Emerging Contaminant-
Perchlorate
September 2009
FACT SHEET
At a Glance
White crystalline solid or
colorless liquid.
Both naturally occurring and
man-made.
Sampling at current federal sites
as well as Formerly Used
Defense Sites detected
perchlorate primarily in
association with sites historically
involved in the manufacture,
maintenance, use, and disposal
of ammunition and rocket fuel.
* Highly soluble in water; migrates
quickly from soil to ground water.
* Primary pathways for human
exposure to perchlorate include
ingestion of food and
contaminated drinking water.
* Short-term exposure to high
doses may cause eye and skin
irritation, coughing, nausea,
vomiting, and diarrhea.
* Health-based goals or drinking
water standards developed by
various states.
* Various detection methods
available for perchlorate,
including ion chromatography,
liquid chromatography, mass
spectroscopy, and electrospray
ionization.
«J« Common treatment technologies
include ion exchange,
bioreactors, and in situ
bioremediation.
Introduction
An "emerging contaminant" is a chemical or material that is characterized
by a perceived, potential, or real threat to human health or the
environment or a lack of published health standards. A contaminant may
also be "emerging" because a new source or a new pathway to humans
has been discovered or a new detection method or treatment technology
has been developed (DoD 2009). This fact sheet, developed by the U.S.
Environmental Protection Agency (EPA) Federal Facilities Restoration
and Reuse Office (FFRRO), provides a brief summary of the emerging
contaminant perchlorate, including physical and chemical properties;
environmental and health impacts; existing federal and state guidelines;
detection and treatment methods; and additional sources of information.
Perchlorate is a persistent contaminant of concern that has presented a
number of issues to the government, the private sector, and other
organizations and interested parties. These issues include health effects
and risk, regulatory standards and cleanup levels, degradation
processes, and treatment technologies (EPA FFRRO 2005). This fact
sheet provides basic information on perchlorate to site managers and
other field personnel who are addressing perchlorate contamination at
cleanup sites or in drinking water supplies.
What is perchlorate?
Perchlorate is a naturally occurring and man-made anion (CIO4~) that
consists of one chlorine atom bonded to four oxygen atoms (EPA
FFRRO 2005; ITRC 2005).
Perchlorate may occur naturally, particularly in arid regions such as
the southwestern United States (Rao 2007).
Manufactured forms of perchlorate include perchloric acid and salts
such as ammonium perchlorate, sodium perchlorate, and potassium
perchlorate (EPA FFRRO 2005; ITRC 2005).
Perchlorate is found as a natural impurity in nitrate salts from Chile,
which are imported and used to produce nitrate fertilizers and other
products (EPA FFRRO 2005; ITRC 2005).
Perchlorate is commonly used as an oxidizer in solid propellants,
munitions, fireworks, airbag initiators for vehicles, matches, and
signal flares (EPA FFRRO 2005; ITRC 2005;). It is also found in
some disinfectants and some herbicides (ITRC 2005).
Of the domestically produced (high grade) perchlorate, 90 percent is
estimated to be used in the defense and aerospace industries in the
form of ammonium perchlorate (GAO 2005; ITRC 2005).
Perchlorate has been used by the U.S. Department of Defense (DoD) as
an oxidizer in munitions and missiles since the 1940s (Mendiratta et al.
1996).
United States
Environmental Protection Agency
Office of Solid Waste and
Emergency Response (5106P)
1
EPA 505-F-09-005
September 2008
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Emerging Contaminant - Perchlorate
Exhibit 1: Physical and Chemical Properties of Perchlorate Compounds
(EPA FFRRO 2005; ITRC 2005; NIOSH 2007)
Property
Ammonium
Perchlorate
Sodium
Perchlorate
Potassium
Perchlorate
Perchloric Acid
CAS Numbers
7790-98-9
7601-89-0
7778-74-7
7601-90-3
Physical Description
(physical state at room
temperature)
White orthorhombic
crystal
White orthorhombic
deliquescent crystal
Colorless
orthorhombic crystal
or white crystalline
powder
Colorless liquid
Molecular weight
(g/mol)
117.49
122.44
138.55
100.47
Water solubility (g/L at
25°C)
200
2,096
15
Miscible in cold water
Melting / Boiling point
Melting Point: 65.6 to
439
Melting Point: 482
Melting Point: 400
Melting Point: -112
Boiling Point: 19
Vapor pressure at 25°C
(mm Hg)
Not available
Not available
Not available
6.8
Specific gravity
1.95
2.52
2.53
1.664
Octanol-water partition
coefficient (log Kow)
-5.84
-7.18
-7.18
-4.63
Notes: g/mol - gram per mole; g/L - grams per liter; mg/L - milligrams per liter; C - degrees Celsius; mm Hg - millimeters of mercury.
What are the environmental impacts of perchlorate?
»> Perchlorate is highly soluble, relatively stable
and mobile in water. As a result, perchlorate
plumes in ground water can be extensive. For
example, the perchlorate plume at a former
safety flare site (the Olin Flare Facility) in
Morgan Hill, California, extends more than 9
miles (EPA FFRRO 2007).
»> Perchlorate compounds and the perchlorate
anion do not volatilize from water to air (ITRC
2005; EPA IRIS 2005).
What are the health effects of perchlorate?
Sampling at current and Formerly Used Defense
Sites has detected perchlorate primarily in
association with sites historically involved in the
manufacture, maintenance, use, and disposal of
ammunition and rocket fuel (EPA FFRRO 2007).
Recent surveys have detected perchlorate in
food crops and milk (FDA 2008).
Perchlorate has been detected at nearly 270
sites; more than 45 of these sites are on the
National Priorities List (EPA FFRRO 2007).
Primary pathways for human exposure to
perchlorate are ingestion of food and
contaminated drinking water (EPA FFRRO
2007).
At high enough exposures, perchlorate can
interfere with iodide uptake into the thyroid
gland, disrupting the functions of the thyroid and
potentially leading to a reduction in the
production of thyroid hormones. Thyroid
hormones play an important role in regulating
metabolism. Thyroid hormones are critical for
normal growth and development in fetuses,
infants, and young children (MAS 2005).
Potassium perchlorate was historically used to
treat hyperthyroidism and Grave's Disease
because of its ability to inhibit thyroid iodide
uptake (MAS 2005).
Studies conducted on rodents showed that
perchlorate concentration below that required to
alter thyroid hormone equilibrium is unlikely to
cause thyroid cancer in human beings (EPA
IRIS 2005).
The chronic oral reference dose (RfD) is 0.0007
milligrams per kilogram body weight per day.
(Note: A reference dose is an estimate [with
uncertainty spanning perhaps an order of
magnitude] of a daily oral exposure to the
human population [including sensitive
subgroups] that is likely to be without
appreciable risk of deleterious effects over a
lifetime) (EPA IRIS 2005).
Short-term exposure to high doses may cause
eye and skin irritation, coughing, nausea,
vomiting, and diarrhea (NIOSH 2007).
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Emerging Contaminant - Perchlorate
Are there any federal and state guidelines and
health standards for perchlorate?
The RfD established by EPA equates to a
Drinking Water Equivalent Level (DWEL) of 24.5
micrograms per liter (ug/L) (EPA FFRRO 2005).
A DWEL is a lifetime exposure concentration
protective of adverse, noncancer health effects
that assumes all of the exposure to a
contaminant is from drinking water. (Note: The
DWEL is calculated based on a 70-kg body
weight and a drinking water consumption of 2
L/day.)
Massachusetts (2 ug/L) and California (6 ug/L)
have established enforceable standards for
perchlorate in drinking water (California DHS
2007; Massachusetts DEP 2006;).
The Office of Solid Waste and Emergency
Response (OSWER) has established a
preliminary remediation goal (PRG) at NPL sites
of 24.5 ug/L. PRGs are developed based on
readily available information and are modified,
as necessary, before final cleanup goals are
established, based on information that becomes
available during the remedial investigation/
feasibility study (EPA FFRRO 2007).
Certain states have developed advisory levels or
health-based goals ranging from 4 to 51 ug/L
(ITRC 2005).
What detection and site characterization methods
are available for perchlorate?
The following methods can be used to analyze
for perchlorate in drinking water, ground water,
surface water, and irrigation water:
• EPA Method 314.0—Ion Chromatography
(EPA OGWDW 2007).
• EPA Method 314.1—Inline Column
Concentration/Matrix Elimination Ion
Chromatography with Suppressed
Conductivity Detection (EPA OGWDW2007).
• EPA Method 332.0—Ion Chromatography with
Suppressed Conductivity and Electrospray
lonization/Mass Spectrometry (EPA FFRRO
2005).
• EPA Method 331.0—Liquid
Chromatography/Electrospray lonization/
Mass Spectrometry (EPA OGWDW2007).
• EPA Method 6850—High Performance Liquid
Chromatography/Electrospray lonization/Mass
Spectrometry (EPA 2007).
• EPA Method 6860—Ion Chromatography/
Electrospray lonization/Mass Spectrometry
(EPA 2007).
The presence of high amounts of other anions,
such as chloride, sulfate, or carbonate may
interfere with the analysis of perchlorate (EPA
1999).
Researchers have demonstrated the ability to
distinguish man-made and natural sources of
perchlorate using chlorine and oxygen stable
isotope analysis (Bohlke et al. 2005).
What technologies are being used to treat perchlorate?
Ex Situ Treatment
• Ion exchange using perchlorate-selective or
nitrite-specific resins (Boodoo 2003; EPA
FFRRO 2005; GWRTAC 2001).
• Bioremediation using packed-bed orfluidized-
bed bioreactors (EPA FFRRO 2005;
GWRTAC 2001; Hatzinger 2005).
• Liquid phase carbon adsorption using granular
activated carbon (GAG) to remove low levels
of perchlorate; pretreatment may be
necessary to prepare GAG for perchlorate
removal (EPA FFRRO 2005; GWRTAC 2001;
ITRC 2005).
Membrane technologies (electrodialysis and
reverse osmosis) (EPA FFRRO 2005;
GWRTAC 2001; ITRC 2005;).
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Emerging Contaminant - Perchlorate
What technologies are being used to treat perchlorate? (continued)
In Situ Treatment:
• Bioremediation using perchlorate-selective
microbes (EPA FFRRO 2005; GWRTAC 2001;
ITRC 2005).
• Permeable reactive barrier (EPA FFRRO
2005; GWRTAC 2001; ITRC 2005).
Phytoremediation may also be used, although
the mechanism of phytoremediation of
perchlorate is yet to be established (EPA
FFRRO 2005; GWRTAC 2001).
Where can I find more information about perchlorate?
Boodoo, F. 2003. POU/POE Removal of
Perchlorate. Water Conditioning & Purification.
Pages 1-4.
Bohlke, J. K., N.C. Sturchio, B. Gu, J. Horita,
G.M. Brown, W.A. Jackson, J. Batista, and P.B.
Hatzinger. 2005. Perchlorate isotope
forensics. Anal. Chem., 77, 7838-7842.
California Department of Health Services
(California DHS). 2006. Press Release.
http://www.applications.dhs.ca.gov/pressrelease
s/store/pressreleases/06-62.html.
Environmental Protection Agency (EPA). 1999.
Method 314.0 Determination of Perchlorate in
Drinking Water Using Ion Chromatography.
Revision.
EPA. 2007. New Test Methods On-line.
www. e pa. g o v/e paoswe r/h azwaste/test/n ew-
meth.htm
EPA Federal Facilities Restoration and Reuse
Office (EPA FFRRO). 2005. Perchlorate
Treatment Technology Update - Federal
Facilities Forum Issue Paper. EPA 542-R-05-
015.
EPA FFRRO. 2007.
www.epa.gov/fedfac/documents/perchlorate.htm
EPA Integrated Risk Information System (IRIS).
2005. www.epa.gov/iris/subst/1007.htm.
EPA Office of Groundwater and Drinking Water
(OGWDW). 2007. www.epa.gov/safewater/
Food and Drug Administration (FDA). 2008.
U.S. Food and Drug Administration's Total Diet
Study: Dietary intake of Perchlorate and Iodine.
Ground Water Remediation Technologies
Analysis Center (GWRTAC). 2001. Technology
Status Report: Perchlorate Treatment
Technologies. 1st edition.
Hatzinger, P.B. 2005. Perchlorate
Biodegradation for Water Treatment.
Environmental Science & Technology. Vol. A.
Pages 239-247.
Interstate Technology Regulatory Council
(ITRC). 2005. Perchlorate: Overview of Issues,
Status, and Remedial Options.
http://www.itrcweb.org/Documents/PERC-1.pdf.
Massachusetts Department of Environmental
Protection (DEP). 2006. Perchlorate
Information.
http://www.mass.gov/dep/water/drinking/percinfo
.htm#stds.
Mendiratta, S.K., R.L. Dotson, and R.T. Brooker.
1996. Kirk-Othmer Encyclopedia of Chemical
Technology. Vol.18. Pages 157-170.
National Research Council of the National
Academies (NAS). 2005. "Health Implications of
Perchlorate Ingestion."
http://www.nap.edu/catalog.php7record id=11202.
National Institute for Occupational Safety and
Health (NIOSH). 2007.
http://www.cdc.gov/niosh/ipcs/nicstart.html
Rao, B., Anderson, T. A., Orris, et al. 2007.
Widespread natural perchlorate in unsaturated
zones of the Southwest United States.
Environmental Science & Technology. 41 (13),
4522 -4528,2007.
U.S. Department of Defense (DoD). 2009.
Emerging Contaminants. Website accessed
March 9.
https://www.denix.osd.mil/portal/page/portal/deni
x/environment/MERIT.
U.S. Government Accountability Office (GAO).
2005. Perchlorate: A System to Track Sampling
and Cleanup Results is Needed. GAO-05-462.
Additional information on perchlorate can be found at EPA's www.cluin.org/perchlorate.
Contact Information
If you have any questions or comments on this fact sheet, please contact: Mary Cooke, FFRRO, by phone at
(703) 603-8712 or by e-mail at cooke.maryt@epa.gov.
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