Document ID: EPA-HQ-OPP-2007-0007-0002
Agency: epa
Document Type: Supporting & Related Material
Title: 
Posted Date: 2007-01-31T05:00Z

Tolerance Reassessment Eligibility Decision

Urea Sulfate

Special Review and Reregistration Division 

Office of Pesticide Programs

U.S. Environmental Protection Agency

1801 South Bell Street

Arlington, VA  22202

June 14, 2005

Background:

The Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) was
amended in 1988 to accelerate the reregistration of products with active
ingredients registered prior to November 1, 1984.  The amended Act
called 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) to assess the current tolerances.  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 or not the
pesticide meets the “no unreasonable adverse effects” criteria of
FIFRA.

On August 3, 1996, the Food Quality Protection Act (FQPA) was signed
into law.  FQPA amends FIFRA to require tolerance reassessment during
reregistration.  In addition, FQPA requires that all active ingredients
first registered after 1984 would also be reevaluated to reassess their
current tolerances, by 2006.  FQPA also amends the Federal Food, Drug,
and Cosmetic Act (FFDCA) to require a safety finding in tolerance
reassessment based on factors including an assessment of cumulative
effects of chemicals with a common mechanism of toxicity.  

In this document, the current exemption from the requirement for a
tolerance for urea sulfate is being reassessed in order to meet FQPA
standards.  This document represents the Lower Risk Pesticide Chemical
Focus Group’s (LRPCFG) Tolerance Reassessment Eligibility Decision
(TRED) on urea sulfate (monocarbamide dihydrogen sulfate).  Urea sulfate
is used both as an herbicide and desiccant (each current label actually
lists this active ingredient as 1-aminomethanamide dihydrogen
tetraoxosulfate).  This active ingredient was first registered in 1987. 

The Agency has determined that urea sulfate readily degrades to urea and
sulfuric acid and/or sulfate ions in the environment and in the human
body.  Therefore, this tolerance reassessment for the active ingredient
urea sulfate is based on the recent tolerance reassessments performed on
both urea and sulfuric acid and its salts.  Urea tolerances were
reassessed under the 2002 TRED for urea, while the active and inert
tolerances for sulfuric acid were reassessed through the LRPCFG’s
assessment of mineral acids and their ammonium, calcium, ferrous,
ferric, magnesium, potassium, sodium, and/or zinc salts (7/24/2002).  In
addition, the Mineral Acids TRED relied on information from the 1993
Mineral Acids Reregistration Eligibility Decision (RED).

I.  Executive Summary:

Urea sulfate is used primarily as an active ingredient in herbicides and
desiccants on agricultural crops.  Five products are currently
registered with urea sulfate as an active ingredient, three of which
contain urea sulfate as the only active ingredient.  According to an EPA
Pesticide Fact Sheet, “Acute toxicology data indicate that the
chemical is extremely caustic and corrosive.  The appropriate toxicity
category is I (DANGER), based on primary eye and skin irritation
studies.  Chronic toxicology and environmental fate data requirements
are waived.”  Since urea sulfate readily degrades to urea and sulfuric
acid and/or sulfate ions in the environment and in the human body, the
Agency used the tolerance reassessments for urea and sulfuric acid
(sulfate salts) to reassess the tolerance for urea sulfate.

The urea TRED states that “Based on the hazard assessment of urea,
exposures to this compound resulting from reasonably anticipated
patterns of usage present a reasonable certainty of no harm to human
health. Given the low toxicity of urea, a more detailed assessment of
risks resulting from exposure to urea, when used either as a frost
protectant or pesticide inert ingredient, is not necessary based on the
hazard assessment of urea, exposures to this compound resulting from
reasonably anticipated patterns of usage were not believed to present a
reasonable certainty of harm to human health.”  

According to the Mineral Acids RED, sulfuric acid has registered food
uses.  However, because sulfuric acid rapidly degrades in the
environment to sulfate ions, which are of no toxicological concern,
sulfuric acid has been granted an exemption from tolerance requirements.
 While it was determined that the use of sulfuric acid as a potato vine
desiccant might result in dermal and inhalation exposure to workers, all
other uses of pesticide products containing sulfuric acid were
determined to not pose unreasonable risks or adverse effects to humans
or the environment.  According to LRPCFG’s TRED for Mineral Acids and
their Salts, when exposed to liquids, the salts of sulfuric acid would
dissociate to the respective metal cation and the sulfate anion.  That
TRED reported that there was not any available information for the
sulfate ion or any of the salts of sulfuric acid that would indicate a
human health hazard to the general public or any population subgroup
resulting from either the EPA-regulated uses or the FDA GRAS uses, and
that no additional information was needed to assess the safety of the
sulfuric acid or any of its salts.

Based on the findings in the TREDs for both urea and sulfuric acid
(sulfate salts), and the dissociation of urea sulfate to each of these
resulting products, it has been determined that the use of products
containing only urea sulfate as the active ingredient would not present
a human health hazard to the general public.  Products containing urea
sulfate in addition to other active ingredients (ethephon and glyphosate
or any other mixed active ingredient products which might become
registered in the future) would need to be assessed as part of those
respective REDs and/or TREDs for those active ingredients, but it is
determined in this TRED that urea sulfate alone may be reassessed as not
presenting an unreasonable risk to humans or the environment. 
Furthermore, the current exemption from the requirement of a tolerance
for urea sulfate has been reassessed and meets the reasonable certainty
of no harm as defined by FQPA.

II.  Use Information:

Urea Sulfate

Urea sulfate (CAS Number 21351-39-3) has several synonyms:
1-aminomethanamide dihydrogen tetraoxosulfate (the name listed as the
active ingredient on all the current labels); monocarbamide dihydrogen
sulfate; Enquik; N-TAC Desiccant; sulfuric acid monourea; sulfuric acid,
monourea adduct; urea sulfuric acid monoadduct; and urea sulfate (1:1). 
As mentioned above, urea sulfate is used primarily as an active
ingredient in herbicides and desiccants on agricultural crops (PC Code
128961).  The first urea sulfate product was registered in 1987.  The
sole registrant listed in OPPIN Query is Entek Corporation.  Recently,
Griffin LLC purchased Entek, and DuPont Crop Protection is a primary
owner of Griffin, so DuPont is now considered to be the registrant for
the urea sulfate products.

Five products are currently registered with urea sulfate as an active
ingredient, 3 of which contain urea sulfate as the only active
ingredient (See Table 1).  Each of the current products is formulated as
soluble concentrates, except for one, Enquik MP (68891-6), which is a
Manufacturing Use product.  All of the products with urea sulfate as the
sole active ingredient are listed as containing 79% ai, although two
other products also contain other active ingredients.  In addition,
there is currently one SLN (FL960011), while the OPP REFS lists 18 other
SLNs, which have been cancelled, as well as 4 SLNs, which have been
withdrawn.  



Table 1. Registered Products Being Reassessed Containing Urea Sulfate

Registration Number	

Registration Name	

Percent Urea Sulfate	

Other Active Ingredients	

Formulation Type	

Date first registered

68891-1	

SuperQuikTM	

79	

None	

soluble concentrate	

30 Dec, 1987

68891-4	

WilThin Blossom Thinner	

79	

None	

soluble concentrate	

12 Jan, 1995

68891-6	

Enquik MP	

79	

None	

formulation intermediate	

2 Feb, 1996

68891-7	

ETK-2201	

58.6	

18.3% ethephon	

soluble concentrate	

1 Feb, 1996

68891-8	

ETK-2301 Herbicide	

71.1	

9.6% glyphosate	

soluble concentrate	

18 Dec, 1996

FL960011	

Enquik	

79	

None	

soluble concentrate	

22 Oct, 1992

The BEAD Screening Level Usage Analysis (SLUA) in Appendix A indicates
that most of the urea sulfate is applied to cotton, that is, the
ETK-2201 product (also know as CottonQuik), a product also containing
ethephon.  DuPont has submitted confidential sales data to the Agency
indicating that their records, as well as those of Entek, indicate that
ETK-2201 is the only product which has any sales over the last few
years.

The tolerance exemption being reassessed in this document, with the
respective citation in the Code of Federal Regulations (CFR), and the
use pattern as an active ingredient are listed in Table 2. 
Specifically, the tolerance expression at 40 CFR 180.1084 is stated as
follows:  “monocarbamide dihydrogen sulfate is exempted from the
requirement of a tolerance when used as an herbicide or desiccant in or
on all raw agricultural commodities.”

Table 2. Exemption from the Requirement for a Tolerance Being Reassessed
for Urea Sulfate

Tolerance Exemption Expression	

CAS No.	

40 CFR	

PC Code 	

Use Pattern

Active Ingredient

“monocarbamide dihydrogen sulfate”	

21351-39-3	

180.1084	

128961	

as an herbicide or desiccant

Urea

Urea was registered by EPA in 1995 for use as a frost protectant
pesticide under the trade name Enfrost. Enfrost is a 43% liquid
formulation of urea that may be applied commercially to a wide variety
of field crops, vegetables, fruit trees and ornamentals to reduce frost
damage.  There are currently no residential uses for urea as a pesticide
product.  Enfrost is the only currently registered pesticide product
containing urea as an active ingredient, but Enfrost has not been
actively produced or sold by the registrant, Entek Corporation, since
1995.  However, according to the Urea TRED (EPA, 2002a), the registrant
maintains active registration of Enfrost for potential future production
and use. 

In addition, urea is used as an inert pesticide ingredient as a
stabilizer, inhibitor, or intensifier.  Also, several million tons of
urea are produced annually for use in fertilizer and as an animal feed
supplement, with some of the urea being added as a fertilizer in
pesticidal products.  Moreover, urea is used in the manufacture of dyes,
fire retardant paints, plasticizers, and stabilizers for explosives
(EPA, 2002a).

The tolerance exemptions reassessed for urea, with the respective
citation in the Code of Federal Regulations (CFR), and the use pattern
as an active and inert ingredient are listed in Table 3. 

Table 3. Exemption from the Requirement for a Tolerance Reassessed in
the 2002 Urea TRED

Tolerance Exemption Expression	

CAS No.	

40 CFR	

PC Code 	

Use Pattern

urea	

57-13-6 	

Active Ingredient

180.1117	

085702	

frost protectant

Inert Ingredient

180.1001 (c), (d), (e)	

885702	

stabilizer, inhibitor, or intensifier

Sulfuric Acid and its Salts

As an active ingredient in pesticides, sulfuric acid is used as a
desiccant, and it is also used to kill bacteria on potatoes, in milking
equipment, and within food processing areas.  It was first registered as
a desiccant/herbicide in the U.S. as early as 1971 and was exempted from
the requirement for a residue tolerance for this use (40 CFR 180.1019). 
A food processing sanitizer product, containing sulfuric acid as well as
other active ingredients, was registered in 1992.   Sulfuric acid as an
active ingredient was evaluated in the 1993 Mineral Acids RED (EPA,
1993).  In addition, sulfuric acid is registered for use as an inert
ingredient in certain pesticide products.  It is primarily used as a pH
control agent and is included at concentrations of up to 0.1% of the
pesticide formulation, according to the Sulfuric Acid and its Salts TRED
(EPA, 2002b).    

The tolerance exemption reassessed for sulfuric acid, with the
respective citation in the Code of Federal Regulations (CFR), and the
use pattern as an active ingredient are listed in Table 4.

Table 4. Exemption from the Requirement for a Tolerance Reassessed in
the 2002 Mineral Acids (Sulfuric Acid) TRED

Tolerance Exemption Expression	

CAS No.	

40 CFR	

PC Code 	

Use Pattern

sulfuric acid	

7664-93-9 	

Active Ingredient

180.1019	

078001	

used to kill bacteria on potatoes, milking equipment and in food
processing areas; as a desiccant

Inert Ingredient

180.1001(c)	

878001	

pH control agent

III.  Physical/Chemical Properties:

The physical and chemical properties of urea sulfate are provided in
Table 5.  This information was obtained from the profiles in TOXNET
(ChemIDplus) and CambridgeSoft (ChemFinder), as well as various MSDS
sheets for urea sulfate/monocarbamide dihydrogen sulfate. 



Table 5.  Physical/Chemical Properties of Urea Sulfate

	

References

Structure	

	

ChemIDplus Lite (2004)

Chemical Name	

urea sulfate; uronium hydrogen sulphate

	

Molecular formula	

CH4N2O · H2SO4	

MSDS (2004)

Color/Form	

Clear to slightly hazy liquid

	

Odor	

odorless

	

Boiling point	

Decomposes (110oC or 230oF)

	

Melting point	

5.6oC (42oF) Salt out temp.

	

Density/Specific Gravity 	

12.65 lbs/gal; 1.52 (Water =1)

	

pH	

 1 (for a 10% solution in water)

	

Solubilities	

Easily soluble in cold water, hot water

	

Volatility	

18% (w/w)

	

IV.  Hazard Characterization:

A. Toxicity

Acute toxicity studies were conducted to support registration of urea
sulfate.  Table 6 provides the information available on the acute
toxicity of urea sulfate.  Currently, there are no chronic toxicity
studies available for urea sulfate.  According to an EPA Pesticide Fact
Sheet (EPA, 1987), chronic toxicity studies were waived in accordance
with provisions of 40 CFR 162.45 (c).



Table 6.  Acute Toxicity Profile for Urea Sulfate (monocarbamide
dihydrogen sulfate)

Study Type	

Species	

Results	

Toxicity Category	

Reference

Acute Oral 	

Rat	

1,200 mg/kg (male)

350 mg/kg (female)	

II	

EPA Pesticide Fact Sheet (1987)

Acute Dermal	

Rabbit	

>2 g/kg

Study terminated at 48 hrs because of extreme caustic action and dermal
necrosis.	

Not determined

	

Acute Inhalation	Rat	

>10.8 mg/L	

III

	

Primary Eye Irritation	

Rabbit	

Severe corneal involvement, grade 4 chemosis of conjunctivae at 24 hrs.	

I

	

Primary Skin Irritation	

Rabbit	

Caustic on intact and abraded skin at 24 hours.  Study was terminated at
24 hours after similar results were obtained with 1:4 v/v dilution with
water	

I

	

For urea, the acute toxicity studies were submitted by the registrant. 
These acute studies indicated that the registered product for urea
(i.e., the frost protectant) was a slight eye irritant and had a low
toxicity to animals.  In addition, there were other studies cited from
the available literature.  In subchronic studies, no severe toxicity was
observed for urea in dogs, and no adverse organ pathology was found.  In
addition, animal studies provided no evidence of adverse chronic or
carcinogenic effects, nor developmental or teratogenic effects.

For sulfuric acid, the available toxicity studies indicate that is
corrosive to the eyes and skin and is toxic via the inhalation route. 
However, sulfuric acid readily degrades in the environment to sulfate
ions.  In addition, studies conducted with the salts of sulfuric acids
indicate that these salts are not of toxicologic concern, especially
since these salts dissociate in water into the respective metal cation
and the sulfate anion.

B.  Metabolism

The Agency has determined that urea sulfate rapidly degrades to urea and
sulfuric acid and/or sulfate ions in the human body.  Thus, the data
requirements for the higher tier toxicity studies have all been waived
by the Agency, and there are no repeated dose toxicity studies available
for urea sulfate.   

C.   Special Considerations for Infants and Children

Data from repeated dosing toxicity studies with animals does not exist
for urea sulfate.  However, urea sulfate readily degrades to urea and
sulfuric acid and/or the sulfate ion in the body.  Based on the toxicity
data reviewed in this tolerance assessment documents for urea and for
sulfuric acid and its salts, there are no adverse effects that would be
expected in infants and children for urea sulfate.  For urea, animal
studies provide no evidence of developmental nor teratogenic effects. 
In an aqueous environment, sulfuric acid rapidly ionizes to sulfate ions
which are of no toxicological concern to infants and children.  For
these reasons, a safety factor analysis has not been used to assess the
risks resulting from the use of urea sulfate; therefore, an additional
tenfold safety factor for the protection of infants and children is
unnecessary.

V.  Exposure Assessment:

The Agency has determined that urea sulfate breaks down readily into
both urea and sulfuric acid and/or sulfate ion in the human body.  Since
the risks have already been assessed for these various other chemicals,
it is not necessary to repeat these other risk assessments to reassess
the food-use tolerance for urea sulfate.  The conclusions of the RED
documents for urea and mineral acids (sulfuric acid), as well as the
TRED documents for urea and the mineral acids (sulfuric acid and its
salts), indicate that these chemicals have been determined to not
present unacceptable risks to humans or the environment.

VI.  Dietary  Exposure:

Based on the dissociation of urea sulfate in the human body to urea and
sulfuric acid and/or sulfate ion, the Agency has determined that only a
qualitative dietary assessment is needed, based on the results of the
REDs and TREDs for these constituent products.  Thus, the Agency has
determined that there are no dietary risk concerns, whether from the
ingestion of food or water or both, for urea sulfate (or at least for
the consumption of products containing urea sulfate as the sole active
ingredient).

VII.  Aggregate Assessment:

In examining aggregate exposure, FFDCA section 408 directs EPA to
consider available information concerning exposures from the pesticide
residue in food and all other non-occupational exposures, including
drinking water from ground water or surface water and exposure through
pesticide use in gardens, lawns, or buildings (residential and other
indoor uses).  In developing this tolerance assessment document for urea
sulfate, a qualitative assessment for all pathways of human exposure
(food, drinking water, and residential) is appropriate given the lack of
human health concerns associated with exposure to this chemical, as well
as its constituent products (urea and sulfuric acid and/or sulfate
ions).

VIII.  Cumulative Exposure:

Section 408(b)(2)(D)(v) of the FFDCA requires that, when considering
whether to establish, modify, or revoke a tolerance, the Agency consider
“available information” concerning the cumulative effects of a
particular pesticide’s residues and “other substances that have a
common mechanism of toxicity.”  If chemicals are structurally related
and all are low toxicity chemicals, then the risks either separately or
combined should also be low.

EPA does not have, at this time, available data to determine whether
urea sulfate has a common mechanism of toxicity with other substances. 
Unlike other pesticides for which EPA has followed a cumulative risk
approach based on a common mechanism of toxicity, EPA has not made a
common mechanism of toxicity finding as to urea sulfate and any other
substances, and urea sulfate does not appear to produce a toxic
metabolite produced by other substances.   

For the purposes of this tolerance action, therefore, EPA has assumed
that urea sulfate does not have a common mechanism of toxicity with
other substances.  For information regarding the Agency’s efforts to
determine which chemicals have a common mechanism of toxicity and to
evaluate the cumulative effects of such chemicals, see the policy
statements released by EPA’s Office of Pesticide Programs concerning
common mechanism determinations and procedures for cumulating effects
from substances found to have a common mechanism on EPA’s website at
http://www.epa.gov/pesticides/cumulative/.

IX.  Risk Characterization:

As mentioned above, the Agency has been determined that urea sulfate
readily breaks down into urea and sulfuric acid and/or sulfate ion in
the environment and in the human body.  Assessments performed on both
these substituent compounds indicate no reasonable certainty of harm to
human health from either the EPA-registered uses or the FDA-GRAS uses. 
Therefore, it has been determined that the use of products containing
urea sulfate (as the sole active ingredient) also would not present a
human health hazard to the general public.   

X.  Environmental Fate/Ecotoxicity/Drinking Water Considerations:  

Urea Sulfate

All of the environmental fate data requirements for urea sulfate have
been waived by the Agency because the environmental fate is so well
known for its two substituent compounds, urea and sulfuric acid.  In
addition, many of the ecotoxicity data requirements have also been
waived.  It has also been determined that the use of products containing
urea sulfate is not expected to impact groundwater, according to a
document prepared by the New York State Department of Environmental
Conservation regarding the uses of various urea sulfate end-use products
(EPA, 1997).

Urea

Available data from literature reviews show that urea degrades rapidly
in most soils, with it generally hydrolyzed to ammonium through soil
urease activity.  In various soils, the hydrolysis may near completion
within 24 hours; however, the rate of hydrolysis can be much slower
depending upon soil type, moisture content, and urea formulation.  Soil
adsorption studies show that urea sorbs very weakly to soil; therefore,
leaching is possible.  Ultimate degradation of urea produces ammonia and
carbon dioxide as volatile products.  Biodegradation is expected to be
the major fate process in the aquatic ecosystem.  The rate of
biodegradation generally decreases with decreasing temperatures. 
Naturally-occurring phytoplankton increases the degradation rate,
because phytoplankton can use urea as a nitrogen source.  In
phytoplankton-rich waters, degradation occurs much faster in sunlight
than in the dark.  Abiotic hydrolysis of urea occurs very slowly in
relation to biotic hydrolysis (EPA, 2002a).

Sulfuric Acid

Sulfuric acid generally dissolves in the environment and release sulfate
ions and hydrogen ions, and these hydrogen ions, in turn, increases the
acidity of the soil or water (EPA, 1993).  The extent of the increased
acidity depends on the amount of the neutralizing ions present, the
buffering capacity, and the amount of dilution possible. 

XI.  References

ChemIDplus Lite.  Printed 2004.  Urea, sulfate (1:1). CAS Reg. No.:
21351-39-3.

http://chem.sis.nlm.nih.gov/chemidplus/jsp/chemidlite/ChemFull.jsp

ChemFinder.com Database and Internet Searching.  Printed 2004.  Urea
Sulfate.

http://chemfinder.cambridgesoft.com/result.asp

Material Safety Data Sheet for SuperQuik TM.  Printed 2005; Date of
preparation 3/8/99, with revised sections: New MSDS Issue.  http://www.

Material Safety Data Sheet for Wilthin.  Printed 2005; Date of
preparation 1/22/99, with revised sections: New MSDS Issue.  http://www.

Material Safety Data Sheet for Monocarbamide Dihydrogen Sulfate. 
Printed 2004; Date of preparation 7/28/99. 
www.spindlerenterprises.com/files/pH_Perfect.PDF 

Material Safety Data Sheet for Monocarbamide Dihydrogen Sulfate. 
Printed 2004; Date of preparation 9/27/04. 
http://www.agrium.com/products_services/msds/liquid.cfm

Material Safety Data Sheet for Monocarbamide Dihydrogen Sulfate
Solution.  Printed 2004.

http://www.yourgrowingsolutions.com/id13.html

U.S. EPA. 1987.  Monocarbamide (Enquik, WilThin) Herbicide Profile.  EPA
Pesticide Fact Sheet. #151.

U.S. EPA. 1993.  Mineral Acids Reregistration Eligibility Decision
(RED).  Prevention, Pesticides, and Toxic Substances (7508W). 
EPA-738-F-93-025.

U.S. EPA. 1997.  Monocarbamide (Enquik, WilThin) NYSDEC Registration
Approval.  New York State Department of Environmental Conservation,
Division of Solid and Hazardous Materials.  

U.S. EPA.  2002a.  Urea Tolerance Reassessment Eligibility Decision
(TRED).  Federal Register: April 15, 2002.  Volume 67, Number 72.  

U.S. EPA. 2002b.  Tolerance Reassessment Decisions Completed by the
Inert Ingredient Focus Group (IIFG): IIFG Decision Documents on
Reassessing Exemptions from the Requirement of a Tolerance for the
Mineral Acids, (Hydrochloric, Carbonic, Phosphoric, and Sulfuric) and
their Ammonium, Calcium, ferrous, Magnesium, Potassium, Sodium, and/or
Zinc Salts.



Appendix 1.  BEAD Screening Level Usage Analysis 

for Urea Sulfate for Agricultural Uses tc \l1 "Appendix 1.  BEAD
Screening Level Usage Analysis for Urea Sulfate for Agricultural Uses 
and Other Information

Urea Sulfate (128961)

Screening Level Usage Analysis (SLUA)

Date: 6/2/05

What is a Screening Level Usage Analysis (SLUA)?

	Available estimates of pesticide usage data for a particular active
ingredient that is used on agricultural crops in the United States.

What does it contain?

	Pesticide usage data for a single active ingredient only.

-	Agricultural use sites (crops) that the pesticide is reported to be
used on. 

-	Available pesticide usage information (i.e., does not include all of
the United States).

-	Annual percent of crop treated (average & maximum) for each
agricultural crop.

-	Average annual pounds of the pesticide applied for each agricultural
crop (i.e., for the states surveyed, not for the entire United States).

What assumptions can I make about the reported data?

	Average pounds of active ingredient applied - Values are calculated
by merging pesticide usage data sources together; averaging by year,
averaging across all years, & then rounding.  Note:  If the estimated
value is less than 500, then that value is labeled <500.  Estimated
values between 500 & <1,000,000 are rounded to 1 significant digit. 
Estimated values of 1,000,000 or greater are rounded to 2 significant
digits.)

	Average percent of crop treated - Values are calculated by merging
data sources together; averaging by year, averaging across all years, &
rounding to the nearest multiple of 5.  Note:  If the estimated value is
less than 1, then the value is labeled <1.

	Maximum percent of crop treated - Value is the single maximum value
reported across all data sources, across all years, & rounded up to the
nearest multiple of 5.  Note:  If the estimated value is less than 2.5,
then the value is labeled <2.5.

What are the data sources used?

	USDA-NASS (United States Department of Agriculture’s National
Agricultural Statistics Service) – pesticide usage data from 1998 to
2003.

	NCFAP (National Center for Food and Agricultural Policy) –
pesticide usage data from 1997 & is only used if data is not available
from the other sources.

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et research – pesticide usage data from 1998 to 2003. 

	California DPR data can be requested separately.

What are the limitations to the data?

	Additional registered uses may exist but are not included because
the available surveys do not report usage (e.g., small acreage crops).

	Lack of reported usage data for the pesticide on a crop does not
imply zero usage.

	Usage data on a particular site may be noted in data sources, but
not quantified.  In these instances, the site would not be reported in
the SLUA.

	Non-agricultural use sites (e.g., turf, post-harvest, mosquito
control, etc.) are not reported in the SLUA.  A separate request must be
made to receive these estimates.

 



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Uses of Urea Sulfate (128961)

Sorted Alphabetically

  	 		

  	 Crop		   Lbs. A.I.      	Percent Crop Treated

                                    	 Avg.        Max.

1 	Apples		9,000			 <1           <2.5

2 	Cotton	  3,000,000	      	  5           10

3 	Peppers	    200,000			  5            5

4 	Tomatoes	     80,000			 <1           <2.5

  	 		

______________________________________		

  	 		

All numbers rounded.		

'<2.5' indicates less than 2.5 percent of crop is treated.	

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