United States
               Environmental Protection
Office of
Pesticides and Toxic Substances
Washington DC 20460
January 1985
               TPTH  (Triphenyltin Hydroxide)
               Special Review Position
               Document 1

   U.S. Environmental Protection Agency

Office of Pesticides and Toxic Substances

       Office of Pesticide Programs

            401 M Street, S.W.

             Washington, D.C.




                    TRIPHENYLTIN HYDROXIDE


AGENCY:  Environmental Protection Agency  (EPA).

ACTION:  Notice.

SUMMARY:  JT,his Notice announces that EPA  is initiating a

Special Review of all pesticide products  containing the

active  ingredient triphenyltin hydroxide  (TPTH^j.  EPA has

determined that TPTH which is registered  as a fungicide and

mite suppressant, produces teratogenic effects  in laboratory

rats and that sufficient exposure to applicators exists to

meet the risk criterion described in 40 CFR 162.11.  Accordingly,

a Special Review of products containing TPTH has been initiated

to determine whether additional regulatory actions, if any,

are required.  During the Special Review  process, EPA will

carefully examine the risks and benefits  of using TPTH products.

DATE:   Comments, evidence to rebut the presumptions in this

Notice, and other relevant information must be  received no  later

than 45 days from the date this notice is received or until

(insert date 45 days after date of publication  in the

FEDERAL REGISTER) (whichever is later).


ADDRESS:  Written comments identified as "OPP-30000/42"

should be sent by mail to:

     Information Services Section,

     Program Management and Support Division (TS-757C),

     Office of Pesticide Programs,

     Environmental Protection Agency,

     401 M St., SW.,

     Washington, D.C. 20460.

     In person, bring comments to:

     Rm. 236, CM #2,

     1921 Jefferson Davis Highway,

     Arlington, VA.

     Information submitted in any comment concerning this

notice may be claimed confidential by marking any part or all

of  that  information as "Confidential Business Information"

(CBI).   Information so marked will not be disclosed except in

accordance with procedures set forth in 40 CFR Part 2.  An

edited copy of the comment containing material claimed to be

CBI must be submitted (with the CBI portions deleted) for

inclusion in  the public record.  Information not marked

confidential  may be disclosed publicly by EPA without prior

notice to the submitter.  All non-CBI written comments will

be  available  for public inspection in Rm. 236 at the Virginia

address given above, from 8 a.m. to 4 p.m., Monday through

Friday, excluding legal holidays.


     Betty Shackleford,

     Registration Division (TS-767C),

     Office of Pesticide Programs,

     Environmental Protection Agency,

     401 M St., SW.,

     Washington, D.C. 20460.

     Office location and telephone number:

     Rm. 717, CM #2,

     1921 Jefferson Davis Highway,

     Arlington, VA,


SUPPLEMENTARY INFORMATION: The term "Special Review" is the

name now being used by EPA for the process previously called

the Rebuttable Presumption Against Registration (RPAR) process.

Modifications in the process will be proposed in regulations

in the near future.  Until other applicable final regulations

are adopted, the present Special Review will adhere to RPAR

procedures now in effect and set forth in 40 CFR 162.11.

     EPA has determined that a Special Review will be conducted

for all pesticide products containing TPTH as an active

ingredient.  EPA has also determined that data necessary to

conduct the Agency's risk assessment must be developed on an

accelerated basis, and that precautionary labeling is required

to reduce risk during the Special Review process.

     Issuance of this Notice means that potential hazards

associated with the use of TPTH have been identified.  These

                            - 4 -

hazards will be examined further to determine the nature and

extent of the risk, and considering the benefits of TPTH,

whether such risks cause unreasonable adverse effects on the


     A document entitled "Guidance for the Interim Registration

of Pesticide Products Containing TPTH" (Guidance Document) has

been issued.  (The Guidance Document is also referred to as a

Registration Standard.)  The Guidance Document is available to

the public from the contact person named above.  This Guidance

Document explains the basis of EPA's decision to start a Special

Review and also contains references, background information,

data requirements, and other information pertinent to the con-

tinued registration of pesticides containing TPTH.


                          A. GENERAL

     A pesticide product may be sold or distributed in the

United States only if it is registered or exempt from registra-

tion under the Federal Insecticide, Fungicide, and Rodenticide

Act (FIFRA)  (7 U.S.C. 136 e_t seq. ) .  Before a product can be

registered,  it must be shown that it can be used without "un-

reasonable adverse effects on the environment" (FIFRA section

3(c)(5)), that is, without causing "any unreasonable risk to

man or the environment, taking into account the economic,

social, and environmental costs and benefits of the use of the

pesticide" (FIFRA section 2(bb)).  The burden of proving that

a pesticide meets this standard for registration is on the

proponent of initial or continued registration.  If at any

                            - 5 -

time the Agency determines that a pesticide no longer meets

this standard for registration, the Administrator may cancel

the registration under section 6 of FIFRA.

     The Agency has created an administrative process for

fully evaluating whether a pesticide satisfies or continues to

satisfy the statutory standard for registration.   This Special

Review process provides an informal procedure through which

EPA may gather and evaluate information about the risks and

benefits of a pesticide's use.  It also provides  a means by

which interested members of the public may comment on and

participate in EPA's decision making process.  The regulations

governing this process are set forth at 40 CFR 162.11.

     A Special Review is begun when EPA determines that a

pesticide meets or exceeds one or more of the risk criteria

set out in the regulations (40 CFR 162.11(a)(3)).  The Agency

generally announces the beginning of the Special  Review by

issuing a Position Document 1 (PD 1) which is published in

the FEDERAL REGISTER.  In addition, registrants of affected

products will receive the PD 1 by certified mail.  Registrants

and other interested persons are invited to scrutinize the

basis for the Agency's decision to initiate the Special

Review and to submit data and information which rebuts or

supports the Agency's determination of risk.  Commenters may

also suggest methods to reduce risks of use of the pesticide.

In addition to addressing risk issues, commenters are encouraged

to submit evidence and discussions of the biological, economic,

                            - 6 -

social, and environmental costs and benefits of use of the

pesticide.  The public participation stage is described in more

detail in Unit IV.  This Notice constitutes Position Document 1

for pesticide products containing TPTH.

     If risk issues are not satisfactorily resolved, EPA will

proceed to evaluate the risks and benefits of TPTH  in order  to

determine whether to propose regulatory actions to  reduce the

risks.  After providing an opportunity for comment  by the Scientific

Advisory Panel, the Secretary of Agriculture, registrants, and the

public on those actions and the reasons for them, EPA will issue

an appropriate final notice.  If EPA determines that the risks of

use exceed the benefits, EPA will issue a notice of intent to

cancel the registration of products intended for such use.   The

notice may state  athe  intention to cancel registrations outright

or may require certain changes in the composition,  packaging,

application methods and/or labeling of the product.  These changes

would  be  intended to reduce the risks to levels that when considered

against the benefits will not pose unreasonable adverse effects

to man or the environment.

     A notice initiating a Special Review is not a  notice of

intent to cancel the registration of a pesticide, and a Special

Review may or may not lead to cancellation.  This notice initiating

the Special Review for TPTH products is an announcement of EPA's

concern about the safety of the pesticide's use, and only after

carefully considering the risks and benefits of TPTH and determining

that it appears to cause unreasonable adverse effects on the

environment,  would EPA issue a notice of intent to  cancel.

                            - 7 -
                       B.  PRESUMPTION

     EPA has determined that the use of pesticide products

containing TPTH has exceeded one of the risk criteria in

40 CFR 162.11(a)(3)(ii)(B) which provides that a Special

Review shall be conducted if the use of a pesticide "produces

any other chronic or delayed toxic effect in test animals at

any dosage up to a level, as determined by the Administrator.-

which is substantially higher than that to which humans can

reasonably be anticipated to be exposed, taking into account

ample margins of safety."  Studies submitted to the Agency in

support of the continued registration of TPTH have shown that

TPTH produces teratogenic effects in laboratory animals.

Based on these data and on an evaluation of potential exposure

of applicators to TPTH, the Agency concluded that TPTH has

exceeded the risk criterion for initiation of a Special


     1.  Toxicological concerns.  As part of the data require-

ments necessary to maintain the continued registration of the

pesticide, two independent laboratories conducted studies in

Sprague-Dawley rats to ascertain the teratogenic potential of

TPTH.  In the first study, conducted in 1976 by Cannon Labora-

tories, Inc., varying dosage levels of technical grade TPTH

were orally administered by gavage to pregnant rats on days 6

through 15 of gestation.  Increases in the incidences of

hydrocephalus (the abnormal accumulation of serous fluid with-

in the cranium accompanied by enlargement of the head, prominence

of the forehead, atrophy of the brain, mental weakness and.

convulsions) and hydronephrosis (distention of the pelvis

and calyces of the kidney with urine, as a result of obstruction

of the ureter with accompanying atrophy of the parenchyma of

the organ) above the incidences in concurrent control animals

were observed in the fetuses at all dosage levels tested.

     A second teratogenicity study was performed by Battelle

Columbus Laboratories and submitted to the Agency in 1981.  In

this study, rats were mated and dosed with TPTH on days 5

through 19 of gestation.  Increased incidences of hydronephrosis

above the  incidence in the concurrent control fetuses were

again observed at all dosage levels tested.  Although hydro-

cephalus was seen in only one fetus, an increased incidence

of hydroureter  (abnormal distention of the ureter of the kidneys

with urine  or with a watery fluid) above the concurrent control

incidence  occurred at all dosage levels tested.  Based on

these studies, the Agency has determined that TPTH produces

teratogenic effects in laboratory animals.  A "no-observed-

effect-level" (NOEL) for these teratogenic effects has not

been determined because these lesions were observed at all

dosage levels.  The "lowest-observed-effect-level" (LOEL) was

1.0 mg/kg/day.

     To clarify whether some or all of the effects observed

in the teratogenicity studies are true developmental anomalies,

delayed maturation, or the like, the Agency has required a

"postnatal" teratology study.  The Agency believes this study

will elucidate the nature, severity, and/or reversibility of

the teratogenic effects manifested in the two studies referred

to above.

                             - 9 -
     In the postnatal teratology study, twice the number of

dams typically observed in a teratology study are to be used.

One half of the dams are to be sacrificed near parturition

and the remaining half of the animals are permitted to deliver

normally with post-weaning sacrifice and examination of the

pups.  The specific test requirements are outlined in the

Guidance Document.  Results of the postnatal teratology study

must be submitted to the Agency by December 7, 1985.  In addition,

the Agency is conducting a teratogenicity "screening test" at

Research Triangle Park, N.C.  This testing is being performed

in two phases and is designed to provide insight into the

severity of the observed teratogenic effects.  Based on the

results of these data, which will be available in March 1985,

the Agency may initiate additional immediate regulatory actions.

     2.  Applicator risk assessment.  The Agency has estimated

potential applicator exposure to TPTH.  Because most applicator

exposure occurs by the dermal route, a risk assessment has been

performed based on dermal exposure to TPTH resulting from the

air blast application to pecan trees.  The risk assessment was

limited to this site and application method because 72 to 82

percent of the pesticidal use of TPTH is for controlling fungal

diseases in pecan culture.  TPTH is generally applied by air

blast application in pecan culture, although it may be applied


     In calculating the dermal exposure risk calculation for

pecan tree applicators, the Agency made the following assumptions.

                             - 10 -

     a.  Applicators have an average body weight of 70 kg.

     b.  Mixing/loading and pesticide application are done by

the same individual.

     c.  Potential inhalation exposure would be minimal when

compared to potential dermal exposure.

     d.  It was estimated that 3,000 cm2 of the skin surface

area would be exposed during the pesticide application.   This

is equivalent to wearing a short-sleeved, open-necked shirt,

long pants, and neither head covering nor gloves.

     e.  Exposure during mixing/loading assumes a worker  handles

a  50 percent wettable powder (WP) formulation packaged in

conventional bags.

     f.  In the absence of empirical dermal absorption data,

the Agency assumed dermal absorption would be 100 percent.

     Unit dermal exposure (mg/kg body weight/day) (mg/kg/ bw/day)

during  application was calculated from the linear regression

correlation derived from the Office of Pesticide Programs

Exposure Assessment Branch data base for air blast application

to orchards (p < 0.01).  Exposure during mixing and loading of

the wettable powder was calculated from the same data base.

Application rates typically range from 1.5 to 18.4 oz active

ingredient per acre (ai/A).

     The Agency estimated a typical exposure value for a

mixer/loader/applicator of 0.74 mg/kg/day, with a lowest  value

of 0.68 mg/kg/day and an upper value of 0.88 mg/kg/day.   This

range is derived from the range in application rates.

                             - 11 -

     Because the teratogenic effects seen in the animal studies

occurred at all test dosage levels, the Agency has been unable to

determine "margins of safety" (MOS) (ratio of NOEL to exposure)

from the available test results.  Therefore, teratogenic "risk

quotients" (ratio of LOEL to exposure) were calculated based on

the LOEL.

     The risk quotient determination for teratogenicity indicates

that potential exposure of pesticide applicators in pecan

culture to TPTH occurs at a level that is known to produce

teratogenic effects in laboratory animals, thereby resulting in

a highly significant teratogenic risk for pregnant women.

     3.  Dietary exposure.  To assess potential teratogenic

hazards that might be associated with dietary exposure to TPTH,

the Agency has performed a risk assessment for the food commodities

listed in 40 CFR 180.236.  "Risk quotients" were again determined

because a NOEL was not observed in the teratogenicity studies.

The risk quotients are based on eating a single serving of the

respective food items by a 60 kg pregnant woman.  These data

are presented in Table I.

Serving Weight
Size (kg)l/

1 cup
1 cup
1/2 cupV
1/2 cup
1/2 cup
1 cup
3 oz .
3 oz .






11 R
mg/kg/body (
b .w. =60kg


isk Quotient"
LOEL of 1.0
mg/kg/day divided
by mg/kg body weight)


    From "Nutritive Value of American  Foods,"   Agriculture Handbook No. 456, USDA
    Washington, D.C.,  1975.
_/ Estimated total daily  intake

                             - 13 -

     The risk quotients presented in Table I indicate that

the existing tolerances provide a substantial or ample level of

protection from potential teratogenic effects that may be

associated with dietary exposure to the parent TPTH.  Because

the risk quotient determinations are based on a single serving

of the respective food commodities, individual dietary practices

may augment or lessen the risks accordingly.  However, adequate

protection exists even if multiple servings of the food commodities

listed in Table I are consumed.

     The Agency does not expect residues of the parent TPTH to

exceed the current existing tolerance levels.  However, there

is significant concern about the potential toxicological

activity of the mono- and diphenyltin metabolites of TPTH and

their contribution to the total food residue.  A reassessment

of the existing tolerances will be made once the analytical

methodology and residue data, including storage stability data,

for TPTH and its mono- and diphenyltin metabolites are submitted

for the plant commodities listed in 40 CFR 180.236.  Similar

residue data and storage stability studies for processed com-

modities derived from peanuts, potatoes, and sugarbeets are

also needed.  Studies on processed commodities must include

data for tetraphenyltin in addition to data for TPTH and the

mono- and diphenyltin metabolites.  Residue data and analytical

methodology for meat, milk, poultry, and eggs are also being

required.  The above information is being requested from the

registrants in the Guidance Document.

                            - 14 -

     The Agency is also aware that TPTH and its acetate and

chloride analogues are used abroad.  The treated commodities

include dry beans (Bolivia), cocoa (Brazil), potatoes  (Brazil,

Cyprus, Ireland, Switzerland, and the United Kingdom), and rice

(Brazil).  The recommended international maximum residue limits

for the triphenyltin derivatives do not include contributions

that may be made by inorganic tin and di- and monophenyltin

moieties.  Subsequently, international commodities which do

not have an existing tolerance listed in 40 CFR 180.236 may be

subject to administrative action if found to contain TPTH residues


     Additional data submitted to the Agency in support of the

continued registration of TPTH have precipitated further

concerns about the safety of the pesticide.  At this time, the

available data on these effects are insufficient to determine

whether a Special Review risk trigger has been met or exceeded.

However, the Agency believes the effects described below merit

additional investigation and has required data to delineate

their exact nature and extent.

     TPTH has produced immunotoxic effects in mice and guinea

pigs.  A 90-day subchronic study using guinea pigs indicated

that the pesticide may inhibit lymphopoiesis and produce atrophy

of lymphoid tissues.  In this study, performed in 1960,

leukocyte counts were depressed at the lowest dosage level

tested (2.5 ppm or 0.1 mg/kg/day).  Although the Agency has

classified this study as minimally acceptable, the small number

of animals used in each test group as well as the absence of

                            - 15 -

a NOEL for the observed effects have resulted in additional

data requirements.

     Exposure to TPTH also produced decreased testicular

weights in rat pups in a three-generation reproduction study

performed in 1967.  In this study, the F2b generation exhibited

decreased testicular weights when compared to the concurrent

controls at dosage levels of 1.0 ppm and above.  A NOEL for

the reproductive effects was estimated to be 0.025 mg/kg/day.

This study has been classified as provisionally invalid because

only summary data were submitted.  Registrants should submit

these supporting data, if available, to the Agency.  In the

event these data are not available, a new study as required

in the Guidance Document must be submitted.

     The oncogenic potential of TPTH cannot be determined

at this time.  In one study, female mice dosed with TPTH

developed endometrial hyperplasia at the lowest dosage level

tested, 1.05 mg/kg/day.  The development of a test chemical-

induced change in a reproductive organ is considered a serious

adverse effect by the Agency and because of the low dosage at

which the effect was observed it must be considered in the

overall assessment of TPTH toxicity.  Additional studies have

been required on an expedited basis in the Guidance Document

to clarify this concern.

     The Agency has also performed a preliminary risk

assessment, based on a 90-day inhalation study in rats and

calculated applicator inhalation exposure at 0.0016 mg/kg/day,

to determine potential risks to applicators by this exposure

                              - 16 -

route.  A NOEL was not established for the effects observed

in the rat study (ie., alopecia, nasal discharge, red ears,

piloerection, etc.) and the resultant risk quotient (151) deter-

mination indicates it may be prudent to require respiratory

protection since any "margin of safety" assessment would result

in a lower safety factor.  TPTH is in EPA Toxicity Category I

(highest toxicity rating) by the inhalation exposure route.

     Additional studies which have been submitted to support the

continued registration of TPTH indicate the pesticide is highly

toxic to aquatic invertebrates, warmwater fish and estuarine/

marine organisms and is moderately to highly toxic to birds.

These studies suggest continued use of TPTH may have potentially

deleterious effects on wildlife and aquatic organisms.

      Data requirements are being mandated in the Guidance Document

on an expedited basis to clarify the environmental fate of TPTH.

These data include accumulation in rotational crops and fish,

leaching, adsorption, desorption, aerobic and anaerobic soil

metabolism, soil dissipation and photodegradation of the pesticide,

re-entry data, avian reproduction and dietary studies, and a

coldwater fish study.

     Based on the evaluation of the results of the studies required

above, the Agency will determine whether additional information

and/or restrictions are necessary.  Pivotal data requirements and

an expedited submission schedule are summarized in Table II.

                              - 17 -
Data Requirements
 Submission Date
Studies Pivotal to Teratogenicity


Postnatal Teratogenicity

(Dermal Exposure Route)

Analytical Methodology for
Plant and Animal Residues
Including Metabolites and
Tetraphenyltin Hydroxide

Residue Storage Stability

Crop and Processed Commodities
Storage Stability Data
Including Metabolites and
Tetraphenyltin Hydroxide

Studies Pivotal to Additional Concerns

Soil and water photodegradation

Mobility Studies

Soil Dissipation Studies

Immunotoxicity Studies

Dermal Penetration

General Metabolism

Residue Determination for Food
Use Crops, Tobacco, Meat, Milk
Poultry and Eggs

Reproduction 2-generation

Chronic Toxicity

 December 7, 1985

       ii  11   n


     June 7, 1985
 December 7,  1985

     June 7,  1986
       n  n   n
       n   n    M
  January 1,  1986

       it  n   n

    March 7,  1986

     June 7,  1986

September 7,  1986

 December 7,  1988

       it  M   n
    Contingent on the results of the postnatal and standard
    teratogenicity and dermal penetration studies.


     Because the Agency has determined that TPTH produces terato-

genic effects in laboratory animals at concentrations to which

applicators may be exposed, the Guidance Document requires that a

warning be added to the pesticide label stating that TPTH causes

birth defects in laboratory animals and that exposure during

pregnancy should be avoided.  Additional label changes include

the  "Restricted Use" classification which limits the use of the

pesticide to certified applicators or to persons directly under

their supervision.  Protective clothing including a long-sleeved

shirt, long pants,  impermeable gloves, hat, boots, and an approved

pesticide respirator are also required.

     In addition to the protective clothing described above, a

face shield  is  required when the technical product is being

handled.  The Registration Standard also stipulates that no new

permits will be issued for the experimental use of TPTH as an

anti-fouling agent  in marine paints, nor will any FIFRA section 3

registration applications be considered during the Special Review.

     All currently registered TPTH products will remain registered

while the Special Review is in progress.  However, the Agency is

deferring final decisions on the reregistration of any products

containing TPTH as a sole active ingredient until the Special

Review is concluded.  No new uses for TPTH will be issued during

this period.  The Agency also will not approve pending requests

for  tolerances for TPTH on rice and soybeans or issue any new

tolerances during the Special Review.

                            - 19 -

     The Agency is also currently considering the issuance

of a Data Call-in Notice pursuant to FIFRA section 3(c)2(B)  in

order to require registrants to submit specific information

on the use, exposure potential, and benefits of TPTH.


     Prior to the initiation of a Special Review, technical

registrants receive private notification of the Agency's

determination that the criteria to initiate a Special Review

may have been met.  This notification includes information on

the toxicity findings, route of exposure and related general

information.  Registrants then have 30 days following receipt of

the notification to rebut the Agency's conclusions.

     In response to the Agency's notification that a Special

Review of TPTH was being considered, Uniroyal Corporation

proposed amending their product label in an effort to reduce

risks and obviate the Special Review of the pesticide.  Uniroyal

proposed classifying the pesticide as a restricted use chemical,

a 24-hour reentry label statement, a prohibition for female

applicators of childbearing age, and cancellation of all products

except those packaged in water soluble bags.

     The Agency believes the proposals submitted by Uniroyal

are generally in agreement with the requirements stipulated  in

the Guidance Document.  However, the Agency does not have the

information necessary to determine if these and other measures

will adequately reduce the risks from exposure to the pesticide

to an acceptable level.  This determination will be made through

the Special Review of TPTH.

                             - 20 -

                     F.  REBUTTAL CRITERIA

     All registrants, applicants for registration, and other

interested members of the public are invited to submit evidence

either to support or to rebut the presumption that TPTH causes

teratogenic effects in rats and may cause such effects in humans.

Under 40 CFR 162.11(a)(4)(iii) the presumption initiating a

Special Review must be rebutted by proving, in the case of acute

and chronic toxicity criteria, "that the determination by the

Agency that the pesticide meets or exceeds any of the criteria

for risk was in error."

                   G.  BENEFITS INFORMATION

     The Agency will conduct a comprehensive benefits review

and analysis for TPTH during the Special Review process and will

consider that information in setting forth the Agency's proposed

regulatory decision in the Position Document 2/3 (PD 2/3).  A

preliminary analysis of the benefits of TPTH has been performed

and is presented here.

     The major use of TPTH is on pecans.  Over 72 percent of the

pesticide used annually is applied to this crop.  Georgia is the

primary pecan-producing State accounting for between one third

and one half of the total annual production of pecans in the

United States.  New Mexico, Texas, Alabama, and Louisiana make up

the remaining major pecan-producing States.  Any one of the

following States, Arkansas, Florida, Mississippi, North Carolina,

Oklahoma, and South Carolina generally account for less than

3  percent of the total national production.  Most of the

                             - 21 -

TPTH applications occur in the Southeast because the environmental

conditions are conducive to disease development.

     Scab is the most important fungal disease in pecan culture

both in the Southeast and Southwest.  Preliminary data suggest

that although TPTH is the pesticide most commonly used in pecan

culture, registered alternatives are available for all pests with

the exception of sooty mold which is of minor concern.  It is

estimated that without the use of any fungicide, there would be a

substantial loss in the annual yield.  Use of the alternative

fungicide benomyl in pecan culture may reduce this loss signif-

icantly, although a major concern with the use of benomyl is

the development of benomyl resistant strains of fungi.  To

date, fungal strains that attack pecans have not demonstrated

a resistance to TPTH.  For this reason, TPTH and benomyl are

often used on an alternating schedule or applied in combination.

The chemical cost per acre difference between benomyl and TPTH

is minor.

     TPTH is also registered for use in controlling fungal

diseases in sugarbeets, peanuts, carrots, and potatoes.  On

peanuts, TPTH is used to control early leafspot and incidentally

contributes to mite suppression.  TPTH is also registered for use

on potatoes in controlling late and early blight.  Late blight  is

the more serious concern in potato culture, especially in the

Northeast.  Use of TPTH for control of diseases of carrots appears

to be minor but important for the control of Cercospora leafspot

of sugarbeets.  Benomyl is often applied for control for Cercospora,

                            - 22 -

but TPTH is used where benomyl-resistant strains have developed.

The efficacy and potential unreasonable adverse effects  that may

be associated with alternatives for TPTH such as benomyl , metiram,

maneb, captafol, thiophanate-methyl, and others will be  fully

reviewed in Position Document 2/3.

     In addition to submitting evidence to rebut the presumptions

of risk in the Special Review, 40 CFR 162.11(a)(5)(iii)  provides

that a registrant or applicant "may submit evidence as to whether

the economic, social and environmental benefits of  the use of

the pesticide subject to the presumption outweigh  the risk of

use."  If  the presumption of risk is not rebutted,  the benefits

evidence submitted by registrants, applicants, and  other inter-

ested persons will be considered by the Agency when determining

the appropriate regulatory action.

     Registrants, applicants or other interested persons who

desire to  submit benefits information should consider submitting

information on the following subjects along  with any other

relevant information they desire:

     1.  Identification of the biological and economic importance

of TPTH uses.

     2.  Identification of alternative chemical and nonchemical

methods of control and any associated health effects and potential

for human  exposure.

     3. Determination of any change in costs to TPTH users for

obtaining  equivalent disease control with available substitute

products or management techniques.

                            - 23 -

     4.  Assessment of the expected changes in the level of

efficacy, crop yield, crop quality, crop injury, and environmental

impacts associated with the use of alternative control measures.

     5.  Identification of increased or reduced risks associated

with the mixing, loading, and applying of alternative chemicals,

with their potential increase in use if TPTH were not available.

     6.  Identification of cultural and spray application

practices, that impact on farmworker exposure to TPTH.

     7.  Identification of cultural or integrated pest manage-

ment practices which are enhanced or limited by use of TPTH.


     All registrants and applicants for registration are

being notified by certified mail of the Special Review being

initiated on their products containing TPTH.

     The registrants and applicants for registration will

have 45 days from the date this notice is received or until

(insert date 45 days after date of publication in the FEDERAL

REGISTER) (whichever is later) to submit evidence in rebuttal

to the Agency's presumption.  Other interested parties may

submit comments during the same period.


     Registrants are required by section 6(a)(2) of FIFRA to

submit any additional information regarding unreasonable adverse

effects on man or the environment which comes to their attention

at any time.  Registrants of TPTH products must immediately

                            - 24 -

submit any published or unpublished information, studies,

reports, analyses, or reanalyses regarding any TPTH effects

in animal species or humans, and claimed or verified accidents

to humans, domestic animals, or wildlife which have not been

previously submitted to EPA.  These data should be submitted

with a cover letter specifically identifying the information

as being submitted under section 6(a)(2) of FIFRA.  Registrants

should notify EPA of any studies on TPTH currently in progress,

their purpose, the protocol, the approximate completion date,

a summary of all  results observed to date, the name and

address of the laboratory performing the studies, and a

statement as to whether these studies are being conducted  in

accordance with the Good Laboratory Practices specified in

40 CFR  Part 160,  published  in the FEDERAL REGISTER of

November  29, 1983  (48 FR 53946).


      During the time allowed for submission of rebuttal

evidence, specific comments are solicited on the presumptions

set forth in this  Notice and in the Registration Standard.  In

particular, any documented  episodes of adverse effects on

humans or domestic animals  should be submitted to the Agency

as soon as possible.  Any information as to any laboratory

studies in progress or completed should be submitted to the

Agency as soon as possible  with a statement as to whether

those studies are  in compliance with the Good Laboratory

Practices specified in 40 CFR Part 160.  Specifically, infor-

mation on any adverse toxicological effects of TPTH, its

                            - 25 -

impurities, metabolites, and degradation products is solicited.

Similarly, submission of any studies or comments on the

benefits from the use of TPTH is requested.  All comments and

information and analyses, which come to the attention of EPA,

may serve as a basis for final determination of regulatory

action following the Special Review.

     All comments and information should be sent to the

address given above, preferably in triplicate, to facilitate

the work of EPA and others interested in inspecting them.

The comments and information should bear the identifying

notation  [OPP-30000/42].

     During the comment period, interested members of the

public or registrants may request a meeting to discuss the

risk issues and methods of reducing risks.  Any records

pertaining to such meetings, including minutes, agendas, and

comments received will  be filed under docket number OPP-30000/42
Dated:  /"I/  /7 /
           /    /
                              Office of Pesticide Programs.