This document provides an overview of copper naphthenate (CuN) as a wood preservative. It discusses CuN's regulatory status, production process, efficacy in studies, major markets and commodity uses. CuN is classified as a general use pesticide and studies show it performs as well or better than alternatives like pentachlorophenol. Major current markets are in utility poles, railroad ties, and bridge timbers. CuN provides effective protection of wood while having favorable environmental and safety properties compared to other preservatives.
4. • Naphthenic acid is a natural
component of petroleum
– Carboxylic acid like acetic acid (vinegar)
– Mixture of C6-C25 acids
– Recovered for commercial uses
– Previously disposed of as waste
• Copper used in CuN recovered from electronics waste
4
CH3
CH3
OH
O
CH3
OH
O
5. • Produced by the reaction of naphthenic acid and
copper compounds
– Pure CuN is a glassy solid or paste, ~11-13% Cu
– Insoluble in water
– Concentrate formulations
• Solvent-based: Diluted in #2 D or mineral spirits to 8% Cu
• Waterborne: Diluted to 5% Cu
• Copper is the main active component in CuN
– Organic naphthenate portion provides oil solubility 5
6. 6
• Consumer pressure for a cleaner end product
• Cleaner handling characteristics & lower odor
• Not a restricted use pesticide & no listed carcinogens
• Diverse studies show it works as well as alternatives
• Good lubricating and waterproofing qualities, and non-conductive
• Works great with borates as a dual treatment
– borates prevent incipient decay in wood while seasoning
7. • Used extensively in agriculture
– Tens of millions of lbs applied
annually in crop and algaecide
applications
– Major crop applications include citrus, tree nuts,
tomato, pepper, grape, berries and peach
• Direct water applications as an algaecide, aquatic
herbicide, bactericide and molluscicide
• Copper is a micronutrient with minimal toxicity
to higher life forms
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8. • EPA non-restricted use pesticide
– General Use Classification
– Sold over the counter for consumer use
– Non-hazardous waste
– Non-hazardous air pollutant
– No reportable quantity required if
spilled
• EU/ECHA BPR: Not currently
registered as an active in PT 8
– Working to get added as new active
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9. • 2007: Re-registration Eligibility Decision
– All studies identified in data call-in are complete
– Data submitted to EPA in 2013 & 2014.
• 2010: Registration Review
– EPA does not anticipate needing additional data
– Final decision due in 2015
• 2015: 10 active registrations for oil-borne CuN
– 8.0% Cu concentrate containing 68% CuN
– 1% Cu (8.5 to 10% CuN) ready to use
– 2% Cu (17 to 21.6% CuN) ready to use 9
10. • Low acute mammalian toxicity by oral,
dermal, inhalation routes of exposure
• Skin irritant, but not a skin sensitizer
• Not a carcinogen or mutagen
• No reproductive toxicity
• Minimal avian toxicity
• Moderate to high aquatic toxicity
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11. Cu/CuN Pentachlorophenol Creosote Arsenic
Use Classification General Restricted Restricted Restricted
Toxicity Category III I I I
RCRA Listed Waste Not Listed F021, F027,
F028,F032,K001
F034, K001,
K035, U051
F035, P011
CERCLA RQ, lbs None 10 1 1
OSHA carcinogen No Yes Yes Yes
Drinking Water MCL,
mg/l
1.3 (Cu) 0.0001 0.002
(B[a]P)
0.010
EPA 2011 tap water
RSL, μg/l
620 (Cu) 0.17 0.0029
(B[a]P)
0.045
EPA 2011 res. soil RSL,
mg/kg
3100 (Cu) 0.89 0.015
(B[a]P)
0.39
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12. • Recommended practices for treating wood using
CuNap and other preservatives
• Ensures a clean surface & minimal drippage
• Minimizes environmental exposure for wood
intended for use in aquatic, wetland and other
sensitive environments
• Available at www.wwpinstitute.org
• Refer to AWPA Standard M20-14 12
14. • Risk assessment completed 2007
• CuN eligible for Re-registration 2007
– Conditions identified in RED must be satisfied
• Data gaps: aquatic toxicity, inhalation toxicity, exposure
• Data Call-In issued June 2010
• All 3 producers voluntarily canceled all labels
• EPA had not anticipated CuN might disappear
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15. In 5 Months:
• Met with EPA in 2011
• Completed test batches
• Committed to meet EPA data call-in
• Obtained Federal and State registrations
• Manufactured, tested and shipped 20,000
gallons 8% Cu, trade named as QNAP®
• New Rockford, TN plant operational 2Q2012
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27. • Increasing interest in railroad ties
– Major Class I railroads switching to CuN
– Bridge ties & timbers in addition to crossties
• Fence posts, highway bridge/guardrails,
glulam
28. Major market in railroad ties
–Major Class I railroads switching
to CuN
–Bridge ties & timbers in addition
to crossties
32. Service Southern Pine Douglas-fir Western Red Cedar
UC3B
(crossarms)
0.040 0.040 0.040
UC4A 0.060 0.075 0.120 (0.150)*
UC4B 0.080 0.095 0.120 (0.150)*
UC4C 0.130 0.150 0.120 (0.150)*
32* By thermal (non-pressure) process
34. • Ground-line & end cut treatment to
extend service life
• 1-2% minimum copper in CuN
solutions
• Appropriate for wood originally
treated with other preservatives,
including waterbornes
• Std. M4 revised in 2014 to require
field treatment if lumber/timbers are
cut or drilled 34
35. • Field stake tests in MS
• Treated wood
properties
– Electrical conductivity
– Gaff penetration
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36. • B. Woodward, C. Hatfield, S. Lebow. “Comparison of Wood
Preservatives in Stake Tests - 2011 Progress Report”
• 2" x 4" x 18" Southern Pine stakes
• Pressure treated, installed 1948-1953 in MS
• AWPA Hazard Zone 5 (most severe exposure)
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37. Actives, % in
solution
Retention, pcf,
AI / Solution
AI Retention, %
of AWPA UC4B
Average Life,
years
Untreated Control -- -- 2.2
Cat. Gas Oil Control -- / 4.0 -- 7.6
CuN, 0.5% 0.021 / 4.2 28 14.3
CuN, 0.75% 0.033 / 4.4 44 17.4
PCP, 5.0% 0.21 / 4.2 42 14.2
C.T. Creosote 4.1 41 16.3
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38. Active, % in
solution
Retention, pcf, by
Weight / Assay
AI Retention, %
of UC4B
Post
treatment
Avg. Life, years
Untreated Control -- -- -- 2.4
CuN, 0.5% Cu 0.023 / 0.020 31 / 27 None 11.0
CuN, 0.5% Cu 0.022 / 0.020 29 / 27 Steam 12.0
CuN, 0.5% Cu 0.023 / 0.018 31 / 24 Vapor 11.8
CuN, 0.59% Cu 0.026 / 0.023 35 / 31 Steam 14.3
PCP, 5.0% 0.230 / 0.186 46 / 37 None 14.1
PCP, 5.0% 0.240 / 0.222 48 / 44 Steam 12.9
PCP, 5.0% 0.300 / 0.173 60 / 35 Vapor 12.3 38
39. • Samples: 1-foot sections of southern pine poles
• Moisture content ~16 +/- 1%
CuN contains copper but is non-conductive 39
Chemical Treatment Conductivity, Siemens/m
CuN 1.01 x 10-8
Untreated 1.68 x 10-8
Pentachlorophenol 2.13 x 10-6
CCA 2.96 x 10-6
41. • CuN – a proven and effective preservative
• CuN-treated wood – properties advantageous to utilities, railroads
and other users
– a renewable natural material
– from a sustainable, managed source
– treated with a non-restricted use preservative, manufactured
domestically using reclaimed substances
– options for uses after normal service life
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