Tolerance Reassessment 

Eligibility Decision for Urea Sulfate 

June 2005 
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 

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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. 

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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, 

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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 

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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 (110o

C or 230oF) 

Melting point 5.6o

C (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). 

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

Study Type 

Acute Oral 

Species 

Rat 

Results 

1,200 mg/kg (male) 

350 mg/kg (female) 

Toxicity 

Category 

II 

Reference 

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 

6 
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 

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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. 

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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. 

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Appendix 1. BEAD Screening Level Usage Analysis 

for Urea Sulfate for Agricultural Uses and Other Information 

10 
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. 

_ 	 Private pesticide market 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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______________________________________ 

Wednesday, June 1, 2005 15:24 


Screening Level Estimates of Agricultural 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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