the value of DBCP to growers in California is
substantial. If DBCP were unavailable, there would be severe
reductions in grape production and revenues would decline
$64,700,000 for the first 3 years. Vineyard life would be
reduced from 30-60 years to 10-15 years.
While individual grower impacts cannot be determined
for all varieties of grapes and soil types, one example
illustrates the economic implications to table grape growers
if DBCP is not available. For the first year, Thompson
Seedless table grape producers would suffer reduced revenues
°f $161 per acre, assuming 10% yield reduction, constant
Prices and 100% nematode infestation. A representative
producer with 74 acres would therefore lose about $12,000
in revenue, or 5.2% of gross revenue (Benefits Analysis).
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In the short term, consumers would pay higher prices
as grape production falls, especially for table grapes,
since most of the table grape acreage is treated for nema-
todes. In the long term, consumers might be faced with
smaller supplies and up to a 5% price increase. Total
production would be likely to stabilize at near "normal"
levels as new production procedures, resistant varieties or
new nematicldes were developed.
(4) Regulatory Options and Their Impacts
Option 1; Continue registrati on without add itional
regulatory restrictions.
(i) Adve'rse Impacts - The risks to 2,578 appli-
cators would continue.
(1i) Beneficial - The nematode control
advantages of DBCP would continue.
Option 2: Classify for restricted uje; require
full-body protective clothing and respirator during transfer,
maintenance or cleanup operations; and require boots and
gloves during application.
(i) Adverse Impacts - The risks from inhalation
exposure to DBCP during application would continue. The
costs of requiring protective equipment, including respirator,
would total $110 per person in the affected operations.
* *
(ii) Beneficial Impacts - DBCP use by untrained
persons would be eliminated. The risks to all applicators from
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dermal exposure to DBCP would be virtually eliminated by the
protective clothing. The risks to applicators from inhalation
exposure during mixing and loading, spill cleanups, etc.
would be reduced at least fiftyfold. Applicators would have
to wear full protective clothing for only about 30 minutes
per day, a practice with which most persons may be expected
to comply. The nematode control advantages of DBCP would
cont inue.
Option 3: Option 2 plus requ-ire a respirator and
reentry interval for application by irrigation.
(i) Adverse Impacts - There would still be some
risk, at one-fiftieth the level described in the grapes risk
discussion, from inhalation exposure during irrigation. The
risks from inhalation exposure during soil injection would
continue. The costs of imposing these restrictions would be
$110, as in Option 2.
(ii) Beneficial Impacts - These would be the same
as in Option 2; in addition, the risks from inhalation exposure
during irrigation would be reduced at least fiftyfold. The
risks from inhalation exposure during reentry into treated
areas following irrigation would also be reduced. The
nematode control advantages of DBCP would continue.
Option 4: Option 2 p.lus require a respirator and
reentry interval for all application techniques .
(i) Adverse Impacts - There would still be some
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risks from inhalation exposure during application, at one-
fiftieth the level described in the grapes risk discussion.
The costs of imposing these restrictions would be $110, the
same as in Option 2.
(ii) Beneficial Impacts - These would be the same as
in Option 2, but the risks from inhalation exposure during
irrigation would be reduced at least fiftyfold. The risks from
inhalation exposure during reentry into treated areas after
Irrigation would also be reduced. The nematode control advant-
ages of DBCP would continue.
Option 5: Option 4 plus prohibit application b'y
irrigation.
(i) .Adverse Impacts - The 2,320 growers who
had been using irrigation would be forced to switch to soil
injection to maintain economic levels of production. If
all growers applied DBCP themselves, the cost of application
would increase $8 per acre, a total of $594,000 every 3 years,
$256 per grower. If the DBCP were applied by commercial
applicators, the costs would be $35 per acre, a total of
$2,600,000 every 3 years,- or $1120 per grower. The risk to
applicators would be the same as in Option 4. The costs of
protective equipment would be $110 per person. If all growers
did not switch to injection, the total impact would be about
$58,500,000. Although soil injection can cause some root
damage, most growers woul'd probably switch, since DBCP is
necessary for economic production.
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(il) Beneficial Impacts - The high risks from
inhalation and dermal exposure during and after irrigation
would be completely eliminated, and the risks from inhala-
tion during soil injection would be reduced at least fifty-
fold. The risks from inhalation exposure during reentry
into treated ar*;as after soil injection would be reduced.
The nematode control control advantages of DBCP would
continue.
Option 6: Cancel registrations.
(i) Adverse Impacts - There would be severe short
and long term impacts on growers, as described earlier in the
grape benefits oiscuss ion. Consumers will be significantly
affected for the short term and moderately affected for the
long term-
(ii) Beneficial Impacts - All risks from the use
of DBCP would be eliminated.
(5) Regulatory Option Chosen
Option 1 is rejected, because without further restrictions
this use of DBC"• will result in unreasonable adverse effects
on the environment. The Agency has selected Option 4, since
it will adequately reduce risks without significant impacts
on the benefits of this use. Options 2 and 3 will not satis-
factorily reduce risks and will result in unreasonable adverse
effects. Options 5 and 6 will eliminate the risks of DBCP, but
will result in unaccspt-abl e adverse impacts on the economic
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benefits of this use. Thus, in order to continue a registration
of DBCP on grapes, the conditions of registration must be modi-
fied as described in Option 4.
d. Peaches and Nectarines
(1) Usage
DBCP may be applied pre- and post-plant to control nema-
todesin peach and nectarine orchards. In California and several
Eastern states, about 327,000 poui.ds are used annually in new
orchard plantings, or 44% of the total acreage planted per year.
In the East, about 871,000 pounds are applied post-plant to
.24,000 acres over a two-year cycle. In California, about
3,180,000 pounds are applied postplant to 65,700 acres over
a three-year period (Benefits Analysis).
The standard application techniques are soil injection
in the Eastern states and irrigation in California. The
respective application rates are 7 gallons per acre and 3.5
to 5 gallons per acre (12 Ibs a.i. per gallon).
DBCP is the sole registered nematicide for post-plant
treatment of nematodes in peach orchards. Likely alterna-
tives for pre-plant applications are EDB, D-D and Telone.
(2) Risks
Only to 1,714 applicators in the East and 1,095 appli-
cators in California are at risk from DBCP use on peaches
-------
-90-
and nectarines. The cancer risk to California growers
from inhalation exposure during irrigation is 5.^8 X 10~^;
during mixing and loading, the cancer risk is 2.08 X 10~ .
For Eastern growers, the risk from inhalation exposure
during application by soil injection is 5.11 X 10~ in-
.creased probability of cancer; fror. inhalation exposure
during mixing and loading, the increased risk of cancer is
-6
3.36 X 10 . For all male applicators there is a risk of de-
creased sperm counts. Risks from all other potential
exposure situations are summarized in Table 4.
(3) Benefits
The unavailability of DBCP would have immediate cost
impacts due to higher costs for pre-plant alternatives and
would lead to major reductions in peach production on
affected acres in subsequent years due to the lack of
post-plant substitutes. For pre-plant nematode control,
growers would spend an additional $673,000 per year for
pre-plant nematode control. The unavailability of DBCP
for post-plant aplications.- would significantly reduce
production and result in a total Joss of $40,161,000 over
the initial three years following cancellation. This, is a
worst-case estimate, since projected crop losses would lead
to higher market prices, thereby offsetting to some extent
the reduced revenue (Benefits Analysis).
-------
Without an effective post-plant neraaticide the average
peach tree life would be reduced from 12-13 years to 6-7
Bears in the East and from 20 to 10 years in California.
Chronically infested orchards areas would be converted to
use for other crops; new peach tree lands would be developed
feo the extent that uninfested land was available and econom-
ically feasible. Peach producers not affected by a loss of
DBCP would probably have higher returns; they would probably
intensify production practices and increase plantings.
However, affected growers would be severely impacted, and
related, industries (e.-g., peach, processors) -might-be forced
to shift to other commodities.
Consumers would pay up to 25% higher retail prices
for fresh a'nu processed peach products in the short-term.
For the long term, factors such as production increases by
growers in unaffected areas or the introduction of an ef-
fective post-plant neinaticide could lower peach prices to
"normal" levels.
Regulatory Options and Their Impacts
Option 1 : Continue registrations without additional
restrictions .
(1) Adverse Impacts - The risks to 1,714 applica-
tors would continue.
(ii) Beneficial Impacts - The^nematode control
advantages of DBCP would continue.
-------
Option 2i Classify for restricted use; require full-
body protective clothing and respirator during transfer,
maintenance or cleanup operations; and require boots and
gloves during application.
(i) Adverse Impacts - The risks from inhalation
exposure to DBCP during application would continue. The
costs of requiring protective equipment, including respirator,
would be $110 per person in the affected operations.
(ii) Beneficial Impacts - DBCP use by untrained
persons, would be eliminated. The risks from dermal exposure
to DBCP by all applicators would be virtually eliminated by
the protective clothing. The risks to applicators from inhala-
tion exposure during mixing and loading, spill cleanups,
etc. would be reduced at least fiftyfold. Applicators would
have to wear full protective clothing for only about 30
minutes per day, a practice with which most persons may be
expected to comply. The nematode control advantages of DBCP
would continue.
Option 3; Option 2 plus require a-respirator
*
?nd reentry interval for application by irrigation.
(i) Adverse Impacts - There would still be some
risks, at one-fiftieth the level described in the peach risk
discussion, from inhalation e-xposure during irrigation. The
risks from inhalation exposure during soil injection would
continue. The cost of imposing these restrictions would be
$110, the same as in Option 2.
-------
(ii) Beneficial Impacts - These would be the
same as in Option 2, in addition to which the risks from
inhalation exposure during irrigation would be reduced at
least fiftyfold. The risks from inhalation exposure during
reentry into treated areas after irrigation would also be
reduced. The nematode control advantages of DBCP would
continue.
Option 4: Option 2 plus require a respirator and
reentry interval for all application techniques.
(i) Adverse Impacts - There would still be some
risks at one-fiftieth the level described in the peach risk
discussion, from inhalation'exposure during application.
The cost of imposing these restrictions would be $110, the
same as in Option 2.
(ii) Beneficial Impacts - These would be the same
as in Option 2, but the risks to applicators from inhala-
tion exposure during all applications would.be decreased at
least fiftyfold. The risks from inhalation exposure during
reentry into treated areas after all applications would be
reduced. The nematode control advantages of DBCP would con-
tinue
Option 5; Option 4 plus prohibit application by irri-
gation.
(i) Adverse Impacts - The 1,095 growers who
had been using irrigation would be forced to switch to soil
injection to maintain economic levels of production. If
-------
all growers applied DBCP themselves, the cost of application
would increase $8 per acre, a total of $175,000 every 3
years, or $160 per grower. If the DBCP were applied by
commercial applicators, the costs would be $35 per acre, a
total "of $767,000 every 3 years, or $700 per grower.
The risk to applicators would be the same as in Option
4. The costs of protective equipment would be $110 per
person. If all growers did not switch to injection, the
total impact would be about $52,000,000. Although soil
injection can cause some root damage, most growers would
probably switch, since DBCP. is necessary for economic
production.
(ii) Beneficial Impacts - The high risks from in-
halation and dermal exposure during and after irrigation
would be completely eliminated, and the risks from inhalation
during soil injection would exposure during reentry into
treated areas after sot! injection would be reduced.. The
nematode control advantages of DBCP would continue.
Option 6; Cancel registrations.
(i) Adverse Impacts - There would be severe short-
and long-term adverse economic impacts as described in the
peach benefits discussion.
There may be some chronic risks to applicators from
increased pre-plant use of the substitute pesticides DO, EDB
and Telone II (Table 5).- About 1,400,000 pounds of DD,
500,000 pounds of EDB and 1,00,000 pounds of Telone might be
-------
Peanut growers in Oklahoma and Texas could suffer
severe impacts which might force them out of business.
Producers would have to consider alternative farm enter-
prises. In the other regions, producers' returns would
decrease if DBCP were not available, but returns would still
be positive. The total impact of the unavailability of DBCP
on all growers would be minor.
The loss of DBCP would have a minimum impact on con-
sumers, since most if not all of any price increase would be
offset by a decrease in price support payments (Benefits
Analysis).
(4) Regulatory Options and Their Impacts
Option 1;. Continue registration without-additional
restrictions.
(i) Adverse Impacts - The risks to the U.S. popu-
lation from consumption of DBCP residues would continue and
the risks to 7,397 applicators would continue.
(ii) Beneficial Impacts - The nematode control
advantages of DBCP would continue.
Option 2: Classify for restricted use; require full-
body protective clothing and respirator during 'transfer,
maintenance or cleanup operations; and require boots and
gloves during application.
(i) Adverse Impacts - The risks to the U.S.
population from consumption of DBCP residues would continue.
The risks from inhalation exposure to DBCP during application
-------
Alternative fumigants are EDB, Telone II and D-D. The
most practicable registered granular alternatives are Carbofuran,
Mocap and Dasanit. However, all of these are less effica-
cious against some or all nematode species, are less effica-
cious under some soil moisture conditions, and all are more
expe'ns-i ve.
(2) Risks
The increased risk of cancer to the U.S. population
-5
from residues in food is 3.26 X 10 , or 103 cases per year. .
There is also a risk of decreased sperm counts for men.
Also at risk are 7,397 applicators. The risk from inhala-
-5
tion of DBCP during application is 2.63 X 10 increased
probability of cancer; from inhalation exposure during
— fi *
mixing and loading, this risk is 6.57 x 10" . There is also
a risk of decreased sperm counts for men. Table 4 summarizes
the risks from all other potential exposure situations.
(3) Benefits
The grower impact of the unavailability of DBCP would
be $6,800,000 per year in production losses and from the
increased control costs of substitute chemicals. After 3
years, the total impact would be $19,500,,000. The greatest
impacts would occur in Oklahoma and Texas, where about 10%
of the peanut growers there (i.e., 648) would have negative
returns and would be forced to grow other crops (Benefits
Analysis).
-------
applied in place of DBCP (Table 9). These amounts are 20%,
7% and 16%, respectively, of the amounts of these chemicals
produced in 1974 or 1975. Thus, there might be a moderate
degree of chronic risk to applicators from the use of these
substitutes on peaches and nectarines.
(i.i Beneficial Impacts - All risks from DBCP would
be eliminated.
(5) .Regulatory Option Chosen
Option 1 is rejected, because without further restrictions
this use of DBCP will result in unreasonable adverse effects on
the environment. The Agency has selected Option 4, since it
will adequately reduce risks without significant impacts on
the benefits: of this use. Options 2 and 3 will not satis-
factorily reduce risks and will result in unreasonable adverse
effects. Options 5 and .6 will eliminate the risks of DBCP, but
will result in unacceptable adverse impacts on the economic bene-
fits of this use. Thus, in order to continue a registration of
DBCP on peaches and nectarines, the conditions of registration
must be modified as described in Option 4.
E. Peanuts
(1) Usage
About 3,200,000 pounds of DBCP are applied annually to
355,000 acres throughout nine peanut-producing states.
Generally, DBCP is applied 6 to 8 inches deep by chisel injec-
tion at a rate of 9 pounds a.i. per acre (.Benefits Analysis).
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-98-
would continue. The cost of requiring protective equipment,
including respirator, would be $110 per person in the affec-
ted operations.
(ii) Beneficial Impacts - DBCP use by untrained
persons would be eliminated. The risks to all applicators
from dermal exposure to DBCP by all applicators would be
virtually eliminated by the protective clothing. The risks
to applicators from inhalation exposure during mixing and
loading, spill cleanups, etc. would be reduced at least
fiftyfold. Applicators would have to wear full protective
clothing for only about 30-minutes per day, a practice with
which most persons may be expected to comply. The nematode
control advantages of DBCP would continue.
Option 3; Option 2 plus require^ a respirator and re-
entry interval for application by irrigation—Not applicable.
Option 4; Option 2 plus require a respirator and reentry
interval for all application techniques.-
(i.) Adverse Impacts - The risks to the U.S; popula-
tion from consumption of DBCP residues would continue. There
would still be some risk/ at one-fiftieth the level described
in the peanut risk discussion, from inhalation exposure during
application. The cost of imposing these restrictions would
be $110, the same as in Option 2.
(ii) Beneficial Impacts - These would be the
same as in Option 2, but the risks to-applicators from
inhalation exposure during all applications would be de-
-------
creased at least fiftyfold. The risks from inhalation
exposure during reentry into treated areas after soil
injection would be reduced. The nematode control advan-
tages of DBCP would continue.
Option 5; Alternative 4 plus prohibit application by
irrigation—Not applicable.
Option 6: Cancel registrations
(i) Adverse Impacts - There would be minor adverse
economic impacts, except on growers in Texas and Oklahoma, who
would sustain major losses (see peanut benefits discussion).
There would be risks from substitute pesticides.
There may be some chronic risks to applicators from in-
creased use of the substitutes DD, EDB and Telone II. There
may also be some acute risks to wildlife from increased use of
Carbofuran, Dasanit, Mocap and Nemacur (Table 5). In place of
DBCP, 1,300,000 pounds of DD, 6,900,000 pounds of EDB, 1,100,000
pounds of Telone, 48,000 pounds of Carbofuran 48,000 pounds of
Dasanit, and 200,000 pounds of Mocap and 200,000 pounds of Nemacur
might be used (Table 9). These amounts are 18%, 95%, 16%, 1%,
1%, 20% and (unknown)% of the amounts of these chemicals produced
in 1974 or 1975. Thus, chronic risks to applicators might be
substantial, while the acute risks to wildlife might be moderate.
(ii) Beneficial Impacts - All risks from DBCP
will be eliminated.
-------
(5) Regulatory Option Chosen
" Option 1 is rejected, because, this use of DBCP will result
in unreasonable adverse effects on the environment. The Agency
has selected Option 6, since it will eliminate risks from DBCP,
while only adversely affecting 10% of the peanut growers in
Texas and Oklahoma; it will also result in some potential risks
from use of substitute nematicides. Options 2 and 4 will not
satisfactorily reduce risk and will result in unreasonable
adverse' effects. Thus, the Agency has determined that all regis-
trations of DBCP for peanuts must be cancelled in order to
prevent unreasonable adverse effects.
F. Pineapple
(1) Usage
The only state in which pineapples are commercially
produced is Hawaii. About 300,000 pounds of DBCP are
used on 5,000 acres per year at a rate of 60.5 pounds
a.i. per acre. Since affected acres are treated every
3 years, a total of 15,000 acres may be treated (Bene-
fits Analysis).
About 98% of DBCP applied to pineapples is applied by
soil injection to a depth of 8 to - 12 inch'es. in combination
with D-D or Telone. Plastic mulch is laid over the planting rows
immediately after injection, behind the injection shanks, to
seal in the fumigant. This theoretically results in less
exposure to DBCP than would result from the standard soil
injection technique without the plastic mulch (Exposure
Analysi s).
-------
The only registered alternative to DBCP is EDB.
(2) Risks
The only risks are to approximately eight fumigant
supply truck drivers who handle the mixing and loading of
DBCP and about 68 persons who work on or around the soil
injection equipment during application.
Truck drivers, who are exposed to 0.22 mg/hr via
inhalation during 8.5 hours per year, have an increased risk
of cancer of 2.7^ X 10. For equipment operators, hydraulic
operators, supervisors and mulch operators involved in the
t
application operation, exposure to 0.013 mg/hr for ah average'
of 338 hours year results in an increased probability of
cancer of 6.57 X 10 . All exposed men risk a decreased
sperm count. Table 4 summarizes risks from other potential.
exposures.
(3) Benefits
Without DBCP, growers would have to spend $200,000 more
per year to apply EDB and would lose $5,600,000 after 3 years
due to decreased production. The total impact would be a 9.3$
•
decrease in grower revenue over 3 years, -Eventually, the annual
yield loss would lead to an increase in prices that would parti-
ally or even completely offset decreased grower revenues. Because
of the structure of the industry (two of three major growers
are also processors), any long-term impact cannot be accurately
estimated (Benefits Analysis.).
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-102-
In the short term, consumers might expect up to a
9% increase in prices.
(4) Regulatory Option and Their Impacts
Option 1; Continue registration without additional restric-
tions.
(1) Adverse Impacts - The risk to 76 persons
would continue.
(ii) Beneficial Impacts - The nematode control
.advantages of DBCP would continue.
Option 2; Classify for restricted use; require
full-body protective clothing and respirator during transfer,
maintenance or cleanup operations; and require boots and gloves
during application.
(i) Adverse Impacts - The risks from inhalation
exposure to DBCP during application would continue. The costs
of requiring protective equipment, including respirator, would
be $110 per person in the affected operations.
(ii) Beneficial Impacts - DBCP used by untrained
trained persons would be eliminated. The risks from dermal
exposure to DBCP by all applicators would be virtually
eliminated by the protective clothing. The risks to truck
drivers from inhalation exposure during mixing and loading,
spill cleanups, etc. would be reduced at least fiftyfold.
They would have to wear full protective clothing for only about
-------
-103-
15 minutes per day, a practice with which most persons may be
expected to comply. The nematode control advantages of DBCP
would continue.
- Option 3; Option 2 plus require a respirator and re-
entry interval for application by irrigation.
Not applicable.
Option 4; Option 2 plus require a respirator and re-
entry interval for all application techniques.
(i) Adverse Impacts - There would still be some
.risk from inhalation exposure during application, at one-
fiftieth the the level described in the pineapple risk dis-
cussion. The costs of imposing these restrictions would be
$110r the same as in Option 2.
(ii) Beneficial impacts - These would be the same
as Option 1, but the risks to applicators from inhalation ex-
posure during all applications would be decreased at least
fiftyfold. The risks from inhalation exposure during reentry
into treated areas after soil injection would be reduced. The
nematode control advantages of DBCP would continue.
Option 5; Option 4 plus prohibit application by
irrigation—Not applicable.
Option 6; Cancel registrations.
-------
(i) Adverse Impacts - There would be minor to severe
economic impacts as described earlier in the pineapple benefits
discussion. There are no .known environmental risks from using
EDB as a substitute. However, several chronic hazards are associ-
ated.with this chemical, namely oncogenicity, mutagenicity and
adverse reproductive effects. These risks are being evaluated
through the RPAR review process at this time. In place of DBCP,
720,000 pounds of EDB would be applied every 3 years.
(ii) Beneficial Impacts - All risks from the use of
DBCP would be eliminated.
(5) Regulatory Option Chosen
'Option 1 is rejected, Because without further restrictions
this use of DBCP will result in unreasonable adverse effects
on the environment. The Agency has selected Option 4, since
it will adequately reduce risks without significant impacts
on the benefits of this use. Option 2 will not satisfactorily
reduce risks and will result in unreasonable adverse effects.
Option 6 will eliminate the risks of DBCP, but will result in
unacceptable adverse impacts on the economic benefits of this
use and will create significant potential risks from use of
the substitute EDB. Thus, in order to continue a registration
of DBCP on pineapples, the conditions of registration must
be modified as described in Option 4.
G. Soybeans
(1) Usage
DBCP may be applied preplant or at-planting by chisel
injection 6 to 8 inches below the surface at a rate of 9 to
-------
-105-
12 pounds a.i. per acre, (Cooperative Assessment). In 1976,
12,378,000 pounds were applied to 1,100,000 acres, 5% of all
soybean acres planted in the Southeastern and Delta states.
(Benefits Analysis). The most practicable substitute pesti-
cides are D-D, Telone, Mocap and Nemacur.
(2) Risks
9,655 applicators are at risk. Inhalation exposure
'during mixing and loading may result in 1.86 X 10 increased
probability of cancer. Inhalation during application would
result in 6.9*1 X 10 increased probability of cancer- All
exposed men would risk a decreased sperm count. Risks from
other potential exposures are summarized in Table M.
(3) Benefits
If DBCP were no.t available, the use of substitutes
would cost an average of $22 more per acre, or $2,600,000
per year. This impact represents about 0.1J of the
$3,000,000,000 farm, value of soybeans (Benefits Analysis).
On the other hand, about 6,600 growers in the Delta region
would sustain a U4J reduction in returns, and 3,000 growers
in the Southeast would lose 36J of their returns. Thus,
farmers with a severe nematode problem might forced to grow
other crops.
There would be only a negligible increase in prices for
consumers in the short and long terra.
-------
— JLUO—
(4} Regulatory Options and Their Impacts
'Option 1; 'Continue registrations without additional
restrictions.
(i) Adverse Impacts - The risks to 9,655 applicators
would continue.
(ii) Beneficial Impacts - The nematode control
advantages of DBCP would continue.
Option 2; Classify for restricted use; require
full-body protective clothing and respirator during transfer,
maintenance or cleanup operations; and require boots and
gloves during application.
(i) Adverse Impacts - The risks from•inhalation
exposure to DBCP during application would continue. The
costs of requiring protective equipment, including respirator,
would $110 per person in the affected operations.
(ii) 'Beneficial Impacts - DBCP used by untrained
persons would be eliminated. The risk from dermal exposure
to DBCP by all applicators would be virtually eliminated by
the protective clothing. Risks to applicators from inhalation
exposure during mixing and loading, spill cleanups, etc.
would be reduced at least fiftyfold. Applicators would have
to wear full protective clothing only for about 30 minutes
per day, a practice with which most persons may be expected
to comply. The nematode con.trol advantages of DBCP would
continue.
-------
Option 3; Option 2 plus require a respirator and re-
entry interval for application by irrigation--Not applicable.
Option 4; Option 2 plus require a respirator and re-
entry interval for all application techniques.
(i) Adverse Impacts - There would still be some
risks, at one-fiftieth the level described earlier in the
soybean risk discussion, from inhalation exposure during appli-
cation . The cost of imposing these restrictions would be
$110 as in Option 2.
(i) Beneficial Impacts - These would be the same
as in Option 2, in addition to which the risks to Applicators
from inhalation exposure during all applications would be
decreased at least fiftyfold. The risks from inhalation
exposure during reentry into treated areas after soil
injection would be reduced. The nematode control advantages
of DBCP would continue.
Option 5; Option 4 plus prohibit application by irri-
gation—Not applicable.
Option 6; Cancel registrations.
(i) Adverse Impacts - While the economic impact of
cancellation is insignificant (<0.1% of the value of the
soybean production in the United States), growers who use
DBCP would be affected significantly, as described in the
soybean benefit discussion.
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-108-
Th ere may be some chronic risks to applicators from
increased use of the substitutes DD and Telone II {Table 5).
Also,'there may be some acute risks to wildlife from in-
creased use of Mocap and Nemacur. In place of DBCP 62,000,000
pounds of DD, 41,000,000 pounds of Telone II, 1,500,000
pounds of Mocap and" 340,000 pounds of Nemacur might be used
(Table 9). These amounts are 884%, 594%, 153% and (unknown)% of
•
the amounts of these chemicals produced in 1974 or 1975.
Thus, chronic risks to applicators and acute risks to
wildlife from use of these substitutes might be very sub-
stantial.
(ii) Beneficial Impacts - Ml risks associated
with use of DBCP would be eliminated.
(5) Regulatory Options Chosen
Option 1 is rejected, because-without further restric-
tions this use of DBCP will result in unreasonable adverse
effects on the environment. The Agency has selected Option 4,
since it will adequately reduce risks without significant
impacts on the benefits of this use. Option 2 will not satis-
factorily reduce risks and will result in unreasonable adverse
effects. Option 6 will eliminate the risks of DBCP, but will
result in unacceptable adverse impacts on the economic bene-
fits of this use and will create significant potential risks
from use of substitute nematicides. Thus, in-order to continue
a registration of DBCP on soybeans, the terms and conditions
of registration must be modified as described in Option 4.
-------
•H. Commercial Vegetables, Melons and Strawberries
(1) Usage
DBCP is registered for use on 22 annual or semi-annual
veget.able and fruit crops--broccoli, brussel sprouts, cabbage,
carrot, cauliflower, celery, cucumber, eggplant, endive,
lettuce, lima bean, melons, okra, parsnip, peppers, radish,
snap bean, southern pea, tomato, turnip and strawberry. Of
these DBCP uses, 19 have be unconditionally suspended (see Table
13).- About 3,392,000 pounds per year were applied to 374,000
*
acres of these crops during 197^-1976. Nationwide the percentage
of each crop treated varied from <0.15o for strawberries and
several other crops, to 95$ for okra (Benefits Analysis).
Usually DBCP is injected 6 inches deep into the soil. If
*
granules are used, they are spread on the soil surface and im-
mediately incorporated with tillage equipment. Rates vary from
6 to 2*1.2 pounds a.i. per acre (Cooperative Assessment).
The practicable alternative pesticides are EDB, DD, Vor-
lex and Telone II. However, in some crops in some Locations,
no alternative pesticide is effective.
(2) Risks
The major source of risk to the general public is con-
sumption of 18 of the crops which may be expected to contain
DBCP residues after treatment (Table 2). As shown in this table,
-8
the maximum lifetime risk of cancer range from 1.09 X 10 . for
-------
-J.J.U-
-4
russel sprouts to 4.36 X 10 for carrots. These risks translate
•nto a total risk of approximately 1905 cases of cancer per
vear, with carrots accounting for about 68% of that number.
jhere is also a risk of decreased sperm counts for males who
would consume DBCP residues.
A total of about 8,272 applicators are also at risk.
The number of growers and the hours per year of exposure vary
by state (see Table 11). As shown in Table 3, the cancer risk
to the 200 applicators in California from inhaling
-4
DBCP during application are 6.21 X 10 ; their risk from
-4
inhalation during mixing and loading is 1.61 X 10 . In
Florida, the risk to 709 applicators from inhaling DBCP during
»
application is 2.37 X 10 ; their risk from inhalation during
mixing and loading is 6.21 X 10~ . In all other states,
the cancer risk to 7,400 applicators from inhaling DBCP dur-
ing application is 6.94 X 10 ; their risk from inhalation
during mixing and loading is 1.86 X 10 . All exposed men
would also risk reduced sperm counts. Risks from other
Potential exposure situations are summarized in table 4.
(3) Benefits
At $6.00 per acre for material costs, DBCP is the most
6conomical method of controlling nematodes in vegetables.
material cost per acre for the alternative nematicides
-------
ranges from $9.17 for EDB to $48.00 for Vorlex. If DBCP
were not available growers would have to pay $7,730,000 per
year more for the cost of alternative materials and the labor to
apply, them. On acreage where alternatives would not be ef-
fective, growers would suffer $6,760,000 losses in production;
Thus, the total short term impact would be $1.4,500,000 per
.year or $43,400,000 after 3 years. Compared to the
value of all affected vegetables, this is a minor impact
(Benefits Analysis).
On a per acre basis,, the potential losses to growers
would range from $13 per acre for cucumbers to $136 per acre
for celery. The impacts of this range might lower returns
enough to force growers to switch to other crops. As these
adjustments are made, the price of the affected vegetables
might rise, shifting the cost to the consumer. It is esti-
mated that such an increase would not exceed 0.1J overall
(Benefits Analysis).
(4) Regulatory Options and Their Impacts
Option 1: Continue registrations without additional
restrictions.
(i) Adverse Impacts - The risks to the U.S.
population from consumption of DBCP residues in 18 of
22 crops would continue as would the risks to 8,272 appli-
cators .
(ii) Beneficial Impacts - The nematode control
advantages of DBCP would continue.
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-112-
Option 2: Classify for restricted use; require
full-body protective clothing and respirator during transfer,
maintenance or cleanup operations; and require boots and gloves
jnH_ng application.
(i) Adverse Impacts - The risks to the U.S. popula-
tion from consumption of DBCP residues in 18 of 22 crops
would continue. The risks from inhalation exposure to DBCP
during application would continue. The cost of requiring
protective equipment, including respirator, would be $110 per
person in the affected operations.
(ii) Beneficial Impacts- DBCP used by untrained
persons would be eliminated. The risks from dermal exposure
to DB'CP by all applicators would be virtually eliminated by
the protective clothing. The risks.to applicators from inhal-
ation exposure during mixing and loading, spill cleanups, etc.
would be reduced at least fiftyfold. Applicators would have
to wear full protective clothing for only about 30 minutes per
day, a practice with which most persons may be expected to com-
ply. The nematode control advantages of DBCP would continue.
Option 3: Option 2 plus require a respirator and
reentry interval for application by irrigation — Not applicable.
Option 4: Option 2 plus require a respir-
Ajor and reentry interval for all application techniques.
(i) Adverse Impacts - The risks to the U.S. popula-
tion from consumption of DBCP residues in food in 18 of 22
Crops would continue. There would still be some risk at one-
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-113-
fiftieth the level described in the vegetable risk discussion,
from inhalation exposure during application. The cost of im-
posing these restrictions would be $110 as in Option 2.
(i i) Beneficial Impacts -These would be the
same as Option 2, but the risks to applicators from inhal-
ation exposure during all applications would decrease by a
minimum factor of fifty. The risks from inhalation exposure
during reentry into treated areas after soil injection would
be reduced. The nematode control advantages of DBCP would
conti nue.
Option 5: Option 4 plus prohibit application by
irri gation--Not applicable.
Option 6: Cancel registrations.
(i) Adverse Impacts -.There would be minor ad-
verse economic impacts on growers and negligible impacts
on consumers. There will be some risks from increased use of
substitute chemicals (see Tables 5 and 9).
There maybe some chronic risks to applicators from in-
creased use of the substitutes DD, EDB, Telone II and Vorlex
13,000,000 pounds of DD, 3,000,000 pounds of EDB, 5,000,000
pounds of Telone and 340,000 pounds of Vorlex might be used in
place of DBCP (Table 9). These amounts are 181%, 41%, 72% and
120%, respectively, of the amounts of these chemicals produced
in 1974 or 1975. Thus, the chronic risks to applicators from
use of these substitutes on commercial vegetables might be
substantial. '
(11 )• Beneficial Impacts - All -risks from the use
of DBCP would be eliminated.
-------
(5) Regulatory Option Chosen
Option 1 is rejected, because this use of DBCP will
result in unreasonable adverse effects on the environment.
The Agency has selected Option 6 for 18 of the 22 crops,
since this option will eliminate risks from DBCP, especially
to the U.S. population from consumption of DBCP residues in
food; at the same time, it will have some adverse health ef-
fects for about 8,100 growers from DBCP exposure and result in
some potential risks from use of substitute nematicides.
Options 2 and 4 .will not satisfactorily reduce risk and will
result in unreasonable adverse effects. Thus, the Agency has
determined that in order to prevent unreasonable adverse effects
all registrations of DBCP must be cancelled effects for
these crops: -broccoli, brussel sprouts, cabbage, carrots,
cauliflower, celery, cucumbers, eggplant, endive, lettuce,
melons, parsnips, peppers, radishes,squash, tomatoes, turnip
and strawberry (except strawberry nursery stock). The
.Agency has also determined that in order to continue a
registration of DBCP on the four crops which do not have in
food residues (i.e., lima bean, okra, snap bean and southern
pea), the terms and conditions of registration must be
modified as described in Option 4.
I. Commercial Turf
(1) Usage
Almost all DBCP turf use is on golf courses (Benefits
Analysis). In Florida, South Carolina, Georgia and Texas,
golf course turf planted on sandy soils are heavily damaged
by nematodes, especially where a course is used heavily.
DBCP, the most effective treatment, is injected 3 to 6
-------
inches into established turf at 24-36 pounds a.i. per acre
(Cooperative Assessment). From conversations with knowledge-
able USDA Extension Service personnel, it is estimated that
11,900 acres are treated annually by custom applicators and
6,600 acres are treated annually by golf course superinten-
dents in Florida, Georgia, South Carolina and Texas (see
Footnotes m and o to Table 1). Assuming an average applica-
tion rate of 30 Ib/A, it can be estimated that about 555,000
pounds of DBCP were applied in 1976 (30 Ib/A X
18,500 A = 555,000 Ibs).
Mocap and Nemacur are the most likely alternative
registered pesticides. They are more expensive, .less
efficacious and must be applied twice a year.
(2) Risks
The population at risk is 11 custom applicators and
199 golf course superintendents. The increased
.4
cancer risk for the custom applicators is 5.11 X "10
from inhalation exposure' during application and 1.35
X 10 from inhalation during mixing and loading. For go'f
course superintendents, the increased risk of cancer is
-5
5.11 X 10 from inhalation exposure during application and
1.35 X 10" from inhalation during mixing and loading. For
all exposed males, there is also a risk of decreased sperm
count. Table 4 summarizes the risks from other potential
exposure situations.
(3) Benefits
DBCP is the only nematicide which controls most nema-
todes on turf for more than 2 to 3 months. If DBCP were
-------
unavailable, the substitutes Mocap or Nemacur would have to
be applied twice a year, will cost much more than DBCP and
will control nematodes less well (Cooperative Assessment).
Although the Benefits Analysis did not quantify the cost
impact of using these substitutes, the Cooperative Assess-
ment arrayed the comparative per acre costs of materials:
DBCP, $24-$56; Nemacur, $85-$140; Dasanit, $85~$140; a'nd
Mocap, $140-$210. Thus, the cost of the substitute materi-
als range from $60 to $150 more per acre than DBCP. Multi-
plying these prices by two applications per year and by
the total acres treated, the total impacts would ra.nge from
$2,200,000 to $5,600,000 for all affected areas. Since 310
golf courses may be affected, the average net impact of
*
using the substitute materials would be between,$7,000 and
$18,000 per course per year.
The Cooperative Assessment concludes.'that at these high
costs it would be impossible to treat fairways, in which
case the untreated turf would die. Only ample irrigation,
additional fertilizer and increased "use of herbicides would
prevent total loss of the turf (Smart, 1978a), If putting
*
greens only were treated with a substitute nematicide, the
net increased costs of substitute materials woul-d be about
$250 to $300 per year per golf course (Bottlinger, 1978).
Increased treatment costs may be passed on to the
consumer (i.e., the golfer or club member). Further, where
alternatives are not or cannot be used, the aesthetic
appearance of a golf course would be adversely affected
(Benefits Analysis).
-------
(4) Regulatory Options and Their Impacts
Option 1: Continue registrations with-
out additional restrictions.
(i) Adverse Impacts - Risks to 210 applicators
would continue.
(ii) Beneficial Impacts - The nematode control
advantages of DBCP would continue.
Option 2: Classify for restricted use;
require full-body protective; clothing and respirator during •
transfer, maintenance or cleanup operations; and require
boots and gloves during application.
(i) Adverse Impacts - The risks from inhalation
exposure to DBCP during application would continue. The
cost of requiring protective equipment, including respirator,
would be $110 per person in the affected operations.
(ii) Beneficial Impacts - DBCP use by untrained
persons would be eliminated. The risks from dermal exposure
to DBCP by all applicators would be virtually eliminated by
the protective clothing. The risks to applicators from
inhalation exposure during mixing and loading, spill clean-
ups, etc. would be reduced at least fiftyfold. Applicators
would have to wear full protective clothing for only about
30 minutes per day, a practice with which most persons may
be expected to comply. The nematode control advantages of
DBCP would continue.
-------
Option 3: Option 2 plus require
a respirator and, reentry interval for application by irri-
gation—Not applicable.
Option 4: Option 2 plus require
a respirator and reentry interval for all application
techniques.
(i). Adverse Impacts - There would still be some
risks at one-fiftieth the level described in the commercial
turf benefits discussion, from inhalation exposure during
application-. ••The cost of imposing these restrictions would
be $110 as in Option 2.
(ii) Beneficial Impacts - These would be the same
as in Opt ion-2, but in addition the risks to applicators
from inhalation exposure during all applications would be
decreased at least fiftyfold. The risks from inhalation
exposure during reentry into treated areas after soil
injection would be reduced. The nematode control advantages
of DBCP would continue.
Option 5: Option 4 plus prohibit application by
Irrlgation--Not applicable,
Option 6: Cancel registrations
(i) Adverse Impacts - There would be significant
adverse economic consequences for affected golf courses, most
of which are in Florida. There would be some acute environ-
mental hazards from the use of the granular alterna-
-------
119
tives. There maybe some acute risks to wildlife from increased
use of the substitutes Mocap and Nemacur (Table 5). In place of
DBCP 230,000 pounds of Mocap and 130,000 pounds of Nemacur might
be used (Table 9). These amounts are 23% and. (unknown)% of the
amounts of these chemicals produced in 1974 or 1975. Thus,
acute risks to wildlife from use of these chemicals on golf
courses might be moderate.
(ii) Beneficial Impacts - The risks from DBCP use
- t ^«M^^««—™»^**«i«»
would be eliminated.
(5) Regulatory Option Chosen
Option 1 is rejected, because without further restrictions
this use of DBCP will result in unreasonable adverse effects on
the environment. The Agency has selected Option 4, since it
will adequately reduce risks without significant impacts on the
benefits of this use. Option 2 will not satisfactorily reduce
risks and will result in unreasonable adverse effects. Option 6
will eliminate the risks of DBCP, but will have in unacceptable
adverse impacts on the economic benefits of this use and will
create some potential risks from use of substitute nematicides.
Thus, in order to continue a registration of DBCP on turf on
golf courses, the terms and conditions of registration must be
modified as described in Option 4.
J. Strawberry Nursery Stock
(1) Usage
The only strawberry nursery stock (i.e., plants grown
for transplanting rather than immediate fruit production)
-------
known to be treated with DBCP is grown on 625 acres in
Maryland and Delaware, where DBCP is applied in accordance
with the requirements of the States' strawberry plant
certification programs. Basically, the programs call for
two to three post-plant side-dressing chisel applications,
the first 4 to 6 weeks after planting, the second 10 to 12
weeks after planting and the third, if necessary, 14 to 16
weeks after planting. The rate of application is 1 gallon
DBCP or 12.1 pounds a.i. per acre. No alternative nemati-
cides are effective for postplant control of nematodes on
strawberry nursery stock (Benefits Analysis)..
(2) Risks
With only four farms growing strawberry plants for
transplant, it is assumed that there are four applicators
exposed to DBCP. For the single applicator in Delaware, the
risk from inhalation exposure during application is 2.63 X
-4
10 increased probability of cancer; from inhalation exposure
during mixing and loading the risk is 6.56 X 10" increased
probability of cancer. For the three applicators in Maryland, the
risk from inhalation exposure during application are 1.06 X
-4
10 increased probability of cancer; from inhalation exposure
-5
during mixing and loading the risk is 2.56 X 10 proba-
bility of cancer. All exposed males risk decreased sperm counts.
Table 4 summarizes risks from other potential exposure situa-
tions .
-------
(3) Benefits
If DBCP were cancelled, strawberry nurserymen in
Maryland and Delaware would be seriously affected in the
.short-term, and possibly forced out of production. Signi-
ficant but localized community and social disruptions would
be likely for nursery employees, since alternative employ-
ment opportunities are limited. Gross receipts from
strawberry plant sales in Maryland exceed $1,500JQOO per
year and provide considerable economic stimulus to the area.
Thie situation in Delaware is li.kely to be similar (Benefits
Analysis).
In the long term, without an effective postplant
nematicide, production of strawberry.pi ants would shift to
other areas. Production of certified plants in Delaware and
Maryland might cease. Higher returns in unaffected areas.
would stimulate production on new or existing acreages.
Unaffected growers would benefit from increased sales and
higher product prices. Thus, income redistribution to other
states may offset some losses in Maryland and Delaware.
Commercial and home growers in the East would be moder-
ately affected as quality strawberry plant supplies become
increasingly short 3 to 5 years following cancellation.
•
Consumers would experience some retail strawberry price
increases in markets supplied by Eastern berry producers.
-------
Since states east of the Rockies produce only 18% of U.S.
strawberry tonnage, and since Maryland and Delaware account
for 60% of the planting stock for the Eastern states, the
overall U.S. retail price increases would be moderate. In
the long term, consumer prices would return to precancella-
t'ion production expands in unaffected areas (Benefits
Analysis).
(4) Regulatory Options and Their Impacts
(a) Option 1: Continue registrations without addi
tional restrictions.
(i) Adverse Impacts - The risks to 4 applica-
tors would continue.
:-. (ii) Beneficial Impacts - The nematode control
advantages of DBCP would continue.
• (b) Option 2: Classify for restricted use;
require full-body protective clothing and respirator during
transfer, maintenance or cleanup opreations; and require
boots and gloves during application.
(i) Adverse Impacts - The risk from inhalation
exposure to DBCP during application would co'ntinue. The
cost of requiring protective equipment including respirator
would be $110 per person in the afffected operations.
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-123-
(11) Beneficial Impacts - DBCP use by untrained
persons would be eliminated. The risks from dermal exposure to
DBCP by all applicators would be virtually eliminated by the
protective clothing. The risks to applicators from inhalation
exposure during mixing and loading, spill cleanups, etc. would
be reduced at least fiftyfold. Applicators would have to wear
full protective clothing for only about 30 minutes per day, a
practice with which most persons may be expected to comply. The
•nematode control advantages of DBCP would continue.
(c) Option'3: Option 2 plus require a respirator and
reentry Interval for application by 1 rrl gat i on — Not applicable.
(d) Option 4: Option 2 plus require a respirator and
reentry interval for all application techniques'.
(i) Adverse Impacts - There would still be some
risks at one-fiftieth the level described in the strawberry
•*
risk discussion, inhalation exposure during application. The
cost of Imposing these restrictions would be $110, the same as
in Option 2.
(ii) Beneficial Impacts - There would be the snme
as In Option 2, but the risks to applicators from inhalation
exposure during all applications would be decreased at least
fiftyfold. The risks from inhalation exposure during reentry
into treated areas after soil injection would be reduced. The
nematode control advantages of DBCP would continue.
Option 5: Option 4 pi us prohibit application
by irrigat1on--Not applicable.
-------
0p t i on 6: Cancel regi s t r a t i o n s
(i) Adverse Impacts - There would be severe short
and long term adverse economic effects on strawberry plant
producers in Maryland and Delaware. Consumers in the East
would 'pay higher prices for the short term, although the
nationwide average would probably not significantly increase
(ii) Beneficial Impacts - All risks from the use
of DBCP would be eliminated.
(5) Regulatory Option Chosen •
Option 1 is rejected, because without further restric-
tions this use of DBCP will result in unreasonable adverse
effects on the environment. The Agency has selected Option
4, since it will adequately reduce risks without significant
impacts on the benefits of this use. Option 2 will not
satisfactorily reduce risks and will result in unreasonable
adverse effects. Option 6 will eliminate the risks of DBCP,
but will result in unacceptable adverse impacts on the
economic benefits of this use. Thus, in order to continue a
registration of DBCP on strawberry nursery stock, the
conditions of registration must be modified as described in
Option 4.
K. Other Berries
(1) Usage
Other berries for which DBCP is registered include
blackberries, blueberries, boysenberries, dewberries,
loganberries, and raspberries. However, DBCP has been used
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-125-
to a significant extent only on boysenberries and rasp-
berries, in the amount of 25,000 pounds and 67,000 pounds of
DB.CP per year, respectively (Benefits Analysis). The primary
method of application is post-plant soil injection. No
effective postplant alternative methods of nematode control
are available.
(2) Risks
Because the only known use of DBCP on other berries
is on boysenberries and raspberries, risks have only been
estimated for these two crops.
About 300 applicators are estimated to be at risk.
From inhalation exposure during application the increased
probability of cancer is 2.63 X 10 . From in-halation
exposure during mixing and loading, males hnve a risk of
reduced sperm count. Table 4 summarizes other potential
exposure situations.
. (3) Benefits
Without DBCP, boysenberry production could initially
decline by 10%-15% in California. However, in Oregon
and Washington, where most U.S.boysenberries are produced,
:DBCP is only minimally important to production (Benefits
Analysis). In affected areas, production losses would
continue at 5%-8% per year. Severely affected areas
would probably go out of production, but would be probably
replaced to some extent by new plantings in .unaffected
-------
areas. Consumers could expect some short term retail price
increases of 5% - 7% if production losses were to be passed
along in corresponding price increases. Long term effects
are likely to diminish if new plantings in unaffected areas
are brought into production. Thus, long term effects
would probably be minimal.
For raspberries, U.S. production is concentrated in
Oregon and Washington. There, only 7.3% of the 6,860
acres benefit from DBCP treatments. Without DBCP, there
would be a $150,000 loss in production over 3 years. Th.is
loss is only 1.8% of the total U.S. crop value. In the long
run, affected acres would probably be treated with a pre-
plant fumigant. Some severely infested acres may go out
of production and revert to the best alternative crop.
Higher returns to unaffected growers and increased planting
in-unaffected areas would probably offset this loss.
Consumers would pay slightly higher retail prices for the
short term, but in the long term, pri-ces would be expected
to return to near precancel1ation levels (Benefits Analysis).
For all remaining berries, the major production regions
are in Oregon and Washington. Contacts with Extension
Service nematologists in these states revealed very limited
use of DBCP. Some isolated instances of production losses
could, occur, but no major shifts in the quantity or geograph-
ical area of production would be expected. Market and
consumer effects would be minimal for the short and long
term.
-------
(4) Regulatory Options and Their Impacts
Option 1: Continue registrations without additional
restrictions.
(i) Adverse Impacts - The risk to 300 applica-
tors would continue.
(ii) Beneficial Impacts - The nematode control
advantages of DBCP would continue.
Option 2: Classify for restricted use; require
full-body protective clothing and respirator during transfer,
maintenance or cleanup operations ; and require boots and
gloves during application.
(i) Adverse Impacts - The risks from, inhalation
exposure to DBCP during application would continue. The
costs of requiring protective equipment, including respirator,
would be $110 per person in the affected operations.
(i.i) Beneficial Impacts - DBCP use by untrained
persons would be eliminated. The risks from dermal exposure
to DBCP by all applicators would be virtually eliminated by
the protective clothing. The risks to applicators from
inhalation exposure during mixing and loading, spill clean-
ups, etc. would be reduced at least fifty.fold. Applicators
would have to wear full protective clothing for only about
15 minutes per day, a practice with which most persons may
be expected to comply. The nematode control advantages of
DBCP would continue.
-------
(i) Adverse Impacts - These would be the same as
for Option since no D8CP is known to be applied by irriga-
tion.
(ii) Beneficial Impacts - These would be the same.
as for Option 2, since no DBCP is known to be applied by
irrigation. However, if DBCP were applied by irrigation,
the risks to applicators from any inhalation exposure would be
eliminated. Risks to persons reentering a treated area would
also be eliminated.
Option 6: Cancel registrations.
(i) Adverse Impacts - There would be some
localized adverse impacts as described in the berry benefits
di scussion.
(ii) Beneficial Impacts - All risks from DBCP use
would be eliminated.
(5) Regulatory Option Chosen
Option 1 is rejected, because.without further restric-
tions this use of DBCP will result in unreasonable adverse
effects on the environment. The Agency has selected Option
4, since it will adequately reduce risks without significant
impacts on the benefits of this use. Options 2 and 3 will
not satisfactorily reduce risks and will result in unreason-
able adverse effects. Options 5 and 6 will reduce or eliminate
the risks of DBCP, but will have unacceptable adverse impacts
on the economic benefits of this use. Thus, in order to continue a
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-129-
registration of DBCP on raspberries and boysenberries, the
terms of registration must be modified as described in
Option 4.
L. Plums
(1) Usage
DBCP is currently applied to a total of 22,000 acres of
domestic plums, about 70% of California plantings. About
9,300 acres are treated with 452,000 pounds of DBCP per
year. Applications are post-plant by irrigation every 18 to
36 months, depending on the degree of infestation; No
effective substitute method of postplant nematode control is
available (Benefits Analysis).
(2) Risks
450 applicators are at risk. Inhalation exposure
during application and mixing and loading results in in-
—3 -4
creased cancer risks of 3.43 X 10 and 2.08 X 10 ,
respectively. All exposed males have a risk of decreased
sperm count. Table 4 summarizes risks from other potential
exposure situations.
(3) Benefits
If DBCP were unavailable, all treated orchards would
begin to be affected by the end of 3 years. Decreases in
value of production minus the cost of treatment with DBCP
would total $13,754,000 for that period. Severely infested
-------
orchards (38% of California acres) would go out of produc-
tion within 3 to 5 years. Moderately infested acreage (32%
of California acres) would remain in production for a longer
iperiod. In the long term, plum production might begin in
areas not subject to infestation. Higher returns would be
expected to stimulate intensified production and increased
planting by unaffected growers. Both effects would offset
to some extent the production reductions in the affected
areas (Benefits Analysis).
For consumers, short term retail price increases of up
to 20% are possible* However, since plums represent a minor
part of food consumption, the overall consumer impact is
negligible. In the long term, production and retail prices
might return to normal if new plum plantings in uninfested
areas are developed and come into production.
(4) Regulatory Options and Their Impacts
Option 1; Continue registration without addi-
tional restrictions.
(i) Adverse Impacts - The risks to 450 applica-
tors would continue.
(ii) Beneficial Impacts - The nematode control
advantages of DBCP would continue.
Option 2; Classify for restricted use; require
full-body protective clothing and respirator during transfer,
maintenance or cleanup operations; and require boots and
gloves during application.
-------
(1) Adverse Impacts - The risks from inhalation
exposure to DBCP during application would continue. The
costs of requiring protective equipment, including respira-
tor, would be $110 per person in the affected operations.
(ii) Beneficial Impacts - DBCP use by untrained
persons would be eliminated. The risks from dermal exposure
to DBCP by all applicators would be virtually eliminated by
the protective clothing. The risks to applicators from
inhalation exposure during mixing and loading, spill clean-
ups, etc. would be reduced at least fiftyfold. Applicators
would have-to wear full protective clothing for only about
30 minutes per day, a practice with which most persons may
be expected to comply. The nematode control advantages of
DBCP would continue.
Option 3: Option 2 plus require a respirator and
reentry interval for application by irrigation.
(i) Adverse Impacts - There would still be
some risk, at one-fiftieth the level describved in the plum
risk discussion, from inhalation exposure during irrigation.
The costs of imposing these restrictions would be $110, as
In Option 2.
(ii) Beneficial Impacts - These would be the same
as in Option 2, in addition to which the risks from inhala-
tion exposure during irrigation would be reduced at least
fiftyfold. The risks from inhalation exposure during
reentry into treated areas after irrigation would also be
reduced. The nematode control advantages of DBCP would
cont i nue.
-------
Option 4:Option 2 plus require a respirator and
reentry interval -for all application techniques--
This Option is the same as Option 3, since all acres are
treated by irrigation.
(e) Option 5: Option 4 plus prohibit application
by i rri gati on .
(i) Adverse Impacts - The 450 growers who
had been using irrigation would be forced to switch to soil
injection to.maintain economic levels of production. If
all growers applied DBCP themselves, the cost of application
would increase $8 per acre, a total of $75,000 every 3
years, or $166 per grower. If the DBCP were applied by
commercial applicators, the costs would be $35 'per acre, a
total of $327,000 every 3 years, or $726 per grower.
The risks to applicators would be the same as in Option
4. The costs of protective equipment would be $110 per
person. If all growers did not switch to injection, the
total impact would be about $13,800,000. Although soil
injection can cause some root damage, most growers would
probably switch, since DBCP is necessary for economic
producti on.
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133
(ii) Beneficial Impacts - The high risks from
inhalation and dermal exposures during and after irrigation
would be completely eliminated, and the risks from inhala-
tion during soil injection would be reduced at least fifty-
fold. The risks from inhalation exposure during reentry
into treated areas following soil injection would be reduced.
The nematode control advantages of DBCP would continue.
(f) Option 6: Cancel registrations.
(i) Adverse Impacts - There would be some
localized adverse economic impacts as described in the plum
benefits discussion.
(ii) Beneficial Impacts - All risks from DBCP use
would be eliminated.
(5) Regulatory Option Chosen
Option 1 is rejected, because without further restric-
tions this use of DBCP will result in unreasonable adverse
effects on the environment. The Agency has selected Option
4 (which is the same as Option 3), since it will adequate
by reduce risks without significant impacts on the benefits
of this use. Option 2 will '.not satisfactorily reduce risks
and will result in unreasonable adverse effects. Options 5
and 6 will eliminate the risks of DBCP, but would have
unacceptable adverse impacts on the economic benefits of
this use. Thus, in order to continue a registration of DBCP
on plums, the terms of registration must be modified as
described in Option 4. '
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M. Almonds
(1) Usage
Approximately 3,417,000 pounds of DBCP are applied to
70,600 acres of almond orchards annually, with a total of
181,200 acres, (54% of domestic almond acreage), subject to
treatment. Almost all almonds are grown in California and
all use of DBCP on almonds is in that state. Applications
are done by post-plant irrigation every 18 to 36 months,
depending on the severity of infestation. DBCP is generally
applied in the San Joaquin Valley where the lighter soils
support more nematode populations and where the trees are
set on higher-yielding, but more nematode-susceptible
peach-type rootstocks. No effective alternative' method of
postplant control is available.
(2) Risks
About 1,108 applicators are at risk^ Inhalation
exposure during application, and mixing and loading will
-2
result in increased cancer risk of 1.13 X 10 and 6.94 X
-4
10 , respectively. There will also be risks of reduced
sperm count for exposed males. Table 4 summarizes risks
for other potential exposure situations.
(3) Benefits
If DBCP were unavailable, all treated orchards,- 54% of
total acres, would incur losses of $26,502,000 within 3
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-135-
year s. Consumers might experience up to a 20% increase in
retail prices in the short term. Shippers and almond
processors would be adversely affected to the extent that
almond production would shift to other parts of California
of the U.S. (Benefits Analysis).
In the long term, affected orchards would go out of
production. Severely affected acres, 18% of the total planted,
would begin to fail within 3 to 5 years and moderatelyr
affected acres, 36% of total planted, would go out of
production within 10 to 15 years. Almond producers in
unaffected areas will have higher returns, -which in turn
would be expected to stimulate new plantings. Both factors
would offset to some extent the losses suffered in current
DBCP use areas. Production and retail prices may return
to normal if new plantings are developed in uninfested
areas.
(4) Regulatory Option and Their Impacts
Option It Continue registration without additional
restrictions.
»
(i) Adverse Impacts - Risks to applicators would
continue.
(ii) Beneficial Impacts— The nematode control
advantages of DBCP would continue.
Option 2; Classify for restricted use; require
full-body protective clothing and respirator during transfer,
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-136-
maintenance or cleanup operations; and require boots and
gloves during application.
'. (i) Adverse Impacts - The risks- from inhalation
/
exposure to OBCP during application would continue . The
-costs of requiring protective equipment, including respirator,
would total approximately $110 per person in the affected
operations.
(ii) Beneficial Impacts - DBCP use by untrained
persons would be eliminated. The risks from dermal exposure
to DBCP by all applicators would be virtually eliminated by
the protective clothing. The risks to applicators from
inhalation exposure during mixing and loading, spill clean-
ups, etc. would be reduced at least fiftyfold.- Applicators
would have to wear full protective clothing for only about
30 minutes per day, a practice with which most persons may
be expected to comply. The nematode control advantages of
DBCP would continue.
Option 3: Option 2 plus require a respirator and
reentry interval for application by irrigation.
(i) Adverse Impacts - There would still be some
risks at one-fiftieth the level described in the almond and
risk discussion, from inhalation exposure during irrigation.
The costs of impostion these restrictions would be $110, the
same as in Option 2.
(ii) Beneficial Impacts - These would be the same
as in Option 2, but also the risks from inhalation exposure
-------
-137-
during irrigation would be reduced at least fifty-fold. The
risks from inhalation exposure during reentry into treated
areas after irrigation would also be reduced. The nematode
control advantages DBCP would continue..
Option 4: Option 2 plus require a respirator and
reentry interval for all application techniques--
This Option is the same as Option 3, since all DBCP is
applied by irrigation.
Option 5: Option 4 plus prohibit application by
irri gat i on.
(i) Adverse Impacts - The 1,108 growers who
had been using irrigation would be forced to switch to soil
injection to maintain economic levels of production. If
all growers applied DBCP themselves, the cost of application
would increase $8 per acre, a total of $565,000 every 3
years or $515 per grower. If the DBCP were applied by
%
commercial applicators, the costs would be $35 per acre, a
total of $2,888,000 every 3 years or $2,606 per grower.
The risk to applicators would be the s~me as in Option 4.
The costs of protective equipment would bo $110 per person.
If all growers did not switch to injection, the total impact
would be about $26,500,000. Although soil injection can
cause some root damage, most growers would probably switch,
•
since DBCP is necessary for economic production.
(ii) Beneficial Impacts - The high risks- from
inhalation and dermal exposures during and a-fter irrigation
-------
138
would be completely eliminated, and the risks from inhala-
tion during soil injection would be reduced at least fifty-
fold. The risks from inhalation exposure during reentry into
treated areas after soil injection would be reduced. The
nematode control advantages of DBCP would continue.
Option 6; Cancel registrations
(i) Adverse Impacts - There would be significant
adverse economic impacts as described in the almond benefit
discussion.
(ii) Beneficial Impacts - All risks from DBCP use
would be eliminated.
(5 ) Regulatory Chosen
Option 1 is rejected, because without further restric-
tions this use of DBCP will have unreasonable adverse
effects on the environment. The Agency has selected Option
4 (which is the same as Option 3) since it will adequate by
reduce risks without significant impacts on on the benefits
of this use. Option 2 will not satisfactorily reduce risks
and will result in unreasonable adverse effects. Options 5
and 6 will reduce or eliminate the risks of DBCP, but will
have unacceptable adverse impacts on the economic benefits
of this use. Thus, in order to continue a registration of
DBCP on almonds, the terms of registration must be modified
as described in Option 4.
-------
N. Home Gardens
(1) Usage
The Cooperative Assessment (1977) estimated that
250,000 gardens, averaging one-fifth of an acre or less, are
treated with DBCP. Most DBCP (80%) is incorporated into the
soil as a granular formulation, while the remainder is
applied in furrows as a liquid formulation and then covered
with soil. Registered alternative chemicals include DD,
EDB, Vapam and Vorlex. However, suitable equipment for
applying DD and EDB is not generally available to home
gardeners. Moreover, the cost of the alternatives is two to
three times higher than DBCP and would produce equivalent
or lower yield returns. Non-chemical methods of nematode
control are either not practical or not effective,(Benefits
Analysis).
(2) Risks
Assuming one person per treated garden applies the
DBCP, about 250,000 persons are at risk during application.
The risk to 200,000 people from inhalation exposure during use
of the granular formulation is 6.57 X 10 probability of
cancer. During in-furrow application, 50,000 people inhaling
DBCP during application would have an increased cancer risk
of 3.65 X 10 ; during mixing and loading, inhalation of DBCP
would lead to an increased cancer risk of 8.03 X 10 . All
exposed males would risk reduced sperm counts. Table 4 sum-
marizes risks from other potential exposure situation.
-------
-14U-
Assuming that eight persons per garden eat half of
their diet from the 250,000 treated gardens, then these
2,000,000 people would be at risk from consuming DBCP
residues. The lifetime risk per individual would be 3.19 X
—4
10 ;' about five cases of cancer could result in that
population. There would also be a risk of reduced sperm
count for males.
(3) Benefits
Most home gardens have esthetic rather than monetary
value. Some home garden production decreases could'occur,
but the impacts would be minimal (Benefits Analysis).
(4) Regulatory Options and Their Impact's
Option 1; Continue registration without
additional restrictions.
(i) Adverse Impacts - The risks to 2,000,000
persons consuming home garden vegetables containing DBCP
residues would continue. The risks to gardeners who apply
DBCP would continue.
(ii) Beneficial Impacts - The nematode control
advantages of DBCP would continue.
Option 2; Classify for restricted use; require
full-body protective clothing and respirator during trans-
fer, maintenance or cleanup operations; and require
boots and gloves during application.
-------
(i) Adverse Impacts - The risks to 2,000,000
persons consuming home garden vegetables containing DBCP
residues would continue . The risks from inhalation exposure
to DBCP during application would continue. The costs of
requiring protective equipment, including respirator, would
be $110 per person in the affected operations.
(ii) Beneficial Impacts - DBCP use by untrained
persons would be eliminated. The risk from dermal exposure
•to DBCP by all. applicators would be virtually eliminated by
the. protective clothing. The risks to applicators from
inhalation exposure during mixing and loading, spill clean-
ups, etc. would be reduced at least fiftyfold. Applicators
would have to wear full protective clothing for only about
30 minutes per year, a practice with which most persons may
be expected to comply. The nematode control advantages of
DBCP would continue.
Option 3: Option 2 plus require a respirator and
reentry interval for application by i rri gat ion--
Not applicable.
Option 4: Option 2 plus require a respirator and
reentry interval for all application techniques.
(i) Adverse Impacts - The risks to 2,000,000
persons consuming home garden vegetables containing DBCP
residues would continue. There would still be some risks at
one-fiftieth the level described in the home garden risk
discussion, from inhalation exposure during application.
-------
The cost of imposing these restrictions would be $110,
as in Option 2, but it is unlikely that home gardeners
would obtain certification and buy or use protective
equipment.
(ii) Beneficial Impacts - These would be the same
as in Option 2, but the risks to applicators from inhalation
exposure during all applications would be decreased at least
fiftyfold. The risks from inhalation exposure during reentry
into treated areas after soil injection would be reduced.
The nematode control advantages of DBCP would continue.
Option 5: Option 4 plus prohibit application by
Irri gat ion--Not applicable.
.(i) Adverse Impacts - There would be minimal
adverse economic impacts, as described in the home garden
risk discussion.
(ii) Beneficial Impacts - All risks from use of
DBCP would be eliminated.
(5) Regulatory Option
Option 1 is rejected, because this use of DBCP './ill
result in unreasonable adverse effects on the environ-
ment. The Agency has selected Option 6 for the 22
garden crops, since it will eliminate risks from DBCP,
especially to the U.S. population from consumption of DBCP
residues in food; at the same it will minimally adversely
affect about 250,000 gardeners and result in some potential
risks from use of substitute nematicides. Option 2 and 4
will not satisfactorily reduce risk and will result in
-------
-11,3--
unreasonable adverse effects. Thus, the Agency has deter-
mined that in order to prevent unreasonable adverse effects
aVI registrations must be cancelled for these crops:
broccoli, brussel sprouts, cabbage, carrots, cauliflower,
celery, cucumbers, eggplant, endive, .lettuce me!ons,1ima
bean, okra, parsni-ps, peppers, radishes, snap bean, southern
pea and squash.
0. Home Lawns
0) Usage
Since data was not available on'the extent of DBCP
use on home lawns, it was assumed, based on the data obtain-
ed for golf courses, that most applications on home lawns
occur in Florida. There are 2,500,000 lawns, averaging one
quarter acre, in that state (Florida Turfgrass Survey, 1974).
If 5% of these were treated (Smart, 1978b), then there would
be 125,000 users of DBCP or 31,250 acres. Approximately 80%
of homeowners are estimated to use granular DBCP, while 20%
use drench application (Table 11).
(2) Risks
For those persons using granular DBCP, the risk from
inhalation exposure during application is 6.57 X 10"
probability of cancer. For persons using drench, the risks
_3
from inhalation exposure during application is 1.28 X 10
probability of cancer. All exposed males risk decreased sperm
-------
counts. Table 4 summarizes risks from all other potential
exposure situat i on's .especi al ly from potential dermal exposure.
(3) Benefits
According to the Cooperative Assessment, there are no
practicable alternative nematicides for DBCP. Dasanit,
Nemacur and Mocap are not allowed for use by homeowners.
Diazinon (Sarolex) may be used, but it is not available
through retailers at this time and is only effective against
a few nematode species.
«
Without DBCP, affected turf would have to be totally re-
placed every 10 years (Smart, 1978b). The costs for a home-
owner' would vary according to the method of replacement. Com-
pletely covering a quarter-acre area with sod would cost
about $1300, whereas using sprigs of sod and waiting
a year for the lawn to fill in would cost $220. Assuming
most persons would take the latter approach, the total cost
to 125,000 homeowners over 10 years would be $27,500,000, or
$2,750,000 per year.
(4) Regulatory Options and Their Impacts
Option 1: Continue registration without additional
restrictions.
(i) Adverse Impacts - The risks to 125,000 applicators
would continue.
(ii) Beneficial Impacts - .The nematode control ad-
vantages of DBCP would continue.
-------
160
interval for all application techniques: cotton, pineapples,
soybeans, turf, strawberry nursery stock, ornamentals,
bananas, commercial lima beans, commercial okra, commercial
snap beans, commercial southern peas, citrus, grapes,
peaches, nectarines, plums, almonds, apricots, cherries,
figs, walnuts, blackberries, blueberries, boysenberries,
dewberries, loganberries and raspberries.
Option 6: Cancel all registrations: broccoli, brussel
sprouts, cabbage, carrots, cauliflower, celery, cucumbers,
eggplants, endive, lettuce, lima beans (except commercial
uses), melons, okra (except commercial uses), parsnips, peanuts,
peppers, radishes, snap beans (except commercial uses), southern
peas (except commercial uses), squash, tomatoes, turnips and
strawberries (except strawberry nursery stock).
The impacts of and rationale for this course of action
are summarized in Table 33.
-------
BIBLIOGRAPHY
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-------
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-------
Federal Register (March 17, 1978) Occupational Exposure to
l,2-Dibromo-3-Chloropropane (DBCP). 43 (53):11514-33.
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SPRD', concerning DBCP reproductive risk assessment re-
visions .
Gaylor, David W., Ph.D. (March 15, 1978) Memo from Chief,
Biometry, National Center for lexicological Research, HEW,
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on risk analysis of DBCP.
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•Assessment of l,2-dibromo-3-chloro7>ropane.
Hansen,. J. Dean (November 8, 1977). Memo from Plan-t
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Holtorff, T. (February 9, 1978), Economist, Economic Assess-
ment Branch, CED, EPA. personal communication with Dr.
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*
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Economic Analysis Branch, CED, EPA/ concerning DBCP use in the San
Joaquin-Sacramento Valley.
-------
Johnson, D. (January 31, 1978b) Extension Plant Nematolog1st,
University of California, Parlier, CA,. personal communication
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-------
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reduce the probability of detectable DBCP residues.
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South Carolina, Columbia, S.C. personal communication to
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Carolina.
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-------
Stokes, D. (April 26, 1978) Nematologist, Division of Plant
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EPA, concerning DBCP application methods in Hawaii.
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Worthington, John (February 3, 1978a) Memo from Chemist,
Chemistry Branch, RD, EPA, to Jeff Kempter, PM , OSPR, EPA,
concerning DBCP residue data.
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Exposed and Duration of Exposure (Annual Basis).
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•
Table 1. OBCP Sperm Count Data Adjusted to Include Azoospermlc Ken
Exposed Workers
Cohort
Dow-Magnolia
Dow-Midland
Dow-Pi ttsburg
Shell-Denver
Shell -Mobile
Chevron
Velsicol
Occidental
Hen from
Infertile
Marriages 3/.
Hen from
Fertile
Marriages 4/
Num-
berr
117
302
26
56
87
5
24
91
Individuals
<20 M/ml <40 M/ml
53 68
40 73
2 7
11 23
15 35
1 2
12 17
40
Percent
<20 M/ml
45.3
13.2
7.7
19.6
17.2
20.0
50.0
—
<40 M/ml
58.1
24.2
26.9
41.1
40.2
40.0
70.8
44.0
I/
Statistical
Significance
p<.005
n.s.2!/
n.s.
n.s.
n.s.
(no test)
p<.005
p<.005
1 V
Kum-
ber
0
70
0
28
18
0
0
35
9.000
1,000
Controls
Individuals Percent
<20 M/ml <40 M/ml <20 M/ml <40 H/ml
__
9 22
—
5 8
0 4
—
..
-• 4
1,630 2,619
._
12.9 31.4
—
17.9 28.6
0 22.2
_.
—
11.4
18.1 29.1
5 17
T/ The <20 and <40 sperm count groups ofexposea fnalvlduals were tested (chl-square) against their own controls when
~~ available. Otherwise, exposed groups were tested against MacLeod's Infertile marriage data.
2/ Not statistically significant.
3/ Unpublished. PennJsslon for use granted by Dr. John MacLeod, New York Hospital, 1978.
5/ MacLeod, 1951.
data was
-------
r
e 2. Estimated Cancer Risks to U.S. Population
Consuming Potential Food Residues of D8CP
nine re i al
bd
)$S
iccol i
issel
rout
D»age
rrot
ul i f 1 ower
VAry
cumber
g p 1 a n t
cUive
tfcuce
1 on
rsni p
diiut (meat)
pser
dish
uash
rawberry
"•to
rni p
Totals:
Maximum
Dai ly
Intake of
DBCP I/
(ng/kg/day)
0.87
<.0009
0.0071
36.1
0.096
0.038
1.20
0-.0162
<0.0009
0.17
5.60
,<0.005
2.7
<0.0013
<0.0021
0.25
0.0019
- 5\80
<0.0086
52.83
Lifet
Per I
1.05
1.09
8.58
4.36
1.16
4.59
1.45
1.93
1.09
2.06
6.77
6.05
3.26
1.57
' 2.54
3.02
2.30
7.01
1.04
6.39
i me
ndi
2/
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
Risk
v i d u a 1
ID'5
-8
10 °
io-7
io-4
ID'6
io-7
io-6
io-7
10"8
io-6
io-5
io-8
io-5'
io-8
10"8
io-6
10"8
io-5
io-7
10"4 !_/
From Table 12.
cource: Carcinogen Assessment Group, 1978. -The one-hit
mouel of risk assement was used.
This figure is the equivalent of 2,008 cases of cancer
per year. Carrots account for 68% of these cases,
peanuts=57%, melons =5%, tomatoes=5% and all other crop
fbogether add up to 17%.
rl: These same crops grown in home gardens have been
estimated to have a lifetime risk per individual of 3.19
-4
X TO . For the 2,000,000 persons potentially exposed,
this risk might result in 5 cases of cancer per year.
[CAG, 1978).
-------
Table 3. Estimated Cancer Risks for Applicators Resulting'From Inhalation of DBCP
I/ !/
Appli- 2/ Appli-
Exposure per Person
Cancer Risks
Crop State
Citrus TX
FL
CA
AZ
Cotton South
Grapes CA
•
-
Peaches and East
Nectarines
CA
cation
Method
irr.
inj.
irr.
inj.
irr.
inj.
inj.
irr.
inj.
irr.
Persons
Exposed
20
20
10
22-28
263
263
132
132
150
150
1,271
1,271
258
258
2,320
2,320
1,714
1,714
1,095.
1,095
cation
Phase
M&L
Appl
M&L
Appl.
M&L
Appl.
M&L
Appl.
M&L
Appl.
M&L
Appl.
M&L
Appl.
M&L
Appl.
M&L
Appl.
M&L
Appl'.
4/
5/
mg/hr hrs/yr
22
18
22
18
•22
18
22
18
22
18
.92
.18
.92
.18
.92
.18
.92
.18
.92
.18
17
333
5
100
.95
19
0.25
5
.95
19
1.5
29
.30
6
1.1
21
0.25
2
.65
13
6/
g/40 yr
15
239
.18
.72
.84 .
14
.0091
.036
.84
14
.055
.21
.011
.043,
.97
15
8/ .0092
.014
.57
9.4
Per Indi- Number
vidual 7/ of Cases
5.48
8.72
. 6.57
2.63
3.07
5.11
3.32
1.31
3.07
5.11
r.oi
7.76
4.02
1.57
3.54
5.48
3.36
5.11
2.08
3.43
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
10-3
io-2
10~5
10-"
10-"
10~3
10
10-5
~1
10
10-3
ID'5
10~^
10"t
10"5
io-4
io-3
10'6
10~6
10~4
10~3
.002
.025
_
_
.001
.020
-
_
.001
.001
-
.001
-
—
.012
.181
-
-
.004
.059
-------
Peanuts
Pineapple
Soybeans
Commercial
Vegetables
•
Turf (golf
courses)
•
Strawberries
(Nursery
Stock)
Other
Berries
South
HW
South
CA
FL
Others
Fl, GA,
SC & TX
MD
DL
WA.OR
inj.
inj.
inj.
inj.
inj.
inj.
comm.
own.
inj.
inj.
inj.
7,397
7,397
8
68
9,655
9,655
200
200
709
709
7,363
7,363
11
11
199
199
3
3
1
1
300
300
M&L
Appl.
M&L
AppV.
M&L .
Appl.
M&L
Appl.
M&L
Appl.
M&L
Appl .
M&L
Appl.
M&L
Appl .
M&L
.Appl .
M&L
Appl..
M&L
Appl .
.92
.18
' .22 9/
.013
.92
.18
.92
.18
.92
.18
.92
.18
.92
.18
.92
.18
.92
.18
.92
.18
.92
.18
.5
10
8.5 9/
338
1.4
27
12
233 1
4.5
90
1.4
27
10
200 1
1
20
2
40
5
100
0.25 11
1
.083
.072
.075
.18
.051
.19
.44
.7
.17
.65
.051
.19
.37
.4 '.
.037
.14
.070
.29
.18
.72
.0092
.0072
6.57
2.63
2.74
6.57
1.86
6.94
1.61
6.21
6.21
2.37
1.86
6.94
1.35
5.11
1.35
5.11
2.56
1.06
6.56
2.63
3.36
2.63
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
10"u
io-5
io-b
10"5
io-5
io-5
-4
10
io-4
io-5
io-4
ID'5
io-5
io-4
10"^
io-5
IO"5
ID'5
io-4
io-b
io-4
io-6
io-6
;001
.003
-
_
.003
.010
_
.002
_
.002
.002
.007
-
-
_
_
_ •
—
_
. _
_
-
-------
r i unii i/n
Almonds CA
Home Gardens South
Home Lawns FL
Woody FL, GA
& c r
Ornamental s
Total s
1 F~ I ' *
Inj.
1rr.
inj.
gran
f urr
gran
dren
.
dren
IO/
.
1
1
1
1
. 200
50
. 100
25
25
5
5
414
•t i»U
450
450
450
,108
,108
,108
,108
,000
,000
,000
,000
,000
,000
,000
,722
rial.
Appl .
M&L
Appl .
M&L
Appl .
M&L
Appl .
Appl .
M&L
Appl .
Appl .
M&L
Appl .
M&L
Appl .
c. c.
18 ,
.92
.18
22
18
.92
.18
.44
1.1
.025
.44
1.1
8.8
1.1
8.8
. U J
13
.65
13
2.2
43
2.2
43
10
0.5
10
10
0.5
10
0.5
10
• ~
-------
Exposures to DBCP
I/
Route of Estimated
Event Exposure dose
Spill Cleanup
(85% DBCP)
Mixing and
Loading (85%
DBCP)
Dermal
Inhalation
Dermal
91
23
91
mg/drop
mg/hr
mg/drop
2/
Probability
Cancer
6
8
6
.15
.40
.15
x
x
X
10
10
10
of
-4
-6
-4
During apol ication:
Granular
(5% DBCP)
Dermal
Drench or In- Dermal
furrow (0.02%
DBCP)
Irrigation
(0.0003% DBCP)
Reentry after:
Injection
1 day
7 days
Irrigation
1 day
7 days
In- furrow
1 day
7 days
Drench
." 1 day
3 days
Granular
1 day
7 days
Dermal
I/
Inhalation
Inhalation
Inhalation
Inhalation
Inhalation
60
0.
0.
mg/hr
01 mg/drop
0015 mg/drop
4
6
1
.06
.76
.01
X
X
X
10
10
10
-4
-8
-8
(mg/hr)
0.
0.
2.
N.
0.
0.
0.
0.
N.
N.
07
02
9
A.I/
025
020
001
0003
A.
A.
2
7
1
9
7
3
1
-
.56
.30
.06
.12
.30
.65
.10
X
X
X
X
X
X
X
10
10
.
10
10
10
10
10
-8
-9
-6
-9
-9
-in
— Iv
-10
I/ Assumes no protective equipment is worn by worker (Exposure
Analysis).
2J Risks are upper 95% confidence intervals using one-hit
model andbased on EDB human data and relative potencies
of DBCP to EDB (CAG.1978). Assumes one exposure in a lifetime,
3/ Assumes maximum label rates were applied.
Not available.
-------
Table 5. Potential Human and Environmental Hazards from Substitute Pesticides for DBCP-
Hazards to Human
2/ 2/
Chemical Dermal Inhalation" Sensitization Chronic
Environmental
tlazards 3/
Regulatory
Status
Ethylene
dibromide
II
II, III, IV
Slight eye, skin
and respiratory
inflammation.
1) Onoogenicity
2) Teratogenicity
3) HuUigenicity
RPAR issued on basis
of chronic effects.
Telone
Hocap
D-D
II
Ill Severe eye and
skin irritation.
1) Hutagenicity
2) Liver, heart and
kidney damage
3) No antidote
Being reviewed by SPRD
as a candidate for RPAR,
based on potential chronic
hazards.
Vorlex
II II Eye and skin "
-------
Table 6. DBCP SUSPENSION ORDER
FULLY SUSPENDED USES
BROCCOLI
BRUSSELL SPROUTS
CABBAGE
CARROTS
CAULIFLOWER
CELERY
CUCUMBERS
EGGPLANT
ENDIVE
LETTUCE
MELONS
PARSNIPS
PEANUTS
PEPPERS
RADISHES
SQUASH
STRAWBERRIES
TOMATOES
TURNIPS
CONDITIONALLY SUSPENDED USES
CITRUS
COTTON
GRAPES
PEACHES
NECTARINES
PINEAPPLE
SOYBEANS
TURF
STRAWBERRY NURSERY STOCK
OTHER BERRIES
PLUMS
ALMONDS
ORNAMENTALS
CONDITIONS:
RESTRICTED USE.
WEAR RESPIRATOR.
WEAR IMPERMEABLE
-PROTECTIVE CLOTHING.
-------
Table 7. Costs of and Risk Reduction Offered by Protective Clothing and Respirators
Protective
Devi ce
Gloves
Boot
Covers
Coat and
Pants
Face Shield
and Hard Hat
Respl rator
*
Resistant Other
or Filtering Specifl'-
Model Material cations
Full length, Nitrile
heavy duty Neoprene
Di sposabl e
Heavy duty
rai ngear
Can1 ster
or Cartridge
Supplied air
and 50-foot
hose
Sel f-contained
breathi ng
apparatus and
one tank
"
Plastic
Treated
charcoal
Pressure-
demand or
cont i nuous
Pressure-
demand
Demand
0.4 mm thick
0.4 mm thick
"
it
Hal f-f ace
Ful 1-f ace
Half-face
Ful 1 -face
flow
Half-face
Full-face
Half-face
Ful 1-f ace s
Protection
Factor I/
320,000
150,000
H . .
Unknown
10
50
1,000
2,000
1,000
10,000
10
50
Cost
s per Person
Per Operation and
Item 2/ Annual Maintenance
$ 10
$ 5
$ 7
$ 12
$ 12
N.A.
$ 74
$ 132
$ 224
N.A.
$ 626
N.A.
$ 630
Replace when
contami nated
Replace when
contami nated
Replace when
contaminated
Replace when
contami nated
Canister * $12 per
replacement.
Tank refill = $12
for 12 hrs. of
air. 3f
Tank refill = $5
for 30 min. of air
/ A protection factor is calculated by dividing the concentration of a chemical measured outside
a device by the concentration that penetrates the device after a given time. The protection
factor for the clothing materials are based on the penetration of 99% technical grade OBCP after
5 minutes (Sansone and Tewari, 1977). The protection factors listed for respirators are the
minimum protection afforded by any brand of respirator (Hyatt, 1976).
2/ Quoted from Mining Safety Appliance Co. 1977 catalog.
A canister must be thrown away after one day's exposure to DBCP (Kennedy, 1978)
-------
Table 8. Economic Impacts of Cancelling DBCP"
I/
Grower
Consumer
re
ITRUS
CTTON
f*PES
EACHES and
ECTARINES
JMEAPPLE
OYBEAN
FANUT
dlMERCIAL
EGETABLES
OME GARDENS
TRAWBERRY
WSERY STOCK
LMONDS
iiHCOTS,
BERRIES, FIGS
m WALNUTS
ANANAS
THER VINE
$RIES
LUMS
&ME LAWNS
OMMERCIAL
URF
WAMENTALS
OTALS:
Control Cost
Increase/ yr.
0
$2,600,000
0
0
$200,000
$23,471 ,000
$3,515,000
$7,728,000
Negl ig.
0
0
N e g 1 i g . due
to no use
Neglig. due
to no use
Negl i g .
0
$2,750,000 to
replace lawns
$2,200,000 to
$5,000,000
$100/A
(treated acres
unknown )
$44,164,000
Product i on
1 oss/3 years
$26,851 ,000
Neglig.
$65,000,000
$80,672,000
$5,793,000
Negl i g .
$19,500,000
$17,736,000
Negl i g .
Cease produc-
tion in East
$26,502,000
Negl i g. due
to no use
Negl i g . due
to no use
• $ 500,000
$13,754,000
si gni f i cant
losses to
smal 1 producers
$268,253,000 , -
Reta i 1 Price
Increases
Up to 5%
Negl i g .
Major
Up to 25%
Up to 9%
Up to 0.25%
None
Up to 0.1%
Up to 18%
Up to 20%
•
Neglig.
Up to 20%
Not applic.
Unknown
Unknown
/ Source: Benefits Analysis
-------
Table 9. Substitute Pesticides Used if DBCP is Cancelled
3/
Total Ibs.
Acres/Yr Acres Treated/Yr Rate of _!/ Pounds/Yr of Substitute Percent
Treated w/Substitutes if Applica- Substitute if. Used Before Increase
Crop w/DBCP I/ DBCP Cancelled I/ tion (Ib/A) DBCP Cancelled 21 Cancellation 4/
Citrus 31,200 0
Cotton 225,000 *DO = 108,000
*£DB = 31,500
*Telone=85,500
Grapes -82,500 0
Peaches J 8,325 *DD = 2,775
Nectarines preplan: *ED5 = 2,775
*Telone= 2,775
33,900 0
postplant
Peanuts 355,000 **DD = 12,968
**EDB = 96,328
**Telone = 18,525
**furadan = 16,080
**Dasanvt = 16,080
«*Kocap = 97,496
**Nemacur = 97,496
Pineapples 5,000 **EDB = 5,000
Soybeans 1,133,000 "*DD = 516,000
**Telone = 516,000
*Mocap = 76,500
*Nemacur * 17,000
Cotmiercial 374,000 *DD = 115,447
Vegetables *EDB = 148,445
•Telone * 62,880
*Vorlex = 39,400
Coonercial 18,500**Mocap = 9,225 5/
Turf (golf **Nemacur « 9,225 js/
courses, etc.)
All berries, 80,500 None
plums S almonds
Home Gardens None
Home Lawns None
Woody «*Casanit •= N.A.
Ornamentals **Mocap » N.A.
85
30
50
500
180
400
100'
72
60
3
3
2
2
144
120
80
20
20
110
20
80
60
25
14
— .
— .
44
18
0
9,200,000
950,000
4,300,000
0
1,400,000
500,000
1,100,000
0
1,300,000
6,900,000
1,100,000
46,000
48,000
200,000
200,000
720,000 '
62,000,000
41,000,000
1,500,000
-340,000
13,000,000
3,000,000
5,000,000
2,400,000
230,000
130,000
0
0
. 0
N.A.
N.A.
0
7,015,000
7,300,000
6,949,000
0
7,015,000
7,300,000
6,949,000
0
7,015,000
7,300,000
6,949,000
5.000,000
4,000,000
1,000,000
N.A.5/
7,300,000
7,015,000
6,949,000
1,000,000
N.A.
7,015,000
7,300,000
6,949,000
20,000
1,000,000
N.A.
0
0
0
N.A.
N.A.
0
130
13
62
0
20
7
16
0
*
18
95
16
1
1.2
20
—
10
ES4
594
153
--
181
41
72
120
23
—
0
0
0
__
M
j_/Source: USDA-EPA Benefit Analysis.
"2/ Calculated by multiplying Acres treated/yr by the rate of application.
3/ Sources of production data are: OD, ED8, Telone and Furadan—EPA, 1975; Dasanit, Mocap
and Vorlex~NAS, 1974.
_4/ Calculated by dividing Ibs./yr of substitute if DBCP is cancelled
by total pounds of substitute used on all crops before cancellation.
J>/ Not available.
* Substitute pesticide is as efficacious as OBCP.
** Substitute pesticide is not as efficacious as DBCP.
-------
Table 10. DEC? USE PATTERNS
Jse
'1TRUS
•BOTTOM
}RAPES
PEACHES/
NECTARINES
PINEAPPLE
SOYBEAN
PEANUT
COMMERCIAL
VEGETABLES
HOME GARDENS
STRAWBERRY
NURSERY STOCK
ALMONDS
APRICOTS, CHERRIES
FIG AND WALNUTS
BANANAS
OTHER VINE BERRIES
PLUMS
HOME L&7NS
COMMERCIAL TURF
ORNAMENTALS
TOTALS:
Pounds
per Year
1,292,000
2,700,000
3,200,000
1,823,000
302,000
12,378,000
3,195,000
3,392,000
<200,000
16,000
3,417,000
T
Neglig.
Neglig.
92,000
452,000
<200,000
550,000
Unknown
33,000,000
Acres Treated
oer year
31,000
225,000
83,000
42,000
5,000
1,133,000
355,000
374,000
NA
600
71,000
Neglig.
Neglig.
600
9,000
31,250
18,500
Unknown'
2,330,000
Percent of
Total Crop
Treated
7.9
2.0
31.0
44.0
46.0
2.1
23.0
<0.1 to
95
<0.5
10
54.0
-------
If
Crop
Citrus
Cotton
Grapes
Peaches and
Nectarines
Peanut s
Pineapple
Tomme'rcTTl
Veyet abl es
'/
courses )
State
?X
FL
CA
AZ
South
CA
East
CA
South
I(U
South 1
CA
FL
Others .
Sci* TX
Strawberries MO
(nursery stock) OL
Other BerrJe
Plums
Almonds
Home Gardens
Home Lawns
Woody
sfl/WA,OR
CA
CA
South
FL
FL.GA.SC
I/
£/ 3/ Farms or
Acres 2/ Portions of Avg. Homes
Treated Acres Treated Farm Treated
Per By Appllca- Size, By Appllca-
Year tlon Method Acres tlon Method
10,000 100* Irrigation 33 303
3,000 100X Injection 96 31
13.200 66X Irrigation 21-35e/ 263f/
33i Injection 21-35e/ 132f/
5.000 JOOX Irrigation 21-35e/ 150f/
225, OOd 100X Injection 177 e/ 1,271
62.500 lOi Injection • 32 e/ 258
90X Irrigation 32 e/ 2,320
12.000 100X Injection 7 1,714
21,900 100X Irrigation 20 1,095
154,973 100X Injection 29-84 7.397g/
5,600 100X Injection NA h/ NA 0
.133.000 1007, in ectlon 4l-292e/ 9,655q/
130. 000 ,[/ 100* Injection 233 HA '
03.0001./IOOX Injection 117 709
6./ 3p/
250 100X Injection 250 p/ lp/
600 100X Injection 2 300
9,000 lOOt Irrlgat lonq/ 20 450
71,000 100X 1 rr 1 / 0
2.5p/ Ip/ 0
2 300 0
1.5 ' 450 0
1.5 1.100 0
0. 02S/200.000 0
0.02s/. 50,000 0
'0:02s/TOO.OOO 0
0.02s/ 25.000 0
NA 5,000u/ 0
1.271
258
2,320
1,714
1,095
zuyiz
•^TTCS
709
7,363
/ 22
199
3
1
300
450
1,108 .
200,000
50.000
100,000
25,000
5 ,000
6/
Jlrs/
Year/
Person
100 tJ/
14-23
4-6
14-23
29
6
21
2
13
5-14
^•f-2
90 ~
7-47
200 m/
20 ~
40
100
1
13
43
10
10
10
10
Ornamentals
TJ Apricots, cherries, flgSj "walnuts,
Berries are omitted, since the amount
2/-Based on EPA-USDA Dencftts
3/ From 19/4 Census of
bananas, blackberries, blueberries, dewberrles and logan-
of OUCP applied to these registered crops Is•neglIglble.
Analysis, 1978, unless otherwise noted.
Agriculture, Department of Commerce, unless otherwise noted.
3/ Calculated by dividing average farm s-tze Into acres treated by method of application.
5/ For sol! Injection, figures are calculated using the equation: Acres/hr • [Tractor speed (mph)
tool or row width (ft) X 5.200 fl/mtle X 82.5X effIcIencyJ/43^00 square feet per acre.
TracU>r speed
2-J mph
3
4.5
5
mph
mph
mph
Row width
•~!fl-TS"fl
20
,3
TTor 1 il a TI t r u s
Calif, citrus
Cotton, soybeans
Golf fairways
Calif, grapes 3-5 mph
Calif, vegetables 4 mph
Other vegetables 2 mph
Eastern peaches (estimated to be 2-4 A/hr)
Irrigation for citrus, grapes, peaches and
13.
6
12
6.6
6.7
ft.
ft.
ft.
ft.
ft.
ft.
Source
15rDannon,
Johnson. 1970c
Zygadlo, 1970
Broome. 1970
Johnson, 197Ub
Johnson, 1978d
Zytjadlo, 1970
Zehr. 197U
plums was estimated
to be 1-2 A/hr based on average
pipe dldinulL-r. field size and flow rates (Amadore, 1970; Johnson, 1978b).
6/ Calculated by dlvldIng* acres treated per lir. Into avg. farm size, unless-otherw!se noted. One
Treatment per year Is assumed.
7/ Includes annuals listed In Table 6, excluding cotton, peanuts and soybeans.
O/ Includes raspberries and boysetiberr les.
-------
Notes to Table 11
A small group of growers apply all OBCP used in Texas (Amadore, 1978).
10,000 acres/20 persons/1.5 acre/hr = 333 hrs.
p'Bannon, 1S78.
3,000 acres/10 persons/3 acres/hr = 100 hrs.
Derived from Doane Survey, 1975, by dividing growers into acres grown
state.
In California and Arizona, grapefruit = 7% and other citrus = 93% of acres
wn in those states. Average farm sizes for those crops are 21 and 35 acres,
oectively (Doane Survey, 1975). Thus, for California, (.07 X 13,200)/21 +
3 X 13,200)/35 = 395 growers. For application by irrigation, .66 X 395 =
; 'for injection, .33 X 395 - 132. The same method yields the number of
wars in Arizona.
Because of the broad range of farm sizes among different states, the number
farms treated was determined by summing the acres treated per state divided
the average farm size per state.
Not available.
Williams, 1978.
Johnson, 1978b.
138,000 acres/200 persons/3 acres/hr = 233 hr;
The USDA/EPA Cooperative Assessment estimates 375,000 acres of vegetables
treated in the U.S. Subtracting the acres treated in California (133,000),
237,000 acres remaining may be divided between Florida and the Other states
follows. In 1974, Other States (excluding California) planted 375,000 acres,
le Florida planted 214,000 A, fop'a sum of 589,000 acres. If Other States
resent 65% of this sum and Florida represents 35%, then the treated
es in Other States are (.65 X 237,000) = 154,000 A, and the treated acres
Florida are (.35 X 237,000) = 83,000 A.
Figures for custom application are derived as follows: Approximately 10
•sons in Florida apply DBCP for an average of 200 hours per person per year
:ssell, 1978). Only one custom applicator is located in Georgia (Lambert,
8). Eleven persons working 200 hours per year at 3 A/hr. can cover 6,600
es.
Russell, 1978.
Figures for application by golf course owners are derived as follows:
-es treated: 900 (TX) + 3,500 (SC) + 7,500 (FL) = 11,900 acres.
:xas—15 courses x 60 A/course. = 900 A (Walla, 1978) South Carolina—3,500
treated (Miller, 1978a).
orida—The USDA/EPA Cooperative Assessment estimates that 13,500 A were. •,.
ated. Subtracting 6,000 A applied by custom applicators, 7,500 must be
lied by owners.
iber of courses treated: Per above figures, 15 (TX) + 59 (SC) + 125 (FL) -
courses treated.
(Puffinberger, 1978.
Johnson, 197Sa.
derived from USDA/EPA Cooperative Assessment, 11/7/77.
Based on EPA experimental data for drench and in-furrow applications of
P (Hansen _e_t _al_._, 1977).
Assumes 5% of 2,500,000 lawns in Florida are treated, with an average
e of 0.25 A (Florida Turfgrass Survey, 1974).
EPA estimate based on ROC's with knowledgeable persons in FL, SC and GA-
okes, 1973; Miller, 1978; Moody, 1978). It is assumed that one ten-hour
per year per person is spent applying DBCP.
-------
Table 12. Estimated Food Residues.of DBCP in Commercial Crops
Food
Crops
Annuals:
Broccol i
Brussel
Sprout
Cabbage
Carrot
Caul i f 1 ower
Celery
Cottonseed
Cucumber
Eggplant
Endi ve
Lettuce
Lima bean
Melon
Okra
Parsnip
Peanut (meat)
Pepper
Radish
Snap bean
Southern pea
Soybea n
Squash
Tomato
Turnip
Perenni a 1 s :
Almond
Apri cot
Banana
Blackberry
Bl ueberry
" Boysenberry
Cherries
Citrus
Dewberry
Fig
Grape
Loganberry
Nectari ne
Peach
Pineappl e
PI urn
Raspberry
Strawberry
Strawberry 6/
Walnut
!/
Est imated
Range of
Residues
(ppm)
<0. 01-0. 15
<0. 01-0. 15
<0. 01-0. 15
<0.01-1.5
<0. 01-0. 08
<0. 01-0. 15
0
<0. 01-0. 05
<0. 01-0. 05
<0. 01-0. 15
<0. 01-0. 15
0-
<0. 01-0. 05
0
<0. 01-0. 80
<0. 01-0. 15
<0. 01-0. 05
<0. 01-0. 34
0
0
0
<0. 01-0. 05
<0. 01-0. 05
-------
Table 13. lexicological Test Results for DBCP .
Test
Acute oral
LD-50
•
Skin Irri-
tation
Eye Irri-
tation
Acute dermal
Dose Levels
and Duration
DNS*
DNS
DNS
DNS
DNS
DNS
DNS
DNS
DNS
Species
Rat
Rat
Rat
Rat
Rabbit
Guinea Pig
Guinea Pig
Chicken
Mallard
duckling
0.5 ml undiluted Rabbit
DBCP, 20 applications
1.0% DBCP in
propylene glycol
Undiluted DBCP,
for 24 hr
Rabbit
Rabbit
Rabbit
Sex
and number
M
M/F
F
M/F
M/F
M
M/F
unsorted
M/F
4 animals
.not given
not given
Results
170-300 mg/kg
350 mg/kg
260-410 mg/kg
380 mg/kg
180 mg/kg
210 mg/kg
316 mg/kg
60 mg/kg
66.8 mg/kg :
Source
Torkelson 1961
Rakhmatullayev
Torkelson 1961
Rakhmatullayev
Torkelson 1961
Torkelson 1961
Rakhmatullayev
Torkelson 1961
Tucker and
Crabtree 1970
1969
1969
1969
No erythema on intact Torkelson 1961
skin; slight erythema
on abraded skin; micro-
scopic effects more
severe.
Slight irritation of
the conjunctiva and i
. LD-50 = 1400 mg/kg
Torkelson 1961
ris.
Torkelson 1961
* DNS = doses not specified
-------
Table 13- (Continued)
Dose Levels
Sex
Test
Subacute
dermal
and Duration
'.
0.25 g DBCP,
10 24 hr applica-
tions
Species
Rabbit
and
. not
number
given
Results
Slight hypereraia and
scaliness
Source
Torkelson
1961
Acute inhal- DNS
ation
Repeated
inhalation
8 hr exposure
4 hr exposure
2 hr exposure
1 hr exposure
0, 5, 10, 20 and
40 ppm; 50 expo-
sures over 7 wk
0 and 12 ppra;
66 exposures
over 70-92 days
0 and 12 ppm;
66 exposures
over 70-92 days
Rats
M
Rats
15 M per
dose group
Rats 20 M, 20 F
Rabbits 3M, 3F
Torkelson 1961
Eye and respiratory
irritation seen at
60 ppm; kidneys
permanently scarred
at 50 ppm.
LC-50 = 103 ppm
LC-50 = 154 ppm
LC-50 = 232 ppm
LC-50 r 368 ppm
Gross lesions in lungs, Torkelson 1961
intestinal mucosa, kidneys
and testes at 10, 20 and
40 ppm. Testes atrophied
at 20 and 40 ppm. testic-
ular weight reduced in
some males at 5 ppm.
Lung weights significantly Torkelson 1961
greater than controls at
12 ppm; marked pathological
changes occurred in testi-
cles
Severe atrophy and degen- Torkelson 1961
eration of testes at 12 ppm
-------
Table 13. (Cont'd)
Teat
Dose Levels
and Duration
Species
Sex
and number Results
Source
12 ppm; 66 ex- G. Pig
posures over
70-92 days
12 ppm; 50 and Monkey
60 exposures
over 70-92 days
10M •»- 10F Severe atrophy and
degeneration of testes
at 12 ppm.
2F
Developed severe
secondary infections;
aplastic anemia evident
Torkelson 1961
Torkelson 1961
Intramua- 25 mg/kg for 3
cular injec. days, repeated
Sub-chronic 0, 5, 20, 50,
Ingestion 150 450 and 1350
ppm in diet for
90 days
70, 35 and 17-5
mg/kg perorally
for 10 weeks
0, 0.005, 0.05,
0.5 and 5.0 ppm
for 8 months
Rat
Rat
5M + 5F
per dose
Rat
10M/dose
Rat
7M/dose
No significant hemato-
logic changes
Weight gain retarded
at 150 ppm for F, and
at >^50 ppm for M and F.
Minimal cloudy swilling
in 5 male livers and in
several F kidneys.
High dose produced
necrotic changes in the
parenchymatous organs
and testes; other doses
disturbed blood cell counts,
liver function and nucleic acids.
Torkelson 1961
Torkelson 1961
Rakhmatullayev
1970
Rakhmatullayev
1970
Adverse effects on testes
at 5 mg/kg, diminished
fertility at 0.5 mg/kg
and no testicular effect at
.05 mg/kg. Kidneys, liver, reflexes
and blood disturbed at dose as low
as 0.05 mg/kg.
-------
Table 13- (Cont'd)
Dose Levels
Test and Duration
Sex
Species and number Results
Source
Acute 100 ppra; 72 hr.
aquatic
32-180 ppra; 24 hr
48 hr
96 hr
0.25, 0.50, 1,
2.5, 5 and 10 ppm;
DNS; 24 hr
48 hr
DNS; 24 hr
48 hr o
DNS; 48 hr at 22 C
10, 20, 30, 40,
60, 80 and 100
ppra; 72 hr
0, 6.5, 7.5, 10.0,
12.0 and 14.0 ppm
Redeared 20 fish No toxic effect
sunfish per dose
Rainbow - LC-50 = 115.00 ppm
trout LC-50 = 85.00 ppra
LC-50 = 36.50 ppm
Clam - Larvae survival was
14£ at 1 ppm and
<1$ at 2.5 ppm
Bass 20 fish TLm = 30-50 ppm
per dose TLm = 20 ppm
Bluegill 20 fish TLm = 50-125 ppm
per dose TLm = 20 ppm
. I. exustus - TLm = 57 ppra
S. libertina TLm = 50 ppm
C. malleata • TLm = 53 ppm
P. acuta TLm = 24 ppm
Tall freshwater snails)
Lake emer- 5 fish Toxic effects at
aid shiners per dose .20 ppm; LC-100 =
60 ppm.
Pink Shrimp 5 shrimp 96 hr LC-50 = 12.7
per dose ppm
McCann, 1970
McCann, 1977
Davis and Hidu
1969
Davis and Hard-
castle 1959
Davis and Hard-
Castle 1959
Nishiuchi and
Yoshida 1972
Alexander 1973
Heitmuller 1974
for 24, 48 and 96 hr
-------
Table 13. (Cont'd)
Dose Levels
Test and Duration
Mutagenicity
Species
E.
coli
Strain
po1
po1
A,-,
V
Results
DBCP
of E.
which
blocked
coli po
ind
1
icat
growth
V'
es ef-
Source
Rosenkranz,
1975
Salmonella TA1530,
typhimureum TA153&
Salmonella TA100,
typhimureum TA1535,
TA153&
feet on cellular DNA.
DDCP was mutagenic
for TA1530 and not
TA1538, which indi-
cates it induced
base-substitution
mutations, but not
frameshift mutations.
DBCP was mutagenic
for TA1535, which
indicates it induced
base-pair substitu-
tion mutations.
Rosenkranz, 1975
Prival, 1977
-------
se
IHRUS
DTTON
[RAPES
PMCHES/NECTARINES
»INEAPPLE
SOYBEAN
P'llNUT
COMMERCIAL VEGE-
TABLES, MELONS AND
SHUW BERRIES - .
Wffi GARDENS
STRAWBERRY
NURSERY STOCK
AWONDS
APRICOTS, CHERRIES,
FIG AND WALNUTS
BHNANAS
OTHER VINE BERRIES
PLUMS
HOME LAWNS
COMMERCIAL TUrtF
ORNAMENTALS
TOTALS:
Table 14. DBCP Use Patterns
Pounds Acres Percent of
. per Year Treated/Yr. Crop Treated
1,292,000
2,700,000
3,200,000
1,823,000
302,000
12,378,000
3,195,000
3,392,000
<200,000
16,000
3,417,000
Neglig.
Neglig .
92,000
452,000
<200,000
550,000
Unknown
33,000,000
31,000
225,000
83,000
42,000
5,000
1,133,000
374,000
71,000
Not avail.
600
71,000
Neglig.
Neglig .
600
9,000
31,250
18,500
Unknown
2,330,000
7.9
2.0
31.0
44.0
46.0
2.1
23.0
<0.1-95
Not avail.
10
54.0
<0.1
<0.1
<0.1 to
0.6
69.9
5. «
Unknown
Unknown
*
Application
Cvcle
Once/3 yrs.
Annually
Once/ 3 yrs.
Once/3 yrs.
Once/2-3 yrs.
Annually
Annually
Annually
Annually
Annually
Once/3 yrs.
-_. — — —
%
Once/ 3 yrs.
Once/3 yrs.
Once/2 yrs.
Once/ 2 yrs.
Once/2 yrs.
Source: Benefits Analysis and Cooperative Assessment
-------
TABLE 15. IMPACTS OF REGULATOR* OPTIONS FOR EBCP TOR CITRUS IN CALIFORNIA, TEXAS, FLORICA AND ARIZONA.
DBCP RISKS TO HUMANS RISKS FROM
REGULATORY
ALTERNATIVES
1. Continued
Registration
nrx/rES OF
ROXSURE
Inhalation
and dermal
(593 appli-
cators)
SUBSTITUTES ECONOMIC IMPACTS
RISKS ENVIRONMENTAL HUMAN GROWERS
FY>r cancer risk, see None
Tables 3 and 4 for specific
risk estimates. There is
also a risk of decreased
sjxitm count; this risk cannot
'oe quant if icd.
Noi KJ Ni jna Lode
control
continues
CONSUMERS
Current
prices
continue
DISCUSSION OF ISSUES
AND TRADE-OFFS
Unreasonable
continue for
appllciitors.
risks
2. Restricted Use;
Clothing and Respira-
tor during Mix and
Load? Doots and Gloves
During Application,
For mixing and loading, dermal risks None
are reduced nearly 100% and inhalation
risk is reduced by factor of 50
(i.e., 90%). Risk during applica-
tion continues.
None
$175 per person
for protective
equipment.
Grower compliance is
likely.
3. <2 plus: Rf.'.spira--
tor and Reentry
Interval for Irri-
gation Application.
4. 12 plus: Respira-
tor and Reentry
Interval for All
Application Methods.
Additionally, risk during
irrigation application and from
reentry after irrigation are reduced
by factors of at least 50 and 6,
res[iectively.
None
None
Additionally, risks during all other
application neUxxls and from reentry
after tliese methods are reduced by
factors o£ at least 50 and 13, respec-
tively _____
None
None
5. 14 plus: Prohibit
Application by
Irrigation
Additionally, rir.ks fron
irrigation are eliminated, but
growers switching to injection
would be exposed to the same
risks as in fl4.
None
None
6. Cancel
Registrations
Ail DBCP risks are eliminated.
No substitutes available.
Impacts on growers uncertain. If all growers using
irrigation switched to injection, their application
costs would total $190,000-$fi30,000 per 3 yra. on
2.1,700 acres, or S265-S1160 per gtxiwur. Most grow-
ers would probably stop using tJJQ5, since injection
drtnvYjes roots and disrupts no~tiil weed progrcinn.
If all growers stopped using DIG', the Impact wuuld
tie the equivalent of cancellation for__Uiem_ ('$21 M).
"$27,000,000" [vrjr Up to 5% With" no'n^i-plant
3 yr. cycle. price ivmaticide, the slort
Grcwe lite is inct^ease anl Icntj term impacts
styjft.ened frfjni of cancellinfj
60 to 30-40 yrs. are severe.
-------
TABLE 16. IMPACTS OF REGULATORY OPTIONS FOR OBCP ON COTTON.
OBCP RISKS TO HUMANS
RISKS FROM SUBSTITUTES
ECONOMIC IMPACTS
REGULATORY
ALTERNATIVES
1. Continued
Registration
ROUTES OF
EXPOSURE RISKS ENVIRONMENTAL
Inhalation For cancer risk, see None
and dermal Tables 3 and 4 for specific
(1,271 appli- risk estimates. There is
HUMAN
None
GROWERS
Nematode
control
continues
CONSUMERS
Current
prices
continue
DISCUSSION OF ISSUES
AND TRAOE-OFFS
Unreasonable risks
continue for
applicators.
JTTRestricted Use;
Clothing and Respira-
tor during Mix and
Load; Boots and Gloves
During d,PP_l_l£a.LLorL:
TT72 p~1us: Respfra-
tor and Reentry
Interval for Irri-
gation Application.
TT~/2 plus: Resplra-
lor and Reentry
Interval for All
Application Methods.
5. 14 plus: Prohibit
ApplIcatlon by
Irrigation
cators) also .» risk of decreased
sperm count; this risk cannot
be qtvntifled.
6. Cancel
Registrations
For mixing and loading, dermal risk Is None
reduced nearly 100% and Inhalation
risks reduced by factor of 50
(I.e., 98%). Risks during appll-
catUin continue.
"Wd" i t Ton a TTy, ""file during : None
Irrigation application and from
reentry after Irrigation are reduced
by factors of at least 50 and 6,
jres|>ect_i_ye1y_. _
AUdMTTonaTTy, risks during Rone"
application and from reentry
after application are reduced
by factors of at least 50 and 13,
respectively.
None
$175 per person
for protective
equipment.
•....i-Grower compliance is
,,likely.
None
None
Add it tonally, potential risks from
Irrigation are eliminated, but
growers applying by Injection
would be exposed to the same
risks as In "04.
None
None
All DBCP risks are eliminated:
No environmental risks are
known, but some chronic
hazards from 00, EOB and Telone
ex'ut (see Table 5). The pounds
of these that would be applied
are. respectively, 9,200,000
950,000 and 4,300,000 , which
represent 130%, 131 and 62%
of trhe amounts of these chemi-
cals produced in 1974 or 1975.
$2,600,000 perNegligibleThe risks of DBCP
year to use would be replaced
substitutes. with risks from
This cost 1s <0.1X , ...% the substitute
of the value ••*:-'• -chemicals.
However, the average costs
to each of 1,271 affected growers
would be $2,000 .per year.
-------
TABLE 17. IMPACTS OF REGULATORY OPTIONS FOR DBCP ON GRAPES IN CALIFORNIA.
REGULATORY
ALTERNATIVES
OBCPJISKS TO HUMANS
ROUTESTF
RISKS FROM SUBSTITUTES
ECONOMIC IMPACTS
EXPOSURE
1. Continued
Registration
RISKS
Tor cancer risk, see
ENVIRONMENTAL
HUMAN
GROWERS
CONSUMERS
2. Restricted Use;
Clothing and Respira-
tor during Mix and
Load; Boots and Gloves
Ou r 1 ng Application.
TT72 plus: Resplra-
'tor and Reentry
Interval for Irri-
gation Application.
4. T2 pi usTResp I ra-
tor and Reentry
Interval for All
Afifi!teat Ion Methods.
5. H\ plus: Prohibit
Appllea IIon by
Irrigation
Inhalation For cancer risk, see None
and dermal Tables 3 and 4 for specific
(2,578 appll- risk estimates. There Is
cators) also a risk of decreased
sperm count: this risk cannot
be quai.-.lfled.
None
Nematoae
control
continues
Current
prices
continue
DISCUSSION OF ISSUES
AND TRADE-OFFS'
UnreasonabTe risks
continue for
applicators.
For mixing ana loading, dermal risks None
are reduced nearly 100%, and Inhalation
risks reduced by factor of 50
(I.e., 98%). Risks during appl1-
_cdtlon contlnue.
Additionally, risks during None
Irrigation application and
from reentry after Irrigation
are reduced by factors of at
_least 50 and 6, respectively. r———
Addrffoniny, risks during all other None
application methods and from reentry
after these methods are reduced by
factors of at least 50 and 13. respectively.
AddkionalTy, risks from None
irrigation are eliminated, but
growers Switching to injection
would be exposed to the same
risks as In i<\.
None
J1T5 per person
for protective
equipment.
Grower compliance Is
likely.
None
None
None
0. Cancel
Registrations
AIT DBCP risks are eliminated.
No substitutes available.
Impacts on growers uncertain. If all 2,320 growers
who Irrigate switched to Injection, their applica-
tion costs would total $59<1.000-$2,600,000 per 3
yrs. on 74,300 acres, or $256-$1120 per grower per
3 yr. cycle. Although soil Injection can cause
some root damage, nost growers would probably
use It, since OUCP Is necessary for economic
production. However, If all growers who irrigate
stopped using UUCP, the impact would be the equi-
_v£\en_t _of cancel 1 at ion for t hum (.*158-5_I-1J^_
$65,0"00,OdO per~ Up to 5T WHh no'post-pTant
3 yr. cycle. price numatidde, the short
Vineyard life 1s Increase and long term Impacts
shortened from . of cancelling UBCP
30-60 to 10-15 yrs. are severe.
-------
TABLE 18. IMPACTS OF REGULATORY OPTIONS FOR OBCP ON PEACHES AND NECTARINES IN CALIFORNIA AND EASTERN UNITED STATES."
DBCP RISKS TO HUMANS
RISKS FROM SUBSTITUTES
ECONOMIC IMPACTS
REGULATORY
ALTERNATIVES
ROUTES OF
EXPOSURE
TilSKS
1. Continued
Registration
InhalationFor cancer risk, seeRone
and dermal Tables 3 and 4 for specific
(1,714 appll- risk estimates. There Is
cators) also a risk of decreased
sperm count; this risk cannot
be quantified.
For mixing and loading, dermal risks
ENVIRONMENTAL
HUMAN
"Rone
GROWERS
CONSUMERS
DISCUSSION OF ISSUES
AND.TRADE-OFFS
Unreasonable risks
continue for
applIcators.
Nematode
control
continues
Current
prices
continue
Z. Restricted Use;
Clothing and Respira-
tor during Mix and
Load; Goots and Gloves
During Application.
~3. |2 plus: Respira-
tor and Reentry
Interval for Irri-
gation Application.
"None
None
4702 plus: Respira-
tor and Reentry
Interval for All
ApplIcatlon Methods.
?. l4~lilus: Prohibit
ApplIcatlon by
Irrigation
are reduced nearly 100X, and Inhalation
risks reduced by factor of 50
(I.e., 98X). Risks during appli-
ca tIon continue.
iddltfonally, risks during None
Irrigation application and
from reentry after Irrigation
are reduced by factors of at
least SO and 6. respectively.
"AddltlonTny, risks during all other None
application methods and from reentry
after these methods are reduced by
factors of at least SO and 13. respectively.
"Addit tonally, risks from Rone"
Irrigation are eliminated, but
growers switching to Injection
would be exposed to the same
risks as In 14.
•J175 per person
for protective
equipment.
Grower compliance Is
likely.
None
None
None
0. Cancel
Registrations
All DBCP risks are eliminated.
No substitutes available.
Impacts on growers uncertafrv.if all 1,095 growers
who Irrigate switched to Injection, their applica-
tion costs would total $175,000-$767.000 per 3
yrs. on 21,900 acres, or $160-700 per grower per
3 yr. cycle. Although soil Injection can cause
some root damage, most growers would probably
use It, since DUCP Is necessary for economic
production. However, If all growers who Irrigate
stopped using OfiCP. the. Impact would be the equl-
valjMit of cancel latlon for them ("i$2M.
Ifi0,672.0'0tl per Up to 25i WTtTi no
3 yr. cycle. price
Grove life 1s 'Increases
shortened from
1Z-13 to 6-7 yrs.
noindtlclde, the short
and lony term Impacts
of cancelling DUCP
are severe.
-------
TABLE 19. IMPACTS OF REGULATORY OPTIONS FOR OBCP ON PEANUTS IN TEXAS, OKLAHOMA AND THE SOUTHEASTERN UNITED STATES*.
DBCP RISKS TO HUMAVS
RISKS FROM SUBSTITUTES
ECONOMIC IMPACTS
REGULATORY
ALTERNATIVES
T. Continued
Registration
2. Restricted Use;
Clothing and Respira-
tor during Mix and
Load; Boots and Gloves
During Application.
ROUTES OF
EXPOSURE RISKS
ENVIRONMENTAL HUMAN
Inhalation For cancer risk, see None Hone
and dermal tables 2,3 i 4 for specific
(593 appll- risk estimates. There Is
cators) and also a risk of decreased
Ingestlon by sperm count;' this risk
U.S population, cannot be quantified.
For mixing and loading, dermal risk
are reduced nearly 1001 and inhalation
risks are reduced by factor of 50
(I.e.. 98X). Risks during applica-
tion continue.
None None
GROWERS
Nematode
control
continues
J175 per person
for protective
equipment.
•
CONSUMERS
Current
prices
continue
DISCUSSION OF ISSUES
AMD TRADE-OFFS
Unreasonable risks
continue for
applicators and tha
general population.
Grower compliance Is
likely.
TTV2 plus: Respira-
tor and Reentry
Interval for Iprl-
SiLJ °JL Appl Icatl on.
4. 12 plus: Respira-
tor and Reentry
Interval for Al1
Application Methods.
NOT APPLICABLE
Additionally, risks during
application and from reentry
after application are reduced
by factors of at least 50 and 13,
respectively.
None
None
5. 14 plus: Prohibit
Application by
Irrlyatlon
NOT APPLICABLE
Irrigate
6. Cance
Cancel
Registrations
All risks are eliminated.
Wildlife losses can occur
from use of furadan, dasanit,
mocap and nemacur. Chronic
hazards for humans exist from
DO, EOB and Telone (Table 51.
Some of the substitutes would
be applied In large amounts
^_^ (see Tiible_£).
This crop has been unconditionally suspended In the Administrator ^Suspension Order of October 27,19777
I 6,800,000/yr None
Greatest Impacts
would occur In
Oklahoma and Texas, where
It would no longer be profit-
able for 10% of the growers
to grow peanuts.
Risks ofDBCP may be
replaced by signifi-
cant human and envi-
ronmental hazards.
In the long term.
about 610 fanners
may be forced to
grow pther crops.
-------
TABLE 20. IMPACTS OF REGULATORY OPTIONS FOR DBCP ON PINEAPPLES IN HAWAII
DBCP RISKS TO HUMANS
RISKS FROM SUBSTITUTES
ECONOMIC IMPACTS
REGULATORY
ALTERNATIVES
1. Continued
Registration
2. Restricted Use;
riothlng and Respira-
tor during Mix and
Load; Boots and Gloves
During appl (cat Ion.
3. 12 plus: Resplra-
ROUTES OF
EXPOSURE RISKS ' f NVIROMMENTAL HUMAN
Inhalation For cancer risk, see None None '
and dermal Tables 3 and 4 for specific
(76 appl I- risk estimates. There Is
cators) also a risk of decreased
sperm count; this risk cannot
be quantified.
For mixing and loading, dermal risk Is None None
reduced nearly 100X and Inhalation
risks reduced by factor of 50
(I.e.. 981). Risks during appli-
cation continue.
HOT APPLICABLE
GROWERS
Nematode
control
continues
$175 per person
for protective
equipment.
CONSUMERS
Current
prices
continue
DISCUSSION OF ISSUES
AND TRADE-OFFS
Unreasonable risks
continue for
applicators.
Grower compliance is
likely.
tor and Reentry
Interval for Irrl-
f at Ion Appl Icatlon.
7~?2~l>1us: ReipTra-
tor and Reentry
Interval for All
Appl Icatlon Methods.
I. 14 plus: Prohibit
Application by
Irr1ga tIon
"Additionally, risks during
application and from reentry
after application are reduced
by factors of at least 50 and 13,
respectively.
None
None
NOT APPLICABLE
6. Cancel
Registrations
All DBCP risks are eliminated.
There are no known environmen-
tal risks, but several chronic
hazards are associated with
the only substitute, EDB
(see Table 5). 720,000 pounds
would be applied; this quantity
Is 10X of the amount produced in 1975.
}6.200,000 per Up to 9%
year beginning price
on the third increase
year.
The risks of DBCP
would be replaced
with risks from EOB.
-------
TABLE 21. IMPACTS OF REGULATORY OPTIONS FOR DBCP ON SOYBEANS IN THE SOUTHEASTERN UNITED STATES.
REGULATORY
ALTERNATIVES
1. Continued
Registration
DBCP RISKS
ROUTES OF
EXPOSURE
Inhalation
and dermal
(9.655 appl
TO HUMANS RISKS FROM SUBSTITUTES
RISKS ENVIRONMENTAL
For cancer risk, see None
Tables 3 and 4 for specific
1- risk estimates. There Is
HUMAN
None
ECONOMIC IMPACTS
GROWERS
Nematode
control
continues
01
CONSUMERS
Current Ur
prices c(
continue a|
?. Restricted Use;
Clothing and Respira-
tor during Mix and
Load; Boots and Gloves
During application.
3. f2 plus: Respira-
tor and Reentry
Interval for Irri-
gation ApplIcatlon.
T7T2 plus: Respira-
tor and Reentry
Interval for All
Appl1ca11 on Methods.
cators) also a risk of decreased
sperm count; this risk cannot
be quantified.
DISCUSSION OF ISSUES
AND TRADE-OFFS ^
Unreasonable risks
continue for
applicators.
For mixing andloadlng, dermal risk is
reduced nearly 100% and Inhalation
risks reduced by factor of 50
(I.e.. 901). Risks during appli-
cation continue.
None
None
$175 per person
for protective
equipment.
Grower compliance
likely.
Is
NOT APPLICABLE
Additionally, risks during ~
application and from reentry
after application are reduced
by factors of at loast 50 and 13,
respectively.
None
None
57T4 plus: Prohibit
Application by
Irrjj a H on
6. Cancel
NOT APPLICABLE
All risks are eliminated.
Registrations
Wildlife losses can occur
from use of nemacur (see
Table 5). There are chronic
hazards for humans from
DO, tDB and Telone (Table 5),
Unusually large amounts of
of each substitute would be
applled (see Table 9).
$23,500,000/yr Negllg.
This is
-------
TABLE 22. IMPACTS OF REGULATORY OPTIONS FOR DBCP ON COMMERCIAL VEGETABLES, HELONS AND STRAWBERRIES NATIONWIDE*
REGULATORY
ALTERNATIVES
1. Continued
Registration
2. Restricted Use;
Clothing and Respira-
tor during Mix and
Load; Boots and Gloves
During Application.
3. 12 plus: Respira-
tor and Reentry
Interval for Irrl-
?atlon Appl icatlon.
. f2 plus: Respira-
tor and Reentry '
Interval for All
Application Methods.
DBCP RISKS TO HUMAHS
ROUTES OF
EXPOSURE RISKS
RISKS FROM SUBSTITUTES
ENVIRONMENTAL HUMAN
Inhalation For cancer risk, see None None
and dennal tables 2,3 S 4 for specific
(0,272 appll- risk estimates. There Is
cators) and also a risk of decreased :
Ingestion by sperm count; this risk
U.S population, cannot be quantified.
For mixing and loading, dermal risk
are reduced nearly 100% and Inhalation
risks are reduced by factor of 50
(I.e., 911%). Risks during applica-
tion continue.
Additionally, risks during
application and from reentry
after application are reduced
by factors of at least 50 and 13,
respectively.
None • None
NOT APPLICABLE
None None
ECONOMIC IMPACTS
GROWERS CONSUMERS
Nematode Current
control prices
continues continue
$175 per person "
for protective
equipment.
• tt
DISCUSSION OF ISSUES
AND TRADE-OFFS
Unreasonable risks
continue for
applicators and the
general population.
Grower compliance Is
likely.
9 it
5. 14 plus: Prohibit
Application by
Irrigation
NOT APPLICABLE
6. Cancel
Registrations
Risks of OBCP may be
replaced by signifi-
cant human and envi-
ronmental hazards.
All risks are eliminated. There are chronic hazards' $14,500,000/yr None
for humans from 00, EOB and Greatest Impacts
' Telone and Vorlex (see Table would occur In
5). The pounds of these that tomatoes and watermelons.
would be applied are, respectively, 8,100 growers are
13.000.000; 3.000.000; 5,000,000; affected.
and 2,400,000. which represent
1BU, 41%, 72% and 120% of the
amounts of these chemicals
• prnduci-d In 1974 or 1075. .._^-^.
*/ 19 of.23 of these crops have been unconditionally suspended i>y Uic AdministratoPs Suspension Order of October 27, 1977. The four crops
In which no DBCP residues are expected are lima beans, okra, snap beans and southern peas.
-------
TABLE 23. IMPACTS OF REGULATORY OPTIONS FOR DBCP ON COMMERCIAL TURF (GOLF COURSES IN FLORIDA, TEXAS, SOUTH CAROLINA .AND GEORGIA)
REGULATORY
ALTERNATIVES
1. Continued
Registration
DBCP RISKS TO HUMANS RISKS
FROM SUBSTITUTES
ROUTES OF
EXPOSURE RISKS ENVIRONMENTAL HUMAN .
Inhalation For cancer risk, see None
and dermal Tables 3 and 4 for specific
(309 appll- risk estimates. There is
cators) also a risk of decreased
sperm count; this risk cannot
be quantified.
None
ECONOMIC IMPACTS
GROWERS CONSUMERS
Nematode Current
control prices
continues continue
DISCUSSION OF ISSUES
AND TRADE-OFFS
Unreasonable risks
continue for
applicators.
TTRestrkted Use;
Clothing and Respira-
tor during Mix and
Load; Boots and Gloves
During appl Icatlon.
TTlFplus:
For mixing and loading, dermal risk is None
reduced nearly 100% and Inhalation
risks reduced'by factor of 50
(i.e., 90X). Risks during appli-
cation continue.
None
TD5 per person
for protective
equipment.
Grower compliance Is
likely.
NOT APPLICABLE
tor and Reentry
Interval for Ir.rl-
gat.1 on Appl Icatlon.
4. |2 plus: Respira-
tor and Reentry
Interval for All
Application Methods.
1. f4 plus: Prohibit
ApplIcatlon by
Irrlgatlon
6. Cancel
Additionally, risks dunng
application and *rom reentry
after application are reduced
by factors of at least SO and 13,
respectively.
None
None
NOT APPLICABLE
risks are eliminated.
Registrations
Wildlife losses can occur
from use of nemacur and
mocap (see Table 5). The
pounds of these applied are
130,000 and 230,000 pounds,
respectively.
$2,200,000 to None
$5,600,000 per
year from the
higher cost of
the substitutes.
For 310 golf courses,
the costs would be
$/.100-$18.100/yr.
Risks of OBCP may be
replaced by some
wildlife hazard.
-------
TABLE 24. IMPACTS OF REGULATORY OPTIONS FOR DBCP ON STRAWBERRY NURSERY STOCK IN DELAWARE AND MARYLAND'
REGULATORY
ALTERNATIVES
1. Continued
Registration
7. Restricted Use;
Clothing and Respira-
tor during Mix and
Load; Boots and Gloves
During appl (cation.
3. tl plus: Respira-
tor and Reentry
Interval for Irri-
gation Appl iciit ion.
4. 12 plus: Respira-
tor and Reentry
Interval for All
Application Methods.
5. 14 plus: Prohibit
Appl (cation by
Irriyat ion
6. Cancel
Registrations
DBCP RISKS TO HUMANS
ROUTES OF
EXPOSURE RISKS
RISKS FROM SUBSTITUTES
ENVIRONMENTAL HUMAN
Inhalation For cancer risk, see None None
and dermal Tables 3 and 4 for specific
(4 appli- risk estimates. There Is
cators) also a risk of decreased
spenn count; this risk cannot
be quantified.
For mixing and loading, dermal risk is
reduced nearly 100% and inhalation
risks reduced by factor of 50
(I.e., 98%). Risks during appli-
cation continue.
Additionally, risks during
application and from reentry
after application are reduced
by factors of at least 50 and 13,
respectively.
All DBCP risks are eliminated.
None None
NOT APPLICABLE
None None
NOT APPLICABLE
No substitutes available.
ECONOMIC IMPACTS
GROWERS
Neinatode
control
continues
$175 per person
for protective
equipment.
H
$1,500,000 to
$5,600,000 per
year,
CONSUMERS
Current
prices
continue
H
m
Op to 18X
price
Increase
1n the East.
DISCUSSION OF ISSUES
AND TRADE-OFFS
Unreasonable risks
continue for
applicators.
Grower compliance is
likely.
II H
Some growers could
possibly be forced
out of production.
-------
TABLE 25. IMPACTS OF REGULATORY OPTIONS FOR DBCP ON OTHER BERRIESMN WASHINGTON, OREGON AND CALIFORNIA
RISKS FROM SUBSTITUTES
REGULATORY
ALTERNATIVES
1. Continued
Registration
DBCP RISKS TO HUMANS
WfETOT
EXPOSURE RISKS ENVIRONMENTAL
Ifihalation There is a potential None
and dermal risk of cancer If OBCP 1s
(only appll- applied. There is also
cators) a potential risk of decreased
ECONOMIC IMPACTS.
HUMAN
None
GROWERS
CONSUMERS
DISCUSSION OF ISSUES
AND TRADE-OFFS
^Restricted Use;
Clothing and Respira-
tor during Mix and
Load; Boots and Gloves
During applteat Ion.
TT~I2 plus: Respira-
tor and Reentry
Interval for Irri-
gation Application.
sperm count; this risk cannot
be quantified.
Since there Is little or
no use of DBCP on these
berries, no one realizes
an economic benefit from
DBCP.
Unreasonable risks.
could occur for
applicators.If
OBCP were used.
For mixing and loading, dermal risk is None
reduced nearly 100% and Inhalation
risks reduced by factor of 50
(i.e., 98%). Risks during appll-
c a11 on wouId contInue.if ODCP were used.
"ScTditlonaTly, rfsk during None
irrigation application and from
reentry after irrigation would be
reduced by factors of at least 50
47 12 plus: Resplra-
tor and Reentry
Interval for All
Application Methods.
5. 14 pTuTTTrohlbit
Application by
Irrigation
6. Cancel
Registrations
None
$175 per person
for protective
equipment.
Grower compliance
would be likely.
None
an? Ai respectively.
~A~d"3It tonally, rTsk's t
during None
application and from reentry
after application would be reduced
by factors of at least 60 and 13,
respect I veljY_.
~K3dftTonally, potential risks from None
Irrigation are eliminated, but
growers applying by injection
would be exposed to the same
risks as In /4.
All potential OBCP risks would
be eliminated.
None
None
No substitutes available.
>1,000,000 In
production losses
for boysenberrles
and raspberries.
No effect Cancellation would
on consumer prevent DBCP use In
prices. the future If nema-
todes are problem.
*/ .blackberries, blueberries, dewberries, loganberries, raspberries.
-------
TABLE 26. IMPACTS OF REGULATORY OPTIONS FOR DBCP ON PLUMS IN CALIFORNIA.
DBCP RISKS TO HUMANS ' RISKS FROM SUBSTITUTES
REGULATORY
ALTERNATIVES
1. Continued
Registration
ROUTES OF
EXPOSURE
Inhalation
and dermal
(450 appli-
cators)
RISKS ' ENVIRONMENTAL HUMAN
For cancer risk, see None None
Tables 3 and 4 for specific '
risk estimates. There Is
also a risk of decreased
sperm count: this risk cannot
be quantified.
ECONOMIC IMPACTS
GROWERS .
Nematode
control
continues
CONSUMERS
Current
prices
continue
DISCUSSION OF ISSUES
AMD TRADE-OFFS
Unreasonable risks
continue for
applicators.
2. Restricted Use;
Clothing and Respira-
tor during Mix and
Load; Boots and Gloves
During Appl Icat 1 on.
"3772 plus: fies]Hra-
lor and Reentry
Interval for Irri-
gation Application.
4. 12 plus: Resplra-
tor and Reentry
Interval for All
Apjjl icatlon Methods.
¥. f~4"~pTus: P"r6in,bTt~
ApplIcatlon by
Irrigation
For mixing and loading, dermal risksNone
are reduced nearly 100X, and Inhalation
risks reduced by factor of 50
(i.e.. 98%). Risks during appli-
cation continue. ; _____
"Ad"JitTonaTly, risks durfng None
Irrigation application and
from reentry after Irrigation
are reduced by factors of at•
least 50 and 6, respectively.
"Additionally, risks during all other Rone"
application methods and from reentry
after these methods are reduced by
_factor£j)f at least 50 and 13, respectively.
Additionally, risks from None
irrigation are eliminated, but
growers switching to Injection
would be exposed to the same
risks OS In 14.
None
"J175 per person
for protective
equipment.
Grower compliance Is
likely.
None
None
None
6. Cancel
Registrations
ATTDBCP risks are eliminated.
No substitutes available.
Impacts on growers uncertain. If an 450 growers
who Irrigate switched to injection, their applica-
tion costs would total $75.000-$327,OOQ per 3
yrs. on 9,336 acres, or $166-1726 per grower per
3 yr. cycle. Although soil Injection can cause '
some root damage, most growers would probably
use It, since OBCP is necessary for economic
production. However, if all growers who irrigate
stopped using DBCP, the Impact would be the equi-
valent of cancellation fur them (-S13.8M).
$D ,800,00(J per Up to 2Gi36;Tu7TaTrforn\T~
3 yr. cycle. price acres would go out of
Increases production in 3-5,yrs.
-------
TABLE 27. IMPACTS OF REGULATORY OPTIONS FOR DBCP OH ALMONDS IN CALIFORNIA.
REGULATORY
ALTERNATIVES
I. Continued
OBCP RISKS TO HUMANS
MUTES OF
RISKS FROM SUBSTITUTES
ECONOMIC IMPACTS
EXPOSURE
RISKS
I nha TaTTon F'or cancer risk, see None
and dennal Tables 3 and 4 for specific
(1,108 appll- risk estimates. There Is
cators) also a risk of decreased
sperm count: this risk cannot
_ be quantified. __
For mixing and loading, dennal risks None
are reduced nearly 100%, and inhalation
risks reduced by factor of 50
(i.e., 98%). Risks during appli-
cat ion continue.
ENVIRONMENTAL
HUMAN
GROWERS
CONSUMERS
DISCUSSION OF ISSUES
AND TRADE-OFFS
None
Registration
Nematode Current Unreasonable risks
control prices continue for
continues continue applicators.
2. Restricted Use;
Clothing and Respira-
tor during Mix and
Load; Boots and Gloves
During Application.
7775 plus: Respira-
tor and Reentry .
Interval for Irri-
gation Anolication.
4. 12 plus: Respira-
tor and Reentry
Interval for All
Applicatiun Methods.
STj'l plus: Prohibit
Application by
Irrigation
None
$1/5 per person
for protective
equipment.
Grower compliance Is
likely.
risks during None
irrigation application and
from reentry after irrigation
are reduced by factors of at
JjiaAL.^P and 6, respectively. _
Additionally, risks during all other None
application methods and from reentry
after these methods are reduced by
jf _ac t ors of at 1e a st 50 and 13. respectively.
Additionally. rfsTs from None
irrigation are eliminated, but
growers switching to injection
would be exposed to the same
risks as in J4.
None
None
None
67 Cancel
Registrations
All OBCP risks are eliminated.
No substitutes available.
impacts on growers uncertain. If all 1,108 growers
who irrigate switched to Injection, their applica-
tion costs would total $565.000-$?.808,000 per 3
yrs. on 70,000 acres, or $510-$2,606 per grower per
3 yr. cycle. Although soil injection can cause
some root damage, most growers would probably
use it, since OBCP is necessary for economic
production. However, if all growers who irrigate
stopped using UUCP, Hie Impact would be the equi-
_vali.'H j?f cancel 1 at ion for thiiin ('J?H).
i26.502.000" per Up to 20% ~18X"of" CahToFnia
3 yr. cycle. price acres would go out of
increases production in 3-5 yrs.
-------
TABLE 28. IMPACTS Of REGULATORY OPTIONS FOR DBCP ON HOME GARDENS IN THE SOUTH*
OBCP RISKS TO HUMANS
RISKS FROM SUBSTITUTES
ECONOMIC IMPACTS
REGULATORY
ALTERNATIVES
ROUTES OF
EXPOSURE
RISKS
DISCUSSION OF ISSUES
Continued
Registration
2. RestrtctedUse;
Clothing and Respira-
tor during Mix and
Load; Boots and Gloves
DurlnoAjipl icat Ion.
IT"/2 plus: Respira-
tor and Reentry
Interval for Irri-
tjaMon Aj>|>! icdtlon.
"inhalation For cincer 7TsT7 see None
and dermal tables 2,3 & 4 for specific
(250.000 home risk estimates. There Is
gardeners) i also a risk of decreased
Inyestlons by sperm count; this risk
2,000 jjlOO. c a nnot_be__<. \arit_i f led.
Tor mixing and loa3Fng. JeniidTTTslc None
are reduced nearly 100% and inhalation
risks are reduced by factor of 50
(I.e., 981). Risks during applica-
tion continue.
ENVIRONMENTAL
HUMAN
GROWERS
CONSUMERS
None
Nenidtode Current Unreasonable risFs
control prices continue for home
continues continue gardeners and others
wtio eat crops from
treated gardens.
None
$175 per person
for protective
equipment.
"Grower compliance is
unlikely.
NOTAPPLICABLE
4. 12 plus: Respira-
tor and Reentry
Interval for All
Application Methods.
TTTTplus: Prohibit
Application by
Irrigation
Additionally, risks during "
application and from reentry
after application are reduced
by factors of at least 60.and 13.
respectively.
None
None
NOT APPLICABLE
Cancel
Rt-ylst rat Ions
AIT DBCP risks are eliminated.
No substitutes available.
Neglig.
Neglig. Some production de-
creases may occur
for affected home
gardeners.
"/ 19 0(723 of these crops nave been unconditionally suspended by the Administrator s Suspension Order of October 27, 1977.
In which' no OBCP residues are expected are lima beans, okra, snap beans and southern peas.
The four crops
-------
Table 29. IMPACTS OF REGULATORY OPTIONS FOR DBCP ON HOME LAWNS IN FLORIDA
DBCP RISKS TO HUMANS
RISKS FROM SUBSTITUTES
ECONOMIC IMPACTS
REGULATORY
ALTERNATIVES
1. Continued
Registration
ROUTES OF
_EXPOSURE
InhaTation
ami dermal
(125.000
homeowners)
RISKb
ENVIRONMENTAL
HUMAN
TTRestricted Use;
tlothing and Respira-
tor during Mix and
Load; Boots and Gloves
During appllcat ion.
3. |2 plus: Respira-
tor and Reentry
Interval for Jrri-
gaUon Appl leal Ion
For cancer rlsfT. see None
Tables 3 and 4 for specific
risk estimates. There 1s
also a risk of decreased
sperm count; this risk cannot
be quant if Ie d.
For mTxTng and loading, dermal risk isNone
reduced nearly 100X and inhalation
risks reduced by factor of 50
(i.e., 901). Risks during appli-
cation continue.
None
HOMEOWNERS
Nernatode control continues.
DISCUSSION OF ISSUES
___
Unreasonable risks
continue for
applicators.
None
$175 per person
for protective
equipment.
Homeowner compliance
is unlikely.
NOT APPLICABLE
47 tl plus: Respira-
tor and Reentry
Interval for All
Application Methods.
Additionally, risks during
application and from reentry
after application are reduced
by factors of at least 50 and 13,
respectively. _____
None
None
57l4 plus: Prohibit
Appl 1 cat km by
Irrigation
6. Cancel
Registrations
NOT APPLICABLE
All DBCP risks are eliminated.
No substitutes available.
An infested lawn will die Potential property
after ten years If not treat- value declines may
ed. It will cost $200 to re-, occur for affected
place a lawn with turf plugs, homeowners.
Since 5% of the lawns are af-
fected annually, the total
impact is $2.750,000 per year,
-------
TABLE 30. IMPACTS OF REGULATORY OPTIONS FOR DBCP ON ORNAMENTALS IN FLORIDA, GEORGIA AND SOUTH CAROLINA.
OBCP RISKS TO HUMANS RISKS FROM SUBSTITUTES
REGULATORY
ALTERNATIVES
1. Continued
Registration
ROUTES OF
EXPOSURE
Inhalation
and derma 1
(5,000
nurserymen).
RISKS ENVIRONMENTAL HUMAN
For cancer risk, see .None None
Tables 3 and 4 for specific
risk estimates. There Is
also a risk of decreased
sperm count; this risk cannot
be quantified.
ECONOMIC IMPACTS
GROWERS
Nematode
control
continues
CONSUMERS
Current
prices
continue
DISCUSSION OF ISSUES
AND TRADE-OFFS
Unreasonable risks
continue for
applicators.
T. Restricted Use;
Clothing and Respira-
tor during Mix and
Load; Boots and Gloves
Our j nj_ a ppl 1c at jo n .
3. fl pTus: Resplra-
tor anil Reentry
Interval for Irri-
For mixing and loading, dennal risk Is
reduced nearly 100% and inhalation
risks reduced by factor of bO
(I.e.. 98%). Risks during appli-
cation continue.
None
None
TT75 per person
for protective
equi pineal.
Grower compliance Is
likely.
NOT APPLICABLE
A[i|il I cat ion.
4. /F~plus: Respira-
tor and Reentry
Interval for AH
Appl Icatlon Methods,
midTtionally, HsKf curing
application and from reentry
after application are reduced
by factors of at least 50 and 13,
respectively.
None
None
5. J4 plus: Prohibit
Application by
Irrigation
6. Cancel
NOOPPLICABLE
All DBCP risks are eliminated.
Registrations
Some wildlife losses may
occur from use of mocap and
dasanit (see Table 5). The
pounds applied cannot be
estimated.
Substitutes are No substitu-
less effective, tes regis-
must be applied tered for
more often and home use.
cost more. On box-
woods, Mocap costs
$8Q5/A/8yrs. while
DBCP costs only $101/A/8 yrs.
Risks of OBCP would be
replaced by some wild-
life hazard and home-
owners would have to
hire commercial appli-
cators to apply subs-
titutes.
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TABLE 31. IMPACTS OF REGULATORY OPTIONS FOR DBCP ON APRICOTS, CHERRIES, FIGS AND WALNUTS IN CALIFORNIA
REGULATORY
ALTERNATIVES
1. Continued
Registration
DBCP RISKS TO
ROUTES OF
EXPOSURE
Inhalation
and dermal
(nogl Iglble
nuiiiber of
applicators).
HUMANS RISKS FROM SUBSTITUTES
RISKS ENVIRONMENTAL HUMAN
Cancer risk exist None None
If DBCP Is applied.
There Is also a risk
of decreased sperm
count; tills risk cannot
be quantified.
ECONOMIC IMPACTS
GROWERS
Neyliglble
use of OBCP
on these crops.
• DISCUSSION OF ISSUES
CONSUMERS AND TRADE-OFFS
None Unreasonable risks
could occur If UUCP
were to be applied.
27Restricted Use;
Clothing and Respira-
tor during Mix and
Load; Coots and Gloves
During ApplIcatlon.
TTT2 plus: Respira-
tor and Reentry
Interval for Irri-
gation Application.
"4. |2 plus: Respira-
tor and Reentry
Interval for All
Application Methods.
UTT-Tplus: Prohibit
Appl(cation by
I r r i'jatlon
6. Cancel
For mixing and loading, .dermal risks None
are reduced nearly 100%, and Inhalation
risks reduced by factor of 50
(I.e.. 9W). Risks during appli-
cation continue.
None
fT75 per person
for protective
equipment.
Grower compliance Is
likely.
Additionally, risks during None
Irrigation application and
from reentry after Irrigation
are reduced by factors of at
least^ 50 and 6 respectively. _
TiUd it fonally, risks during all other None
application methods and from reentry
after these methods are reduced by
factory of _at least 50 and 13. respectively.
~~Tsk"s from Rone
None
None
None
irrigation would be eliminated
Registrations
AU potent lalDBT.
be eliminated.
r$ks would
Ho substitutes available.
The Impacts of cancella- Although use ofDBCl5
tlon are negltglble at
present, but major
losses in production
could be Incurred If
nematodes Infested any
of these crops.
1s very limited, nema-
tode problems could ocur
In the future, and the
Impact of not having DBCP
could be severe.
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TABLE 32. IMPACTS OF REGULATORY OPTIONS FOR OBCP ON BANANAS IN THE UNITED STATES.
REGULATORY
ALTERNATIVES
1. Continued
Registration
DBCP RISKS TO
ROUTES OF
EXPOSURE
Inhalation
and dermal
(Negligible
number of
appl icators).
HUMANS
RISKS
RISKS FROM SUBSTITUTES
ENVIRONMENTAL
Cancer risks exist None
if ODCP is applied.
There is also a risk
of decreased sperm count;
this risk cannot be quantified.
HUMAN
None
ECONOMIC
GROWERS .
Negligible
domestic use
of OBCP on
this crop.
IMPACTS
CONSUMERS
None
DISCUSSION OF ISSUES
AND TRADE-OFFS
Unreasonable risks
could occur If OBCP
were to be apl led/
2. Restricted Use;
Clothing and Respira-
tor during Mix and
Load; Boots and Gloves
During applIcat ion
For inixTng and loading, dennal risk is None;
reduced nearly 100% and inhalation
risks reduced by factor of 50
(i.e., 901). Risks during appli-
cation continue.
None
"JI75 per person
for protective
equipment.
Grower compliance is
likely.
3. |2 plus: Respira-
tor and Reentry
Interval for Irri-
gation Application.
^. 12 plus: Respira-
tor and Reentry
Interval for All
Application Methods.
NOT APPLICABLE
Additionally, risks during
application and from reentry
after application are reduced
by factors of at least 50 and 13,
respectively.
None
None
5. *4 plus: Prohibit
Application by
NOT APPLICABLE
?7~CanceT
Registrations
All potential DBCP risks would
be eliminated.
No substitutes available.
Negllg.
(Jther countries might follow our
example and prohibit DBCP use
on bananas, which could result in
price Increases (from 23.5 to
27.0'cents/lb) and reduced sup-
lies of Imported bananas. This
Impact could total $150,000,000.
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TABLE 33.. SUMMARY .OF SELECTED COURSES OF ACTION AND THEIR IMPACTS
I/
Use Category
19 Commercial
Vegetables
22 Home Garden
Vegetables
Peanuts
Citrus
Grapes
Peaches/Nec-
tarines
Plums
Almonds
Strawberry Nursery
Pineapple
>
Apricots
Cherries
Figs
Walnuts
Other Berries
Bananas
*
Selected Suspension
Course of Requirements
Action in Effect
Option 6 DBCP use not
(Cancel) permitted
.
Option 4 Restricted
(Restrio Use
ted use)
Stock
Option 4 Restricted
(Restricted Use
Use)
Human Risks
Exposed
People
U.S.
populace
Appli-
cators
Appli-
cators
•
Route
Food
Inhala-
tion
Dermal
Reentry
Inhala-
tion
Dermal
Reentry
Risk
Before
2.013
Cancer
cases;
sperm
count
decrease
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Soybeans
Cotton
Option 4 Restricted
(Restricted Use
Use)
(Same risks described for: Citrus,
Grapes, etc.,
<0.25% price in- 1. if used without restric-
crease tions, IJOCP could cauus un-
$ 2.6 M/ yr. Negligible reasonable Averse ettects.
ett'ect on 2. Risk.-, can t« teducx-0 at
prices. a reasonable cost.
3.' ((eijiiitc-ted substitutes
are available, but they
either cost t nucli ur
nuiy cause inverse
effecta.
Commercial
Beans, Ckra,
Sn£^> Beans
and SoutJwrn Peaa
Option 4 Restricted
(Restricted Use
Use)
(Sane as above for Citrus,. Grapes,
etc.)
Turf and
Ornamentala
TOTAL IMPACTS:
Option 4 Restricted
(Restricted Use by
Use by Certified
Certified Comrwrcial
Comnurcial Ap
Applicators Only.
Cnly)
(Same as above for Citrus, Grapes,
etc.)
Prevent;
§ 2.4 M/ yr.
Unknown effect
on prices.
1. If used without restric-
tions, W3CP cxxjld cause un-
reasonable adverse effects.
2. Risks can t«s reduuixl at
a reasonable coat.
3. It^-jistered substitutes
ate available, but they
Prevent;
$ 2.4 M/ yr. for home lawns.
S 2.2-§5.6H/yr (golf courses)
$ Unknown loss for •
oniainentals
1. if used witltout restcic-
tions, WiCP could cau:x- un-
reascxxable adverse effwctfi.
2. Risks can t»j reduo.-d at
a roamxiable cost.
3. Ki.tjistetx-d uibstituLea
'are either riot available
or not as e£ticiiciouu as
DUC1'».
4. ikait; owners not likely
to Iwy and us«i protective
Cance~r"risk"« I case cancer/yr $11.6 M/ yr. and <0*.1% increase in price's". (Vegetables)
Reproductive risk reduced by 98%. $ 6.6 M/ yr and no increase in prices (Peanuts)
Sone risks to humans may result from § 3.4 M for one-tine investment in protective cquipient
use of substitute fumigants crs peanuts by 31,000 growers.
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