This document summarizes the aquatic fate and effects of pentachlorophenol (PCP). PCP readily dissolves in water but degrades through photodegradation and biodegradation. While PCP can be toxic to aquatic organisms, organisms can also metabolize it rapidly and it does not significantly bioaccumulate or biomagnify in food chains. Modeling studies show exposures from treated wood structures will result in PCP concentrations in water and sediment below EPA toxicity thresholds.

1. Pentachlorophenol Aquatic Fate and Effects David Kent Keller and Heckman LLP 1001 G St. NW, Suite 500 West Washington, DC 20001 [email_address] www.khlaw.com Washington, D.C. ● Brussels ● San Francisco ● Shanghai May 18, 2007 Diana Graham Keller and Heckman LLP 50 California Street, Suite 1500 San Francisco, CA 94111 [email_address]

3. Physical Properties Readily dissolves in most solvents Organic solvent solubility 10 mg/L at pH 6 20 mg/L at pH 8 Water solubility 5.1 (pH 4) 3.3 (pH 7) 1.9 (pH 8) Log K ow 1.6x10 -14 Dissociation Constant K a 0.00415 Pa (1.1x10 -4 Torr at 25°C) Vapor pressure 1.98 g/cm 3 at 22°C Density 310°C (decomposes) Boiling point 191°C Melting point 266.34 Mol wt C 6 Cl 5 OH Formula Structure

4. Speciation and Partitioning Influence of pH on solubility and log K ow pH dependent speciation

7. Biodegradation/Photodegradation Mixed bacterial cultures ~1.5 Yu and Ward (1994) pH 7.3 (natural sun-light) 2.0 Wong and Crosby (1981) Anaerobic in laboratory, dark 190.0 Liu et al. (1981) Aerobic in the laboratory 0.36 Liu et al. (1981) Outdoor mesocosms 2.0 to 4.7 Crossland and Wolff (1985) Anaerobic in the laboratory (dark – biodegradation only) 79.8 Boyle et al. (1980) Aerobic in the laboratory 18.6 Boyle et al. (1980) Conditions Half-life, days Author

11. Monitoring Data – Washington State 1 note that reported values below the MDL of 0.007 ug/L are estimates ND ND 0 2005 0.0051 1 0.0041 1 6 2004 0.0014 1 0.0014 1 5 2003 Spring Creek ND ND 0 2005 0.0054 1 0.0054 1 3 2004 0.0078 0.0063 1 10 2003 Sulfur Creek Wasteway ND ND 0 2005 ND ND 0 2004 0.01 0.01 5 2003 Marion Drain 0.03 0.0081 21 2005 0.078 0.016 42 2004 0.083 0.015 78 2003 Thornton Creek Max, µg/L Median µg/L Frequency %

12. Monitoring Data - Illinois

16. Acute Toxicity – Rainbow Trout Change in formulation has reduced toxicity 2003 160 Dwyer et. al. (2005) 1980 - 1987 34 to 121 Eisler (2000) 1980 and 2001 15 and 75 USEPA (2005) Study Year LC 50 (µg penta/L) Author

18. Chronic Toxicity 1.0 10 100 1000 0 0.8 2.2 3.9 5 10 99% Level of Concern 95% Level of Concern 90% Level of Concern duckweed daphnia daphnia daphnia plant flagfish FHM FHM FHM FHM snail Cerio diatom RBT G algae BG algae FHM RBT sockeye 99 95 50 Pentachlorophenol Concentration, ppb Chronic NOECs FHM – fathead minnow RBT – rainbow trout G algae – green algae BG algae – blue-green algae Cerio - ceriodaphnia Rank order of data (% species tested)

22. Bioconcentration no significant bioaccumulation Sub-adult African clawed frogs Oral - PCP in meal worms 424 Blackworm Lumbriculus variegatus Sediment 229 – water 7.3 sediment Midge larvae Water & sediment 458 midge Chironomus riparius Water & sediment 79 and 62 Duckweed Lemna polyrhiza Water 25.2 – 38.7, 37.7 and 103.4 – 188.5 for eggshell, yolk sac and embryo Salmon eggs Water 132 Scud Hyalella azteca Water 73 Depressed River Mussel Pseudanodonta complanata Water 100 freshwater mussels Anadonta anatina Water 145 to 342 freshwater mussels Anadonta anatina Water BCF Test Species Route of Exposure

31. Sediment Monitoring: Upper Dairy Creek Bridge - Oregon No adverse affects were noted when a bioassay was conducted on sediments collected from under the bridge

34. Thank you! www.khlaw.com Washington, D.C. ● Brussels ● San Francisco ● Shanghai Diana Graham Keller and Heckman LLP 50 California Street, Suite 1500 San Francisco, CA 94111 [email_address] David Kent Keller and Heckman LLP 1001 G St. NW, Suite 500 West Washington, DC 20001 [email_address]