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Introduction 

 The Antimicrobial Division (AD) Registration Review Team has evaluated the status 

of the human health assessments for the active ingredients copper naphthenate (PC Code 

023102) and zinc naphthenate (P.C. Code 088301). According to the reregistration 

eligibility decision (RED) document, copper and zinc naphthenate are formed when 

copper or zinc reacts with naphthenic acid, which is essentially a mixture of cyclic 

carboxylic acids, predominantly cyclopentane derivatives with an average molecular 

weight of 200-300. Copper and zinc naphthenate are currently registered as fungicides, 

insecticides and miticides. This document examines the hazard and exposure databases 

for the registered antimicrobial uses which include material and wood preservation. There 

are no food use tolerances for the active ingredient, no registered food uses and no 

indirect food uses. There is however, one tolerance exemption for residues of copper 

naphthenate when used as an inert ingredient (40 CFR 180.920). 

 The wood preservative use sites for copper and zinc naphthenate include wood for 

utility poles, mine timbers, bridge timbers, cross-ties and stakes. The material 

preservation use sites for copper and zinc naphthenate include textiles used to make tents, 

awnings, tarpaulins, canvas products, nets, ropes, cordage, truck and boat covers, nonrubber fabrics, and burlap. Applications for both use sites are primarily done via 

impregnation, dip, brush, roller and spray. 

 

 The primary source of information for this assessment are the risk assessments and 

supporting documents for the reregistration eligibility decision (RED) documents, which 

were finalized in September, 2007. The purpose of this screen is to determine whether 

sufficient data are available to support registration review, report on whether risk 

assessments have been conducted and to report whether new human health assessments 

are needed to support the registration review process. According to the RED, the 

presence of copper or zinc ion does not have a significant influence on the mammalian 

toxicity of naphthenic acid. Therefore, the toxicity data for both the copper and zinc 

naphthenate are considered together for hazard characterization. 
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The available data indicates that copper and zinc naphthenate are fatty acid salts 

which are practically insoluble in water, soluble in commercial solvents, and have low 

vapor pressures (~1E-5 mm Hg). Table 1 and 2 presents the identity of copper and zinc 

naphthenate respectively. 

Section 1. Chemical Identity 

Table 1. Chemical Identity of Copper Naphthenate 

Common 

Name 

Copper Naphthenate 

CAS name Copper Naphthenate 

PC Code 023102 

CAS registry 

number 

1338-02-9 

Registration 

Review Case 

No. 

3099 

Structure 
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Table 2. Chemical Identity of Zinc Naphthenate 

Common 

Name 

Zinc Naphthenate 

CAS name Zinc Naphthenate 

PC Code 088301 

CAS registry 

number 

12001-85-3 

Registration 

Review Case 

No. 

3099 

Structure 

 

Section 2. Toxicology 

 The Agency reviewed the toxicity database for copper and zinc naphthenate. No new 

toxicity studies and have been submitted since the RED. The Agency issued the DCI for 

both copper and zinc naphthenate on June 9, 2010. The existing toxicology data needs 

can be found in the Agency’s copper and zinc naphthenate RED at 

http://www.regulations.gov in docket number EPA-HQ-OPP-2007-0589. The Agency 

does not anticipate the need for any other toxicity data for copper and zinc naphthenate 

through the registration review program. Although there were no reproductive or 

carcinogenicity data submitted for either copper or zinc naphthenate, these data 

requirements are not considered to be necessary for reregistration since there are no 

registered food uses. 

Acute Toxicity 

 The acute toxicity data for both the copper and zinc naphthenate are considered 

together for hazard characterization and are considered adequate for reregistation will 

also not be needed for registration review. According to the existing RED, there are 

acceptable acute toxicity data available for the technical grade active (60%) of zinc 

naphthenate. Batteries of tests (acute oral, dermal, inhalation, primary eye, primary skin, 

and dermal sensitization) were conducted using 60% a.i. zinc naphthenate. With the 
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exception of an acute inhalation study, acute oral, acute dermal, skin irritation, eye 

irritation and dermal sensitization studies were considered acceptable. In an acute oral 

toxicity study with zinc naphthenate (60%), a toxicity category IV was assigned based on 

a LC50 greater than 5000 mg/kg. A toxicity category of III was also assigned for acute 

dermal toxicity testing of zinc naphthenate with a LD50 for males and females greater 

than 2000 mg/kg. Acute inhalation toxicity testing of 60% a.i. zinc naphthenate indicated 

a toxicity category of IV with a LC50 greater than 11.6 mg/L over a 4 hour exposure 

period, but the study was unacceptable. Skin and eye irritation testing of zinc 

naphthenate at 60% showed the compound to be moderate to severe and slight irritants 

respectively, with a toxicity category of (II, skin) and (III, eye) assigned for skin and eye 

irritation effects. In a dermal sensitization study with zinc naphthenate (60%), the 

material appeared to be a primary skin irritant and a possible sensitizing agent. 

In contrast for copper naphthenate, there are no acceptable acute toxicity studies for 

the technical grade (80-89%) active ingredient in the toxicology database. The highest 

concentration of active ingredient that was tested in acceptable acute toxicity studies was 

45.4% a.i. In an acute oral toxicity study with copper naphthenate (45.4%), a toxicity 

category III was assigned based on testing of a single dose of 501 mg/kg (MRID 

266172). A toxicity category of III was also assigned for acute dermal toxicity testing of 

copper naphthenate but the submitted study was not acceptable (HED document number 

008158). Acute inhalation toxicity testing of 48% and 58% a.i. copper naphthenate) 

indicated a toxicity category of IV, but the studies were unacceptable. Skin and eye 

irritation testing of copper naphthenate at 45.4% showed the compound to be a severe 

irritant in both cases, with a toxicity category of I assigned for skin and eye irritation 

effects. Dermal sensitization studies on copper naphthenate from the BIBRA Toxicity 

profile indicate that copper naphthenate is not a dermal sensitizer; there is no acceptable 

dermal sensitization data available to the Agency on the technical grade of the a.i., 

although the available data also indicate no sensitization potential 

Sub-chronic Toxicity 

Dermal Toxicity 

In a 90-day dermal toxicity test (MRID 41615001) designed to determine the 

sub-chronic toxicity effects of repeated dermal exposure to zinc naphthenate (14.5% 

purity) in New Zealand white rabbits, rabbits were dermally exposed to 0, 100, 300, or 

1000 mg/kg/day of zinc naphthenate 6 hours a day, 5 days a week for 13 weeks. Animals 

were observed twice daily for signs of mortality and moribundity and daily for signs of 

toxicity. Systemic toxicity was observed in the form of significantly reduced body weight 

gain in the high dose group throughout the study. In male rabbits, body weight gain 

decrement was also seen in the mid dose group throughout the study. No treatment 

related clinical signs of systemic toxicity were noted (hematology, clinical chemistry or 

histopathology). In terms of dermal effects there were apparent dose related increases in 

macroscopic and microscopic lesions related to dermal irritation. The systemic toxicity 

NOAEL is (100 mg/kg/day, M/F). The systemic toxicity LOAEL is (300 mg/kg/day, 

M/F), based on reductions in body weight gain. The dermal toxicity NOAEL is less than 

100 mg/kg/day and the dermal toxicity LOAEL is less than or equal to 100 mg/kg/day. 
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 Note that in the RED, the NOAEL was converted to different units when assessing 

dermal irritation. The NOAEL is converted to toxic exposure per area of skin, which is 

measured in μg/cm2. The following equation was used to convert the dose: 

(100 mg[a.i.]/kg[rabbit] x 2.0 kg [body weight of rabbit] x 1000 μg/mg ) / 9 cm2 [area of 

rabbit exposed] =22,222 μg/cm2. 

Assumptions involved in this calculation include body weight of the rabbit and area 

of skin exposed. If it is decided during the registration review risk assessment process 

that the Agency will use irritation as the endpoint for short-term dermal exposure, the 

Agency will likely need to convert the NOAEL to a dermal endpoint in the units of 

μg/cm2 to do the risk assessment. 

Inhalation Toxicity 

There are no inhalation toxicity studies available. The existing RED recently called in 

a 90-day inhalation toxicity study (Series 870.3465) for both copper and zinc 

naphthenate. EPA confirmed that the inhalation study required in the RED is still needed 

for registration review in order to assess the occupational inhalation exposures from 

wood preservatives. The Agency issued the DCI for the copper and zinc naphthenate 

RED recently on June 9, 2010; therefore, the Agency does not intend to issue another 

DCI for this study through the registration review program. 

Developmental Toxicity 

In a prenatal developmental toxicity study (MRID 41615101), copper naphthenate 

was administered by gastric intubation to 4 groups of 25 rats/dose by gastric intubation at 

dose levels of 0, 30, 100, or 300 mg/kg/day, respectively, from gestation days (GD) 6 to 

15. Maternal toxicity was noted in the 100 mg/kg/day and 300 mg/kg/day groups in the 

form of decreases in body weight and food consumption. Maternal toxicity was noted in 

the 100 and 300 mg/kg/day groups in the form of decreases in body weight and food 

consumption. Evaluation of developmental toxicity revealed an increase in the mean 

number of early resorptions only, however the mean litter size of the treated and control 

groups was comparable. Therefore, these increases were considered to be of no biological 

significance. The maternal NOAEL is 30 mg/kg/day and the maternal LOAEL is 100 

mg/kg/day. The developmental toxicity NOAEL was determined to be greater than or 

equal to 300 mg/kg/day and the developmental toxicity LOAEL was greater than 300 

mg/kg/day. 

In another prenatal developmental toxicity study (MRID 41615002), zinc naphthenate 

was administered orally at 0, 50, 250, or 500 mg/kg/day from days 6-15 of gestation. The 

NOAEL of 500 mg/kg/day derived is the highest dose tested. This study was reviewed as 

an unacceptable guideline study.

Mutagenicity 

The Agency identified several mutagenicity studies in the RED. These studies 

included two gene mutation assays submitted to satisfy guideline 870.5300, two 

chromosome aberration assays submitted to satisfy guideline 870.5385, and two 
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unscheduled DNA synthesis (UDS) studies. The RED DCI did not specify the need for 

any other mutagenicity studies and no new mutagenicity studies were submitted since the 

RED. The Agency does not anticipate the need for additional mutagenicity studies for 

registration review. 

 

870.5300 In vitro mammalian cell gene mutation test 

There were two gene mutation assays. In the first study, MRID 41402502, copper 

naphthenate was evaluated for mutagenic potential using the L5178Y TK+/- mouse 

lymphoma mutagenesis assay. A repeat test confirmed the increase of mutant frequencies 

with copper naphthenate in the presence of metabolic activation (+S9). In another mouse 

lymphoma assay (MRID 41400701), zinc naphthenate was tested with mouse lymphoma 

L5178Y TK +/- cells without and with rat liver activation (male Sprague-Dawley, 

Aroclor 1254 induced). There was a possible adverse effect since the mutation frequency 

was increased in a concentration-dependent response both without and with activation. 

There was also a greater increase in small colonies versus large colonies with exposure to 

zinc naphthenate as opposed to copper naphthenate exposure. Although the Office of 

Pesticide Programs reported these two studies to be unacceptable, California Department 

of Pesticide Regulation (CAL EPA) found the studies to be acceptable. 

870.5385 Mammalian bone marrow chromosomal aberration test 

There were two chromosome aberration tests submitted to the Agency. In the first 

study (MRID 41402503), copper naphthenate was tested in the first trial in a chromosome 

aberration assay using Chinese hamster ovary (CHO) cells. No effect on the mitotic index 

was seen at any concentration with activation. There were no significant reproducible 

increases in CHO cells with aberrations for any of the copper naphthenate doses. 

In the other study (MRID 41400702), zinc naphthenate was tested in two trials 

without metabolic activation and in the presence of metabolic activation. With activation, 

in the first trial, positive results were found at 80 ug/ml in the repeat +S9 trial and 

positive results were reported at 60, 80 and 100 ug/ml. In both repeat trials, there was a 

concentration dependent increase. There was a possible adverse effect of an increase in 

chromosomal aberrations with increasing concentrations of zinc naphthenate. Although 

the Agency reported these two studies to be unacceptable, the California Department of 

Pesticide Regulation (CAL EPA) found the studies to be acceptable.

870.5550 Unscheduled DNA synthesis in mammalian cells in culture 

Two Unscheduled DNA Synthesis (UDS) studies were also reviewed by OPP. In the 

first study (MRID 41402504), copper naphthenate was evaluated in the unscheduled 

DNA synthesis test using rat primary hepatocytes and autoradiography. The mean 

number of net nuclear grains did not increase significantly at any dose level over the 

solvent control. It was concluded, therefore, that copper naphthenate was tested over 12 

an appropriate range of concentrations and failed to induce a genotoxic response. In the 

other UDS study (MRID 41400703), primary rat hepatocytes, isolated from male livers, 

were treated with zinc naphthenate at concentrations. There was no evidence for the 

induction of UDS by zinc naphthenate to toxic doses. Toxicity was also evaluated 
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microscopically by cellular morphology. There was no adverse effect under the 

conditions of the assay. It was concluded, therefore, that zinc naphthenate was tested over 

an appropriate range of concentrations and failed to induce a genotoxic response. 

Section 3. Dietary Assessment 

Dietary 

Dietary (food) exposures are not anticipated as a concern. Copper and zinc 

naphthenate residues are not expected to be introduced into the food. There are no food 

use tolerances for the active ingredient, no registered food uses and no indirect food uses. 

There is however, one tolerance exemption for residues of copper naphthenate when used 

in accordance with good agricultural practices as an inert ingredient in pesticide 

formulations applied to growing crops only (40 CFR 180.920). This exemption from the 

requirement of a tolerance was reassessed separately as an inert tolerance assessment and 

is not reconsidered in this document. For the inert ingredient, no more than 2.5% copper 

naphthenate can be present, and products containing copper naphthenate can only be 

applied before the edible portions of the plant begin to form. 

Drinking Water 

According to the product chemistry chapter of the RED, copper and zinc naphthenate 

are highly to moderately immobile in soil and only slightly soluble in water. Copper and 

zinc naphthenate leached from treated wood poles would likely remain immobile in soil 

and break down and not migrate to groundwater. 

Copper and zinc naphthenate products are registered for the use in treated wood to 

construct docks and piers and the Agency will model environmental concentrations of 

copper and zinc naphthenate in the surface water during the registration review risk 

assessment process and will also develop a drinking water assessment. 

Section 4. Occupational/Residential Exposure 

 An occupational and/or residential exposure assessment is required for an active 

ingredient if (1) certain toxicological criteria are triggered and (2) there is potential 

exposure to handlers (mixers, loaders, applicators, etc.) during use or to persons entering 

treated sites after application is complete. For copper and zinc naphthenate, the Agency 

needs to select toxicological endpoints before a risk assessment can be conducted. The 

Agency also anticipates needing to conduct occupational and residential dermal and 

inhalation risk assessments once the needed exposure data from the RED has been 

submitted, reviewed, and accepted by the Agency. 

 Based on the available use information, AD concludes that there is potential exposure 

to occupational handlers (i.e., from applications of wood preservatives and textiles) and 

residential handlers (e.g., homeowner wood treatment applications). In addition, the 

Agency expects there also will be exposure from occupational post-application exposures 

(i.e., workers exposed to wood treatment facilities) and residential post-application 

exposure concerns for children (i.e., contact with treated wood playsets and decks). 
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Hander Exposure 

Occupational Handlers 

 The Agency identified potential occupational handler exposures for copper and zinc 

naphthenate previously in the RED. No other new uses were identified during the 

registration review process. The potential occupational handler risk assessments (both 

short-term (1-30 days) and intermediate-term (>30 days)) by scenario that the Agency 

expects to conduct during registration review include: 

• Incorporation into Textiles During Industrial Manufacturing; 

• Handler Exposure to Workers at Non-pressure Treatment Facilities (i.e., diptank 

operator, blender/spray operator, and chemical operator); 

• Handler Exposure to Workers at Pressure Treatment Facilities (i.e., treatment 

operator and treatment assistant); 

• Handler Exposure to Workers at Commercial Wood/Lumber Facilities; and 

• Application to In-service Utility Poles, Pilings, Posts, and Other Standing 

Timbers. 

 The methods of direct application include liquid pour and liquid pump, low pressure 

spray, brush/roller, non-pressure treatment, pressure treatment, brush, trowel or grease 

gun, and pre-manufactured bandage. 

 

Residential Handlers 

Residential handler exposure can occur through the application of copper and zinc 

naphthenate preservative coatings via paintbrush or sprayer application. The Agency 

expects to conduct residential handler risk assessments for these scenarios and the 

Agency is likely to conduct risk assessment only of short-term duration (1-30 days). 

Postapplication Exposure 

Occupational 

 The Agency identified potential occupational postapplication exposures for copper 

and zinc naphthenate previously in the RED. No other new uses were identified during 

the registration review process. The potential occupational scenarios include: 

 

• Post-application Exposure to Workers at Sawmills/Planer Mills (e.g., grader, trim 

saw operator, millwright, and clean-up); and, 

• Post-application Exposure to Workers at Pressure Treatment Facilities (e.g., tram 

setter, stacker operator, loader operator, supervisor, test borer, and tallyman). 

Residential 

 

The Agency expects that it will need to conduct a residential assessment to examine 

hand-to-mouth and dermal exposures to children from playsets and decks. 
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Section 5. Aggregate and Cumulative Exposure 

 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. Food exposures of concern are not anticipated as a 

concern based on the fact that copper or zinc naphthenate are not expected to be 

introduced into the food, there are no food use tolerances, no registered food uses and no 

indirect food uses. 

The Agency expects that it will need to conduct a residential assessment to examine 

hand-to-mouth and dermal exposures to children from playsets and decks. The aggregate 

assessment will include both residential and drinking water exposures. 

 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 copper and zinc naphthenate has a common mechanism with other compounds, 

consequently a cumulative assessment will not be performed. 

Section 6. Endocrine Disruption 

As required under FFDCA section 408(p), EPA has developed the Endocrine 

Disruptor Screening Program (EDSP) to determine whether certain substances (including 

pesticide active and other ingredients) may have an effect in humans or wildlife similar to 

an effect produced by a “naturally occurring estrogen, or other such endocrine effects as 

the Administrator may designate.” The EDSP employs a two-tiered approach to making 

the statutorily required determinations. Tier 1 consists of a battery of 11 screening assays 

to identify the potential of a chemical substance to interact with the estrogen, androgen, 

or thyroid (E, A, or T) hormonal systems. Chemicals that go through Tier 1 screening 

and are found to have the potential to interact with E, A, or T hormonal systems will 

proceed to the next stage of the EDSP where EPA will determine which, if any, of the 

Tier 2 tests are necessary based on the available data. Tier 2 testing is designed to 

identify any adverse endocrine related effects caused by the substance, and establish a 

dose-response relationship between the dose and the E, A, or T effect. 

Between October 2009 and February 2010, EPA issued test orders/data call-ins for 

the first group of 67 chemicals, which contains 58 pesticide active ingredients and 9 inert 

ingredients. This list of chemicals was selected based on the potential for human 

exposure through pathways such as food and water, residential activity, and certain postapplication agricultural scenarios. This list should not be construed as a list of known or 

likely endocrine disruptors. 

Copper and zinc naphthenate are not among the group of 58 pesticide active 

ingredients on the initial list to be screened under the EDSP. Under FFDCA sec. 408(p) 

the Agency must screen all pesticide chemicals. Accordingly, EPA anticipates issuing 

future EDSP test orders/data call-ins for all pesticide active ingredients. 
11

For further information on the status of the EDSP, the policies and procedures, the list 

of 67 chemicals, the test guidelines and the Tier 1 screening battery, please visit our 

website: http://www.epa.gov/endo/. 

Section 7. Incidents 

According to the RED, the Agency reviewed available sources of human incident 

data for incidents relevant to copper and zinc naphthenate. EPA consulted the following 

sources of information for human poisoning incidents related to copper and zinc 

naphthenate use: (1) OPP Incident Data System (IDS) - The Office of Pesticide Programs 

(OPP) Incident Data System contains reports of incidents from various sources, including 

registrants, other federal and state health and environmental agencies and individual 

consumers, submitted to OPP since 1992; (2) California Department of Pesticide 

Regulation (1982-2004) – The California Department of Pesticide Regulation pesticide 

poisoning surveillance program consists of reports from physicians of illness suspected of 

being related to pesticide exposure since 1982; (3) National Pesticide Information Center 

(NPIC) - NPIC is a toll-free information service supported by OPP That provides a 

ranking of the top 200 active ingredients for which telephone calls were received during 

calendar years 1984-1991; (4) National Poison Control Centers (PCC) (1993-1996); and 

(5) Published Scientific Literature on Incidents. 

The RED also reported that since 1992, only one incident associated with copper or 

zinc naphthenate alone has been recorded. The incident report noted a strong odor and 

adverse health effects were reported following residential application of copper 

naphthenate containing wood preservative. However, no clear symptoms were described 

in the report. 

The RED stated that the most common symptoms reported for cases of ocular 

exposure were eye irritation/burning. Eye pain and swelling of eyes also have been 

reported in some cases. No incidents of oral exposure have been reported. No new 

incidents have been reported to the Agency after the completion of the RED in September 

2007. 

Section 8. Anticipated Data Needs 

 The Agency issued the DCI for copper and zinc naphthenate on June 9, 2010. The 

data needs for the DCI for reregistration can be found in the Agency’s copper and zinc 

naphthenate RED at http://www.regulations.gov in docket number EPA-HQ-OPP-2007-

0589. The Agency does not anticipate the need for any other hazard, exposure data for 

copper and zinc naphthenate for registration review since the data were already recently 

called in. The toxicity and exposure data already called in from the RED DCI include: 

• 90-day inhalation toxicity (Series 870.3465); 

• Dermal exposure (Series 875.1100 and 875.1200); 

• Inhalation exposure (Series 875.1300 and 875.1400); 

• Application exposure monitoring (Series 875.1600); 

• Product use (Series 875.1700); and 
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• Wood leaching study (Special Study). 

Section 9. Tolerances 

 There are no tolerances or exemptions from tolerances for the copper and zinc 

naphthenate active ingredients and no registered food uses. Since the only registered uses 

are for non-food uses and no dietary assessment is needed, no tolerance or exemption 

from the requirement of a tolerance will be needed to support the existing active 

ingredient registered uses of copper and zinc naphthenate. 

 

 It should be noted that there is also one inert exemption from the requirement of a 

tolerance for residues of copper and zinc naphthenate when used in accordance with good 

agricultural practices as an inert ingredient in pesticide formulations applied to growing 

crops only (40 CFR 180.920). For this inert tolerance exemption, no more than 2.5% 

copper naphthenate can be present, and products containing copper naphthenate can only 

be applied before the edible portions of plants begin to form. This tolerance was 

reassessed separately as an inert tolerance assessment and is not reconsidered in this 

document since it only reassesses the active ingredient. 

Section 10. Overall Conclusions 

 The Agency reviewed the hazard and exposure databases for copper and zinc 

naphthenate and does not anticipate that additional data will be needed since the Agency 

recently reassessed copper and zinc naphthenate in the RED and also sent out a recent 

RED DCI for pending data needs. Depending on the outcome of the review and 

acceptance of the new data from the copper and zinc naphthenate RED DCI, the Agency 

anticipates the need to conduct new handler and post-application assessments for 

registration review. The EPA also anticipates that occupational, residential, and 

aggregate assessments will be needed to ensure that copper and zinc naphthenate 

registration review case meets the safety standards established by FFDCA, as amended 

by FQPA. After the Agency conducts the surface water modeling, the Agency will then 

be able to develop a drinking water assessment. No additional label changes are 

suggested at this time. 

Section 11. Recommended Label Changes 

The RED, which was finalized in September, 2007, recommended a number of 

label changes to minimize the dermal risks of concern. From zinc naphthenate. The 

Agency noticed in reviewing the labels for registration review that a number of the 

currently registered labels have not been updated to accommodate the risk mitigation 

specified in the RED. Among the changes listed in p46 of the RED were the following: 

• Limit application for preservation of outdoor-use textiles for zinc 

naphthenate products to low-pressure sprayer and liquid pump 

applications. Application to outdoor-use textiles using a brush/roller or 

liquid pour is prohibited. 
13

• Remove pressure treatment and remedial treatment of utility poles from 

all zinc naphthenate labels; 

• Limit application for general preservation of wood for zinc napththenate 

products to low-pressure sprayer applications. Application for general 

preservation of wood using a brush/roller or airless sprayer is prohibited. 

• Reduce maximum application rate for use in wood preservative 

applications by blender spray operators to 15% a.i. by weight. 

Applicators must wear long sleeved shirt, long pants, shoes, socks, 

chemical resistant gloves, and chemical resistant apron; 

• Reduce maximum application rate for use in dip tank operations to 25% 

a.i.; and, 

• Require chemical resistant gloves to be used on all zinc naphthenate 

products. 

Section 12. Reference 

• Reregistration Eligibility Decision (RED) Copper and Zinc Naphthenate Salts, 

September, 2007. http://www.epa.gov/pesticides/reregistration/status.htm