-'\~€O 57"41; -,>'" ~<S' i 8 'u UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

:s m WASHINGTON, D.C. 20460

'" Cl <i

""/..: t:.~&OFFICE OF CHEMICAL SAfETY

~L. PRO"'{~ ASD POLLUTIOS PREVEI\'TIO~

Ju ly 26, 2010

MEMORANDUM

SUBJECT: Summary of Product Chemistry, Environmental Fate, and Ecotoxicity

Data for the CopperNaphthenate and Zinc Naphthenatc Salts Registration

Review Decision Document.

RR Case Names

Copper naphthenate

Zinc naphthenate

RR Case No.: 3099

PC Codes

023 102

088301

DP Barcode: 380250

CAS #

1338-02-9

12001·85·3

FROM:

THRU:

TO:

Srinivas Gowda, Microbiologist/Chemist V

Risk Assessme nt and Science Support Branch (RASSB)

Antimicrobials Division (751OP)

Nader Elkassabany, Branch Chief11""dzSiroos Mostaghimi, Peer Revi ewer~ '- u:zr:J-¥"

Risk Assessment and Science Support Branch (RASSB) /

Antimicrobials Division (751OP)

Monisha Harris, Chemical Review Manager

Regulatory Management Branch II

Antimicrobials Division (751OP)

Attached is the summary of available product chemistry, environmental fate, and ecotoxicity data

to support the registration review of copper naphthenate and zinc naphthenate salts.

Page I of28
COPPE R AND ZINC NAPHTIIENATE SALTS

ENVIRONME NTAL SCOPING DOCUMENTS

TA BLE OF CONTENTS

PAGE No.

COPPER NAPIITHENATE ..•..•..•..•..•..•..... ...... ... ......... ... ..•....••. 3

ZINC NAPHTIIENATE ..... ... ......... ... ... ... ....•... .. ....•..•...................... 17

Page 2 of28
NAPHTHENATE SALTS: COPPER NAPIITIIENATE

REGISTRATION REVI EW DECISION

PRODUCT CHEMISTRY, EI'iVIRONM ENTAL FATE AND

ECOLOGICAL EFFECTS SUMMA RY

PC Code: 023102; Case No. 3099

Introduction:

Copper naphthenate is a fatty acid salt also known as metal soap or copper soap. It is a

reaction product of copper salts and naphthenic acid s deri ved from petroleum. Copper

naphthenate soap is a green-blue solid which is prac tically insoluble in water, soluble in organic

solvents, and has no measurable vapor pressure. Copper naphthenate-treated wood is not

conductive to electricity. Copper naphthenate is used as an (1) ant imicrobial fungicide for control

of decay, mold. rot, mildew, stain and (2) an insecticide against certain wood-boring insects

(e.g., termites, powder-post beetles and carpenter ants) in various wood preservat ive

applications.

Copper naphthenate is an active ingredient used pred ominantl y in industrial and

commercial wood preservation (Use Site Category X -wood preservatives} for non-pressure

(diplbrush/spray) and pressure treatments (vacuumlfull-cell) to protect against fungal rot, decay,

termites and wood-boring insects in unfinished wood and various fabricated wood products.

This preservative is also used for remedial treatments to in-service poles (internal/external

surfaces at ground or below-ground level via brush/trowel, mechanical injection, or bandage

wrap). Wood treated copper naphthenate is specified for exterior above-gro und, ground-contact.

below-ground and fresh or salt water contact use applications. Copper naphthenate is also used

as protective wood preservative surface treatments when applied to bare seasoned wood. For

this use. it is readily available to the general public. and sold over-the-counter to consumers as

wood protection coatings (and water-repellents).

Copper naphthenate is also used for commercia l/industrial materials preservation (Use

Site Category VII - materials preservativessof cellulose-based cordage/textiles. Products are

used as fungistats to control rot and mildew and are registered for impregnation by dip

(primarily). or by spray and brush surface treatment. It is additionally used for incorporation into

industrial textiles meeting military or government-specified needs.

Examples of the materials/wood preserved using copper naphthenate include cellulosebased fibers in cordage (ropes. twine. nets) and non-apparel and industrial textiles (tents,

awn ings, tarpauli ns, canvas products, burlap, truck and boat covers. and non-rubber fabrics);

outdoo r wood building materi als. such as particle board; lumber. patio decking. fence posts. and

other wood products; and in-service wood utility poles and similar members. The registered

copper naphthenate wood/materials preservatives are classified as general-use (not restricted use)

products. Products formulated or repackaged from these compounds must be labeled for

"Exterior Use Only:' Treated wood/materials preserved with copper naphthenate sa lts

Page3 of 28
preservatives are intended for exterior use-site applications only; indoor installation and uses are

not allowed.

Copper naphthenate has been registered with the Agency since October 29. 1951. At

present, there are 30 active registrations for products containing copper naphthenate which are

listed in Table 1. These are registered for use as a material preservative (rope, burlap, canvas

including nets (except fish nets), seines, tents, awning s, textiles, particle board, insulation board,

and other wood base fiber and particle materials tarpaulins) and as a wood preservative (lumber,

timbers, posts, poles, and other wooden members, all exterior wood exposed to moisture or

weather. wooden boat hulls. piers). The copper naphthenate technical grade active ingredients

(TGAls) are fonnulation intermediates, all registered to OMG Americas, Inc. They are technical

chemical source products for use by formulators in manufacturin g wood preservative/materials

preservative end-use products requiring EPA registration. The percentage of copper naphthenate

in the formulator-use technical source products are 58% to 77%. The percent of copper

naphthenate in various end-use products can range from 7.5% to 80%. Products containing

copper naphthenate are formulated as soluble concentrates, emulsifiable concentrates and readyto-use liquids. A Reregistration Eligibility Decision (RED) was issued by EPA in September

2007. There are two active ingredients in the naphthenate salts case 3099: copper naphthenate

(PC Code 023102); and zinc naphthenate (PC Code 088301).

There are inert products under the inert PC Code 823102. There are Special

Local Need (SLN) registrations of copper naphthenate as an inert under Section 24(c) of FIFRA.

is for control

is for the control of

and is a

.

As an inert ingredient, copper naphthenate is used mainly in insecticide and nematicide

formulations when applied to soil and/or growing crops (prior to formation of edible parts). The

tolerance exemption for copper naphthenate is provided below.

There is no direct or indirect food uses associated with the naphthenate salts. There is

however. one tolerance exemption for residues of copper naphthenate when used as a mercaptan

scavenger in technical pesticide in accordance with good agricultural practices as an inert

ingredient in pesticide formulations applied to growing crops only (40 CFR 180.920). No more

than 2.5% copper naphthenate can be present, and products containing copper naphthenate can

only be applied before the edible portion s of plants begin to form.

As described in 40 CFR Part 180, copper naphthenate (CAS# 1338-02-9), is permitted for

use as inert ingredient in nonfood use pesticide products.

As described in 40 CFR Part 180, naphthenic acid (CAS# 1338-24-5), is permitted for

use as inert ingredient in nonfood use pesticide products.

Page 4 of 28
FDA Indirect food Add itive Uses for copper naphtheoate: Copper naphthenate is approved by

the Food and Drug Administration (FDA) as an indirect food additive and an adjuvant substance

used to facilitate the production of resins. It is used as an accelerator, not to exceed 1.5%. 21

CFR 177.2420(b).

Copper soaps have a low order of toxicity. Historica l regulatory approvals include the following:

• 21 CFR 177.242O(b), use as a polyester accelerator.

• 21 CFR 524.463; use as topical solution to prevent thrush fungal infection on non-food

animal feet.

• 40 CFR 180.920; use as inert ingredient mercaptan scavenger in agricultural chemicals

prior to emergence of edible portion of fruit.

FDA Uses for copper naphthenate: There is a topica l over-the counter use of copper

naphthenate solution on horses and ponies hooves as an aid in treating thrush caused by

organisms susceptible to copper naphthenate, 37.5% purity. 21 CFR 524.463.

Copper naphthenate solution is recommended once daily for drying superficial sores & necrotic

material of wounds for subsequent removal as well as for cleaning open lesions & treatment of

udder sores. ...in cattle for treatment of heel cracks, hoof punctures. & dehorning wounds.

In the horse the preparation is used in treatment of thrush and scratches and for toughening

spongy hooves. Its use in the dog includes treatment of cracked skin over the elbows and

toughening of the footpads. For best effect, necrotic tissue should be removed as completely as

possible before copper naphthenate is applied.

A preparation containing 37.5% copper naphthenate has been approved by FDA in treatment of

wounds, foot rot. & ringwonn in horse, cow, pig, sheep, goat, and dog.

Copper itself is essential to human health and is prevalent in the body. Copper is an essential

soil micronutrient and must be added to deficient soil to improve productivity.

Table 1 Regis . tered Active Products of Copper Naphthenate

Registration # Registratio n Name Company Name

Formulation 0./0 of Active

type Ingredient

577-541 Cuprinol Wood The Sherwin-Williams Ready-to-Use 22.3 Preservative Co. Solution

Copper Naphthenate WR Ready-to-Use 1022-409 Wood Preservative Ready IBC Man ufacturing Co. Solution 25

To Use

1022·507 Co pper Nap hthenate 1% iec Manufacturing Co. Ready-to-Use 7.5 Solution

1022-518 Cunapsol- I IBC Manufacturing Co. Ready -to-Use 9.08

Page 5 of28
Registration # Regist ration Name Company Name

Formulation % of Active

typ e Ingredient

Solution

1022-522 Cunapsol-S !BC Manufacturing Co. Soluble 45 .4 Concentrate

1022-523 Cunapsol-2 !BC Manufactur ing Co. Ready-to-Use 18.16 Solution

1022-528 Copper Na phthenate IBC Manufacturing Co. Soluble 68 Concentration 8% Concentrate

1022-536 POL·NU CURAP 20 IBC Manufacturing Co. Ready-to-Use 18.16 So lution

1022-568 CHAPCO CU·NAP 800 !BC Manufacturing Co. Emulsifi able 80 EC Concentrate

1022-571 CHAPCO CU·NAP 400 !BC Manufacturing Co. Soluble 40 Concen trate

1022·579 CU RAP 20 PAK (BC Manu facturing Co. Ready-to-Use 18.16 Solution

CO P-R-TOX Wood Mobile Paint Ready-to-Use 17 19-43 Manufacturing 22.59 Preservative Company Inc. Solution

9630-4 6% Co pper Nap--All OMG Americas Inc. Formulation 67 Intermediate

9630-5 M..(JARDSI20 OMG Ame ricas Inc. Formulation

77 Interm ed iate

9630-12 M-GARD S520 OMG Americas Inc . Soluble 80 Concentrate

43437-4 8% Copper Naphthe nate OMG Belleville Solub le 89 Limited Concentrate

60061 - 16 No. 00 Ready To Use Kop-Coat, Inc. Ready-to-Use 2 1.6 Co pper Treat Solutio n

6006 1-19 Co pper Treat 120 Ready- Kop-Coat, Inc. Ready-to-Use 2 1.6 To-Use Solution

6659 1·1 Co pper Green Wood Green Products Co. Ready-to-Use 10 Prese rvative So lution

7 1653· 1 Cobra Wrap Genie s Inc. Ready-to-Use 17.8 Solution

7 1992- 1 CUN AP-S Wood Merichem Chemica ls & Solub le 68 Preservative Refinery Services LLC Concentrate

Page 6 of 28
Registration # Registration Name Company Name Formula tion % of Active

type Ingredient

7 1992-2 CUNAP-2 Merichem Chemicals & Soluble 18 Refinery Services LLC Concentrate

71992 -3 CU NAP-5W Wood Merichem Chemicals & So luble 42 Preservative Refinery Services LLC Concentra te

75340-3 COP-R-NAP RTU Osmose Railroad Ready-to-Use 19.25 Solution Serv ices, Inc. Solut ion

75340-4 Osmose CU-89-RTU II Osmose Railroad Ready-to-Use 17 Services, Inc. Solution

7534 1-5 COP-R-Plastic Wood Osmose Utilities Ready-to-Use 20 Preserving Compound Services, Inc. Solution

7534 1-8 Osmose COP-R-NAP Osmose Utilities Soluble 77 Services, Inc. Concentrate

7534 1-11 COP-R-NAP Osmose Utilities Soluble 68 Services. Inc. Concentrate

75341·1 2 Hollow Heart CF Osmose Utilities Soluble 41 .27 Services. Inc. Co ncentrate

7534 1· 13 COP-R-Plastic 11 Wood Osmo se Utilities Ready-to-Use 17.68 Preserving Compound Services. Inc. Solution

Science Findings

The Agency has conducted a review ofthe available product chemistry, environmental

fate. and ecotoxicity data for copper naphthenate. The findings are summarized below.

Product Chemistry Summary

The copper naphthenate active ingredient is technically within a class of compounds

known as metal soaps. Copper naphthenate is also described as the coppe r salt of naphthenic

acid and is the reaction product of a copper compound with naphthenic acids. The chemical

reaction used to generate copper naphthenate is simply the replacing ofthe naphthenic acid

hydrogen with one valence ofthe copper metal. Copper naphthenate is highly soluble in nonpolar solvents such as mineral spirits and other hydrocarbon solvents, and is essentially insoluble

in water.

Naphthenic acid is a by-product of the petroleum refinery process. removed from crude

oil by treating with sodium hydroxide. and regenerated from the resultant sodium naphthenate.

Naphthenic acids are alicyclic acids (an impure , unspecific mixt ure ofseveral cyclopentyl and

cyclohexyl carboxylic acids) that are insoluble in water but soluble in organic solvents. The

generic formulas for the most important naphthenic acids are: CnH2n_2 0 2; CnH2n4 0 2; CnH2n-602

Page 7 0f28
The data submitted pertaining to the physical and chemical characteristics ofthe active

ingredient, copper naphthenate is adeq uate. All product chemistry data requirements have been

satisfied for the active ingredient coppe r naphthenate. Therefore, the Agen cy does not anticipate

need ing add itional product chemistry data for copper naphthenate at this time. Tables 2 and 3

contain the complete product chemistry information for the active ingredient copper naphthenate.

Table 2. Chemical Identity

Chemical Name Naphthenic acids, copper salts

Common Names Copper naphthenate

Synonyms CNC

Cupric naohthenate

Trade Name Copper Uverso l

Chapeo Cu-nap

Troysan

Wiltz-65

Wirrox-C

CuNap-8, Penn-E8,

Cop-R-Nap

Cunapsol

Cuprinol

Coooer-nao-all

lUPAC Name Copper naphthalene-2-carboxylate

Molecular Weight 405.90 g/mole (variable)

PC Code 023102

CAS Registry Number 1338-02-9

Molecular Formula 2(Cl1H7O,)Cu

C22HI4CU0 4

Registration Review Case No. 3099

Registration Review Case Name Naohthenate salts

Classification Fatty Acid Salt

Chemical Family Inorganic-Copper

Metal Carboxylate

Pesticide Type Antimicrobial

Conventional Chemical

Page 8 of28
Table 2. Chemical Identity

Molecular Structure:

2(CI1H,O,lCu o

Cu- . r-f"iJ LV0

o

Copper naphthenate

2(CI1H,O,lCu

Copper naphthen ate

Copper naphthenat e

o

H3C~OH Naohthenic acid (CAS# 1338-24-5)

Ta ble 3. Product Chemistrv Data Summary orConner Nanbthenate (TGAI 990/. )

Guideline :'\0. Physiea l and Chemical Value

Properties

830.1550 Product identity and Refer to Table 2.

comeosirion

830.1600 Description ofmaterials CBI

used to oroduce the oroduct

Page 9 of 28
G uid eline No. Physical and Chemical Valu e

Pronerties

830.1620 Description of prod uction CBI

process

830.1650 Description offormulation CBI

process

830.1670 Discussion offormation of CBI

imnurities

830.1700 Preliminarv ana lvsis CB1

830.1750 Certified limits CB1

830.1800 Enforceme nt analytical GLC

method EDTA titration

Standard Method for Determination of Copper in Copper

Naphthenate Solution or In Wood Treated With Copper

Naphthenate; AWPA Standard AS • Analysis ofOil-Borne

Preservatives. Method #7.

The method is based on the oxidation ofiodide ions to iodine by

cupric ions. followed by titration ofthe iodine by thiosulfate.

Atom ic Absomtion Snectrosconv.

830.1900 Submittal of samples NA

830 .6302 Color Green-blue solid

Bluish-green solid

830.6303 Phvsical State Solid

830.6304 Odor Musty hydrocarbon odo r

Burnt and slightly aromatic

Diesel-like odor or musty smell of the naphthenic acid

Uneleasant taste and a mild , characteristic odor

830.6313 Stabil ity to sunlight, norma l Stable for 14 days under ambient temp erature of 20-24"<: and

and e levated temperature, elevated temperature of 50 - 55° C.

metals/metal ions

830.6314 OxidationIReduction: Incompatible with strong alkalie s. strong oxidizing agents, stro ng

Chemical Incompatibility acids.

Not compatible with concentrated acids and alkalis

Does not contain oxidizing or reducing agents.

Contains no readily oxidiza ble or reducible components.

Conditions to avoid instability : Avoid heat and any source of

ignition.

Incompatibility: Contact with oxid izing agents. Reducing agents.

830 .6315 Flammability Flash Point: 38"<:(I00"F) (Closed cup) (typical)

830.6316 Exclodebilirv Does not contain explosive ingredients.

830.63 17 Storage Stab ility Do not use. pour, spill or store near heat or open flame. Keep

container closed. Use with adequate ventilation.

Stable under norma l conditions.

830.63 19 Miscibilitv NA

830.6320 Corrosion Characteristics Non-corrosive

830.6321 Dielectric break down Not intended for use in or around electrical equipment.

voltage

830.7000 I pH Data for this guideline is not required because the technical grade

Page 10 of28
Guideline No. Ph ysical and Chemical Value

Properties

active ingred ient is insol uble in water and can not be diluted .

Non-anclicable - cannot be diluted or dispersed with water.

830 .7100 viscositv NA

830.7200 Melting point - 102"C

830.7220 Boiling point I54-202"C (310-395° F) @ I aun

121"C, decomposes at 267"C

Approx. 3500F

TGAI is solid at 25"C

830.73 00 Density t .055 glml at 20°C

Density (g/cm"): 1.055

Specific Gravity:

1.08 errvcc at 2O"C

830.7370 Dissoc iation Consta nt Copper naphthenate readily dissociate in solution into copper and

naohthen ic acid .

830.7550 Partition coefficient (n· 1.I0 @ 20"C

octanoVwater)

830.7840 Solubility in water Insoluble in water. Not miscible .

So lubility in water 0.0046 /100 ml (46 ppm) at 20"C.

Solu ble in wate r at 25"C at a concentra tion of0.0 15 erams per liter

830.xxxx Solubility in organic Soluble in most organic solvents; moderately soluble in petroleum

solvents oils.

Soluble in gasol ine, benzene, and mineral oil distillates.

So luble in non-polar organic solvents.

Soluble in keros ene, toluene, turpentine, and similar solvents.

The TGAI is completely soluble in aromatic and aliphatic

petroleum hydrocarbon solvents. It is slightly soluble (1% or less)

in polar solvents ofless than three carbon chain lengths. It is

moderatel y soluble (1·20% ) in polar sol vents of more than three

carbon chain lengths.

soluble in most organic solvents, in petroleum oil 900 glkg

water 0.004 6 (46 ppm);

g/IOOml at 20°C;

toluene 147.4; 2-propanol37.3;

chloroform 102.9; ethyl ether 171.4; cyclohexane 116.3;

methylene chloride 113.4; acetone 22.0

830.7950 Vapor pressure <133 mPa (I00"C)

<1.0 mm Hg

1 x lO.

s mm Hg at 25°C

0.00012 8 mm Hg

Non-volatile

Temp VP

32"F - None

77"F - None

100°F- None

I50°F- None

2l2°F- None

Page 1\ of28
Gu ideline No. Ph ysical and Che mical Val ue

Properties

280°F None

These data prove that copper naphthenate, up to irs decomposition

temperature, is non-volatile. This non-volatility property of copper

nachtbenate undoubtedly carries rhroueh to irstreatments.

N /A Not applicable: TGAI Technical Grade Active Ingredient, CBI Confidential Business Information;

Enviro nmenta l Fate Summary

Copper naphthenate has been in use as a wood preservative since about 1947 and the

name applies to a group of compounds that are coppe r salts of naphthenic acids. Naphthenic

acids, sometimes referred to as petroleum acids, are the carboxylic acids derived from petroleum

during the refining of the various distilled fractions. They are natural components of crude oil

that are not formed during the refining, and are predominately monocarboxylic acids. Despite

intensive investigation by a variety of chemists, the number of component acids that have been

identified remains small. The simplest ofthese acids is cyclopentylethanoic acid but structures

can include many more methylene groups between the ring and the carboxyl group and may

include several fused rings. The exact composition of naphthenic acids depends on the crude oil

from which they are derived and is usually quite complex. Commercial naphthenic acid contains

all the acidic components of crude oil, and varyin g amounts, usually less than 10%, of

hydrocarbons.

Copper naphthenate is manufactured either from copper sulfate and naphthenic acid in

combination with a strong base or by heating naphth enic acid and copper oxide. Copper

naphthenate is insoluble in wate r but miscible with most organic solvents. Copper naphthenate

has no vapor pressure, is easily dissociated in solutions, and has low solubility in non-aqueous

systems other than mineral spirits type solvents. Melting and boiling points vary with the

composition of the naphthenic acids. Copper naphthenate tends to hydrolyze after application to

wood. The acid is lost by volatilization comparatively rapidly, but the metal persists.

Environmental fate parameters listed for zinc naphthenate on page 44 are also apply to

copper naphthenate. The metal carboxylate salts such as copper naphthenate are designed to

deliver metals to chemical reactions; therefore, they are designed to readily dissociate into the

free metal and free acid. The dissociation constant is important because it determines the

proportion of acid or metal that is dissociated at a given pH. The properties of the free acid and

corresponding free metal can be much differe nt than those of the salt (ion pair) moiety for

characteristics such as solubility, adsorption, and toxicity and the extent of dissociat ion is

determined by pH. The amount of dissociation influences the behavior ofthe substance in the

environment and bioavailability ofthe acid and meta l constituents ofmetal carboxy late salts.

Copper Naphthenate - Lea eha hility from Treated Wood (MRID No. 438611-01)

Non Guideline numbe r 168-1-55 Aqueous Availability Study: The objective of this study

was to determine the leachability ofcopper from copper naphthenate wood products under

typical use conditions. The two typical methods of application of copper naphthenate to wood

are pressure treatment or surface treatment. Both types were prepared for use in this study. The

Page 12 of 28
treatments were as close as possible to normal application methods. A "dipping" method was

elected as the surface treatment because it represents a typical surface application producing a

maximum treatment rate.

The amount of copper from copper naphthenate in repre sentative samples oftreated and

untreated wood was determined . To simulate worst case end-use conditions, treated wood

products and untreated (contro l) wood stakes were totall y submerged in unbuffered deionized

(01) water, and with 01 wate r buffered to pH 5, pH 7, and pH 9. Leachates were analyzed for

total copper over a Ju-day interval.

A Labo ratory study on sapwood stakes of southern yellow pine wood has shown that

copper naphthenate does leach out from the surface-treated wood and pressure treated wood .

The rates ofleaching from the surface-treated wood and pressure treated wood follow the order:

rate of leaching is highest in pH 5» pH 7 > unbuffered solution > pH 9. The rate of leaching

from surface treated wood at pH 5 is: 0.047 ppm/ern" /day and for pH 9 it is O. 00048, ppm/ern"

/day 100 fold-fold less. Similarly the rate ofleaching from a pressure treated wood at pH 5 is:

0.0 3 ppm/cm2 / day and for pH 9 the value is 0.00029, again the rate of leaching is 100-fold less.

The rate of copper naphthenate that leach from the treat ed wood is shown below in Table 4.

T bl 4 Ra e . ate 0 fLeaehime rrom N P on- ressure Trea ted andPressure T reatedWood

Copper Naphthe nate

Methods Of Application (Amount of Leachate)

Non-pressure Treated Wood pH 5 - 0.047 ppm/cm' /day

I DH9 0.00048 DDm/cm' ldav

Pressure Treated Wood pH 5 - 0.03 ppm/cm' /dal

I oll 9 0.00029 nom/em Idav

The maximum total leached copper levels over the 3D-day test for each matri x followed the

order:

pH 5» pH 7> unbuffered Dl> pH 9 (See Table 5 below).

maxImum solution concentration/surface area obtained m lV-day test

b below detection limit

Table 5: Maximum Leaching Levels

Total Leach ed Conner nn linc ~'

Treatment

Pressure Surface Untreated

Matrix 1 2 3 I 2 3 1 2 3

1 nH 5 0,684 0.685 0.663 0.116 0.633 1.800 0.003 0.002 0.002

1 pH 7 0.094 0.094 0.081 0.043 0.064 0.098 0.003 0.002 0.002

OJ 0.033 0.052 0.034 0.024 0.026 0.074 NO 0.001 0.001

I pH 9 0.030 0.026 0.026 0.012 0.0 18 0.020 0.001 0.001 0.001

•

Water Quality

Page 13 of28
Copper naphthenate is not identified as a cause of impainnent for any water bod ies listed

as impaired under section 303(d) of the Clean Water Act, based on information provided at

http://iaspub.epa.gov/tmdl waterslO/attains nation cy.cause detail 303d?p cause group id=88

In addition, no Total Maximum Daily Loads (TMDL) have been developed for copper

naphthenate, based on information provided at

http://iaspub.epa .gov/tmdl waterslO/attains nation.tmdl pollutant detail?p pollutant grOUP id

=885&p wllutant group name=PESTICIDES . More information on impaired water bodies

and TMDLs can be found at http://wv,w.epa.gov/owow/tmdll. 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 ofthe 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: http://www.epa.gov/oppfead l/cb/ppdc/2006/november06/session 1-

sop.pdf), in order to ensure they can be used quantitatively or qualitatively in pesticide risk

assessments.

Ecological Effects Sum ma ry

The Agency has reviewed eleven ecotoxicology studies for copper naphthenate salt. The

eleven studies submitted on the technical grade active ingredients and formulated products were

all found to be acceptable for use in a hazard assessment. Ecotox icity guideline studies and the

results are summarized in Table 6. The Agency's conclusio ns for the avian and aquatic effects

studies are as follows.

Toxicity to Birds

To evaluate the acute toxicity to birds. the Agency reviewed two acute oral toxicity

studies for the copper naphthenate salt. These acute oral toxicity studies on the bobwhite quail

indicate that the copper naphthenate salt is practically nontoxic on an acute oral basis.

The subacute toxicity for the copper naphthenate salt was determined from four studies

conducted on the bobwhite quail and the mallard duck. The results ofthese studies indi cate that

the copper naphthenate salt is practically nontoxic to avian species through subacute dietary

exposure.

Toxicity to Aquatic Animals

On an acute basis, the copper naphthenate salt is moderately toxic to freshwater fish and

highly toxic to freshwater invertebrates.

Page 14 of28
Table 6. Ecotoxicitv Data Summa v for Copper Na hthenate (TGAI

GUIDE CIIEMICAUMRID COMMON TAXONOM IC TYPE % Sn1DY DOSE TaXI TOX CArE

Lll'oiE NAME ;"IlAME AI TI.\-IE TYPE CITY LEVEL NOEL GORY

Avlan Acute Oral TOXicity

850.2100 Copper naphthmllle Bobwhite Colima 0 9.55 14 D LD", >2250 MGK <292 Core

7 1-1 ~RID 42 34860 quail virgimanus

Practically

Nontoxic

850.2100 Copper Bobwhite Colinus 0 20/80 14 D LDso >2250 MGK <292 Core

7 1-1 naplh enat elMincral quail virginianus spmts mixtu re Practically

~RI04 30 801 Nontoxic

Avian Subacute Dietary Toddl)'

850.2200 Copper naphlhenlll c Bobwhite CoJinus D 9.5 8 D LC", >5620 PPM 5620 Core

71-2a MRID 42348602 quail virgi nianus

Practically

nontoxic

850.2200 Copper naphthenate Mallard duck Anas D 9.5 8 D LC", >5620 PPM 5620 Core

71-2b \1RID42348603 Iplotyrhynchos

Practically

Nontoxic

850.2200 Copper Bobwhite Colinus D 20/80 8 D LC", >5620 PPM 5620 Core

71-2a napthmatclM incul quail virginianus spirits mixture Practically

MR[D 40308802 Nontoxic

850.2200 Mallard duck f< nos D 20/80 8 D LC", >5620 PPM 5620 Core

71-2b naphlhcnateIMinCTai Iplatyrhynchos SpIrits nuxture Practically

\tRIO 40308803 Nontoxic

Freshwater Fish Acute Toxicily

850.1075 Copper naphtbenate Bluegill Lepomis SR 98.9 96 hr LC", 3.1 PPM 1.6 Core

72-la

\-lRJO 42489 [01 sunfish macrochirus

Moderately

Toxic

850.1075 Copper Rainbow Oncorhynchus S 25n5 96 '" LC", 0.74 PPM NR Suppl

72-1 naphthrnatcJ1>etroleum trout my kiss distillate mix

MRID 00 11402 7

850.1075 Coppa- Bluegill Lepomis S 25n 5 96 Hr LC", 3.85 PPM NR Suppl

72-1 naphthenatelPetroleum sunfish macrochirus distillate mill;

MRID OOI 14028

Freshwater Invertebrate Acute Tealcity

850.1010 Copper naphlhenale Water flea Daphnia S 98.9 481rr EC", 034 PPM 0.12 Core

72-2 MRID 424 8910) magna

Highly

Toxic

Page 15 of28
Ecotoxicity data are adequate to provide the Agency with sufficient information to

determine appropriate label precautions.

Naphthenic Acid

Naphthenic acids are slightly-to-moderately toxic to aquatic organisms (Table 7) and

practically non-toxic to mammals on an acute basis (Table 8).

Ta hIe 7 F b . res water A«matt'e TOXICltv 0 f ,

Na Db b . I emc ACI'd

Common Name Scientific Name LC,. (m!VLl Toxicitv Rating:

Alea Novicula Sem inulum 30.5 -80 ,5 Sllahtlv toxic

Invertebrate Notocra Soimoes 4.8 Mode rarelv toxic

Zeb ra Fish Brachvdanio rerios 16.3 Slightly toxic

Zebra Fish Embrvo Brachvdan io rerios 3.5 Moderatelv toxic

Three-spine Stickleback Gasterosteus aculeatus 5.0 Moderately toxic

Blueaill Leooomis macr ochirus 5.6 Moderatelv toxic

Ta hi 8 e . NaDIbibemc. A id CI TOX"1> ICI • I0 TerresIria. 10raamsms

Common Name Scientific Name LC,.lm!!ILl Tox lcltv Rating

Rat Acute Oral 5.9 Practically Non-toxic

Mouse AcuteO ral 3.6 Practicallv Non-toxic

Adverse Ecological Incidents

There are no report ed incidents in the Agency's Ecological Incident Information System

(EllS) regard ing copper naphthenate (PC Code 022102). The absence of documented incidents

does not necessarily mean that such incidents did not occur.

Ecological Effects Risk Assessment

The Agency has not conducted a risk assessment that supports a complete endangered

species determination. The ecological risk assessment planned duri ng registration review will

allow the Agency to determine whether copper naphthenate' s use has "no effect or "may affect"

federally listed threatened or endangered species (listed species) or their designed critical

habitats. When an assessment concludes that a pesticide 's use "may affect" a listed species or its

designated critical habitat, the Agency \\;11 consult with the U.S. Fish and Wildlife Service

and/or National Marine Fisheries Services (the Services), as appropriate.

Environmental Fate and Ecotm lciry Data Gaps and Anticipated Work

None .

Page 16 of 28
NAPHTHENATE SALTS : ZINC NAPHTIIENATE

REGISTRATION REVIEW DECISION

PRO DUCT CHEM IST RY, ENVIRONMENTAL FATE AND

ECOLOGICAL EFFECTS SUMMARY

PC Code: 088301 ; Case No. 3099

Introduction:

Zinc naphthenate is a fatty acid salt also known as zinc carboxylate, metal soap or zinc

soap. Zinc naphthenate, isthe reaction product ofzine oxide and naphthenic acids. It is a tarry.

dark brown semi-solid (TGAI) with a pungent odor and contains 13.7 percent zinc . It is highly

soluble in non-polar solvents and insolub le in water and has no measurable vapor pressure.

Zinc naphthenate was first registered on November 26, 1975. There are to registered zinc

naphthenate products which are listed in Table t. Zinc naphthenate prod ucts are registered for

use as a wood preservative (foundations, boats, construction posts, docks & piers, door frames,

doors, fence posts, fences, fencing, end cuts, foundation timbers greenhouse wood and stakes,

house siding, landscape logs lawn furniture, millwork, planking, planter boxes, plywood, poles,

porches, posts, pressure treated wood end cut protection, roofs, shake s, shingles, sidings, sills,

stairs, structural logs, structural lumber; structural timber, subflooring, windows and frames) and

a material preservative (non-apparel fabrics, ropes, fishnets, twine, canvas, burlap and other nonapparel fabric material).

The zinc naphthenate technical grade active ingredients (TGAIs) are formulation

intermediates, all registered to OMG Americas, Inc. They are technical chemical source products

for use by formulators in man ufacturing wood preservative/materials preservative end-use

products requiring EPA registration. The percentage of zinc naphthenate in the formulator-use

technical source products are 63%. The various end-use products can range from 7.5% to 69%.

Products containing zinc naphthenate are formulated as soluble concentrates, emulsifiable

concentrates and ready-to-use liquids. A Reregistration Eligibility Decision (RED) was issued by

EPA in September 2007 . There are two active ingredients in the naphthenate salts case 3099 :

copper naphthenate (PC Code 023102); and zinc naphthenate (PC Code 08830 1).

Zinc naphthenate is approved by the Food and Drug Administration for a variety of food

contact use including the following:

21 CFR 175.300 (b) (3), food contact surface as a component ofresinous and polymeric

coatings. Resinous and polymeric coatings may be safely used as the food-contact surface of

articles intended for use in producing, manufacturing, packing, processing, preparing, treating,

packaging, transporting, or holding food, in accordance with the following prescribed conditions:

(a) The coating is applied as a continuous film or enamel over a metal substrate, or the coating is

intended for repeated food-contact use and is applied to any suitable substrate as a continuous

Page 17 of28
film or enamel that serves as a functional barrier between the food and the substrate.

21 CFR 175.105, Adhesive component in packaging material. Adhesives may be safely

used as components of articles intended for use in packaging, transporting. or holding food.

As described in 40 CFR Part 180, zinc naphthenate (CAS# 12001-85-3), is permitted for

use as inert ingredient in nonfood use pesticide products.

Zinc is a healthy diet and a necessary nutrient in soil for better yield of food crops.

Table 1 R . egistered Active Products of Zinc Naphthenate

Registrat ion N Registration Name Compa ny Na me Formulation % of Active

Type Ingredient

577-545 Clear Cuprinol Brand Wood The Sherwin-Williams Co Ready-to-Use 13.5 Preservative No. 20 Solution

1719-44 Zin-Tox Wood Preservative Mobile Paint Manufacturing Ready-to-Use 16.00 Company Inc. Solution

7424-9 Jasco Termin-8 H20 Clear Jasco Chemical Corporation Ready-to-Use 15.75 Wood Preservative Solution

8% Zinc Nap-All

% 30-6 OMG Americas Inc. Formulation 63.0 M-GARD SI50 Wood Intermediate

Preservative

Zinc Hydro-Nap Formulation %30-7 M-GARD WI52 Wood OMGAmericas Inc. Intermediate 63.0

Preservative

M-GARD W550 wood Emulsifiable

% 30-10 Preservative OMG Americas Inc. Concentrate 63.0

End use Product

9630-21 M-GARD S550 wood OMG Americas Inc. Soluble 63.0 Preservative Concentrate

43437·3 8% Zinc Naphthenate OMG Belleville Limited Soluble 69.0 Concentrate

60061·9 Wolman Wood Preservative Kcp-Coat, Inc. Ready-to-Use 7.5 With Water Repellent Clear Solution

6659 1-3 Green's Clear Wood Green Products Co Ready-to-Use 23.6 Preservative Solution

Page 18 of 28
Science Findings

The Agency has conducted a review ofthe available product chemistry, environme ntal

fate, and ecotoxicity data for zinc naphthenate. The findings are summarized below.

Product Chemistry Summary'

The data submined pertaining to the physical and chemical characteristics of the active

ingredient, zinc naphthenate is adequate. All produ ct chemistry data requirements have been

satisfied for the active ingredient zinc naphthenate. Therefore, the Agency does not anticipate

needing additional product chemistry data for zinc naphthenate at this time. Tables 2 and 3

contain the complete product chemistry information for the active ingredient zinc naphthenate.

Table 2. Chemiealldentity

Chemical Name Naphthenic acids, zinc salts

Commo n Names Zinc naphthenate

Synonyms Naphthenic acids, zinc salt; 6SN-Zn; Cuprinol clear;

Naphthenic acid, zinc salt; Naphthex Zn; Nikka Naphthex

Zinc; Nikka Naphthex Zn; Zinc naphthenate; Zn

Nanhthenate

Trade Name Zinc uversol

Zinc salt of naphthenic acid

IUPAC Name Zinc naphthalene-2-carboxylate

Zinc naphthenate

Molecular Weight 319.71 glmole

PC Code 088301

CAS Registry Number 12001-85-3

Molecular Formula 2(CI1H,O,)Zn

22 0~

Registration Review Case No. 3099

Registration Review Case Name Naphthenate salts

Classification Carboxylic Salt

Chemical Family Organo zinc

Molecular Structure:

[(CIJ,).COOJ,Zn

°

2(CIlH,O,) Zn aY'

~~ 0-In"0"yCC~~I

Zinc naphthenate

°

Page 19 of 28
Table 2. Chemical Identity

m

Zinc naphthenate

Zincnaphthenate

2

.. ,.

Zinc naphthenate

Zinc naphthenate

Page 20 of 28
Table 3. Product Chemistrv Data Summarv of Zinc na nhthen ate (TGAI 80%)

Gu ideline No. Physical and Chemical Value

Prceertles

830.1550 Product identity and Refer to Table 3.

composition

830.1600 Description ofmaterials CBI

used to produce the product

830.1620 Description of production CBI

nrocess

830.1650 Description offormu lation CBI

crocess

830. 1670 Discussion of formatio n of CBI

imnurities

830.1700 Preliminary ana lysis CBI

830.1750 Certified limits CBI

830.1800 Enforcem ent analytical HPLC

method

830 .1900 Submitta l ofsamn les NA

830 .6302 Color Tarry, dark brown semi-solid

Naphthe nic acid : Gold to black liquid

830 .6303 Phvsical State

830.6304 Odor Odorless.

Musty hydrocarbon odor

830.63 13 Stability to sunlight. nonnal Material is stable over a wide range oftemperature and not subject

and elevated tempera ture, to UV degradation

metals/metal ions Zinc Napthenate is recognized as an extremely stable compound.

To confirm this reputation, analyzed two year old samples from

the laboratory shelf. New analysis as well as visual examination

confirm ed stability of the TGAI.

830.63 14 OxidationIReduction: NA

Chem ical Incomnatibilitv Prod uct does not contain oxidizing or reduc ing ae ents

830.63 15 Flammability NA

Flash oo int : 135 OF

830.6316 Exc lodabilitv NA because there is no explosive ingredient.

830.6317 Storage Stability Indefinite stability. No loss of a.i. ingredient zinc as metal.

The NP is standard mild steel cont ainers was stor ed in an unheated

warehouse and ana lyzed for periods up to 2 years. Within the

limits of the analytica l method napht henate percentages did not

vary in the two year period.

Stable at 25"C in commercial packaging. The physical prope rties

of the prod uct have not changed and the quantity ofthe active

ingredient has not changed after storage for one year.

830.6319 Miscibility Miscib le in most hydrocarbons aliphatic and aromatic

830.6320 Corrosion Chara cteristics Non-corrosive

830.6321 Dielectric breakdown NA voltaQe

830.7000 pH This is not required because the techn ical grade ofthe act ive

ingredient cannot be diluted or dispersed with wate r.

830.7100 Viscosity NA

Page 21 of28
G uideline No. Phys ical and Ch emica l Valu e

Properties

830.7200 Melting point A distinct melting point would not be expected for I n naphrhenate

due its complex chem ical compos ition.

66°e

For commercially -available naphthen ic acids, the reported melting

point is between -35°C and +2°C.

830.7220 Boiling point 116°C

The boiling point for commercially-available naphthenic acids is

within the range 140 - 200°C.

830.7300 Density Density: 0.962 g1mL at 25 °C (lit.)

Refractive index : n201D 1.4630(lit.)

1.02 gmIml at 20°C

The reported density for naphthenic acids is 0.91 - 0.96 g/cm' at

15°C.

Specific gravity: 0.966 at 25cC

Naphthenic acid: Sp er: 0.982 at 20CC!4CC (liquid )

830.7370 Dissociation Constant 7.13 and 9.18 @20'e

The pKa values for In napthenate were 7.31 (SO = 0.0131) and

9.18 (SO = 0.0466). This indicates that In naphthenate will be

50010 dissociat ed into an ionized metal moiety and ionized organic

acid at a pH of7.3 1. Because I n is divalent and In naphthe nate

has two moles of naphthenic acid per mole of Zn. there is a second

dissociation point (Le., pH 9.18) where the metal moiety will

dissociate from the second mole of nanhthenate.

830.7550 Partition coefficient (n- log Partition Coefficient: 1.10 @ 20cC

octanol!water)

The log Partition coefficient of 1.10 is very low indicating little or

no potential for significant bioaccumulation.

830.7840 Solubility in water Water dispersa ble

It is soluble in wate r at 24"C at a concentration of 0.015 grams per

liter.

The estimated water solubility for a range of molecular weight

naphthenic acids ranged from 0.0003 to 2.1 mglL.

80 mgIL @ 200e

Water Sol: 15.4 mgIL (EPI Suite) - Zn Nap

830 .xxxx Solubility in organic The TGA I is completely soluble in aromatic and aliphatic

solvents petroleum hydrocarbon solvents. It is a slightly soluble (I % or

less) in polar solvents of less than three carbon chain lengths. It is

moderately soluble ( 1- 20%) in polar solvents of more than three

carbon chain lengths.

Highly soluble in non-polar solvents.

Naohthe nic acid: soluble in oil

830.7950 Vapor pressure I X 10" mm Hg at 25cC

9.33E-008 mm Hg (EPI Suite)

HLC: 2.549E-009 atm-m3/mole (EPI Suite)

Biodegradation 50% degradation to CO2 in 24 d (based naphthenic acid)

Page 22 of 28
Guideline No. Ph ysical and Chemical Va lue

Pronerties

Photodegradation NA

In solution at environmental plfs, Zn naphthenate will dissociate

to a significant degree . Zn will not photodegrade. Naphthenic acid

is a complex distillate fraction for which photodegradation cannot

be reliabl y estimated or accurately measured.

NfA Not applicable; TGAI Technical Grade Active Ingredient: CBI Confidential Business lnformation

Environmental Fate summary

The Agency recognizes that zinc naphthenate dissociates in water to form zinc and

naphthenic acid. These degradates are pesticides and hence should be considered in the

environmental fate profile of zinc naphthenate. The Agency believes there is sufficient

information to address the environmental fate on Zn2

+. Conversely, the environmental chemistry

of naphthenic acid is not well known. Therefore, fate studies should provide information on the

environmental chemistry of naphthenic acid.

Naphthenic Acids: Naphthenic acids are a family of carboxylic acids, composed

predominantly of alkyl-substituted cycloaliphatic carboxylic acids with smaller amounts of

acyclic aliphatic (paraffinic or fatty) acids. Aromatic olefinic, hydroxyl, and dibasic acids are

also present as minor components of naphthenic acids. The cycloaliphatic acids include single

rings and fused multiple rings. The carboxyl group is usually bonded or attached to a side chain

rather than directly to the cycloa liphatic ring.

Zinc naphthenate is zinc salt of naphthenic acids. Zinc naphthenate is a member of the

metal carboxy lates group and naphthenic acids are a complex group of carboxylic acids. All of

the metal corboxylates salts are designed to add metals to chemical reactions. They therefore are

expected to dissociate into free metal and free acid.

One characteristic of zinc naphthenate and other metal carboxylates is that they readily

dissociate from an ion pair into free metal and free acid. They are found as partially dissociated

products in the ambient environment (i.e., neutral pH). Dissociation is a reversible process and

the proportion of dissociated salt is dependent on the pH and pKa (the dissociation constant),

which is the pH at which 50% dissociation occurs. In the low pH environment ofthe digestive

tract (e.g., pH 1.2) complete dissociation will occur for these metal carboxylates. The transport

and bioavailability of the metals and acids are determi ned by their solubility in environmental

media and biological fluids which is determined by environmental parameters such as pH.

Summar)' of Existing Data

The existing data is summarized below. The data is derived primarily from the FIFRA

dataset, which supports a current registration of zinc naphthcnate as a fungicide. This data has

been reviewed by the U.S. EPA Office of Pesticide Programs and accepted as part of the

registration process. Zinc naphthenate readily dissociate into the corresponding metal and

carboxylic acid, The Agency believes there is sufficient information to address the

Page 23 of 28
environmental fate on Zn2

+ . Therefore. fate summaries are provided for the parent compound

(zinc naphthenate), and the acid (naphthenic acid).

Physicochemical Prop erties

A distinct melting point would not be expected for zinc naphthenate due its complex chemical

compo sition. Existing data are available for water solubility, boiling point, vapor pressure and

partition coeffic ient. The low vapor pressure « 1.0 mm Hg) indicates a low tendency to

vaporize. The log partition coe fficient of 1.10 is very low indicating little or no potential for

significant bioaccumulation. Log Partition Coefficient for Naphthenic acids: <5.1 to 9.2. See

Table 3.

Environmental Fate Parameters:

Dissociation in water: Dissociation constant is a key property, because the fate and effects ofthe

compound are based upon the dissociation products. One key characteristic of any metal

carboxylate is that it readily dissociates from an ion pair into free metal and free acid as the pH is

decreased. A dissociation study was conducted to determine the equilibrium constant of zinc

naphthenate. The results demonstrated two pKa values, 7.3 and 9.18, at 20°C. This indicates that

zinc naphthenate will be 50010 dissociated into an ionized metal moiety and ionized organic acid

at a pH of 7.31. Because zinc is divalent and zinc naphthenate has two moles of naphthenic acid

per mole of zinc, there is a second dissociation point (i.e., pH 9.18) where the metal moiety will

dissociate from the second mole of naphthenate.

Naphthenic acid: Dissociation in water approx. 5. Naphthenic acids are weak acids, with most

pKa values around 5.

Biodegradation: An evaluation of the biodegradat ion of zinc naphthenate is unnecessary. The

parent. metal salt, dissociates into zinc, which does not biodegrade, and naphthenic acid, which

is knO\\TI to biodegrade. Biodegradation is not relevant for the element zinc . Mixtures of sodium

salts of naphthenic acids have exhibited degradation (50% in 24 days; 60% in to days). Fifty

percent of naphthenate (sod ium salt) was reported to be minera lized to CO2 in 24-days by

microbial popul ations indigenous to oil sands tailings.

Photodegradanon: In solution at environmental pHs, zinc naphthenate will dissociate to a

significant degree. Zinc will not photodegrade. Naphthenic acid is a complex distillate fraction

for which photodegradation cannot be reliably estimated or accurately measured. Experimental

photolysis data are available to indicate that naphthenic acids (both mixtures and individual

compounds) are not significantly degraded by exposure to natural sunlight, anificial solar

radiation, or artifici al UV-range radiation. Therefore, the photodegradability of zinc is not

relevant, as the element zinc does not degrade further.

Transport: Fugacity models rely upon a compound being pure and non-ionized and are

inappropriate for a metal carboxylate such as zinc naphthenate, which dissociates into ionized

moieties. In addition, because naphthenate is not a pure chemical, but rather a complex

petroleum distillate fraction, mode ling cannot be used to accurately and reliably predict

transport. Fugacity model ing is designed for unionized, pure compounds and thus is considered

inappropriate for zinc naphthenate and its dissociation products.

Page 24 of28
Transport (Fugacity): 98% partit ioning to soil pred icted for naphth enic acid. The distribution of

a range of naphthenic acids was predicted using the Level I Fugacity model in EPIWIN v.3.1O.

The principal distribution following environmental release woul d be to soil and/or sediment,

with 98% partitionin g to sediment.

Zinc Napbthena te Leachability from T reated Wood (J\1RID No. 440951-01 ):

Non GuidelineI68- I-SS Aqueous Availability Study: The objective ofthis study was to

determine the leachability of zinc from zinc naphthenate wood products under typical use

conditions. The two typical methods of application of zinc naphthenate to wood are pressure

treatment or surface treatment. Both types were prepared for use in this study. The treatm ents

were as close as possible to nonnal appl ication methods. A "dipping" method was elected as the

surface treatment because it represents a typical surface application producing a maximum

treatment rate.

The amount of zinc from zinc naphthenate in repre sentative samples oftreated and

untreated wood was determined. To simulate worst case end-use conditions, treated wood

products and untre ated (control) wood stakes were totally submerged in unbuffered deionized

(DI) water, and with DI wate r buffered to pH 5, pH 7, and pH 9. Leachate s were analyzed for

total zinc over a 30-day interval.

A laboratory study on sapwood stakes of southern yellow pine wood has shown that zinc

naphthenate does leach from the surface-treated and pressure -treated wood. The rates of leaching

from the surface-treated wood and pressure treated wood follow the order: rate of leaching is

highest in pH 5> pH 7 - unbuffered solution > pH 9. The rate ofleachinyfrom surface treated

wood at pH 5 is: 0.112 ppm/em' /day and for pH 9 it is O. 0026, ppm/em Iday a 40-fold less.

Similarly the rate of leaching from a pressure treated wood at pH 5 is: 0.0 19 ppmlcm2 /day and

for pH 9 the value is 0.00 12, a rate ofleaching is 16-fold less. The rate of zinc naph thenate that

leach from the treated wood is shown below in Table 4.

Table 4. Rate 0 f Leaehi102 from Non-Pressure T r eated and Pr essur e T reated Wood

Methods of Ap plication Zinc Naphthena te

IAmount of Leachate)

Non-pressure (Surface) Treated Wood pH 5 - 0.112 ppm/cmv day

oH 9 0.0026 oom/em' /dav

Pressure Treated Wood pH 5 0.019 ppm/em Iday

pl1 9 0.0012 ppm/em' /day

The maximum total leached zinc levels over the 3D-day test for each matrix and each treated

wood type (pressure treated and surface treated) generally followed the order:

pH 5> pH 7 - unbuffered de ionized water> pH 9 (See Table 5 below)

Page 25 of 28
•

•

Table 5: Maximum Leac hing Lenis

Total Leached Zinc(ppmJ1n.

2

)

Treatment

Pressure Surface Untreated

Matrix 1 2 3 1 2 3 1 2 3

pH5 0.501 0.603 0550 .404 .85\ .286 0.005 .004 .005

pH7 .286 0315 305 .289 .778 1566 0.003 ",D" ID

Dl .26 .170 .400 .1 84 .993 1.472 ND f'lD IND

pH 9 0.014 0.020 .02 .042 0.047 ND

maxunumsolutIonconcentrQ/Ion/surface area obtainedIn JO-day test.

below delectUm limit

Water Quality

Zinc naphthenate is not identified as a cause ofimpairment for any water bodies listed as

impaired under section 303(d) of the Clean Water Act, based on information provided at

http://iaspub.epa.gov/tmdl watersl O/attains nation cy.cause detail 303d?p cause group id=88

In addition , no Total Maximum Daily Loads (TMDL) have been developed for zinc

naphthenate, based on information provided at

http://iaspub.epa.gov/tmdl waterslO/attains nation.tmdl pollutant detail?p pollutant group id

- 885&p pollutant group name-PESTICIDES . More information on impaired water bodies

and TMDLs can be found at http://W\\-w .epa.gov/owow/tmdl/. 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 ofthe Of f Standard Operating Procedure: Inclusion a/Impaired

Water Body and Other Water Quality Data in OfP's Registration Review Risk Assessment and

Management Process (see: http://\\'\\w.epa.gov/oppfead1/cb/ppdcI2006/november06/session1-

sop.pdf ), in order to ensure they can be used quantitatively or qualitat ively in pesticide risk

assessments.

Ecological Effects Summary

The Agency has reviewed five ecotoxicology studies for zinc naphthenate salt. The five

studies submitted on the formulated products were all found to be acceptable for use in a hazard

assessment. Ecotoxicity guideline studies and the results are summarized in Table 6. The

Agency's conclusions for the avian and aquatic effects studies are as follows.

Toxicity to Birds

To evaluate the acute toxicity to birds, the Agency reviewed one acute oral toxicity

study for the zinc naphthenate salt. The acute oral toxicity study on the bobwhite quail indicate

that the zinc naphthenate salt is practically nontoxic on an acute oral basis.

The subacute toxicity for the copper naphthenate salt was determined from two studies

conducted on the bobwhite quail and the mallard duck. The results ofthese studies indicate that

Page 26 of28
the zinc naphthenate salt is practically nontoxic to avian spec ies through subacute dietary

exposure.

Toxicity to Aquatic Animals

On an acute basis, the zinc naphthenate salt is sightly to moderately toxic to freshwater

fish.

TahI 6 E I e co OXICI cirv DI S Z· N hth I S It . . aa ummarv or IDC ! apr ena e a

GUIDE COMMON TAXOl'iOMIC TEST .;. STUDY DOSE TOXI TOX , St udy TOX

UJ'olE NAME NAME TYPE AI TIME TYPE CITY LEVEL ;'IlOEL Status CATEGORY

Avian Acute Oral Toxicity

850.2100 Bobwhite Colinus 0 14.3 14 D LO", >2250 MGK <175 Suppl Practically

7 1-1 qua il virginianus Nontoxic

MRID 42348604

Avia n Subacute Dietarv Toxicity

850.2200 Bobwhite Colinus D 14.3 8D LC", >5620 PPM 5620 Suppl Prac tica lly

71-2a quail virginianus Nontoxic

MRID 42348605

850.2200 Mallard f'nas D 14.3 8D LC", >5620 PPM 5620 Supp l Practically

71·2b duck [platyrhynchos Nontoxic

MRID 42348606

Freshwater Fish Acute Toxicity

850.1075 Rainbow Oncorhynchus S 13.0 96 hr LC", l.l PPM 0.3 Core Moderately

72- 1c Trout my k.iss Toxic

MRID42489102

850.1075 Bluegill Lep omis S 13.0 96 hr LC", 92 PPM 32 Suppl Slightly Toxic

72- l a sunfish macrochirus

MRID TN 0629

Ecotoxicity data are adequate to provide the Agency with sufficient information to

determine appropriate label precautions.

Adverse Ecological Incidents

There are no reported incidents in the Agency' s Ecological Incident Information System

(Ell S) regarding zinc naphthenate (PC Code 08830 1). The absence of documented incidents does

not necessarily mean that such incidents did not occur.

Ecological Effects Risk Assessment

The Agency has not conducted a risk assessment that supports a complete endangered

species determ ination. The ecological risk assessment planned during registration review will

allow the Agency to determine whether zinc naphthenate's use has "no effect or "may affect"

federally listed threatened or endangered species (listed species) or their designed critical

Page 27 of 28
habitats. When an assessment concl udes that a pesticide's use "may affect" a listed species or its

designated critical habitat, the Agency will consu lt with the U.S. Fish and Wildlife Service

and/or National Marine Fisheries Services (the Services), as appropriate.

Environmental Fate and Ecotoxicity Data Gaps and Anticipated Work

None.

Page 28 of28