United States Prevention, Pesticides EPA738-R-99-012
Environmental Protection And Toxic Substances September 1999
Agency (7508C)
&EPA Reregistration
Eligibility Decision (RED)
Sulfotepp
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UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
WASHINGTON, D.C. 20460
OFFICE OF
PREVENTION, PESTICIDES
AND TOXIC SUBSTANCES
CERTIFIED MAIL
Dear Registrant:
I am pleased to announce that the Environmental Protection Agency has completed its
reregistration eligibility review and decisions on the pesticide chemical case which includes the
active ingredient sulfotepp. The enclosed Reregistration Eligibility Decision (RED), which was
approved on September 30, 1999, contains the Agency's evaluation of the data base of this
chemical, its conclusions of the potential human health and environmental risks of the current
product uses, and its decisions and conditions under which these uses and products will be eligible
for reregistration. The RED includes the data and labeling requirements for products for
reregistration. It may also include requirements for additional data (generic) on the active
ingredients to confirm the risk assessments.
If EPA determines, as a result of this later implementation process, that any of the
determinations described in this RED are no longer appropriate, the Agency will pursue whatever
action may be appropriate, including but not limited to reconsideration of any portion of this
RED.
If you have questions or wish to meet with the Agency, please contact the Special Review
and Reregistration Division representative Robbi Farrell (703) 308-8065.
Sincerely yours,
Lois A. Rossi, Director
Special Review and
Reregistration Division
Enclosures
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INSTRUCTIONS FOR RESPONDING TO THE REGISTRATION ELIGIBILITY
DECISION (RED)
You may submit comments by mail, in person, or electronically. To ensure proper receipt
by EPA, it is imperative that you identify the docket control number in the subject line on the first
page of your response. The docket control number is found in the Federal Register notice
announcing the availability of this RED. The case number for this RED is OPP-34146B.
Do not submit any information that you consider to be Confidential Business Information
(CBI). You may claim information that you submit to EPA in response to this RED as CBI by
marking any part or all of that information as CBI. Information so marked will not be disclosed
except in accordance with procedures set forth in 40 CFR part 2. In addition to one complete
version of the comment that includes any information claimed as CBI, a copy of the comment that
does not contain the information claimed as CBI must be submitted for inclusion in the public
version of the official record. Information not marked confidential will be included in the public
version of the official record without prior notice. If you have any questions about CBI or the
procedures for claiming CBI, please consult the person listed under "FOR FURTHER
INFORMATION CONTACT" in the Federal Register notice announcing the availability of this
RED.
Submission Formats
Paper: 3 copies
Disk: Electronic submissions are accepted in WordPerfect 6.1/8.0 or ASCII file format.
Avoid the use of special characters and any form of encryption.
E-Mail: Send to "opp-docket@epa.gov." Electronic submissions are accepted in
WordPerfect 6.1/8.0 or ASCII file format. Avoid the use of special characters and any form of
encryption. Electronic comments may also be filed online at many Federal Depository Libraries.
Delivery
Mail: Submit your written comments or disk to: Public Information and Records Integrity
Branch (PIRIB), Information Resources and Services Division (7502C), Office of Pesticide
Programs (OPP), Environmental Protection Agency, 401 M St., SW., Washington, DC 20460.
In person or by courier: Deliver your written comments or disk to: Public Information
and Records Integrity Branch (PIRIB), Information Resources and Services Division (7502C),
Office of Pesticide Programs (OPP), Environmental Protection Agency, Rm. 119, Crystal Mall
#2, 1921 Jefferson Davis Hwy., Arlington, VA. The PIRIB is open from 8:30 a.m. to 4 p.m.,
Monday through Friday, excluding legal holidays. The PIRIB telephone number is (703) 305-
5805.
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REREGISTRATION ELIGIBILITY DECISION
Sulfotepp
LIST A
CASE 0338
ENVIRONMENTAL PROTECTION AGENCY
OFFICE OF PESTICIDE PROGRAMS
SPECIAL REVIEW AND REREGISTRATION PROGRAM
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Table of Contents
Executive Summary 1
I. INTRODUCTION 3
II. CHEMICAL OVERVIEW 4
A. Regulatory History 4
B. Chemical Identification 4
C. Use Profile 5
D. Estimated Usage of Pesticide 6
E. Benefits of Sulfotepp 6
III. OVERVIEW OF SULFOTEPP RISK ASSESSMENT 6
A. Human Health Risk Assessment 6
B. Ecological Effects Risk Assessment 11
IV. RISK MANAGEMENT & REREGISTRATION ELIGIBILITY DECISION 11
A. Risk Management Considerations 11
B. Status of the Database for Sulfotepp 11
C. Summary of Remaining Risks from Use of Sulfotepp at Current Label ... 12
D. Risk Management Decision 12
V. Actions Required of Registrants 15
A. Manufacturing-Use Products 15
B. End-Use Products 15
References 25
Appendix: Related Documents and How to Access Them 26
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List of Acronyms
a.i. Active Ingredient
Agency U.S. Environmental Protection Agency
EPA U.S. Environmental Protection Agency
FFDCA Federal Food, Drug, and Cosmetic Act
FIFRA Federal Insecticide, Fungicide, and Rodenticide Act
FQPA Food Quality Protection Act of 1996
HED Health Effects Division
MOE Margin of Exposure
MP Manufacturing Use Product
MRID Master Record Identification Number
MSHA Mine Safety and Health Administration
NIOSH National Institute of Occupational Safety and Health
NOEL No Observed Effect Level
OPP Office of Pesticide Programs
OVR Organic-Vapor-Removing
PHED Pesticide Handlers Exposure Database
PPE Personal Protective Equipment
PR Pesticide Reregi strati on
RED Reregi strati on Eligibility Decision
REI Restricted Entry Interval
SCBA Self-Contained Breathing Apparatus
TRAC Tolerance Reassessment Advisory Committee
USD A U.S. Department of Agriculture
WPS Worker Protection Standard
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Executive Summary
This document and the process used to develop it are the results of a pilot process to
facilitate greater public involvement and participation in the U.S. Environmental Protection
Agency (EPA or the Agency) reregi strati on decisions on organophosphate pesticides. As part of
the Agency's effort to involve the public in the implementation of the Food Quality Protection Act
of 1996 (FQPA), the Agency is undertaking a special effort to maintain open public dockets on
the organophosphate pesticides and to engage the public in the reregi strati on and tolerance
reassessment processes for these chemicals. The idea of using such an open process was
discussed by the Tolerance Reassessment Advisory Committee (TRAC), a large multi-stakeholder
advisory body which is advising the Agency on implementing the new provisions of the FQPA.
The organophosphate pesticides are the pilot project for this initiative.
EPA has completed its review of public comments, and has revised the risk assessment
and developed risk management proposals for sulfotepp. The risk assessment is based on review
of the available data supporting the use patterns of currently registered products and new
information received during the 60-day public comment period. After considering the risk
identified in the assessment associated with the use of sulfotepp, EPA has developed a
reregi strati on eligibility decision for sulfotepp.
Sulfotepp is a restricted use, organophosphate insecticide/acaricide used on greenhouse
ornamentals, including carnations, chrysanthemums, geraniums, gladiolus, poinsettias,
snapdragons, azaleas, and roses. Sulfotepp is used to control whitefly prior to shipment of plants,
which is important for ensuring that plants are pest-free when shipped as mandated by intrastate,
interstate, and international requirements. Sulfotepp was first registered in the U.S. in 1951. The
available usage data suggests that approximately 5,800 pounds of active ingredient (a.i.) are
applied per year. However, use has declined recently to approximately 1,000-3,000 pounds a.i.
per year, primarily due to increased use of imidacloprid as a non-organophosphate alternative for
whitefly treatment in poinsettias.
EPA's human health risk assessment for sulfotepp indicates that there is concern for
workers during application as well as in postapplication tasks such as watering, cutting,
harvesting, sorting, and packing. Because proper use of sulfotepp requires that the greenhouse in
which it is used be sealed, ecological risks are not of concern. Sulfotepp is not used on any food
and poses no dietary risk. Current labels, however, do not prohibit its use in residential
greenhouses by certified applicators. There are reported incidents in residential areas resulting
from leakage of sulfotepp from treated commercial greenhouses.
The database for sulfotepp is incomplete. The registrants have been unable to support the
data requirements for reregi strati on and have signed an agreement for voluntary cancellation. The
cancellation will take effect September 30, 2002, with an existing stocks provision in effect until
September 30, 2004. The registrants have agreed to request interim label amendments to address
risks of concern posed by the use of sulfotepp. For occupational risk, labels must be amended to
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increase the level of personal protective equipment for workers, specify the sequence of
application procedures, strengthen ventilation requirements and reentry intervals for
postapplication workers, restrict use to commercial greenhouses, and restrict use in greenhouses
with attached structures. To address risk to bystanders outside of treated structures, a 100-foot
buffer zone around a greenhouse where sulfotepp is applied is required.
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I. INTRODUCTION
The Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) was amended in 1988 to
accelerate the reregi strati on of products with active ingredients registered prior to November 1,
1984. The amended act calls for the development and submission of data to support the
reregistration of an active ingredient, as well as a review of all submitted data by the U.S.
Environmental Protection Agency (referred to as EPA or the Agency). Reregistration involves a
thorough review of the scientific database underlying a pesticide's registration. The purpose of
the Agency's review is to reassess the potential hazards arising from the currently registered uses
of the pesticide; to determine the need for additional data on health and environmental effects; and
to determine whether the pesticide meets the "no unreasonable adverse effects" criteria of FIFRA.
On August 3, 1996, the Food Quality Protection Act of 1996 (FQPA) was signed into
law. This Act amends both FIFRA and the Federal Food, Drug, and Cosmetic Act (FFDCA), but
does not amend any of the existing reregistration deadlines. Therefore, the Agency is continuing
its reregistration program while it resolves the remaining issues associated with the
implementation of FQPA.
This document and the process used to develop it are the results of a pilot process to
facilitate greater public involvement and participation in the reregistration decisions on
organophosphate pesticides. As part of the Agency's effort to involve the public in the
implementation of FQPA, the Agency is undertaking a special effort to maintain open public
dockets on the organophosphate pesticides and to engage the public in the reregistration and
tolerance reassessment processes for these chemicals. The idea of using such an open process
was discussed by the Tolerance Reassessment Advisory Committee (TRAC), a large multi-
stakeholder advisory body which is advising the Agency on implementing the new provisions of
the FQPA. The organophosphate pesticides are the pilot project for this initiative.
This document presents the Agency's risk management decision for sulfotepp. The
Agency is requesting public comments on this Reregistration Eligibility Document (RED) for
sulfotepp during a 60-day time period, as announced in a Notice of Availability published in the
Federal Register.
This document consists of five sections. Section I contains the regulatory framework for
reregistration as well as a description of the process developed by TRAC for public comment on
science policy issues for organophosphate pesticides. Section II provides a profile of the usage of
the chemical. Section III gives an overview of the human health risk assessment resulting from
public comments and other information. Section IV presents the Agency's risk
management/reregistration eligibility decision. Section V summarizes required label changes
based on the risk mitigation measures outlined in Section IV. Finally, an Appendix lists all related
documents and how to access them. The complete risk assessment is not included in this
document, but is available on the Agency's web page (www.epa.gov/oppsrrdl/op), and in the
Public Docket.
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II.
CHEMICAL OVERVIEW
A. Regulatory History
Sulfotepp was first registered in the United States in 1951 for use as an insecticide/
acaricide. A Registration Standard was issued in September, 1988. Data Call-Ins (DCIs) issued
in June 1991, August 1993, and October 1995 required additional data for sulfotepp. Currently, 2
sulfotepp products are registered.
B. Chemical Identification
! Chemical Structure:
(C2H5O)2P- O-P(OC2H5)2
Common Name:
Chemical Name:
Chemical Family:
CAS Registry Number:
OPP Chemical Code:
Empirical Formula:
Molecular Weight:
Trade and Other Names:
Technical Registrants:
Special Local Need
24(c) Registrant:
Sulfotepp
Tetraethyl thiodiphosphate (0,0,0,0-
tetraethyl dithiopyrophosphate)
Organophosphate
3689-24-5
079501
C8H20O5P2S2
322.3
Bladafum, Sulfotep
Plant Products Corporation (8241-11) and
Fuller System, Inc. (1327-39)
Glad-A-Way Gardens
(8241-4-AA; CA89005900)
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C. Use Profile
The following information is based on the currently registered uses of sulfotepp with an
overview of use sites and application methods.
Type of Pesticide: Acaricide/Insecticide
Summary of Use Sites:
Food: None.
Residential: None.
Public Health: None.
Other Nonfood: Products containing sulfotepp are intended for indoor (greenhouse) use
only, by certified commercial applicators. Sulfotepp-containing products may be used on
carnations, chrysanthemums, geraniums, gladiolus, poinsettias, snapdragons, azaleas, and roses in
bloom, as well as gladiolus tissue culture material, bulblets and corms.
Target Pests: Red spider mites, thrips, whiteflies, aphids, soft-brown scale, mealybugs.
Formulation Types Registered: Plant Products Corp. formulates and distributes the
end-use product Plantfume 103® (8241-10). The special local need permit issued by the State of
California is associated with Plantfume 103®. Fuller System, Inc. formulates the end-use product
Fulex Dithio Smoke® (1327-38). End-use product is formulated as impregnated material in smoke
generators (canisters) containing 14-15% active ingredient.
Method and Rates of Application:
Equipment: Smoke-generating canister (containing product), sparkler and ignitor.
Method and Rate: Sulfotepp is applied by inserting the sparkler provided into the product
container and igniting the sparkler. A smoke containing the active ingredient is dispersed from
the container upon ignition. Maximum application rate is .0033 pound of active ingredient (a.i.)
per 1,000 cubic feet.
Timing: Sulfotepp may be applied every three days until the greenhouse is pest-free.
Use Classification: Restricted-use for all use sites.
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D. Estimated Usage of Pesticide
This section summarizes the best estimates available for use of sulfotepp. These estimates
are derived from a variety of published and proprietary sources available to the Agency. The
data, reported on an aggregate basis, reflect annual fluctuations in use patterns as well as the
variability in using data from various information sources.
The available usage data suggests that approximately 5,800 pounds a.i. of sulfotepp were
applied per year in the period 1991 to 1994. However, use has declined in recent years to
approximately 1,000-3,000 pounds a.i. per year, primarily due to emergence of imidacloprid as a
non-organophosphate alternative for mid-season use.
E. Benefits of Sulfotepp
Sulfotepp remains the most effective treatment for whitefly on ornamentals at the end of
the growing season. As a smoke, it effectively penetrates areas where eggs are deposited. In
addition, the smoke does not result in discoloration of foliage as would a wet application. This
makes it attractive for use just before shipment of plants from the greenhouse. Sulfotepp also
plays a role in integrated pest management. (Sutherland and Wise, 1997)
III. OVERVIEW OF SULFOTEPP RISK ASSESSMENT
Following is a summary of EPAs human health risk findings and conclusions for the
organophosphate pesticide sulfotepp, as fully presented in the document, "Human Health Risk
Assessment: Sulfotepp," dated June 30, 1999. This risk assessment for sulfotepp was placed into
the Public Docket on June 30, 1999, opening a 60-day public comment period on risk
management for this pesticide. The risk assessment presented here forms the basis of the
mitigation measures agreed to by the Agency and the registrants, and for the Agency's
reregi strati on eligibility decision for sulfotepp.
A. Human Health Risk Assessment
EPA issued its preliminary risk assessment for sulfotepp in September, 1998 (Phase 2 of
the TRAC process). No significant substantive comments were received that resulted in major
revisions to the human health risk assessment.
1. Dietary and Drinking Water Risk
Sulfotepp has no food uses, and is used in sealed greenhouses only. Therefore, dietary
and drinking water exposures are not expected.
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2. Residential Risk
There are currently no registered homeowner products for sulfotepp. However, current
labels do not prohibit application in residential greenhouses by certified commercial applicators.
The Agency believes this represents a potential risk to residents. In addition, residential
(bystander) exposures have occurred when sulfotepp has leaked from treated commercial
greenhouses and exposed bystanders in nearby residential areas. The Agency and registrants have
agreed to label amendments that will address both of these scenarios for potential residential risk.
3. Occupational Risk
Workers can be exposed to a pesticide through mixing, loading, or applying a pesticide,
and by postapplication activities in treated areas. Occupational handlers of sulfotepp include
certified commercial applicators who apply sulfotepp and re-enter a greenhouse to operate
ventilation equipment. Postapplication workers include those who water, pack, prepare for
shipment or otherwise handle treated plants. Occupational risk is measured by a Margin of
Exposure (MOE) which determines how close the occupational exposure comes to a No
Observed Effect Level (NOEL). For workers entering a treated site, Restricted Entry Intervals
(REIs) are calculated to determine the minimum length of time required before workers or others
are allowed to reenter.
a. Factors Forming the Basis for Occupational Handler Risk
Assessments
No guideline or otherwise acceptable chemical-specific handler exposure data have been
submitted to the Agency. Available data in the Pesticide Handlers Exposure Database (PHED) do
not reflect the use patterns of sulfotepp. This occupational risk assessment was based on the
limited toxicology data submitted, published sources, and on assumptions drawn from similar
acutely toxic organophosphate pesticides.
Due to the significant lack of data, sulfotepp has not been reviewed by the Agency's
Health Effects Division (HED) Hazard Identification Committee. This Committee evaluates
toxicological data for adequacy, establishes endpoints and doses for risk assessment, and most
significantly for sulfotepp, establishes MOEs for risk assessment and regulatory purposes. An
MOE of 100 or greater is generally considered adequate by the Agency for both the short- and
intermediate-term dermal and inhalation risk assessments. This includes a 10-fold safety factor for
interspecies variability, and a 10-fold safely factor for intraspecies variability. When data gaps
exist, MOEs much higher than 100 are typically used to account for greater uncertainty. Due to
the lack of acceptable data for sulfotepp, HED has not determined an MOE that is considered
adequate.
Occupational handler exposure assessments are conducted by the Agency using different
levels of personal protective equipment (PPE). The Agency typically evaluates all exposures with
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minimal protection and then adds additional protective measures using a tiered approach to obtain
an appropriate MOE (i.e., going from minimal to maximum levels of protection). The lowest tier
is represented by the baseline exposure scenario. If MOEs from the lowest tier are less than 100,
MOEs are calculated using increasing levels of risk mitigation [PPE and engineering controls
(EC)]. The current labels for sulfotepp require handlers to wear a respirator, long pants, long-
sleeved shirt, socks, and shoes. The levels of protection that formed the basis for calculations of
exposure from sulfotepp activities include:
Baseline: Long-sleeved shirt, long pants, socks and shoes
Minimum PPE: Baseline scenario + half-face or full-face organic-vapor-removing
(OVR) respirator
Maximum PPE: Baseline scenario + self-contained breathing apparatus (SCBA)
The inhalation NOEL was established at 1.94 mg/m3, based on a subchronic rat inhalation
study (Kimmerle and Klimmer, 1974). The endpoint is based on significant inhibition of plasma
and red blood cell cholinesterase.
The NOEL of 0.014 mg a.i./kg/day from a subchronic dog feeding study (Hoffman and
Schilde, 1975) was used for the intermediate-term dermal endpoint. The endpoint is based on
inhibition of plasma and red blood cell cholinesterase.
Due to the lack of sulfotepp dermal and oral toxicity data, the short-term dermal NOEL
was established by using the ratio of the short- and intermediate-term NOELs of similar toxic
organophosphate pesticides, and applying it to the intermediate-term NOEL for sulfotepp. The
Agency assumes 100% dermal absorption for sulfotepp, based on data showing that sulfotepp
penetrates the skin in amounts sufficient to induce systemic toxicity. The short- term dermal
NOEL for sulfotepp was, therefore, estimated to be 0.14 mg a.i./kg/day.
b. Occupational Risk Characterization
i. Applicator Scenarios and Risks
Based on the use patterns, two pesticide handler scenarios were identified:
opening/lighting of canisters; and reentering fumigated greenhouses to open vents and dispose of
canisters. Note that reentry to open vents is considered a handler task under the Worker
Protection Standard (WPS). Both handler scenarios are assumed to involve only short-term
exposure. The same individual could perform both of these tasks; however, this assessment does
not combine the risk from these two scenarios.
For handlers, dermal exposures are assumed to be small, infrequent and of short duration
relative to exposures from inhalation. Potential dermal exposure is limited to possible contact
with the sulfotepp formulated product while opening the canisters and inserting the sparkler, in
the event of an accidental spill, and possible contact with residue on the outside of a spent
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canister. Because these exposures are expected to be negligible when compared with the
estimated inhalation exposure and the potentially high air concentrations of sulfotepp during
handling activities, only inhalation exposures and risks were estimated for handlers.
Two air concentrations (exposure levels) were used in the risk assessment. The first, 2.7
mg a.i./m3, was taken from a study by Williams et al. (1980) in which a greenhouse having a
volume of 450 m3 was fumigated using two cans each containing 11 g formulated product. Air
concentration levels were measured approximately four hours after the start of fumigation and
before opening the vents to aerate. This level, 2.7 mg a.i./m3, was selected to represent a
reasonable level possibly encountered by applicators igniting the canisters or persons entering to
activate the ventilation system. The second, 52.5 mg a.i./m3, was estimated to be the maximum
air concentration possible, assuming that during fumigation all of the active ingredient in the
canister enters the greenhouse air at the label application rate and is uniformly distributed
throughout the greenhouse. Inhalation risks are summarized in Table 1 below.
Table 1. Occupational Handlers' Inhalation Risks from Sulfotepp
Level of Protection
Baseline (no respirator)
Half -face OVR respirator
Full-face OVR respirator
SCBA
Air Concentration
(mg ai/m3)
52.5
2.7
52.5
2.7
52.5
2.7
52.5
2.7
Inhalation MOE
(0.5 hr/1 hr)
0.3/0.2
6/3
3/2
65/32
17/8
320/160
3,300/1,700
65,000/32,000
11.
Postapplication Scenarios and Risk
Two postapplication scenarios were identified: entry to perform watering or other routine
low exposure tasks and entry to perform harvesting, transferring, or other high exposure tasks.
For postapplication exposure, both dermal and inhalation exposures were assessed. Based
on the Williams study referenced above, inhalation exposures were calculated from air
concentrations after ventilation (including off-gassing after watering), monitored continuously for
48 hours and air concentrations measured 18 days after fumigation.
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Short- and intermediate-term risks were calculated. Intermediate-term risks were
assessed because, in practice, two to three applications at three-day intervals are possible and
workers may reasonably be expected to have daily exposures for more than a week, depending on
how rapidly sulfotepp dissipates. To estimate the level of dermal exposure, the amount of residue
available on the treated foliage was obtained from a study conducted in 1986 (CDFA, 1987). The
levels from three sites (two poinsettia sites and one geranium site) were used for risk assessment
purposes. In lieu of chemical-specific data showing how readily residues transfer from foliage to
workers who contact the foliage, the Agency applies a standard transfer coefficient for low and
high dermal exposure activities. Standard values are determined based on the limited data that are
available to the Agency. For sulfotepp, a transfer coefficient of 1,000 was used for low exposure
activities, and 10,000 for high exposure activities.
Results indicate that for total risk (combined dermal plus inhalation), short-term MOEs
range from 1 for high-exposure activities to 14 for low exposure activities. Intermediate-term
MOEs range from 0.3 to 7 (at all air concentration levels for both high and low exposure
activities, respectively, up to 38 hours following fumigation). Current labeling allows reentry
between two and 24 hours after fumigation, depending on how the greenhouse is ventilated.
These MOEs represent a concern for all postapplication scenarios. Total risks for postapplication
workers are summarized in Table 2 below.
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Table 2. Postapplication Total Risks from Sulfotepp
Exposure Scenario
Low exposure
activity (tending)
High exposure
activity
(harvesting,
preparing for
shipping)
15 hours after
fumigation
24 hours after
fumigation
38 hours after
fumigation
15 hours after
fumigation
24 hours after
fumigation
38 hours after
fumigation
Total Short-Term
MOE
2- 10
2-13
2- 14
1-3
2-4
2-7
Total Intermediate-
Term MOE
1 -3
2-4
2-7
0.3
0.5-0.6
0.8-1
B. Ecological Effects Risk Assessment
Toxicity data for sulfotepp indicate that it is toxic to wildlife, fish, and aquatic
invertebrates. Based on this information, the Agency presumes it is also toxic to birds. However,
because sulfotepp is registered for indoor (greenhouse) use only, ecological exposure to sulfotepp
is expected to be minimal (Grim, 1999).
IV. RISK MANAGEMENT & REREGISTRATION ELIGIBILITY DECISION
A. Risk Management Considerations
This section describes EPA's decisions for mitigating risks associated with sulfotepp use
based on the Agency's human health risk assessment. The risk management decision for
sulfotepp has been developed based on careful consideration of the human health risk assessment,
apparent benefits, and the public comments received on the preliminary risk assessment. The
Agency has also consulted with the registrants, the U.S. Department of Agriculture, and grower
groups in developing its risk management decision.
B. Status of the Database for Sulfotepp
The database for sulfotepp is incomplete. Only one toxicity study, a subchronic feeding
study in dogs (Hoffman and Schilde, 1975; MRID 43615401), has been determined to be
acceptable for regulatory purposes. No acceptable sulfotepp-specific exposure studies have been
submitted. Waivers have been granted for two fate studies. A waiver was also granted for
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guideline study 133-4 (inhalation passive dosimetry exposure); however, the Agency has since
determined that the inhalation data are critical to the occupational risk assessment.
The following data sets are incomplete: product chemistry, acute toxicity, specific
organ/tissue toxicity, neurotoxicity, subchronic toxicity, chronic toxicity, general metabolism, and
postapplication worker exposure. All outstanding studies are overdue except guideline studies
132-l(a) (foliar residue dissipation), and 133-3 (dermal passive dosimetry exposure), which were
due by March 31, 2000. Because the registrants have elected to voluntarily cancel their
registrations, these data will not be required.
Using the available data and making conservative assumptions to estimate risk, the Agency
was able to estimate handler risk and to develop mitigation measures to address these risks.
However, postapplication risk remains a concern. At a minimum, 21-day dermal toxicity,
postapplication dermal exposure, postapplication inhalation exposure, and foliar dislodgeable
residue dissipation data would have been required if this chemical were to be considered for
reregi strati on.
C. Summary of Remaining Risks from Use of Sulfotepp at Current Label
The limited data available for sulfotepp indicates that risks to workers who apply
sulfotepp, enter treated areas to ventilate, and work in treated areas or with treated plants, are of
significant concern. Current labeling does not provide adequate protection for workers engaged
in application activities. EPA and the registrants have agreed on label amendments for the end-
use products that will mitigate these risks for application workers.
Risk to postapplication workers, i.e., workers involved in watering, harvesting, packing
and shipping, are of concern to the Agency. As indicated above, short- and intermediate-term
MOEs are under 20 for both high and low exposure activities up to 38 hours following
fumigation. Current labeling allows reentry between 2 and 24 hours. The Agency and registrants
have agreed on label amendments that will partially address these concerns. Reentry intervals
which fully address these estimated risks are not practical for growers.
At least two incidents of sulfotepp exposure have been reported in the California Pesticide
Illness Surveillance Program, 1982-1995, that resulted from sulfotepp leaking from a treated
greenhouse. In one of those cases, eight people in a residential area 200-300 feet away from the
treated greenhouse were exposed. Label amendments include a requirement of a buffer zone
around treated greenhouses.
D. Risk Management Decision
Risks to applicators have been addressed by mitigation measures outlined below. These
measures are reflected in label amendments that have been agreed to by the registrants. Risks to
postapplicators cannot be adequately mitigated, and remain a concern to the Agency. The
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registrants have signed an agreement for voluntary cancellation with a five-year phase-out. The
rationale for this decision is discussed in detail below.
1. Applicator Risk
For applicators, dermal exposure can occur while opening a canister and inserting the
sparkler, in the event of an accidential spill, and in case of possible contact with residue on the
outside of a spent canister. To mitigate this risk, the registrants have voluntarily agreed to amend
labels to require chemical-resistant gloves.
Applicators are at risk for inhalation exposure to sulfotepp during lighting of canisters, and
upon reentry to activate ventilation. To manage these risks, the registrants have voluntarily
agreed to amend labels as follows:
• In addition to baseline attire of long-sleeved shirt, long pants, shoes, socks, and PPE
consisting of chemical-resistant gloves, a full-face respirator will be required for
applicators opening five or fewer canisters, OR if exposure will be ten minutes or less
from the time the first canister is ignited.
In addition to baseline attire of long-sleeved shirt, long pants, shoes, socks, and PPE
consisting of chemical-resistant gloves, SCBA will be required for applicators opening six
or more canisters, OR if exposure will be greater than ten minutes from the time the first
canister is ignited.
• Application directions will be amended to minimize potential exposure time by specifying
the sequence of steps required to apply the product. Specifically, labels will state
explicitly that all canisters shall be in place before the first is ignited. See Table 3 for more
detail.
If circulating fans are used during treatment, the fans may not be turned on until after the
applicator(s) has exited the greenhouse.
• An additional person outside of the greenhouse must maintain constant visual or voice
contact with any handler who is applying or otherwise handling sulfotepp in a greenhouse.
This includes handlers who enter a greenhouse during fumigation to operate ventilation
equipment. The person monitoring the sulfotepp handler must have immediate access to
the PPE that the fumigant labeling requires for applicators.
2. Postapplicator Risks
Postapplication workers are at risk for dermal exposure during activities such as watering,
harvesting, packing and shipping plants. Risks were found to be very high even after 38 hours
following fumigation. These estimated risks cannot be adequately mitigated.
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Inhalation exposure is a concern for postapplication workers. MOEs range from 2 to!6
for all air concentrations measured within 48 hours of fumigation and after initial ventilation. This
suggests the possibility of risk to retail customers in a treated commercial greenhouse. The
registrants have voluntarily agreed to amend labels to strengthen ventilation criteria and increase
reentry intervals, with the following provisions:
• No person, other than a certified applicator wearing PPE as specified above, shall enter a
treated structure from the start of application until the following ventilation has occurred:
11 hours with no ventilation followed by (1) five air exchanges; or (2) one hour of
mechanical ventilation (fans); or (3) two hours of passive (vents) ventilation.
Following the initial ventilation period described above, workers may enter a treated
structure to perform hand labor tasks for limited provided (1) they work in the sulfotepp-
treated area no more than 4 hours in the first 24 hours following application; (2) they
work in the sulfotepp-treated area no more than 4 hours in the period 24 hours to 48
hours following aplication; AND (3) for the first 48 hours following application when any
worker is present in the treated greenhouse, the greenhouse is ventilated — continuously
or intermittently — so that within each hour one of the following ventilation criteria has
been met: 2 air exchanges or 5 minutes of mechanical (fans) ventilation, or 10 minutes of
passive (vents, windows) ventilation.
Prohibit entry by retail customers for 48 hours after application or until ventilation criteria
have been met.
3. Residential and Bystander Risks
Incidents due to leakage from greenhouses treated with sulfotepp indicate that there is
some degree of risk to bystanders in proximity to treated structures. In addition, current labels do
not prohibit use in residential greenhouses if applied by a certified pesticide applicator. The
registrants have voluntarily agreed to label amendments to address these risks as follows:
Prohibit use in greenhouses with attached structures, unless the greenhouse is entirely
sealed off from the attached structure.
• Restrict use to commercial greenhouses only. Use in residential greenhouses or other
indoor plant sites is prohibited.
Prohibit use in any greenhouse that is located within 100 feet in any direction of a
residential area (e.g., homes, apartments, schools, playgrounds, recreation areas).
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4. Benefit Considerations
The Agency recognizes that sulfotepp fills a specific niche as an end-of-season treatment
for whitefly in ornamentals. As a dry smoke, it effectively penetrates the foliage and leaves no
discoloration as a wet application would. Sulfotepp also plays a role in integrated pest
management. In light of the benefits of sulfotepp to the industry as well as its low volume of use,
the Agency agreed to a five-year phase-out of sulfotepp production, distribution, and use. The
five-year timeframe is intended to allow growers time to transition to alternatives to sulfotepp
before it becomes unavailable.
V. Actions Required of Registrants
Both registrants have been unable to support the data requirements for reregi strati on and
have signed an agreement for voluntary cancellation of the registration of technical grade
sulfotepp as well as their end-use products containing sulfotepp. Production of end-use product
will cease by September 30, 2002. From October 1, 2002, until September 30, 2004, remaining
stocks of sulfotepp products may be sold. After September 30, 2004, it will be unlawful for any
sulfotepp product to be sold or used. The registrants have committed to submit by October 8,
1999, a request to revise labels in accordance with Table 3. All sulfotepp products
manufactured, sold or distributed will bear the revised labeling within 45 days after the registrants
receive the EPA-approved labels.
A. Manufacturing-Use Products
The generic database for sulfotepp is inadequate for regulatory purposes. As a result of
the voluntary cancellation, the registrants will not be required to submit the data.
Until the cancellation takes effect, to remain in compliance with FIFRA, manufacturing-
use product (MP) labeling must be revised to comply with all current EPA regulations, Pesticide
Reregi strati on (PR) Notices, and applicable policies. The MP labeling must bear the labeling
contained in the table at the end of this section.
B. End-Use Products
Label changes are necessary to implement measures outlined in Section IV above. These
changes include personal protective equipment requirements, user safety requirements, reentry
intervals, and other restrictions. Specific language to implement these changes is specified in
Table 3, which follows.
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Table 3: Summary of RED Labeling Requirements for Sulfotepp
Description
Required Labeling
Placement on
Label
Manufacturing Use Products
Required on all MUPs
"Only for formulation into insecticide products for the following use(s):" [fill blank only
with those uses that are being supported by MP registrant].
Directions for
Use
One of these statements
may be added to a label
to allow reformulation
of the product for
specific use or all
additional uses
supported by a
formulator or user
group.
"This product may be used to formulate products for specific use(s) not listed on the MP
label if the formulator, user group, or grower has complied with U.S. EPA submission
requirements regarding support of such use(s)."
"This product may be used to formulate products for any additional use(s) not listed on the
MP label if the formulator, user group, or grower has complied with U.S. EPA submission
requirements regarding support of such use(s)
Directions for
Use
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Table 3: Summary of RED Labeling Requirements for Sulfotepp
Description
Required Labeling
Placement on
Label
Environmental Hazards
Statements Required by
the RED and Agency
Label Policies
"This pesticide is toxic to fish, birds, and wildlife. Do not discharge effluent containing this
product into lakes, streams, ponds estuaries, oceans or other waters unless in accordance
with the requirements of a National Pollutant Discharge Elimination System (NPDES)
permit and the permitting authority has been notified in writing prior to discharge. Do not
discharge effluent containing this product to sewer systems without previously notifying the
local sewage treatment plant authority. For guidance contact your state Water Board or
Regional Office of the EPA."
Directions for
Use
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Table 3: Summary of RED Labeling Requirements for Sulfotepp
Description
Required Labeling
Placement on
Label
End Use Products Intended for Occupational Use (WPS)
Restricted Use
Pesticide
"RESTRICTED USE PESTICIDE
Due to very high dermal toxicity to humans.
For retail sale to and use only by certified applicators and only for those uses covered by the
applicator's certification. Use by non-certified applicators, even those under the direct
supervision of a certified applicator, is prohibited."
Top of Front
Panel and
Beginning of
Directions for
Use
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Table 3: Summary of RED Labeling Requirements for Sulfotepp
Description
Required Labeling
Placement on
Label
PPE Requirements
Established by the RED
"Personal Protective Equipment (PPE)
Some materials that are chemical-resistant to this product are (registrant insert correct material). If you want more
options, follow the instructions for category [insert A,B,C,D,E,F,G,or H] on an EPA chemical-resistance category
selection chart."
Applicators and other handlers must wear:
— Long-sleeved shirt & long pants
— Shoes plus socks
— Chemical-resistant gloves
— NIOSH-approved air-supplying respirator that is one of the following types:
- a supplied-air respirator (MSHA/NIOSH approval number prefix TC-19C) or
- a self-contained breathing apparatus (SCBA) (MSHA/NIOSH approval number prefix TC-13F)."
EXCEPTION: Handlers are permited to wear a NIOSH-approved organic-vapor-removing respirator (see types
below) instead of an air-supplying respirator provided they meet one of the following criteria: (1) the handler
will ignite five or fewer canisters and will be in the greenhouse for less than 10 consecutive minutes starting
when the first canister is ignited OR (2) the handler will enter the treated greenhouse to operate ventilation
equipment after application is complete (smoke is no longer being generated) but before full ventilation has
taken place and will remain in the treated greenhouse for less than 10 consecutive minutes.
The NIOSH-approved organic-vapor-removing respirator must be equipped with:
- an organic-vapor removing cartridge with a prefilter approved for pesticides (MSHA/NIOSH approval
number prefix TC-23C), or
- a canister approved for pesticides (MSHA/NIOSH approval number prefix TC-14G), or
- a NIOSH-approved organic vapor cartridge or a canister equipped with any N2, R, P, or HE prefilter."
"The organic-vapor cartridge must be replaced with a new organic-vapor cartridge and new HEPA prefilter
just prior to each use in sulfotepp-treated areas."
Precautionary
Statements:
Hazards to
Humans and
Domestic Animals
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Table 3: Summary of RED Labeling Requirements for Sulfotepp
Description
Required Labeling
Placement on
Label
User Safety
Requirements
"In addition, any handler who handles this product in a greenhouse, including a handler who
enters the greenhouse before the ventilation criteria have been met to initiate ventilation,
must maintain continuous visual or voice contact with another handler. That other handler
must have immediate access to the PPE required on this labeling for handlers in the event
entry into the fumigated greenhouse becomes necessary for rescue."
"Follow manufacturer's instructions for cleaning/maintaining PPE. If no such instructions
for washables exist, use detergent and hot water. Keep and wash PPE separately from other
laundry."
Precautionary
Statements:
Hazards to
Humans and
Domestic Animals
(immediately
following the PPE
requirements)
User Safety
Recommendations
"User Safety Recommendations"
"Users should wash hands before eating, drinking, chewing gum, using tobacco, or using the
toilet."
"Users should remove clothing/PPE immediately if pesticide gets inside. Then wash
thoroughly and put on clean clothing."
"Users should remove PPE immediately after handling this product. Wash the outside of
gloves before removing. As soon as possible, wash thoroughly and change into clean
clothing."
Precautionary
Statements under:
Hazards to
Humans and
Domestic Animals
immediately
following
Engineering
Controls
(Must be placed
in a box.)
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Table 3: Summary of RED Labeling Requirements for Sulfotepp
Description
Restricted-Entry
Interval
Early Entry Personal
Protective Equipment
Required Labeling
"Entry (including early entry that would otherwise be permitted under the WPS) by any
person — other than a correctly trained and equipped certified applicator who is performing
a handling task permitted by the WPS — is PROHIBITED in the entire greenhouse (entire
enclosed structure/building) from the start of application until the greenhouse is ventilated
as follows: 1 1 hours with no ventilation followed by (1) 5 air exchanges; (2) 1 hour of
mechanical ventilation (fans); or (3) 2 hours of passive (vents) ventilation."
"After the initial ventilation criteria have been met, workers are permitted to enter the
treated greenhouse to perform tasks, including hand labor tasks, provided (I) they work in
the sulfotepp-treated area no more than 4 hours in the first 24 hours following application;
(2) they work in the sulfotepp-treated area no more than 4 hours in the period 24 hours to
48 hours following application; AND (3) for the first 48-hours following application when
any worker is present in the treated greenhouse, the greenhouse is ventilated — continuously
or intermittently — so that within each hour one of the following ventilation criteria has been
met: 2 air exchanges or 5 minutes of mechanical (fans) ventilation, or 10 minutes of passive
(vents, windows) ventilation."
Not needed for this product. Early entry by workers is prohibited.
Placement on
Label
Directions for
Use, Agricultural
Use Requirements
Box
Directions for Use
under General
Precautions and
Restrictions and/or
Application
Instructions
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Table 3: Summary of RED Labeling Requirements for Sulfotepp
Description
Double Notification
Statement
Required Labeling
"Notify workers of the application by warning them orally and by posting fumigant warning
signs at all entrances to the greenhouse. The signs must bear the skull and crossbones
symbol and state: (1) "Danger/Peligro". (2) "Greenhouse under fumigation, DO NOT
ENTER/NO ENTRE", (3) the date and time of fumigation. (4) (insert name of product) in
use, and (5) name, address and phone number of the applicator. Post the fumigant warning
sign instead of the WPS sign for this application, but follow all WPS requirements
pertaining to location, legibility, size, and timing of the posting and removal."
Placement on
Label
Directions for
Use, Agricultural
Use Requirements
Box
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Table 3: Summary of RED Labeling Requirements for Sulfotepp
Description
General Application
Restrictions
Required Labeling
"Do not apply this product in a way that will contact workers or other persons, either
directly or through drift. Only protected handlers may be in the area during application."
"For use in commercial greenhouses only. Use in residential greenhouses or other indoor
plant sites is prohibited."
"Do not apply this product to a greenhouse that is attached to another structure, including
another greenhouse, unless the greenhouse to be treated is entirely sealed off from the other
structures."
"Do not apply this product in any greenhouse that is located within 100 feet in any direction
of a residential area (e.g., homes, apartments, schools, playgrounds, recreation areas)."
"Entry to a treated structure by retail customers is prohibited for 48 hours after treatment,
or until ventilation criteria have been met."
Use of this product after September 30, 2004 is prohibited.
Placement on
Label
Direction for Use
directly above the
Agricultural Use
Box.
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Table 3: Summary of RED Labeling Requirements for Sulfotepp
Description
Required Labeling
Placement on
Label
Site Specific
Application
Restrictions
Application Instruction must include the following steps. The importance of performing the steps in the
sequence presented must be made explicit.
(1) All entries to the structure must be blocked^arricaded and posted with the required fumigant warning
signs;
(2) All greenhouse vents must be closed and all circulating fans must be turned off.
(3) All misting systems must be turned off.
(4) A certified applicator wearing the baseline attire plus chemical-resistant gloves must perform the
remaining tasks.
(5) Remove or puncture (whichever is appropriate) the tops or sides (whichever is appropriate) of the
canisters. (Choice of words should be appropriate to the container.)
(6) An ignitor (sparkler) must be inserted into each canister so that the coated portion is facing downward
with the bare wire portion plus a small part of the coated portion remaining exposed.
(7) Each canister must be placed in position in the greenhouse.
(8) After all canisters are set out, the canister furthest from the exit to the greenhouse must be ignited first.
(9) Applicator(s) must wear the appropriate respirator and must be monitored continuously from the start of
ignition until the applicator has exited the greenhouse.
(10) If the canisters are placed in parallel walks, rather than one central aisle, one applicator must be
assigned to light the canisters in each walk, at least one of which shall be a certified pesticide applicator, so
that fumigation starts simultaneously and all applicators exit the greenhouse simultaneously.
(11) Each applicator lights the ignitor in each canister using a hand-held propane torch or butane lighter
(not matches or wicked cigarette lighter) that should remain lit for the entire application.
(12) Each applicator continues quickly to the next can until all cans are ignited, then exits the greenhouse
immediately.
(13) Entry into the greenhouse to relight igniters that failed to activate the smoke generator is prohibited (if
any smoke generator is activated in the greenhouse) unless the task is performed by a certified applicator
wearing the specified personal protective equipment, including an air-supplied respirator or SCBA. The use
of an organic-vapor removing respirator is prohibited for this task, regardless of the length of time spent in
the treated area.
(14) If circulating fans are used, the fans may not be turned on until after the applicator(s) have exited the
greenhouse.
Direction for Use
under General
Precautions and
Restrictions and
or Application
Instructions
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References
California Pesticide Illness Surveillance Program, 1982-1995.
Griffin, R., 1999. Human Health Risk Assessment: Sulfotepp. U.S. Environmental Protection
Agency, Office of Pesticide Programs, Health Effects Division, June 30, 1999.
Grim, B., 1999. EFED RED Chapter for Sulfotepp. U.S. Environmental Protection Agency,
Office of Pesticide Programs, Environmental Fate and Effects Division, January 11, 1999.
Hoffman, K. and Schilde, B., 1975. Subchronic Toxicity Study on Dogs with Administration in
Food (Thirteen Week Study). Unpublished study prepared by Bayer AG, Institute of
Toxicology, Wuppertal-Elberfeld.
Kiely, T., 1999. Quantitative Usage Analysis for Sulfotepp. U.S. Environmental Protection
Agency, Office of Pesticide Programs, Biological and Economic Analysis Division, March
23, 1999.
Kimmerle, G. and Klimmer, O.R., 1974. Acute and subchronic toxicology of sulfotep. Arch.
Toxicol. 33:1-16.
O'Connell, L., Fong, H.R., Cooper, C., Maykowski, R., and Wroe, M., 1987. A study to
establish degradation profiles for six pesticides (triforine, endosulfan, chlorothalonil,
sulfotepp, dodemorph acetate, and daminozide) used on ornamental foliage in San Diego
County, California, during Fall 1986. California Department of Food and Agriculture.
Sutherland, W.S. and Wise, S., 1997. Mini-Analysis of the Use/Usage of the Insecticide
Sulfotepp. U.S. Environmental Protection Agency, Office of Pesticide Programs,
Biological and Economic Analysis Division, September 5, 1997.
U.S. EPA, 1999. Memorandum of Agreement Between the Environmental Protection Agency
and Fuller System Inc. and Plant Products Corporation Regarding the Registration of
Pesticide Products Containing Sulfotepp, executed September 30, 1999.
Williams, D.T., Denley, H.V., Lane, D.A., 1980. On-site determination of sulfotepp air levels in a
fumigating greenhouse. American Industrial Hygiene Association Journal 41:647-651.
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Appendix: Related Documents and How to Access Them
This Reregi strati on Eligibility Decision is supported by documents that are presently
maintained in the OPP docket. The following sections indicate the means to view or obtain copies
of paper or electronic versions of these documents and lists titles of documents that are now in the
docket files.
Availability at OPP Docket Room
The OPP docket is located in Room 119, Crystal Mall #2, 1921 Jefferson Davis Highway,
Arlington, Virginia. It is open Monday through Friday, excluding legal holidays, from 8:30 am to
4 p.m.
The docket initially contained the preliminary risk assessment and related documents as of
September 9, 1998. Sixty days later the first public comment period closed. The EPA then
considered comments and updated the risk assessment. The response to comments, risk
assessment, summary and overview of the risk assessment were added to the docket on June 30,
1999.
All documents, in hard copy form, may be viewed in the OPP docket room. Some
documents may be downloaded or viewed via the Internet (http://www.epa.gov/oppsrrdl/op/)
Documents Added to Docket After June 30,1999
The following documents were added to the docket after June 30, 1999:
Dumas, Richard. Notes of Meeting on Sulfotepp, April 15, 1999.
Farrell, Robbi. Notes of Meeting on Sulfotepp, August 11, 1999.
Farrell, Robbi. Notes of Conference Call on Sulfotepp, August 30, 1999.
Farrell, Robbi. Potential Occupational Labeling Changes for Sulfotepp.
No author. Sign-in Sheet, Meeting on Sulfotepp, August 11, 1999.
Farrell, Robbi. Notes of Meeting on Sulfotepp, September 22, 1999.
No author. Sign-in Sheet, Meeting on Sulfotepp, September 22, 1999.
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