Document ID: EPA-HQ-OPP-2006-0576-0007
Agency: epa
Document Type: Supporting & Related Material
Title: 
Posted Date: 2007-03-26T04:00Z

COMPANY FEDERAL REGISTER DOCUMENT SUBMISSION TEMPLATE

NOTICE OF FILING 

EPA Registration Division Contact: Mary Waller (PM#21), 703-305-9354

ISAGRO S.p.A.

[5F6971]

EPA has received a pesticide petition ([5F6971]) from Isagro S.p.A.,
Centro Uffici San-Edifico D-ala 3, Via Caldera, 21-20153 Milan, Italy
proposing, pursuant to section 408(d)of the Federal Code, Drug, and
Cosmetic Act (FFDCA), 21 U.S.C. 346a(d), to amend 40 CFR part 180.:

1. by establishing a tolerance for residues of 

tetraconazole in or on the raw agricultural commodities: soybean, seed
at 0.1, aspirated grain fractions (AGF) and refined oil at 0.5; and
poultry, meat, liver, byproducts, egg at 0.01, and fat at 0.05 parts per
million (ppm).  EPA has determined that the petition contains data or
information regarding the elements set forth in section 408(d)(2) of the
FFDCA; however, EPA has not fully evaluated the sufficiency of the
submitted data at this time or whether the data supports granting of the
petition.  Additional data may be needed before EPA rules on the
petition.

Residue Chemistry

1. Plant and animal metabolism.  In plants and animals, the metabolism
of tetraconazole is adequately understood for the purposes of
establishing the proposed tolerances.  Tetraconazole metabolites include
1,2,4-triazole, and two conjugates, triazolylalanine and triazolyl
acetic acid, which are common to most of the triazole fungicides.  Based
on the available metabolism and toxicology data, parent tetraconazole is
proposed to be considered as the residue of concern in plant and animal
matrices.

2. Analytical method. In plants and animals, the residue of concern,
parent tetraconazole, can be determined using High Pressure Liquid
Chromatography (HPLC) with a Mass Spectrometer (MS) detector.  The
proposed limit of quantitation (LOQ) for the methods are 0.01 ppm for
soybean seed and processed commodities, and 0.02 ppm for poultry meat,
fat, byproducts, liver, and 0.01 ppm for egg.

3. Magnitude of the residues. For soybean, a total of twenty residue
trials were conducted to evaluate the magnitude of the residues of
tetraconazole following two applications of Domark 230 ME at 0.09 lbs of
active ingredient (ai) per acre with treatments at growth stages R3 and
R5.  Soybean mean and relative standard deviation residue for all sites
was 0.022 ppm ± 0.0125 ppm with a maximum residue of 0.068 ppm. 
Soybean seed residues concentrated in AGF and refined oil by factors of
5.8 and 4.6, respectively.

For poultry, a total of 10 birds each were dosed at 0.077, 0.231, and
0.77 mg ai/kg (equivalent to 2, 6, and 20x the anticipated soybean
residue dietary burden).  Residues at the lowest dose were 0.038 ppm for
fat, <0.01 ppm for meat, liver, and kidney, and <0.005 for egg.

Toxicological Profile

1. Acute toxicity. Acute oral lethal dose (LD)50 = 1,031
milligrams/kilogram (mg/kg) (toxicity category III); acute dermal LD50 <
2,000 mg/kg (toxicity category III); acute inhalation lethal
concentration (LC)50 = 3.66 mg/liter (toxicity category IV); primary eye
irritation - clear by 72 hours (toxicity category III); primary skin
irritation - slight irritation (toxicity category IV); and dermal
sensitization - negative.

  

2. Genotoxicity. Numerous mutagenicity studies were conducted with
tetraconazole and no genotoxic effects were reported,

3. Reproductive and developmental toxicity. A two-generation
reproduction study was conducted in rats at dietary concentrations of 0,
10, 70 or 490 ppm.  The LOAEL for parental toxicity = 70 ppm, equivalent
to 4.9/5.9 (male/female) mg/kg/day based on increased mortality in P
generation females. The NOAEL = 10 ppm, equivalent to 0.7/0.8 (M/F)
mg/kg/day. The LOAEL for off spring toxicity = 490 ppm (40.6 mg/kg/day
from the P generation female intake) based on decreased litter weight
and mean pup weight in litters of all generations before weaning and
increased relative liver weights at weaning in both sexes of all
litters. The NOAEL = 70 ppm (5.9 mg/kg/day). The LOAEL for reproductive
toxicity = 70 ppm, equivalent to 4.9/5.9 (M/F) mg/kg/day based on
increased mean gestation duration in P generation parental females and
related evidence of compound toxicity in the parturition process.  The
NOAEL was 10 ppm (0.7 mg/kg/day for males and 0.8 for females).

A developmental toxicity study was conducted using rats gavaged with
doses of 0, 5, 22.5, and 100 mg/kg/day from days 2 through 15 of
gestation. The maternal toxicity LOAEL is 100 mg/kg/day based on
decreased body weight gain, and food consumption and increased liver and
kidney weights. The maternal toxicity NOAEL is 22.5 mg/kg/day.
Developmental toxicity was noted at 100 mg/kg/day and consisted of an
increased incidence of small fetuses, and supernumerary ribs. The LOAEL
and NOAEL for developmental toxicity were 100 and 22.5 mg/kg/day,
respectively.

A developmental toxicity study was conducted using rabbits gavaged with
doses of 0, 7.5, 15, or 30 mg/kg/day.  The maternal toxicity NOAEL = 13
mg/kg/day and LOAEL = 30 mg/kg/day, based upon decreased body weight
gain.  The developmental toxicity NOAEL = 30 mg/kg/day and the LOAEL was
not established.

4. Subchronic toxicity. Ninety-day feeding studies were conducted in
rats and mice.  The rat study was conduced at dietary concentrations of
0, 10, 60, or 360 ppm.  The NOAEL = 4.1/5.5 (M/F) mg/kg/day.  The LOAEL
= 23.9/28.7 (M/F) mg/kg/day, based on single liver cell degeneration in
males, and increased SGPT and SGOT, decreased BUN levels, increased
absolute and relative liver weights and presence of hepatocellular
single cell necrosis in females.  The mouse study was conducted at
dietary concentrations of 0, 5, 25, 125, or 625 ppm.  The NOAEL = 4
(M/F) mg/kg/day.  The LOAEL = 16/20 (M/F) mg/kg/day, based on single
liver cell degeneration in males, and increased SGPT and SGOT, decreased
BUN levels, increased absolute and relative liver weights and presence
of hepatocellular single cell necrosis in females.  

5. Chronic toxicity. A two year combined chronic
toxicity/carcinogenicity study was conducted in rats at dietary
concentrations of 0, 10, 80, 640 or 1280 ppm.  The NOAEL = 3.4/4.4 (M/F)
mg/kg/day.  The LOAEL = 27.7/39.4 (M/F) mg/kg/day, based upon
histopathology of the bone (osseous hypertrophy of the cranium/parietal
bone), pale and thickened incisors, and decreased absolute and relative
adrenal and pituitary weights in males; decreased body weight (at
terminal sacrifice) in females.  No treatment-related increases in tumor
incidence were observed.  

A 52-week chronic toxicity study was conducted in dogs at dietary
concentrations of 0, 22.5, 90 or 360 ppm.  The NOAEL = 0.73/0.82 (M/F)
mg/kg/day.  The LOAEL = 27.7/39.4 (M/F) mg/kg/day, based upon increased
absolute and relative kidney weights and histopathological changes in
the male kidney.      

6. Carcinogenicity.  An 80 week mouse oncogenicity study was conducted
at dietary concentrations of 0, 10, 90, 800, or 1250 ppm.  The NOAEL =
1.4/1.5 (M/F) mg/kg/day.  The LOAEL = 12/14.5 (M/F) mg/kg/day, based
upon increased liver weights and hepatocellular vacuolation in both
sexes and increased kidney weights in males.  Treatment-related
increased incidences of combined benign and malignant liver tumors in
both sexes were observed.

7. Animal metabolism. The nature of tetraconazole residues is adequately
understood.  Tetraconazole is extensively metabolized very quickly and
eliminated from the body by fecal and urinary routes.

8. Metabolite toxicology.  1,2-4-Triazole is the major metabolite
identified in urine and feces with minor amounts of triazole acid and
alcohol.  The most conservative toxicology endpoint for 1,2,4-triazole
is 15 mg/kg/day, based on body weight decreases in male rats in the
reproductive study.

9. Endocrine disruption. Tetraconazole did not have effects on endocrine
organs or tissues, nor were there any indications of effects on fetal
development in either rats or rabbits, or on reproductive performance in
rats.  Therefore, at doses likely to be encountered, tetraconazole in
not likely to be an endocrine disruptor.

C. Aggregate Exposure

1. Dietary exposure.  Using 100% crop treated scenarios and existing
sugar beet, cattle, horse, goat, and sheep RAC tolerances and proposed
soybean and poultry RAC tolerance for residue exposure assumptions,
acute dietary exposure from food to tetraconazole occupies 0.5% of the
aPAD (0.225 mg/kg at UF = 100) for females 13 to 49 years old, the only
population subgroup for which an acute toxicity endpoint was determined.
 Using the same exposure assumptions, chronic dietary exposure from food
to tetraconazole occupies 3.9% and 11.1% of the cPAD (0.0073 mg/kg/day
at UF = 100) for the U.S. population and the most sensitive
subpopulation, non-nursing infants, respectively.  The most potent unit
risk used for the purpose of lifetime cancer risk assessment by the
Agency is Q1* = 2.30 x 10-2 in human equivalents.  Using the same
assumptions except for 50% and 10% crop treated scenarios for sugar beet
and soybean, respectively, and mean residue exposure for soybean oil and
seed, the estimated aggregate cancer risk from dietary exposure for the
proposed use on soybeans is 0.21 x 10-6, a value that falls within the
Agency's acceptable risk standard for cancer in the range of <1 x 10-6. 

i. Food. The cRfD and aRfD values of 0.0073 mg/kg bw and 0.225 mg/kg bw,
respectively, were used to assess risk from dietary exposure.  Tier 1
dietary risk assessments indicate that the highest chronic and acute
exposures never exceed 11.1% and 0.5% (at the 99.9th percentile of
exposure) for the cRfD and aRfD, respectively.

ii. Drinking water. The standard EPA Mississippi soybean PRZM/EXAMS
modeling scenario with index reservoir (IR) was used to conservatively
estimate concentrations of tetraconazole in drinking water resulting
from the proposed use on soybeans.  Extensive surface water monitoring
results generated by the Minnesota Department of Agriculture were used
to estimate concentrations of tetraconazole in drinking water resulting
from use on sugar beets.  The drinking water estimated concentrations
(DWECs) from the Mississippi soybean scenario model were 2.19 ppb
(acute), 0.578 ppb (chronic) and 0.441ppb (30 year lifetime average). 
These are 6 to 28 times greater than the highest level of tetraconazole
detected in Minnesota surface water, which was 0.075 ppb (1/2 Level of
Quantitation).  Thus, the Mississippi DWECs were used to assess dietary
risks from exposure to drinking water for uses on sugar beets and
soybeans.  The DWECs are lower than the lowest drinking water level of
comparison (DWLOC) values of 6,720 ppb (acute), 69 to 249 ppb (chronic),
and 1.516 ppb (cancer).  When DWLOC values are not exceed by DWEC values
it can be concluded that dietary risks from exposure to drinking water
are acceptable.

2. Non-dietary exposure. Tetraconazole is currently not registered for
use on any residential non-food site.  Therefore, residential exposure
to tetraconazole residues will be through dietary exposure only.

D. Cumulative Effects

EPA has not made a common mechanism of toxicity finding as to
tetraconazole and any other substance.  However, the Agency does have
concern about potential toxicity to 1,2,4-triazole and two conjugates,
triazolylalanine and triazolyl acetic acid.  To support the extension of
existing parent triazole-derivative fungicide tolerances, EPA conduced
an interim human health assessment for aggregate exposure to
1,2,4-triazole.  

Based on this assessment EPA concluded that for all exposure durations
and population subgroups, aggregate exposures to 1,2,4-triazole are not
expected to exceed its level of concern.

E. Safety Determination

1. U.S. population. Based on the exposure assumptions described above
and on the completeness of the toxicology database, it can be concluded
that total aggregate exposure from food and water to the U.S. population
and all evaluated population subgroups from tetraconazole exposure from
all proposed uses will be below 100% of the RfDs.  EPA generally has no
concerns for estimated exposures below 100% of the RfD, since the RfD
represents the level at or below which daily aggregate exposure will not
pose an appreciable risk to human health.  Thus, ISAGRO believes it can
be concluded that there is reasonable certainty that no harm will result
from aggregate exposure to tetraconazole residues for registered and
proposed uses on sugar beets and soybeans.

2. Infants and children. In assessing the potential for additional
sensitivity of infants and children to residues of tetraconazole, the
data from developmental toxicity studies in both the rat and rabbit and
a two generation reproduction study in rats have been considered.  These
toxicity studies indicate the offspring are not more sensitive and all
developmental and reproductive effects were secondary to severe maternal
toxicity. Thus, ISAGRO believes that infants and children are protected
and that an additional uncertainty factor for infants and children is
not warranted.

F. International Tolerances

Maximum residue levels (MRL) have been established for tetraconazole in
the following countries (in ppm).

Belgium: sugar beet root, 0.05; wheat grain, 0.05; wheat straw, 2.0.

France: apple, 0.2; barley grain, 0.02; grape, 0.2; wine, 0.01; sugar
beet root, 0.05; wheat grain, 0.02. 

Italy: apple, 0.5; artichoke, 0.2; barley grain, 0.1; courgette, 0.2;
cucumber, 0.2; grape, 0.5; melon, 0.05; peach, 0.2; pear, 0.2; pepper,
0.2; tomato, 0.2, watermelon, 0.05; wheat grain, 0.05 

Portugal: apple, 0.3; grape, 0.2; melon, 0.1; peach, 0.2; pear, 0.3;
strawberry, 0.2; sugar beet root, 0.05.

Spain: apple, 0.2; artichoke, 0.05; cucurbit fruit & edible peel, 0.2;
nectarine, 0.2; peach, 0.2; pear, 0.2; sugar beet leaves, 0.3; sugar
beet root; 0.05; tomato, 0.1.

United Kingdom: barley grain, 0.2; barley straw, 10; oat grain, 0.1; oat
straw, 2; wheat grain, 0.05; wheat straw, 5.

Czech Republic: apple, 0.5; grape, 0.05

Hungary: apple, 0.2; grape, 0.5; sugar beet root & leaves, 0.5; sugar
beet root, 0.1; wheat grain, 0.05; wheat straw, 3.

Poland: apple, 0.5; cereal grain, 0.05; cereal straw, 3; cucumber edible
peel, 0.2.

Japan: wheat, 0.05; barley; 0.2 other cereal grain, 0.1; sugar beet,
0.5; artichoke, 0.2; tomato, 1; cucumber, 0.5; pumpkin (including
squash), 1; oriental cucurbitaceous vegetables, 0.2; apple, 0.5,
Japanese pear, 0.5, pear, 0.5 quince, 0.5 peach, 0.3, nectarine, 0.2;
apricot, 0.2; Japanese plum (including prune); 0.2; cherry, 0.2;
strawberry, 2; watermelon, 0.2, melon, 0.2; makuwauri, 0.2; grape, 0.5;
tea, 20.

 	 

      

Page  PAGE  1  of 6