United States
      Environmental Protection
    Technical  Fact Sheet-
                          Perch lorate
                                                                           May 2012
                                               TECHNICAL FACT SHEET - PERCHLORATE
 At  a  Glance

 *  White crystalline solid or colorless
 *  Both  naturally occurring and man-
 *  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 include ingestion of food
     and contaminated drinking water.
 *  Short-term exposure to high doses
     may cause eye and skin irritation,
     coughing, nausea, vomiting, and
 *  Health-based goals or drinking
     water standards developed by
     various states.
 *  Various detection methods
     available include ion
     chromatography, liquid
     chromatography, mass
     spectroscopy, and electrospray
 *  Common treatment technologies
     include ion exchange, bioreactors,
     and in situ bioremediation.
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 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)

EPA 505-F-11-003
       May 2012

  Technical Fact Sheet - Perchlorate
                Exhibit 1:  Physical and Chemical Properties of Perchlorate Compounds
                              (EPA FFRRO 2005; ITRC 2005; NIOSH 2007)
CAS Numbers
Physical Description
(physical state at room
Molecular weight
Water solubility (g/L at
Melting / Boiling point
Vapor pressure at 25°C
(mm Hg)
Specific gravity
Octanol-water partition
coefficient (log Kow)
1 Ammonium Sodium
Perchlorate Perchlorate
White orthorhombic
Melting Point: 65. 6 to
Not available
White orthorhombic
deliquescent crystal
Melting Point: 482
Not available
orthorhombic crystal
or white crystalline
Melting Point: 400
Not available
Perchloric Acid
Colorless liquid
Miscible in cold water
Melting Point: -112
Boiling Point: 19
Notes:  g/mol - grams 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 2009a; ITRC 2005).
    Perchlorate compounds and the perchlorate
    anion do not volatilize from water to air (EPA
    IRIS 2005; ITRC 2005).
    High concentrations of perchlorate  have
    primarily been detected at current and Formerly
    Used Defense Sites historically involved in the
    manufacture, testing, and disposal  of
    ammunition and rocket fuel (ITRC 2005).
    Types of military and defense-related facilities
    with known releases include missile ranges and
    missile/rocket manufacturing facilities. However,
due to unavailable site specific documentation
and historical uncertainties, it is generally
difficult to determine which specific military sites
have known perchlorate releases (ITRC 2005).
In addition, the past disposal of munitions in
either burial pits or by open burning and open
detonation has the potential to result in releases
to the environment. The amount of perchlorate
released can vary depending on the length of
use and types of munitions disposed (ITRC
Recent surveys have detected perchlorate in
food crops and milk (FDA 2008).
Perchlorate has been detected in the ground
water at 54 federal facilities and 29 private
(Superfund or RCRA) sites in 26 states. (EPA
FFRRO 2011).
What are the health effects of perchlorate?
    Primary pathways for human exposure to
    perchlorate are ingestion of food and
    contaminated drinking water (EPA FFRRO
    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).

  Technical Fact Sheet - Perchlorate
What are the health effects of perchlorate? (continued)
    Studies conducted on rodents showed that
    perchlorate concentrations 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).
Are there any federal  and state guidelines and health standards
for perchlorate?
    EPA has decided to regulate perchlorate under
    the Safe Drinking Water Act. EPA has initiated
    the process of proposing a national primary
    drinking water regulation (EPA 2011).

    EPA established an Interim Drinking Water
    Health Advisory of 15 micrograms per liter (ug/L)
    in water (EPA 2009b).

    The Office of Solid Waste and Emergency
    Response (OSWER) has established a
    preliminary remediation goal (PRG) at National
    Priority List sites of 15 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 2009b).
Numerous sates have promulgated enforceable
standards for perchlorate in drinking water. For
example, Massachusetts (2 ug/L) and California
(6 ug/L) have established enforceable standards
for perchlorate in drinking water (CDPH 2010;
Massachusetts DEP 2006).

California EPA released Draft California Human
Health Screening Levels (CHHSLs) for
Perchlorate. The draft CHHSLs for perchlorate is
28 parts per million (ppm) soil for residential
property and 350 ppm soil for
commercial/industrial property (Cal EPA 2009).
Certain states have also 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 2011).
   • EPA Method 314.1—Inline Column
     Concentration/Matrix Elimination Ion
     Chromatography with Suppressed
     Conductivity Detection (EPA OGWDW 2011).
   • EPA Method 332.0—Ion Chromatography with
     Suppressed Conductivity and Electrospray
     lonization/Mass Spectrometry (EPA FFRRO
   • EPA Method 331.0—Liquid
     Chromatography/Electrospray lonization/
     Mass Spectrometry (EPA OGWDW 2011).
• 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
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).

  Technical Fact Sheet - Perchlorate
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 or fluidized-
      bed bioreactors (EPA FFRRO 2005;
      GWRTAC 2001; Hatzinger 2005).
    •  Membrane technologies (electrodialysis and
      reverse osmosis) (EPA FFRRO 2005;
      GWRTAC 2001; ITRC 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).
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 Public Health (CDPH).
    2011.  Perchlorate in Drinking  Water.
    California Environmental Protection Agency (Cal
    EPA. 2009. California Human Health Screening
    Levels for Perchlorate.
    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.
    Massachusetts Department of Environmental
    Protection (DEP). 2006. Perchlorate
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."
www.nap.edu/catalog.php7record id=11202.
National Institute for Occupational Safety and
Health (NIOSH). 2007.
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. 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 pawaste/h aza rd/testm eth ods/sw
846/new meth.htm
EPA 2009a. Region 9. Perchlorate in the Pacific
www.epa.gov/region9/toxic/perchlorate/per ca.h
EPA 2009b. Revised Assessment Guidance for
www.epa.gov/fedfac/documents/perchlorate me
mo 01-08-09.pdf

 Technical Fact Sheet - Perchlorate
Where can I find more information about perchlorate? (continued)
   EPA. 2011. Drinking Water Contaminants.
   Unregulated. Perchlorate.
   EPA Federal Facilities Restoration and Reuse
   Office (EPA FFRRO). 2005. Perchlorate
   Treatment Technology Update - Federal
   Facilities Forum Issue Paper. EPA 542-R-05-

   EPA FFRRO. 2011. Perchlorate and Other
   Emerging Contaminants.
   www.epa.gov/fedfac/documents/emerging cont
EPA Integrated Risk Information System (IRIS).
2005. "Perchlorate and Perchlorate Salts."
EPA Office of Groundwater and Drinking Water
(OGWDW). 2011.
ods ogwdw.html
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 guestions or comments on this fact sheet, please contact:  Mary Cooke, FFRRO, by phone at
(703) 603-8712 or by email at cooke.maryt@epa.gov.