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United States Chemical Safety October 2010

Environmental Protection and Pollution Prevention Agency (7510P)



# Dichromic Acid

Final Work Plan Registration Review

October 2010Doc ket Number; EPA

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3 

### TABLE OF CONTENTS

Dichromic Acid Registration Review Team

................................ ................................ ............................... 4

I. INTRODUCTION

................................ ................................ ................................ ................................ ..... 5

II. COMMENTS RECEIVED ON THE PRELIMINARY WORK PLAN

................................ ............. 6

III. RISK ASSESSMENT AND DATA NEEDS

................................ ................................ ........................ 6

IV. TIMELINE

................................ ................................ ................................ ................................ ............. 9

V. GLOSSARY of TERMS & ABBREVIATIONS

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4 Dichromic Acid R egistration Review Team

Human Health & Environmental Effects

Nathan Mottl A. Najm Shamim

Risk Management Rebecca von dem Hagen

Lance Wormell

Office of General Counsel Philip RossDoc ket Number; EPA

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5 I. INTRODUCTION

This is the Environmental Protection Agency’s ( EPA or “the Agency”) Final Work Plan (FWP) for the registration review of dichromic acid

. The work plan includes the expected registration review timeline. The w ork plan also addresses public comments received concerning the Preliminary Work Plan (PWP) in the Summary Document which was posted in the dichromic acid registration review docket, and any other comments concerning the initial docket postings. The Summa ry Document provided information on what EPA knows about the pesticide and what additional risk analyses and data or information the Agency believes are needed to make a registration review decision.

The Agency is implementing the registration review p rogram pursuant to Section 3(g) of the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) and will review each registered pesticide every 15 years to determine whether it continues to meet the FIFRA standard for registration. Changes in science, public policy and pesticide use practices will occur over time. 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 that stat utory standard. The public phase of registration review begins when the initial docket is opened for each case. Information on this program is provided at: http://www.epa.gov/oppsrrd1/regist ration_review/

.

The dichromic acid Preliminary Work Plan (PWP) (PC Code 068306 ) was published
June 23, 2010 . T he 90

- day c omment period ended on August 23, 2010 . The Preliminary

Work Plan document is available on www.regulations.gov , do cket number EPA

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A pesticide product containing dichromic acid was first registered in 1994. Because dichromic acid was registered after November 1984, this ingredient was not considered under EPA’s reregistration program. However, a Reregistration Eligibility Decision (RED) for chromated arsenicals was completed in 2008. The 2008 RED addressed potential exposure and risk from chromium (VI) oxide (also known as “chromic acid”). C hromic acid and dichromic acid ar e both created through the same chemical processes and composed of chromium in the hexavalent form ( C r (VI)), with dichromic acid being a relatively unstable form of chromic acid. Because chromic acid and dichromic acid are composed of the same chemical of toxicological significance (hexavalent chromium), the Agency intends to incorporate data received in response to

the chromic acid RED DCI into the risk assessments to be performed for the registration

review of dichromic acid. The Agency anticipates issuing the chromic acid RED DCI in FY2011 and anticipates reviewing any data received in response to the RED DCI prior to conducting the registration review risk assessments for dichromic acid

. Also, the Agency notes that this registrat ion review will be based on updated labels received in response to the 2008 chromated arsenicals RED and approved by the Agency in May 2010 for the two active registrations . The updated labels reflect mitigation measures outlined in the

2008 RED.Doc ket Number; EPA

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6 II. COMMENTS RECEIVED ON THE PRELIMINARY WORK PLAN

EPA received one comment during the public comment period on the initial docket, described below. In the PWP, EPA also solicited comments on three specific topics: environmental justice; water body impair ment; and trade irritants. No comments or information were received during the public comment period concerning these issues.

During the public comment period, EPA received one comment as described and discussed below. The comment received during the initial public comment period did not affect the data needs, work plan and timeline described in the PWP and they remain as they were presented initially in the PWP. Further, this document makes final the work plan for the dichromic acid registration revi ew process.

Comment: The FIFRA Endangered Species Task Force (FESTF) submitted a comment requesting that the lead technical registrant for dichromic acid who is not a member of the FESTF (or a company having met its data compe nsation obligations) provide a formal offer

- to

- pay to FESTF for reliance on their data or be required to develop substantially similar data on their own

.

Response: The Agency thanks FESTF for its comment and will consider this information as it conducts the registration review an d makes its registration

review decisions.

III. RISK ASSESSMENT AND DATA NEEDS

Human Health Risk Assessment Status and Anticipated Data Needs

The Agency reviewed the hazard and exposure databases for dichromic acid. As a result of this review, EPA confirmed that the data to be required for dichromic acid as a result of the September 2008 chromated arsenicals RED are still needed. The studies t hat will be required upon issuance of the RED Data Call

- In (DCI) can be found in the Agency’s chromated arsenicals RED at http://www.regulations.gov in docket number

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- 0250. The Agency does not antici pate the need to require any other human health data for dichromic acid through the registration review program.

Di etary Assessment

Acute and chronic dietary assessments are not necessary for dichromic acid

because there are no uses of dichromic acid attributable to the dietary route of exposure.

Because wood preservative use is not expected to result in drinking water exposure, a drinking water assessment is not anticipated to be needed. According to the RED, “studies of sorption into soils from utility poles, have shown that the release of metals into soils/sediments from the base of treated wood, decks or utility poles or from the pressure treatment facilities, do not show a high degree of migration, either toDoc ket Number; EPA

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7 groundwater or to the surface. In most cases, after migration of the metals a few meters down into soil, these metals attain the background level concentration of soil. ”

Tolerances

There are currently no tolerances or exemptions f or the requirement of a tolerance

for dichromic acid

.

Occupational and Residential Assessment and Risk

The Agency reviewed all available data associated with dichromic acid and has determined that the currently registered uses of dichromic acid may resul t in occupational

exposure. An occupational risk assessment for inhalation exposure to Cr(VI) was performed in 2008 for the chromated arsenicals RED. The Agency reviewed the 2008

risk assessment and determined that the data to be called in upon the issu ance of the

chromated arsenicals RED DCI are still needed and does not anticipate the need to require any other human health data for dichromic acid through the registration review

program

. Contingent upon the receipt of the data for chromic acid to be re quired through the reregistration process from chromated arsenicals , t h e Agency may develop new occupational inhalation risk assessments for the dichromic acid registration review.

CCA is no longer registered for use on wood intended to be used for decks or play sets and the remaining two residential uses (shakes/shingles and permanent wood foundations) are not expected to result in significant exposure to dichromic acid. Therefore, a residential assessment is not required for these uses.

Aggregate and C umulative Exposure and Risk

In examining aggregate exposure, EPA takes into account the available and reliable information concerning exposures to pesticide residues in food and drinking water, and non

- occupational pesticide exposures. As previously state d, a cute and chronic dietary assessments will not be conducted for dichromic acid because there are no uses of dichromic acid which would be attributable to the dietary route of exposure. The remaining residential uses of dichromic acid are not expected to result in significant residential exposure. Therefore, no need is anticipated for an aggregate exposure

assessment.

Section 408(b)(2)(D)(v) of 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.” EPA has not yet determined

whether dichromic acid has a common mechanism w ith other compounds, consequently a cumulative assessment will not be performed at this time.

Anticipated Human Health Data NeedsDoc ket Number; EPA

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8 EPA confirmed that the data to be required for dichromic acid as a result of the September 2008 chromated arsenicals RED are still needed and the Agency does not anticipate the need to require any other human health data for dichromic acid through the registration review program.

For further information see the document titled, “Summary of Human Health Effects Data for the Dic hromic Acid Registration Review Decision Document,” dated May 27, 2010.

Anticipated Physical/Chemical Property Data Needs

All product chemistry data requirements have been fulfilled for dichromic acid. Therefore, it is anticipated that additional produc t chemistry data will not be needed for

dichromic acid.

For further information see the document titled, Dichromic Acid: Product Chemistry/Environmental Fate and Eco

- Effects Scoping Document dated May 6, 2010.

Environmental Fate and Ecological Risk Assess ment Status and Anticipated Data

Needs

The Agency reviewed the environmental fate and ecological hazard databases for dichromic acid. As a result of this review, EPA confirmed that the data to be required for

dichromic acid as a result of the chromated arsenicals RED are still needed. The stu dies that will be called in for reregistration can be found in the Agency’s chromated arsenicals

RED at http://www.regulations.gov in docket number EPA

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- 0250. The Agency does not anticipate the need to re quire any additional environmental fate data for dichromic acid through the registration review program.

For f urther information see the document titled, “ Dichromic Acid: Product Chemistry/Environmental Fate and Eco

- Effects Scoping Document ” dated May 6 , 2010.

Endangered Species

The Agency has not conducted a risk assessment that supports a complete endangered species determination for dichromic acid . The ecological risk assessment planned during registration review will allow the Agency to determine whether

chromium (VI), the chemical of toxicological concern found in pesticide products containing dichromic acid (Case 5012) and chromic acid (Case 0132), has “no effect” or “may affect” federally listed threatened or endangered species (listed species) or their designated critical habitats. Because the chemical of toxicological concern and use patterns are the same for chromic acid and dichromic acid, the Agency intends to perform a comprehensive endangered species assessment for chromium (VI). When an assessment concludes that a pesticide’s use “may affect” a listed species or its designated criticalDoc ket Number; EPA

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9 habitat, the Agency will consult with the U.S. Fish and Wildlife Service and/or National Marine Fisheries Services (the Services), as appropriate.

Incide nts:

In the chromated arsenicals RED o nly limited incident reports are associated with exposure to end

- use products containing chromated arsenicals. In contrast, a large body of literature exists on the health effects (acute and chronic) in humans of expo sure to the components of chromated arsenicals, particularly arsenic and, to a lesser degree, chromium and copper. Itching, burning rashes, neurological symptoms, and breathing problems associated with handling unmarked CCA

- treated wood have been reported. Sap draining from CCA treated wood stairs has been reported as a potential source of dermal and inhalation exposure leading to dermatitis and development of film on the teeth. At least one individual reported “ruined” nerves in feet and legs which he attr ibuted to exposure to saw dust and fumes from cutting and routing CCA

- treated lumber. No new incidents have been reported for dichromic acid since the chromated arsenicals RED has been completed.

IV. TIMELINE

The EPA has created the following estimated t imeline for the completion of t he

dichromic acid registration review case. The Agency does not anticipate requiring additional data for this registration review case.

Anticipated Schedule

Activities Estimated Month/Year
Phase 1: Opening the docket
Open Public Comment Period for Dichromic Acid Docket June 2010

- complete

Close Public Comment Period August 2010

- complete
Phase 2: Case Development

Develop Final Work Plan (FWP) O ctober 2010

Issue DCI N/A 1

Open Public Comment Period for Preliminary Risk Assessments June 2016

Close Public Comment Period September 2016

Phase 3: Registration Review Decision
Open Public Comment Period for Proposed Reg. Review Decision December 2016

Close Public Comment Period March 2017
Final Decision and Begin Post

- Decision Follow

- up 2017 Total (years) 7

1 As previously discussed in this document, the Agency does not anticipate issuing a DCI for dichromic acid through the registration review program; however, additional studies are expected to be submitted as a result of the reregistration eligibility decisi on for c hromated a rsenicals (Case 0132) and the risk

assessments for dichromic acid will be conducted once those studies are received.Doc ket Number; EPA

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10 Next Steps

The Agency intends to complete a preliminary risk assessment for dichromic acid

once the studies that will b e called

- in through the chromated arsenicals post

- RED DCI

are received

. The Agency anticipates issuing the chromic acid post

- RED DCI in

FY2011.Doc ket Number; EPA

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11 V. GLOSSARY of TERMS & ABBREVIATIONS

ai Active Ingredient

AR Anticipated Residue

ASTM American Society fo r Testing and Materials

AWPA American Wood Preserver’s Association

CBI Confidential Business Information

CFR Code of Federal Regulations

cPAD Chronic Population Adjusted Dose

CSF Confidential Statement of Formula

CSFII USDA Continuing Surveys for Foo d Intake by Individuals

DCI Data Call

- In

DEEM Dietary Exposure Evaluation Model

DFR Dislodgeable Foliar Residue

DNT Developmental Neurotoxicity

DWLOC Drinking Water Level of Comparison

EC Emulsifiable Concentrate Formulation

EDWC Estimated Drinking Water Concentration

EEC Estimated Environmental Concentration

EP End use Product

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

FOB Functional Observation Battery

GENEEC Tier I Surface Water Computer Model

IR Index Reservoir

LC 50 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.

LD 50 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 Lev el 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

submitted studies.

MUP Manufacturing

- Use Product

NA Not Applicable NAWQA USGS National Ambient Water Quality Assessment

NPDES National Pollutant Discharge Elimination System

NR Not Required

NOAEL No Observed Adverse Effect Level

OPP EPA Office of Pesticide Programs

OPPTS EPA Office of Prevention, Pesticides and Toxic Substances

PAD Population Adjusted DoseDoc ket Number; EPA

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12 PAIRA Pure Active Ingredient Radiolabelled

PCA Percent Crop Area

PDP USDA Pesticide Data Program

PHED Pesticide Handler's Exposure Data

PHI Preharvest Interval phr Pounds Per Hundred ppb Parts Per Billion

PPE Personal Protective Equipment

ppm Parts Per Million

PRZM/EXAMS Tier II Surface Water Computer Model Q 1 * The Carcinogenic Potential of a Compound, Quantified by the EPA's Cancer

Risk Model

RAC Raw Agr iculture Commodity

RED Reregistration Eligibility Decision

REI Restricted Entry Interval

RfD Reference Dose RQ Risk Quotient

RTU Ready to Use

SCI

- GROW Tier I Ground Water Computer Model

SAP Science Advisory Panel

SF Safety Factor

SLN Special Local Need (Registrations Under Section 24©) of FIFRA)

TGAI Technical Grade Active Ingredient

TEP Typical End

- Use Product

USDA United States Department of Agriculture

UF Uncertainty Factor

WPS Worker Protection Standard