United States              Office of Pesticides
                       Environmental Protection       and Toxic Substances
                       Agency                  (H7501C)
                       	:	54Q/FS-89-Q5R
vvEPA            Pesticide
                       Fact Sheet
                                      .     beta-(4-chlorophenoxy)-alpha-(l,I-dimethylethyl
                       Name Of Chemical:  lH-l,2,£-triazole-l-ethanol
                       Reason for Issuance: New Chemical Registration

                       Date Issued:    July 1989

                       Fact Sheet Number:  204

            Generic Name:  beta-(4-chlorophenoxy)-alpha-(1,1-dimethylethyl)-
                          lH-l,2,4-triazole-l-ethanol and its metabolites
                          containing chlorophenoxy and triazole moieties.

            Common Name:  triadimenol

            Trade Name:  Baytan

            EPA Shaughnessy Codes:   127201

            Chemical Abstracts Service (CAS) Number:  5219-65-3

            Year of Initial Registration:  1989

            Pesticide Type:  Fungicide

            U.S. and Foreign Producers:  Mobay Corporation

            APPLICATION SITES:  Seeds  of barley, corn, oats,  rye,
                sorghum and wheat to control seed- and soil-borne
                diseases and to provide early season control  of  foliar

            METHOD OF APPLICATION:  Application will be made  as  a water-
                based slurry through standard slurry or mist  type
                commercial seed treatment  equipment.

            TYPES OF FORMULATION:   25% dry flowable end-use product
                and 90% technical powder for formulating use.  .

            APPLICATION RATES:  For barley, oats, rye and wheat, apply
                0.25-0.5 oz. ai./lOO Ibs of seed; for sorghum, apply
                0.5 oz. ai./lOO Ibs of seed; and for corn, apply 1.0 oz.
                ai./lOO Ibs of seed.



Summary Science Statement
    Available acute toxicity studies indicate that triadimenol
is in toxicity category II (warning) based on an acute inhalation
toxicity study with rats.
    Chronic feeding/oncogenicity studies were conducted in both
the rat and mouse.  Clinical chemistry findings in the chronic
feeding study in the rat suggests that the target organ for
toxicity may be the liver.  Although there was an accompaying
small increase in liver weight in the females of the high
dose group," there were no histopathologic charges in the
liver in either sex.
    In the chronic feeding study in mice, the results of
blood chemistry, organ weights and gross and histological
examinations, again indicated the liver as the target organ.
    Triadimenol did not induce either genotoxic effects or
chromosomal aberrations in a series of mutagenicity studies.
In addition, no strong structural activity correlation to
other carcinogens has been found.'  Triadimenol was also found
not to be teratogenic in either the rat or rabbit.
    Environmental fate data indicates that triadimenol is stable
to hydrolysis and appears to be stable to photolysis on the
soil surface.  In addition, based on low adsorption coefficients,
triadimenol will have a low potential to leach in soil.
However, triadimenol may have a moderate potential to leach
in some Western soils.
    Additional studies indicate that due to the manufacturing
process, triadimenol should have no adverse effects on non-target
organisms provided waste is disposed of properly.  An overview
of the toxicity test results suggests that triadimenol is
practically non-toxic to birds, slightly toxic to fish, and
moderately toxic to aquatic invertebrates.  It is also unlikely
that this registration would affect endangered species because
of its relatively low use rates, agricultural techniques
which involve drill planting of most small grains and corn,
and the low toxicity of triadimenol to all animals.


Acute oral toxicity in rats:
    1050 689 mg/kg in males
         752 mg/kg in females
    Toxicity category III

Acute dermal toxicity in  rats:
    LE>5o >5000 mg/kg
    Toxicity category III

Acute  inhalation toxicity in rats
     LC5Q  >1.56 mg/L
     Toxicity category III

Drimary eye irritation in rabbit:
     slight irritation

Primary dermal irritation in rabbit:
     Toxicity category IV

Dermal sensitization in guinea pigs:
     core  minimum; no effect

Chronic Studies:  Triadimenol has been evaluated in the following

"Rodent Feeding/Oncogenicity

     1.  A 2-year feeding/oncogenicity study with rats using
dietary concentrations of 0, 125, 500, and 2000 parts per
million (ppm) equivalent to 0, 6.25, 25.0, and 100 mg/kg bwt/day
in males  and females.  Clinical chemistry findings suggest
that the  target organ for toxicity may be the liver.  The
levels of SCOT and 9GPT enzymes were consistently higher at
2000 ppm  in males and females when compared to controls, and
some increase in these two parameters was also observed at
500  ppm.  Although there was an accompanying small increase
in liver  weight in 2000 ppm females, there were no accompanying
increases in histopathologic changes of the liver in either
sex.   There were only marginal effects seen on other clinical
chemistry parameters, and no effect of test compound on
clinically observed signs of toxicity, food consumption,
hematologic, or urinalysis parameters.  The systemic NOEL
(no-observed effect level) is 125 ppm (6.25 mg/kg/day for
males  and females) based on the increase in liver enzymes
(SCOT  and SGPT).  The systemic LEL (lowest effect level) was
500  ppm (25 mg/kg/day for males and for females).
    2.  A 2-year chronic feeding/oncogenicity study in mice
using  dietary concentrations of 0, 125, 500, and 2000 ppm
(equivalent to doses of 0, 18, 72, and 285 mg/kg/day for males
and  females).  The results of blood chemistry, organ weights,
and gross and histological examinations indicated the liver to
be the target organ.   There were time- and dose-related increases
in SAP (serum alkaline phosphatase), SCOT and SGPT activities
in both male and female animals receiving 500 and 2,000 ppm of
the test  material.
    In addition, increased incidence of enlarged livers,
hyperplastic nodules and increased liver weights in both
male and  female animals receiving 2,000 ppm of test material
were detected at necropsy.  Female animals receiving 2000 ppm
exhibited a significant increase in the incidences of liver
adenomas only, a compound-related oncogenic effect.  In


males, there were no differences in the incidences of these
lesions in treated and control males, and the incidences of
liver adenomas were similar to those observed in historical
     Based on this evidence the Agency classified triadimenol
as a Category C (possible human carcinogen) in accordance
with the EPA Guidelines for Carcinogen Risk Assessment (September
24, 1986, 51 FR 33992).  This evaluation was confirmed by the
Agency's Scientific Advisory Panel on December 15, 1987.  How-
ever, it was also concluded that this evidence of carcinogenic!ty
did not warrant a low dose extrapolation of risks since the
tumors were only benign, were observed in only one sex, and
only at the highest dose tested.  Moreover, the chemical was
negative in the genotoxic assay battery.
    Based on blood chemistry findings, the systemic NOEL and
the LEL are 125 ppm and 500 ppm respectively (equivalent to
18 and 72 mg/kg/day for males and females).
    3.  A 3-month rat feeding study using doses of 0, 150,
and 600 ppm (equivalent to 0, 7.5, and 30 mg/kg bwt/day for
males and females) demonstrated a decrease in body weight,
decrease in hematocrit values, eosinophil count and medium
cell hemoglobin and increase in the high dose group and dose-
related increase in liver weight.  The NOEL is 150 ppm and                         (
the LEL is 600 ppm.

°Non-Rodent Feeding Study

    1.  A 2-year male and female dog feeding study using doses
of 0, 150, 600 and 2400 ppm (equivalent to 0, 3.75, 15, and
60 mg/kg bwt/day for males and females).  The NOEL is 150 ppm
based on changes in enzyme levels (equivalent to 3.75 mg/kg
bwt/day for males and females).  The LEL is 600 ppm.  Although
there were significant decreases in mean body weights in males
receiving 150 and 2400 ppm and in females receiving 600 and 2400
ppm, the biological significance of these changes could not be
assessed.  There were noted increases in alkaline phosphatase
N-demethylase, and cytochrome P-450 in males receiving 2400 ppm
and significant increases in N-demethylase in females receiving
600 and 2400 ppm and in cytochrome P-450 in females receiving
2400 ppm when compared to controls.
    2.  A 6-month dog feeding study using doses of 0, 10, 30,
and 100 ppm (equivalent to 0, 0.25, 0.75, 2.5 mg/kg bwt/day
for males and females).  The NOEL was demonstrated at doses
up to 100 ppm, the highest dose level tested.
    3.  A 3-month dog feeding study using doses of 0, 150, 600
and 2400 ppm (equivalent to 0, 3.75, 15, and 60 mg/kg bwt/day
for males and females).  Weight gain in all male groups and
in the highest dose female group was significantly less than                       *
the control.  Alkaline phosphatase in males and females showed                     f
a dose-related negative trend.  There was no gross pathological
changes.  Effects at 600 ppm included an increase in serum
cholesterol level in males.  Although the NOEL appeared to be


less than 150 ppm based on reduced body weight and decreased
alkaline phosphatase in males, the Agency has concluded that effects
below 600 ppm in the 2-year dog study were not biologically
significant and the longer-term study supercedes the 90-day dog
study.  Therefore, the NOEL remains at 150 ppm.


    1. A rabbit teratology study with a NOEL for maternal
toxicity of 8 mg/kg.  The maternal LEL was 40 mg/kg based on
decreased body weight gains and food consumption.  The develop-
mental NOEL and LEL were 40 mg/kg and 200 mg/kg respectively.
This study has to be resubmitted with all the findings
statistically analyzed on a per litter and per fetus basis in order
to be upgraded from its current classification as core supplementary.
    2. A rat teratology study using dose levels 0, 30, 60,
and 120 mg/kg/day was determined to be core supplementary
because the NOEL for developmental toxicity (supernumerary ribs)
was not definitively established.  The NOEL and LOEL for maternal
toxicity for this study are 30 and 60 mg/kg/day, respectively,
based on decreases in maternal body weight, body weight gain,
and food consumption at 60 and 120 mg/kg/day.   Furthermore,
increased embryolethality (embryotoxicity) was only observed
at the highest dose level tested (120 mg/kg/day).  This study
must be repeated to clearly define a NOEL for developmental
     The above rat study indicated that triadimenol caused a
dose-dependent, statistically significant increase in the
incidence of rudimentary supernumerary ribs.  Although the
effect at the low dose level was not statistically significant,
it was considered to be treatment related because of the dose-
related trend.
     The biological significance of the manifestation of
supernumerary ribs is subject to scientific debate, especially
if the ribs are not fully developed (rudimentary).  Nonetheless,
the margin of safety (MOS) for this effect must be taken into
consideration.  The MOS is the ratio between the NOEL for the
effect and the acute exposure in mg/kg/day.  A NOEL for
developmental toxicity could not be defined in the rat teratology
study but it is unlikely to be far below the threshold (LEL)
of 30 mg/kg/day observed in the current study.
     Based on worker exposure information and an estimation of
the NOEL at about 15 mg/kg/day for developmental toxicity
(rudimentary supernumerary ribs in rats) and assuming a maximum
dermal penetration of about 10%, a margin of safety was calculated
to be >100 for factory workers involved in seed treatments using
a closed system.  Because of possible developmental toxicity
and the lack of a will defined NOEL for this effect, the product
label must include a recommendation for the use of protective
clothing by factory workers involved in the treatment of seeds
and for farm workers handling the treated seed.

 A rat multigeneration reproduction study using doses of
20,  100, and 500 ppm (equivalent to 0,  1,  5,  and 25 mg/kg
/day for males and females)  indicated that the NOEL and
L for both parental and pup  toxicity are 100  and 500 ppm,
pectively, based on significant body weight and organ weight
nges.   The NOEL for reproductive toxicity is  500 ppm,  highest
e level tested.


 A reverse" mutation assay (AMES),  a dominant  lethal
t in mice, DNA damage/repair,  unscheduled DNA synthesis,
yitro and in vivo (rat) cytogenic  assays,  and a forward
ation in mice,  all of which  were negative for mutagenic


 Hydrolysis:  STABLE.  Triadimenol in sterile aqueous buffer
              solutions showed no  apparent degradation
              at either temperature or  pH tested.
              Recovery was 97% greater  after  32 days of

 Soil  Surface Photolysis:  STABLE.   Triadimenol appears to
              be stable to photolysis on the  soil  surface.
              Studies indicate that triadimenol photodegrades
              with a half-life of  36 hours in distilled
              water and 17 hours in a photo-sensitized
              (acetone) solution.

 Aerobic Soil Metabolism:  STABLE.   Studies indicate that
              triadimenol  has  an estimated aerobic half-life
              of 8 to 9 months.  Triadimenol  reached a maximum
              level of 68% of  that applied at 14C  in 71 days
              and declined slightly to  45.2%  by day 238.
              Consequently,  the anaerobic  half-life is
              considerably greater than 8-9 months.

 Adsorption/Desorption:  Because of its low adsorption
              coefficients,  triadimenol is shown to have  a  low
              to moderate  potential to  bind to soil particles.
              Studies indicate that the adsorption coefficient,
              k,  for triadimenol ranged from  2.37  to 5.26.
              The k values for desorption  ranged from 1.49
              in a silty clay  soil (0.49 ppm) to 9.12 in a
              loam soil (9.57  ppm).   Consequently,  there
              is no correlation between adsorption and
              soil organic matter  content.  The highest

                  degree  of  adsorption  was  observed with the
                  loam  soil,  intermediate in organic matter

    Environmental fate data requirements have been satisfied
with  the  exception of  a  field dissipation  study.  The company will
be  required  to  submit  results of  this  study by July 1990.


    Studies  submitted  show  that this chemical is practically
non-toxic to birds, slightly toxic to  fish and moderately
toxic to1aquatic  invertebrates.   It is unlikely that the seed
treatment use of  triadimenol will affect any terrestrial or
aquatic animals.  Chronic effects are  unlikely due to the low
use rates and because  the seed treatment use requires incorporation
of  seeds  into the soil.  For the  above reasons it is also
unlikely  that this use will  affect any endangered species.


    This  chemical has  been  shown  to be environmentally safe,
is used at low  rates and has a broad biological spectrum.
Triadimenol  controls seed-,  soil-, and wind-borne pathogens of
wheat, barley,  oats, rye, corn and sorghum.  Crops may be
grazed 40 days  after seeding.  The chemical improves winter
survival  and drought tolerance of cereals, lowers the inoculum
levels for overwintering foliar diseases and may eliminate
the need  for early season foliar sprays.


    Tolerances  are established for the fungicide triadimenol
and its butanediol metabolite (calculated as triadimenol) in or
on the following  commodities:  2.5 ppm for green forage of
barley, oats, rye and wheat; 0.1 ppm for straw of barley, oats,
rye and wheat;  0.05 ppm  for  grains of  barley, oats, rye and wheat,
corn  fodder,  fresh corn  (including sweet), corn forage,  corn
grain, and green  forage  of  sorghum; and 0.01 ppm for sorghum grain and
sorghum fodder.    Tolerances  are established for the fungicide
triadimenol  and its metabolites containing the chlorophenoxy
moiety (calculated as triadimenol) in  or on the following
commodities:   0.1 ppm  for fat, meat and meat by-products of cattle,
goats, hogs,  horses,  and sheep; and 1.01 ppm for eggs,  milk, and fat,
meat  and  meat by-products of poultry.
     Where tolerances are established  for residues of both l-(4-
(triadimefon) and triadimenol, including its butanediol metabolite,


in or on the same raw agricultural commodity and its products
thereof, the total amount of such residues shall not yield more
residue than that permitted by the higher of the two tolerances.
The nature of the residue is adequately understood and the
Agency concluded that the pesticide is useful for the purposes
for which tolerances are sought and that the establishment of
the tolerances will protect the public health.


    The Agency concurs with conditional registration of this
chemical for use as a seed treatment fungicide  pending submission
of a field dissipation study by July 1990.


Susan T. Lewis,
Acting Product Manager (PM) 21,
Registration Division (H-7505C),
Environmental Protection Agency,,
401 M St., SW.,
Washington,  DC  20460

Office location and telephone number:
Rm. 227, CM#2,
1921 Jefferson Davis Highway,
Arlington, VA  22202
(703) 557-1900

DISCLAIMER:   The information in this Pesticide  Fact Sheet is
a summary only and is not to be used to satisfy data
requirements for pesticide registration and reregistration.

United States
Environmental Protection Agency
Office of Pesticide Program (H7S04C)
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