This is a fact sheet about a chemical that may be found in some public or
private drinking water supplies. It may cause health problems if found
in amounts greater than the health standard set by the United States
Environmental Protection Agency (EPA).
What is Pentachlorophenol and how is it used?
Pentachlorophenol (PCP) is a white organic solid with needle-like crystals
and a phenolic odor. The greatest use of pentachlorophenol is as a wood
preservative (fungicide). Though once widely used as an herbicide, it
was banned in 1987 for these and other uses, as well as for any
The list of trade names given below may help you find out whether you
are using this chemical at home or work.
Trade Names and Synonyms:
Dura Treet II
Ontrack WE Herbicide
Weed and Brush KillerH
Why is Pentachlorophenol being regulated?
In 1974, Congress passed the Safe Drinking Water Act. This law requires
EPA to determine safe levels of chemicals in drinking water which do or
may cause health problems. These non-enforceable levels, based solely on
possible health risks and exposure, are called Maximum Contaminant Level
The MCLG for pentachlorophenol has been set at zero because EPA
believes this level of protection would not cause any of the potential
health problems described below.
Based on this MCLG, EPA has set an enforceable standard called a
Maximum Contaminant Level (MCL). MCLs are set as close to the MCLGs as
possible, considering the ability of public water systems to detect and
remove contaminants using suitable treatment technologies.
The MCL has been set at 1 part per billion (ppb) because EPA
believes, given present technology and resources, this is the lowest
level to which water systems can reasonably be required to remove this
contaminant should it occur in drinking water.
These drinking water standards and the regulations for ensuring
these standards are met, are called National Primary Drinking Water
Regulations. All public water supplies must abide by these regulations.
What are the health effects?
Short-term: EPA has found pentachlorophenol to potentially cause the
following health effects when people are exposed to it at levels above
the MCL for relatively short periods of time: damage to the central
Long-term: Pentachlorophenol has the potential to cause the
following effects from a lifetime exposure at levels above the MCL:
reproductive effects and damage to liver and kidneys; cancer.
How much Pentachlorophenol is produced and released to the
Production of pentachlorophenol was 45 million lbs in 1983. It may be
released to the environment as a result of its manufacture, storage,
transport, or use as an industrial wood preservative. From 1987 to 1993,
according to EPA's Toxic Chemical Release Inventory, releases to land
and water totalled nearly 100,000 lbs.
The most widespread releases were primarily from wood preserving
industries in many states. However, the greatest volume of releases
occurred at a military munitions plant in Nevada.
What happens to Pentachlorophenol when it is released to the
When released to soil or water, PCP will be slowly broken down by microbes
and may gradually leach into ground water. If released in water, it will
adsorb to sediment, or be degraded by sunlight. Its accumulation in fish
will be moderate.
How will Pentachlorophenol be detected in and removed from my drinking
The regulation for pentachlorophenol became effective in 1992. Between
1993 and 1995, EPA required your water supplier to collect water samples
every 3 months for one year and analyze them to find out if
pentachlorophenol is present above 0.04 ppb. If it is present above this
level, the system must continue to monitor this contaminant.
If contaminant levels are found to be consistently above the MCL,
your water supplier must take steps to reduce the amount of
pentachlorophenol so that it is consistently below that level. The
following treatment methods have been approved by EPA for removing
pentachlorophenol: Granular activated charcoal.
How will I know if Pentachlorophenol is in my drinking water?
If the levels of pentachlorophenol exceed the MCL, 1 ppb, the system must
notify the public via newspapers, radio, TV and other means. Additional
actions, such as providing alternative drinking water supplies, may be
required to prevent serious risks to public health.
This is a factsheet about a chemical that may be found in some
public or private drinking water supplies. It may cause health problems
if found in amounts greater than the health standard set by the United
States Environmental Protection Agency (EPA).
Drinking Water Standards:
Mcl: 1 ppb (parts per billion)
Pentachlorophenol Releases to Water and Land, 1987 to 1993 (in
|TOTALS (in pounds)
|Top Five States|
Note: This fact sheet is part of a larger publication
adapted from U.S. EPA publication: EPA National Primary Drinking Water
* Water/Land totals only include facilities with releases greater
than a certain amount - usually 1000 to 10,000 lbs.