Docket Number:  EPA-HQ-OPP-2008-0023

www.regulations.gov

Coumaphos Summary Document

Registration Review: Initial Docket

June 2008

Registration Review Document for

Coumaphos 

Case No. 0018

Approved By:

								

___________________

								Steven Bradbury, Ph.D.

								Director, Special Review and

		       	      Reregistration Division

TABLE OF CONTENTS

										Page #

Preliminary Work Plan (PWP)					4

Fact Sheet								9

Glossary of Terms and Abbreviations			        16

_________________________________________________

Please Note

This Preliminary Work Plan and Fact Sheet summarize the Environmental
Protection Agency’s current position based on the following documents:

	1.  Revised Registration Review Preliminary Problem Formulation for the
Ecological    

                 Risk Assessment of Coumaphos.  April 28, 2008.

	

	2.  Coumaphos:  Registration Review Scoping Document for Human Health 

	     Assessments.   February 28, 2008.

	3.  Coumaphos – California Department of Pesticide Regulation (DPR)
Usage Report.  

                 October 12, 2007.

Additional supporting documents for coumaphos may be found in the docket
EPA-HQ-OPP-2008-0023 which may be found on the internet at   HYPERLINK
"http://www.regulations.gov"  www.regulations.gov .

I. Preliminary Work Plan – Coumaphos

Introduction:

The Food Quality Protection Act of 1996 mandate: registration review. 
All pesticides distributed or sold in the United States generally must
be registered by EPA, based on scientific data showing that they will
not cause unreasonable risks to human health, workers, or the
environment when used as directed on product labeling.  The registration
review program is intended to make sure that, as the ability to assess
risk evolves and as policies and practices change, all registered
pesticides continue to meet the statutory standard of no unreasonable
adverse effects.  Changes in science, public policy, and pesticide use
practices will occur over time.  Through the registration review
program, the Agency periodically reevaluates pesticides to make sure
that as change occurs, products in the marketplace can be used safely. 
Information on this program is provided at:
http://www.epa.gov/oppsrrd1/registration_review/. 

The Agency has begun to implement the Registration Review program, and
will review each registered pesticide every 15 years to determine
whether it continues to meet the FIFRA standard for registration.  The
public phase of registration review begins when the initial docket is
opened for each case.  The docket is the Agency’s opportunity to state
what it knows about the pesticide and what additional risk analyses and
data or information it believes are needed to make a registration review
decision.  After reviewing and responding to comments and data received
in the docket during this initial comment period, the Agency will
develop and commit to a final work plan and schedule for the
registration review of coumaphos.  

Coumaphos was first registered as a pesticide in the U.S. in 1958.  The
active ingredient coumaphos is a member of the organophosphate (OP)
insecticide class that primarily affects the nervous system through
cholinesterase (ChE) inhibition. The current supported uses for
coumaphos include direct application to animals, including dairy cattle,
beef cattle, swine, and horses, for the control of arthropod pests
including ticks, scabie mites, lice, flies, fleece worms and screw
worms.  Coumaphos is also used in impregnated plastic strips in bee
hives to control varroa mites and small hive beetles.  Coumaphos
currently has no agricultural crop or residential uses.  

Anticipated Risk Assessment and Data Needs:

The Agency anticipates conducting an ecological risk assessment,
including an endangered species assessment for all uses of coumaphos. 
The Agency anticipates that no additional human health risk assessments
or related data will be needed.

	Ecological Risk:

The most recent drinking water and ecological risk assessment was
completed on May 16, 2006, for use in beehives to control varroa mites
and small hive beetles.  

The Agency anticipates needing the following data in order to conduct a
complete ecological risk assessment for coumaphos, including an
endangered species assessment.  Please refer to section 1.11.3, the
Revised Registration Review Preliminary Problem Formulation for the
Ecological Risk Assessment of Coumaphos for a detailed discussion of the
anticipated risk assessment needs.

		Environmental Fate Studies:

                                                                        
                                                                        
                                                                        
                                                                        
                                                                        
                                                                        
                                                                        
                                                                        
                                                                        
                                                                        
                                                                        
                                                                        
                                                                        
                            

		These studies are intended to provide information on how, or by what
mechanism, 		the pesticide degrades, the rate at which it degradates,
where it goes, and what 		  	transformation products are formed:

Guideline Number: 835.4100 - Aerobic Soil Metabolism (Oxygen

		         Analog; Coumaphoxon)

Guideline Number: 835.1220 - Sediment and Soil Adsorption/Desorption
Batch Equilibrium (Oxygen Analog, Coumaphoxon) 

		

		Ecological Toxicity Studies:

		These studies are intended to determine whether coumaphos is toxic to
algae and 			other aquatic plants.  The registered uses of coumaphos as
a direct treatment for 			cattle may result in exposure to aquatic
habitats when treated cattle wade in 			ponds, streams, and other water
bodies.  The aquatic plant studies will allow EPA 			to conduct a risk
assessment for aquatic habitats:

Guideline Number: 850.4400 - Aquatic Plant Toxicity Test, Tier I  

Guideline Number: 850.5400 - Algal Toxicity, Tier I  

The planned ecological risk assessment will allow the Agency to
determine whether coumaphos’s use has “no effect” or “may
affect” federally listed threatened or endangered species (listed
species) or their designated critical habitat.  If the assessment
indicates that coumaphos “may affect” a listed species or its
designated critical habitat, the assessment will be refined.  The
refined assessment will allow the Agency to determine whether use of
coumaphos is “likely to adversely affect” the species or critical
habitat or “not likely to adversely affect” the species or critical
habitat.  When an assessment concludes that a pesticide’s use “may
affect” a listed species or its designated critical habitat, the
Agency will consult with the U.S. Fish and Wildlife Service and/or
National Marine Fisheries Services (the Services), as appropriate.

Human Health Risk:

The previously completed dietary assessments (February 28, 2007) that
considered exposures to coumaphos from food and drinking water are
adequate and there is no dietary risk that exceeds the Agency’s level
concern (LOC).   

 

The Agency does not anticipate requiring any further human health
effects data.  However, the Agency will update the dietary assessment to
reflect tolerances for honey and honeycomb.

The Agency will also need to revisit the United States Department of
Agriculture’s (USDA) Pesticide Data Program (PDP) monitoring data for
beef and milk that were used in the previous dietary risk assessment. 
FQPA requires the Agency to revisit the data five years after the
tolerance assessment decision.  

Occupational risks have been mitigated below the Agency’s level of
concern, and therefore no additional data or risk assessment are needed 


Timeline:

EPA has created the following estimated timeline for the completion of
the coumaphos registration review.  

Registration Review for Coumaphos – Projected Registration Review
Timeline

Activities	Time

Phase 1:  Opening the docket

Open Docket and Public Comment  	2008 - June

Close Public Comment	2008 - September

Phase 2:  Case Development

Final Work Plan 	Nov. 2008

Issue DCI	2009 - Jul. - Sept.

Data Submission	2011 - Oct. - Dec.

Preliminary Risk Assessments and Public Comment 	2013 - Apr. - Jun.  

Close Public Comment Period	2013 - Jul. -  Sept.

Phase 3:  Registration Review Decision

Proposed Registration Review Decision 	2013 - Oct. – Dec.

Close Public Comment Period 	2014 – Jan. - Mar.

Final Registration Review Decision and Begin Post-Decision Follow-up
2014 -  Jul. – Sept. 

Total (years)	6.0



Guidance for Commenters:

The public is invited to comment on EPA’s preliminary registration
review work plan and rationale.  The Agency will carefully consider all
comments as well as any additional information or data provided in a
timely manner prior to issuing a final work plan for the coumaphos case.

Through the registration review process, the Agency intends to solicit
information on trade irritants and, to the extent feasible, take steps
toward facilitating irritant resolution.  Growers and other stakeholders
are asked to comment on any trade irritant issues resulting from lack of
Maximum Residue Limits (MRLs) or disparities between U.S. tolerances and
MRLs in key export markets, providing as much specificity as possible
regarding the nature of the concern. 

Coumaphos is not identified as a cause of impairment for any water
bodies listed as impaired under section 303(d) of the Clean Water Act,
based on information provided at
http://oaspub.epa.gov/tmdl/waters_list.impairments?p_impid=3.  The
Agency invites submission of water quality data for this pesticide.  To
the extent possible, data should conform to the quality standards in
Appendix A of the OPP Standard Operating Procedure: Inclusion of
Impaired Water Body and Other Water Quality Data in OPP’s Registration
Review Risk Assessment and Management Process (see:   HYPERLINK
"http://www.epa.gov/oppfead1/cb/ppdc/2006/november06/session1-sop.pdf" 
http://www.epa.gov/oppfead1/cb/ppdc/2006/november06/session1-sop.pdf ),
in order to ensure they can be used quantitatively or qualitatively in
pesticide risk assessments. 

EPA seeks to achieve environmental justice, the fair treatment and
meaningful involvement of all people, regardless of race, color,
national origin, or income, in the development, implementation, and
enforcement of environmental laws, regulations, and policies. To help
address potential environmental justice issues, the Agency seeks
information on any groups or segments of the population who, as a result
of their location, cultural practices, or other factors, may have a
typical, unusually high exposure to coumaphos compared to the general
population.  Please comment if you are aware of any sub-populations that
may have a typical, unusually high exposure compared to the general
population.

Stakeholders are also specifically asked to provide information and data
in refining the ecological risk assessment, including any
species-specific effects determinations. The Agency is interesting in
obtaining the following information for coumaphos.

any current information pertaining to disposal of bioremediated cattle
dip spent solution (i.e. dried sludge generated in the evaporation
ponds)

confirmation on the following label information

sites of application

formulations

application methods and equipment

maximum application rates

frequency of application, application intervals, and maximum number of
applications per season

geographic limitations on use

use or potential use distribution (e.g., geographical distribution)

use history

application timing (date of first application and application intervals)
- national, state, and county

usage/use information for non-agricultural uses (e.g., direct
application to animals, bee hives) 

directly acquired county-level usage data (not derived from state level
data)

maximum reported use rate from usage data – county

total pounds per year – county

the year the pesticide was last used in the county/sub-county area

the years in which the pesticide was applied in the county/sub-county
area

typical interval (days)

state or local use restrictions

ecological incidents (non-target plant damage and avian, fish,
reptilian, amphibian and mammalian mortalities) not already reported to
the Agency

monitoring data

Next Steps:

After the comment period closes, the Agency will review any comments
received in a timely manner, and then issue a Final Work Plan for this
pesticide.

II. FACT SHEET

 

Background Information:

Coumaphos registration review case number: 0018.

Coumaphos PC Code: 036501, CAS#: 56-72-4. 

Technical registrants:  Bayer HealthCare LLC.

One technical product and 16 end-use products.  

First registered as a pesticide in the U.S. in 1958.

Reregistration Eligibility Decision (RED) completed in August 1996.

Finalization of Interim Reregistration Eligibility Decisions (IREDs) and
Interim Tolerance Reassessment and Risk Management Decisions (TREDs
(September 2000), and Completion of the Tolerance Reassessment and
Reregistration Eligibility Process for the Organophosphate Pesticides
was completed in July 2006.

Special Review and Reregistration Division Chemical Review Manager
(CRM): Wilhelmena Livingston: livingston.wilhelmena@epa.gov.

Registration Division Product Manager (PM): George Larocca:
larocca.george@epa.gov  

Use & Usage Information:  (For additional details, please refer to the
BEAD Appendix A document in the coumaphos docket.)

Coumaphos is an organophosphate insecticide/acaricide.  The current
supported uses for coumaphos include direct application to animals,
including dairy cattle, beef cattle, swine and bedding, and horses, for
the control anthropod pests including ticks, scabie mites, lice, flies,
fleece worms and screw worms.  

Coumaphos is also used in impregnated plastic strips in bee hives to
control varroa mites and small hive beetles.

There are no residential uses for coumaphos.

Coumaphos currently has no agricultural crop uses.

The equipment used to applied coumaphos includes dip vats, low and
high-pressure hand wands, back rubber/oiler, mechanical dusters, dust
bags, and shaker cans. 

Coumaphos is applied primarily during the early spring to late summer or
during fly season for cattle use.  

The CheckMite+ Bee Hive Pest Control Strips consist of plastic strips
(prepackaged) that are impregnated with 10% liquid solution of the
active ingredient, coumaphos. The label allows up to two strips hung in
the hive’s broad chamber for control of varroa mites, and the
concurrent use of another 10% strip attached to the bottom board for
control of beetles. The strips could remain in the hive for up to 45
days. 

The use classification for the two liquid products (11.6% emulsifiable
concentrate and the 42% flowable) are Restricted Use Pesticides (RUP). 
All other products have general use classifications.    

Approximately 71,000 pounds of coumaphos are used annually in the Unites
States.

The formulation types of the registered coumaphos products include the
technical grade active ingredient, dust, emulsifiable concentrate,
flowable concentrate, and impregnated material.

Recent Actions:

A Section 18 emergency exemption for use of coumaphos in beehives to
control varroa mites was issued to 38 states during the 2007 growing
season and expired on February 1, 2008.

A Federal Register notice (72 FR 2887) was issued on May 23, 2007,
establishing permanent tolerances for residues of coumaphos in or on
honey and honeycomb. The Agency issued a Section 3 registration on
January 24, 2008 for honey and honeycomb.  Interregional Research
Project #4 (IR-4) requested these permanent tolerances.

Ecological Risk Assessment Status:

The following are key findings of the coumaphos risk assessment.  Please
refer to Section III, Revised Registration Review Preliminary Problem
Formulation for the Ecological Risk Assessment of Coumaphos, for a
detailed discussion of the anticipated ecological risk assessment needs.
The Agency will utilize the information provided from the previous risk
assessment as a resource for conducting the ecological risk assessment
for the registration review process.  

A new assessment will include risk estimates from two pathways:  the
application of coumaphos to cattle via spray based on the registrant
submitted data on wash-off estimates from cowhide, and from application
of bioremediated spent vat-dip solutions to land.

The indoor use of coumaphos and the placement of the coumaphos-treated
strips in beehives to control varroa mites and small hive beetles
suggest that there are no routes of exposure to surface waters or the
surrounding non-target terrestrial environment.  Therefore there are no
acute or chronic risk concerns and no concerns from the indoor use of
coumaphos for effects to federally listed threatened or endangered
species.

Risk to Terrestrial Animals (Birds and Mammals):

 

Coumaphos is expected to pose a significant acute risk to birds
primarily due to ingestion of hair and skin debris from the treated
cattle or secondary exposure from ingestion of birds killed by the
pesticide, and contaminated with pesticide.  Avian reproduction studies
were not required in the 1996 RED due to the significant acute risk to
birds.  The birds would be killed before chronic effects could occur.

Coumaphos is not expected to pose a risk to endangered or non-endangered
mammals due to the limited use pattern.  The treatment of cattle in
confined areas is not expected to result in significant exposure to
endangered or non-endangered mammals.

Risk to Aquatic Animals (Fish and Aquatic Invertebrates):

 

Coumaphos usage on cattle is expected to pose an acute risk to aquatic
invertebrates.  Coumaphos is not expected to pose chronic or acute risks
to endangered or non-endangered fish. 

The residues of concern are coumaphos and its oxygen analogue
coumaphoxon.  Coumaphoxon is included in the Agency’s tolerance
expression, and was considered in the drinking water assessment.

Risk to Endangered Species:

Before the risk assessments are developed for public comment, the Agency
will ensure that an endangered species assessment is complete for all
currently registered uses of coumaphos.

On July 28, 2004, the Agency completed an Effects Determination for
Coumaphos for Pacific Anadromous Salmonids.  The Agency concluded that
coumaphos will have no effect on any of the listed or proposed ESUs of
Pacific salmon and steelhead. The risk quotients calculated for fish did
not exceed the endangered species level of concern which indicates no
direct risk to endangered fish.  With regards to indirect effects, the
risk quotients for aquatic invertebrates did exceed the level of
concern.  However, there is no risk to invertebrates due to the low
poundage used in the Pacific Northwest and California and its seasonal
localized treatment application.  The Agency also concludes that
coumaphos will have no indirect effects to endangered salmonids from
loss of food supply.

Human Health Risk Assessment Status:

Please refer to Section IV of this document, Coumaphos Registration
Review Scoping Document for Human Health Assessments, for a detailed
discussion of the anticipated risk assessment needs for human health.  A
summary follows:  

Hazard Characterization:

As an organophosphate insecticide, coumaphos primarily affects the
nervous system through cholinesterase (ChE) inhibition.  Systemic
toxicity in the form of decreased body weight gains was observed in
chronic studies; however, the most sensitive hazard endpoint observed
was ChE inhibition.  Females are consistently more sensitive to the
cholinergic effects of coumaphos than males.  In developmental toxicity
studies in rats and rabbits, no developmental toxicity was observed,
while clinical signs of ChE toxicity were seen in the maternal animals. 

The available toxicology data for coumaphos are adequate to support
currently registered uses.  The Agency believes that there are reliable
data to select endpoints for dermal and inhalation exposures resulting
from the occupational uses of coumaphos, and to determine the
appropriate uncertainty factors.

The acute toxicity of coumaphos is high via the oral route of exposure
(Category I), moderate via the inhalation route (Category II), and
slight via the dermal route (Category III).  Coumaphos is not a dermal
sensitizer or a dermal irritant, and it does not cause delayed
neuropathy.

Coumaphos is classified as a Group E chemical, indicating that it is
“Not Likely” to be carcinogenic in humans via relevant routes of
exposure. 

In the current assessment, no discernible difference in exposure was
observed when coumaphos residues in honey and beeswax were or were not
included in an aggregate assessment.  If coumaphos exposure from honey
is insignificant in comparison to exposure to coumaphos from other uses
of the chemical, it necessarily is insignificant in comparison to
exposure to the more than 30 other OPs.  For these reasons, EPA
concludes that the establishment of a coumaphos honey tolerance will not
raise a concern regarding cumulative OP exposure.

Dietary (Food and Water):

Acute and Chronic exposure estimates for food alone are below the
Agency’s level of concern.

The dietary exposure database is adequate for registration review;
however, the dietary assessment will need to be updated to reflect the
tolerances for honey and honeycomb that were established in January
2008.

The GENEEC and SCI-GROW screening models were used to estimate surface
water and groundwater concentrations of coumaphos and its oxygen
analogue, coumaphoxon.  The total (coumaphos and coumaphoxon) acute
estimated environmental concentrations (EECs) in drinking water that was
derived from surface water sources is not likely to exceed 1.86 ppb, and
the chronic EEC is not likely are exceed 0.41 ppb. 

PDP monitoring data for beef and milk were used in a 2007 dietary risk
assessment to estimate the dietary exposure and risk associated with the
Section 3 registration of coumaphos on honey.  FQPA requires that the
Agency revisit the monitoring data five years after the tolerance
assessment decision.  Therefore, EPA will revisit coumaphos monitoring
data.

The existing residue chemistry database for coumaphos is adequate and no
additional data are required.

Residential:

 

There are no residential uses for coumaphos.  Therefore, a residential
risk assessment is not required.    

Aggregate:

The aggregate assessment includes food and drinking water exposures only
(there are no residential uses).  

The acute aggregate dietary exposure estimates are below the Agency’s
level of concern for the U.S. population and all population subgroups. 
The combined dietary exposures from food and drinking water at the 99.9%
percentile of exposure is 15% of the aPAD for the U.S. and 38% of the
aPAD for all infants, the most highly exposed population subgroup.

The chronic aggregate dietary exposure estimates are below the
Agency’s level of concern for the U.S. population and all population
subgroups. The combined dietary exposure from food and drinking water is
6% of the cPAD for the U.S. population and 13% of the cPAD for all
infants, the most highly exposed population subgroup.  

Cumulative Risk Characterization (CRA):

The Agency developed a highly refined and complex cumulative risk
assessment for the OPs that represent’s the state of the science
regarding existing hazard and exposure data and the models and
approaches used.  In accordance with the August 2006 deadline under the
FQPA, the Agency concluded that the results of the OP cumulative risk
assessment support a reasonable certainty of no harm finding.  Although
coumaphos was in the revised OP CRA, through the use of Pesticide Data
Program (PDP) data, there were no residues contributing to the overall
exposure.

EPA does not believe that inclusion of coumaphos residues in honey in
the OP CRA will significantly modify the calculated risk.  This
conclusion is based on three factors.  First, honey is a low consumption
food, and, thus, even if honey contained quantifiable levels of OPs, it
would be unlikely to significantly alter the OP CRA.  Second, available
monitoring data for beef and milk indicates that, despite widespread use
of coumaphos, residues of coumaphos in honey as consumed are exceedingly
low, if present at all.  Finally, a prior risk assessment for coumaphos
indicated that aggregate risk from coumaphos was essentially unchanged
when honey containing levels of coumaphos residues found in field trials
was added to the coumaphos risk assessment. 

Occupational:

In the September 2000, Reregistration Eligibility Decision Addendum and
FQPA Tolerance Reassessment Progress Report for Coumaphos, occupational
risk were mitigated to acceptable levels with the addition of personal
protective equipment, engineering controls and the following label
changes: restriction of the 42 % flowable product to only USDA-APHIS
use, prohibition of the mechanical duster use, limitation on the number
of animals and area of animal bedding to be treated.

Occupational postapplication exposure was not assessed because the
Agency determined that there is likely to be minimal exposure to workers
contacting animals immediately after the application is complete and the
amount of exposure is likely to be substantially lower than the exposure
to handlers.

A February 2000 document, Coumaphos Risk Assessment for Section 18 Use
of Coumaphos in Bee Hives in Florida to Control Vorroa Mites, indicated
that a risk assessment for occupational exposure was not required for a
Section 18 use of coumaphos in bee hives in Florida, however, the Agency
recommended that “chemical resistant” gloves be required for use by
applicators when using the end-use product, CheckMite+ Bee hive Pest
Control Strips to control varroa mites.  This label requirement is
currently on the label. 

There is currently adequate information to support an occupational
assessment of coumaphos.  No new data are required for registration
review.

Incidents:

An analysis of the incidence reports will be included in a separate memo
and placed in the docket.

Data Call-In Status:

There are no current data call-ins for coumaphos.

Tolerances and International Harmonization: 

US	Canada

Residue Definition:

	40CFR180.189

coumaphos ( O,O -diethyl O -3-chloro-4-methyl-2-oxo-2H-1-benzopyran-7-yl
phosphorothioate and its oxygen analog ( O,O -diethyl O
-3-chloro-4-methyl-2-oxo-2H-1-benzopyran-7-yl phosphate)	O-3-chloro-4-

methylcoumarin-7-yl

O,O-diethyl

phosphorothioate



Commodity Tolerance (ppm) /Maximum Residue Limit (mg/kg)

Commodity	US	Canada

Cattle, fat	1.0	0.51

Cattle, meat	1.0	0.51

Cattle, meat byproducts	1.0	0.51

Goat, fat	1.0	0.51

Goat, meat	1.0	0.51

Goat, meat byproducts	1.0	0.51

Hog, fat	1.0	0.51

Hog, meat	1.0	0.51

Hog, meat byproducts	1.0	0.51

Honey	0.15

	Honeycomb	45.0

	Horse, fat	1.0	0.51

Horse, meat	1.0	0.51

Horse, meat byproducts	1.0	0.51

Milk, fat (=n in whole milk)	0.5

	Sheep, fat	1.0	0.51

Sheep, meat	1.0	0.51

Sheep, meat byproducts	1.0	0.51

Poultry, meat

0.51

Poultry, meat-by-products

0.51

1Calculated on the fat content.

Note:  There are no tolerances and international harmonization for
Mexico and Codex (withdrawn from Codex in 1980). 

Labels:

A list of registration numbers may be found in the coumaphos docket and
the labels can then be obtained from the Pesticide Product Label System
(PPLS) website:   HYPERLINK "http://oaspub.epa.gov/pestlabl/ppls.home" 
http://oaspub.epa.gov/pestlabl/ppls.home . 

III. GLOSSARY AND TERMS AND ABBREVIATIONS

Glossary of Terms and Abbreviations   

AGDCI		Agricultural Data Call-In

ai			Active Ingredient

aPAD			Acute Population Adjusted Dose

BCF			Bioconcentration Factor 

CFR			Code of Federal Regulations

cPAD			Chronic Population Adjusted Dose

CSF			Confidential Statement of Formula

CSFII			USDA Continuing Surveys for Food Intake by Individuals

DCI			Data Call-In

DEEM		Dietary Exposure Evaluation Model

DFR			Dislodgeable Foliar Residue

DNT			Developmental Neurotoxicity

EC			Emulsifiable Concentrate Formulation

EDWC		Estimated Drinking Water Concentration

EEC			Estimated Environmental Concentration

EPA			Environmental Protection Agency

EUP			End-Use Product

FDA			Food and Drug Administration

FIFRA		Federal Insecticide, Fungicide, and Rodenticide Act

FFDCA		Federal Food, Drug, and Cosmetic Act

FQPA			Food Quality Protection Act

GLN			Guideline Number

IR			Index Reservoir

LC50			Median Lethal Concentration.  A statistically derived
concentration of a substance that can be 	expected to cause death in 50%
of test animals.  It is usually expressed as the weight of substance 
per weight or volume of water, air or feed, e.g., mg/l, mg/kg or ppm.

LD50			Median Lethal Dose.  A statistically derived single dose that can
be expected to cause death in 	50% of  the test animals when
administered by the route indicated (oral, dermal, 	inhalation).  It is 
expressed as a weight of substance per unit weight of animal, e.g.,
mg/kg.

LOC			Level of Concern

LOAEL		Lowest Observed Adverse Effect Level

MATC		Maximum Acceptable Toxicant Concentration

µg/g			Micrograms Per Gram

µg/L			Micrograms Per Liter

mg/kg/day		Milligram Per Kilogram Per Day

mg/L			Milligrams Per Liter

MOE			Margin of Exposure 

MRID			Master Record Identification (number).  EPA's system of recording
and tracking studies 	submitted.

MUP			Manufacturing-Use Product

NOAEL		No Observed Adverse Effect Level

OPP			EPA Office of Pesticide Programs

OPPTS		EPA Office of Prevention, Pesticides and Toxic Substances

PAD			Population Adjusted Dose

PCA			Percent Crop Area

PDP			USDA Pesticide Data Program

PHED			Pesticide Handler's Exposure Data 

PHI			Preharvest Interval

ppb			Parts Per Billion

PPE			Personal Protective Equipment

ppm			Parts Per Million

PRZM/EXAMS	Tier II Surface Water Computer Model  

Q1*			The Carcinogenic Potential of a Compound, Quantified by the EPA's
Cancer Risk Model

RAC			Raw Agriculture Commodity

RED			Reregistration Eligibility Decision

REI			Restricted Entry Interval

RfD			Reference Dose

RQ			Risk Quotient

SCI-GROW		Tier I Ground Water Computer Model

SAP			Science Advisory Panel

SF			Safety Factor

SLC			Single Layer Clothing

TGAI			Technical Grade Active Ingredient

USDA		United States Department of Agriculture

USGS			United States Geological Survey

UF			Uncertainty Factor

UV			Ultraviolet 

WPS			Worker Protection Standard

 PAGE   

 PAGE   3 

