Emerging  Contaminant-
                                                               Perchlorate
                                                                    December 2010
                                                                                   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 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 include ion
   chromatography, liquid
   chromatography, mass
   spectroscopy, and electrospray
   ionization.
* 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 2010). 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 (CIO/0 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-10-002
  December 2010

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  Emerging Contaminant - Perchlorate
                 Exhibit 1:  Physical and Chemical Properties of Perchlorate Compounds
                              (EPA FFRRO 2005; ITRC 2005; NIOSH 2007)
       Property
     CAS Numbers
   Ammonium
    'erchlorab
    7790-98-9
     Sodium
   Perch lorat
    7601-89-0
    Potassium
    Perch loratt
     7778-74-7
   erchloric Acid
    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 (CDPH 2010;
   Massachusetts DEP 2006).

   California EPA released Draft California Human
   Health Screening Levels (CHHSLs) for
Perchlorate. The draft CHHSLs for perchlorate
are 28 parts per million (ppm) soil for residential
property and 350 ppm soil for
commercial/industrial property (Cal EPA 2009).

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
     (EPAOGWDW2010).
   • EPA Method 314.1—Inline Column
     Concentration/Matrix Elimination Ion
     Chromatography with Suppressed
     Conductivity Detection (EPA OGWDW2010).
   • 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 OGWDW 2010).
• 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 Public Health (CDPH).
    2010.  Perchlorate in Drinking Water.
    http://www.cdph.ca.gov/certlic/drinkingwater/Pag
    es/Perchlorate.aspx
    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.
    http://www.itrcweb.org/Documents/PERC-1.pdf
    Massachusetts Department of Environmental
    Protection (DEP). 2006. Perchlorate
    Information.http://www.mass.gov/dep/water/drin
    king/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). 2010.
Emerging Chemical & Material Risks.
https://www.denix.osd.mil/portal/page/portal/CM
RMD/ECMR
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.
http://www.epa.gov/epawaste/hazard/testmetho
ds/sw846/new 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. Perchlorate.
www.epa.gov/fedfac/documents/perchlorate.htm
EPA Integrated Risk Information System (IRIS).
2005. "Perchlorate  and Perchlorate Salts."
www.epa.gov/iris/subst/1007.htm.
EPA Office of Groundwater and Drinking Water
(OGWDW). 2010.
http://www.epa.gov/safewater/methods/analytica
[methods 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 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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