United States
Environmental Protection
Agency
Office of Water
4601
EPA811-F-95-003x-T
October 1995
National Primary Drinking
Water Regulations
Pentachlorophenol
CHEMICAL/ PHYSICAL PROPERTIES
CAS NUMBER: 87-86-5
COLOR/ FORM/ODOR: White solid with
needle-like crystals and phenolic odor.
Available as: sodium salt in prills/
pellets; emulsifiable concentrate; or in
organic solvents
M.P.: 190-191° C B.P.: 309-310° C
VAPOR PRESSURE: 0.00011mm Hg at 25° C
DENSITY/SPEC. GRAV.: 1.98 at 22° C
OCTANOL/WATER PARTITION:
Log Kow=5.12
SOLUBILITY: 0.02 g/L of water at 30° C;
Slightly soluble in water
ODOR/TASTE THRESHOLDS (WATER):
Taste: 0.03 mg/L; odor: 1.6 mg/L
SOIL SORPTION COEFRCIENT:
Koc = 3000 to 4000 in sediments; low
mobility in soil
HENRY'S LAW COEFFICIENT: N/A
BlOCONCENTRATION FACTOR:
Log BCFs of 1 to 5.7 in humans, 1 to 4
in fish; expected to bioconcentrate in
aquatic organisms.
TRADE NAMES/SYNONYMS:
PCP, Penchlorol, Dowicide 7,
Permasan, Fungifen, Grundier arbezol,
Lauxtol, Liroprem, Chlon, Dura Treet II,
Santophen 20, Woodtreat, Penta
Ready, Penta WR, Forpen-50, Ontrack
WE Herbicide, Ortho Triox, Osmose
WPC, Watershed WP; Weed and Brush
Killer
DRINKING WATER STANDARDS
MCLG: zero mg/L
MCL: 0.001 mg/L
HAL(child): 1 day: 1 mg/L
Longer-term: 0.3 mg/L
HEALTH EFFECTS SUMMARY
treating agent for beans; antibacterial agent in disinfec-
tants/cleaners; preharvest defoliant on some crops; pre-
servative for glues, starches, photographic papers.
Production of pentachlorophenol was 45 million Ibs in
1983.1 n 1983 it was estimated that industries consumed
PCP as follows: Wood Preservative, 90%; Sodium
Pentachlorophenate, 10%
Acute: EPA has found pentachlorophenol to poten- RELEASE PATTERNS
tially cause central nervous system effects from short-
term exposures at levels above the MCL.
Drinking water levels which are considered "safe" for
short-term exposures: Fora 10-kg (22 Ib.) child consum-
ing 1 liter of water per day, an exposure to 1 mg/L for one
day or an exposure to 0.3 mg/L for up to 7 years.
Chronic: Pentachlorophenol has the potential to
cause reproductive effects and damage to liver and
kidneys from long-term exposure at levels above the
MCL.
Pentachlorophenol may be released to the environ-
ment as a result of its manufacture, storage, transport, or
use as an industrial wood preservative for utility poles,
Cancer:There is some evidence that pentachlorophe-
nol may have the potential to cause cancer from a lifetime
exposure at levels above the MCL.
USAGE PATTERNS
The greatest uses of pentachlorophenol are as a wood
preservative (fungicide). Though once widely used as an
herbicide, was banned in 1987 for these and other uses,
as well as for any over-the-counter sales.
Other uses included: soil fumigant for termites; seed
Toxic RELEASE INVENTORY -
RELEASES TO WATER AND LAND:
1987 TO 1993
TOTALS (in pounds)
Top Five States
NV
OR
WA
AR
GA
Major Industries
Explosives
Wood preserving
Misc. Chemicals
Water
18,700
0
4,313
3,310
2,735
783
0
17.720
250
Land
79,780
64,100
5,405
5,995
1,615
1,255
34,100
15,678
30,000
* Water/Land totals only include facilities with releases
greater than a certain amount - usually 1000 to 10,000 Ibs.
October 1995
Technical Version
Printed on Recycled Paper
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cross arms, and fenceposts, and other items that con-
sumes about 90% of its production.
Other former uses that may have lead to its release
were the manufacture of sodium pentachlorophenolate
and minor uses as a fungicide, bactericide, algicide, and
herbicide for crops, leathers and textiles.
Pentachlorophenol's used on wood is "restricted" and its
non-wood use is undergoing special review by EPA.
From 1987 to 1993, according to EPA's Toxic Chemi-
cal Release Inventory, pentachlorophenol releases to
land and water totalled nearly 100,000 Ibs., of which
about 80 percent was to land. The most widespread
releases were primarily from wood preserving industries
in many states. However, the great majority of releases
occurred at a military munitions plant in Nevada.
ENVIRONMENTAL FATE
Releases to soil can decrease in concentrations due to
slow biodegradation and leaching into groundwater. Pen-
tachlorophenol has a tendency to adsorb to soil and
sediment; calculated Koc= 1000, measured sediment
Koc= 3,000-4,000. Adsorption to oxidized sediment is
higher than to reduced sediment. Adsorption to soil and
sediment appears to be pH dependent, stronger under
acid conditions. The Koc values for the total dissociated
phenol was calculated to be 1250 and 1800 for light and
heavy loam, respectively, while for the undissociated
species, the Koc is 25,000.
Pentachlorophenol does biodegrade but may require
several weeks for acclimation. Half-life in soil is approxi-
mately weeks to months. In an artificial stream, microbial
degradation became significant after 3 weeks and ac-
counted for 26-46% removal. Pentachlorophenol miner-
alization in water from several sites was very low (<5 ng/
L per day). 3 and 5 ppm PCP were completely degraded
in 38 and 57 days respectively when incubated in unsat-
urated soils taken at 4 and 4.5 m depths.
If released in water, pentachlorophenol will adsorb to
sediment, photodegrade (especially at higher pHs) and
slowly biodegrade. The low water solubility and moder-
ate vapor pressure would suggest that evaporation from
water is not rapid, especially at natural pHs where pen-
tachlorophenol is present in the dissociated form (pKa=
4.74). Biodegradation in the streams, or in specific stream
compartments such as the sediment or water column,
was characterized by an adaptation period (3-5 weeks for
the stream as a whole, and reproducible from the previ-
ous year), which was inversely dependent on the con-
centration of pentachlorophenol and microbial biomass.
Pentachlorophenol does not appear to oxidize or hy-
drolyze under environmental conditions; however, pho-
tolysis of the dissociated form in water appears to be a
significant process. A measured photolysis half-life has
been reported to be 0.86 hrs.
In air, pentachlorophenol will be lost due to photolysis
and reaction with photochemically produced hydroxyl
radicals.
Bioconcentration in fish will be moderate. Pentachlor^
phenol is expected to bioconcentrate because of its low
water solubility, but the bioconcentration factor will
dependent upon the pH of the water since pentachloro-
phenol will be more dissociated at higher pHs.
The log BCF with goldfish varied from 0.30 at pH 10 to
1.75 at pH 7 to 2.12 at pH 5.5. Other reported log BCF
values are 2.89 in fathead minnow; 2.4-3.73 in rainbow
trout; 0.7-1.7 in sheepshead minnows; and 2.47 in mos-
quito fish; 2.85 in zebra fish; 2.62 in golden orfe. The
accumulation increased with temperature in orfe and
decreased with temperature in zebra fish. The BCF of
PCP in humans was measured from daily intake of PCP
and measured concentration in different tissues, giving
the following results: 5.7, 3.3, 1.4, 1.4, and 1.0 in liver,
brain blood, spleen and adipose tissue respectively.
Humans will be occupationally exposed to pentachlo-
rophenol via inhalation, and dermal contact primarily in
situations where they use this preservative or are in
contact with treated wood product. The general popula-
tion will be exposed primarily from ingesting food con-
taminated with pentachlorophenol.
OTHER REGULATORY INFORMATION
MONITORING:
FOR GROUND/SURFACE WATER SOURCES:
INITIAL FREQUENCY- 4 quarterly samples every 3 years
REPEAT FREQUENCY- If no detections during initial round:
2 quarterly per year if serving >3300 persons;
1 sample per 3 years for smaller systems
TRIGGERS - Return to Initial Freq. if detect at > 0.00004 mg/L
METHOD NUMBERS
515.1; 515.2; 525.2; 555
ANALYSIS:
REFERENCE SOURCE
EPA 600/4-88-039
TREATMENT:
BEST AVAILABLE TECHNOLOGIES
Granular Activated Charcoal
FOR ADDITIONAL INFORMATION:
4 EPA can provide further regulatory and other general information:
• EPA Safe Drinking Water Hotline - 800/426-4791
* Other sources of lexicological and environmental fate data include:
• Toxic Substance Control Act Information Line - 202/554-1404
• Toxics Release Inventory, National Library of Medicine - 301/496-6531
• Agency for Toxic Substances and Disease Registry - 404/639-6000
• National Pesticide Hotline - 800/858-7378
October 1995
Technical Version
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