&EPA
      United States
      Environmental Protection
      Agency
                         Technical Fact Sheet -
Polybrominated Diphenyl  Ethers (PBDEs)
    and Polybrominated Biphenyls (PBBs)
                                             May 2012
                                               TECHNICAL FACT SHEET - PBDEs and PBBs
 At  a Glance
    Introduction
     Groups of man-made chemicals
     that serve as flame retardants for
     electrical equipment, electronic
     devices, furniture, textiles, and
     other household products.
     Structurally similar and exhibit low
     volatility. Lower brominated
     congeners of PBDE tend to
     bioaccumulate more than higher
     brominated congeners.
     May act as endocrine disrupters in
     humans and other animals.
     Exposure in rats and mice caused
     neuro-developmental toxicity and
     other symptoms.
     PBBs have been classified as
     "possibly carcinogenic to humans."
     The American Conference of
     Government Industrial Hygienists
     (ACGIH) has established workplace
     environmental exposure levels
     (WEEL) for PBDEs and PBBs.
     EPA has developed oral reference
     doses for decaBDE, octaBDE and
     pentaBDE.
     Detection methods include gas
     chromatography, mass
     spectrometry, and liquid
     chromatography.
     Treatment methods have not been
     developed for any environmental
     medium; potential treatment
     methods being evaluated at the
     laboratory scale include
     debromination using zero-valent
     iron (ZVI) and enhanced
     biodegradation using microbial
     species.
    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 contaminants polybrominated diphenyl ethers (PBDE)
    and polybrominated biphenyls (PBB), including physical and chemical
    properties; environmental and health impacts; existing federal and state
    guidelines; detection and treatment methods; and additional sources of
    information.
    PBB has been banned in the United States since 1973, when PBB
    accidentally mixed into animal feed exposed 9 million people to
    contaminated dairy products, eggs, and meat (De Wit 2002; DHHS 2011). In
    contrast, PBDEs have been in widespread use in the U.S. since the 1970s;
    however, there is growing concern about their persistence in the
    environment and their tendency to bioaccumulate in the food chain (EPA
    OPPT 2010). Since PBDEs and PBBs belong to the same class of
    brominated hydrocarbons and their chemical structures are similar, they are
    both discussed in this fact sheet. This fact sheet provides basic information
    on PBDEs and PBBs to site managers and other field personnel who may
    encounter these contaminants at cleanup sites.

    What are PBDE  and PBB?                            	
    »>  PBDE and PBB are classes of brominated hydrocarbons, also referred to
        as brominated flame retardant (BFR) chemicals. They are structurally
        similar, containing a central biphenyl structure surrounded by up to 10
        bromine atoms (ATSDR 2004).
    »>  They are used in a wide variety of products, including furniture,
        upholstery, electrical equipment, electronic devices, textiles, and other
        household products (ATSDR 2004; EPA OPPT 2010; WDLI 2011).
    »>  At high temperatures, PBDEs and PBBs release bromine radicals that
        reduce both the rate of combustion and dispersion of fire (De Wit 2002).
    »>  Three PBDE homologs are commercially available, including pentaBDE
        (PeBDE), octaBDE (OBDE), and decaBDE (DeBDE)
        (De Wit 2002).
    »>  PBDEs exist as mixtures of distinct chemicals called congeners with
        unique molecular structures. The PBDE congeners may differ in the total
        number or position of bromine atoms attached to the ether molecule.
        Congeners with equal numbers of bromine atoms are known as
        homologs (ATSDR 2004; De Wit 2002).
United States
Environmental Protection Agency
              Solid Waste and
              Emergency Response (5106P)

                     1
EPA 505-F-11-007
       May 2012

-------
  Technical Fact Sheet - PBDEs and PBBs
What are PBDE and PBB? (continued)
    PBBs also exist as mixtures of congeners. They
    were produced as three primary homologs:
    hexabromobiphenyl (hexaBB), octabromobiphenyl
    (octaBB), and decabromobiphenyl (decaBB)
    (ATSDR 2004; DHHS 2011).
    There are no known natural sources of PBDE and
    PBB (ATSDR 2004).
    Both PBDE and PBB are structurally similar to
    polychlorinated biphenyls (PCB). Both PBDE
               and PBB are fat-soluble and hydrophobic
               (De Wit 2002; Hooper and McDonald 2000).
               Homologs with the highest numbers of bromine
               atoms tend to exhibit the lowest volatilities (De Wit
               2002; DHHS 2011).
               Even though PBDEs and PBBs are relatively
               stable, they are susceptible to photolytic
               debromination when they are exposed to
               ultraviolet light (De Wit 2002; DHHS 2011).
                   Exhibit 1:  Physical and Chemical Properties of PBDEs and PBBs
                                     (ATSDR 2004; De Wit 2002)
                                          PBDE (Penta-, Octa-, and
                                                Oeca-BDE)
                                  PBB (Hexa-, Octa-, and
                                        Deca-BB)
             CAS Numbers
    PentaDBE-32534-81-9
    OctaBDE - 32536-52-0
    DecaBDE-1163-19-5
                                                                     HexaBB-36355-01-8
                                                                     OctaBB - 27858-07-7
                                                                     DecaBB-13654-09-6
  Physical description (physical state at room
             temperature)
Pale yellow liquid or white powder
                                                                         White solid
         Molecular weight (g/mol)
    564 to 959.2 (DecaBDE)
                                                                         627 to 943
       Water solubility (ug/L at 25°C)
             1
                                                                           3 to 30
            Boiling point ( C)
        >300 to >400
                                                                        Not applicable
            Melting point (°C)
         85 to 306
                                            2.2x1Q-7to9x10-'10
                                                                          72 to 386
                                        5.2 x10'8
Vapor pressure at 25 C (mm Hg)
  Octanol-water partition coefficient (log Kow)
         5.7 to 8.27
                                                                         5.53 to 9.10
  Soil organic carbon-water coefficient (K0
        4.89 to 6.80
                                                                     3.33 to 3.87 (HexaBB)
     Henry's Law Constant (atm m /mol)
     7.5x10'8to1.2x10-5
                                                                    1.38x10'° to 5.7x10"
Notes: g/mol - gram per mole; |jg/L - micrograms per liter; °C - degrees Celsius; mm Hg - millimeters of mercury; atm m3/mol - atmosphere-
cubic meters per mole.

What are the environmental  impacts of PBDE and PBB?
    PBDEs may enter the environment through
    emissions from manufacturing processes,
    volatilization from various products that contain
    PBDEs, recycling wastes, and leaching from waste
    disposal sites (Streets et al. 2006).
    PBDEs and PBBs have been detected in air,
    sediments, surface water, fish, and other marine
    animals (Streets et al. 2006).
    Lower brominated congeners of PBDE tend to
    bioaccumulate more than higher brominated
    congeners and are more persistent in the
    environment (De Wit 2002).
    Higher brominated congeners of PBDE tend to
    bind to sediment or soil particles more than lower
    brominated congeners (De Wit 2002).
              PBBs bind strongly to soil or sediment particles,
              which reduces their mobility on the ground but
              increases their mobility in the atmosphere, where
              they are attached to airborne particulate matter
              (ATSDR 2004).
              As of 2004, PBBs had been found at nine National
              Priorities List (NPL) sites (ATSDR 2004).
              PBDEs were not found at any of the current or
              deleted National Priorities List (NPL) sites (the
              total number of sites evaluated was not known). As
              more NPL sites are evaluated, there is a possibility
              that PBDE contamination may be discovered at
              these sites. However, since PBDEs are widely
              used in commercial products, they may be less
              prevalent at hazardous waste  sites (ATSDR 2004).

-------
 Technical Fact Sheet - PBDEs and PBBs
What are the health effects of PBDE and PBB?
   The International Agency for Research on Cancer
   (IARC) classified PBBs as "possibly carcinogenic
   to humans" (IARC 2011). EPA has not classified
   PBBs for carcinogenicity.
   Studies on mice and rats have shown that
   exposure to PBDEs and PBBs cause neuro-
   developmental toxicity, weight loss, toxicity to the
   kidney, thyroid, and liver, and dermal disorders
   (ATSDR 2004; Birnbaum and Staskal 2004; De Wit
   2002).
   Studies on animals and human beings have shown
   that some PBBs and PBDEs can act as endocrine
   system disrupters and also tend to deposit in
   human adipose tissue (ATSDR 2004; Birnbaum
   and Staskal 2004; DHHS 2011; He et al. 2006;
   McDonald 2002).
A study has indicated that octaBDE may be a
potential teratogen (He et al. 2006).
According to EPA, decaBDE is described as
possessing "suggestive evidence of carcinogenic
potential" (EPA IRIS 2008a).
EPA has established the following oral reference
doses (RfD) for PBDEs (EPA IRIS 2008b,c,d;
1990a,b):
•   7 x 10"3 milligrams per kilogram day (mg/kg-
    day) for the decaBDE homolog;
•   3 x 10"3 mg/kg-day for the octaBDE homolog;
•   1 x 10"4 mg/kg-day for the tetraBDE homolog;
•   2 x 10"4 mg/kg-day for the hexaBDE homolog;
•   2 x 10"3 mg/kg-day for the pentaBDE homolog
Are there any existing federal and state guidelines and health standards for
PBDE and PBB?
   EPA continues to evaluate and assess the risks
   posed by PBDEs and PBBs. No federal cleanup
   standards or guidelines have been set for PBDEs
   and PBBs (ATSDR 2004; EPA OPPT 2010).
   EPA has issued a Significant New Use Rule
   (SNUR) to phase out pentaBDE and octaBDE.
   According to this rule, no new manufacture or
   import of these two homologs is allowed after
   January 1, 2005, without a 90-day notification to
   EPA for evaluation (EPA OPPT 2010).
   The two U.S. producers  and the main U.S.
   importer of decaBDE committed to end production,
   import and sales of the chemical for all consumer,
   transportation, and military uses, by the end of
   2013 (EPA 2010).
   American Conference of Industrial Hygienists
   (ACGIH) has developed  a (Workplace
   Environmental Exposure Level) WEEL of 5
   milligrams per cubic  meter (mg/m3) for decaBDE,
with ongoing air monitoring required if dust levels
of penta and octaBDE exceed 5 mg/m3 (WDLI
2011).
The Agency for Toxic Substances and Disease
Registry (ATSDR) has established a minimal risk
level (MRL) of 0.01 mg/kg-day for acute (1 to 14
days) oral exposure to PBBs and an MRL of 10
mg/kg-day for intermediate (14 to 364 days) oral
exposure to decaBDE (ATSDR 2010).
The California Environmental Protection Agency
(Cal/EPA) has proposed a No Significant Risk
Level of 0.02  micrograms per day (ug/day) for
PBBs (Cal/EPA 2006).
The Occupational Safety and Health Administration
(OSHA) has not established occupational exposure
limits for PBDEs or PBBs (ATSDR 2004; OSHA
2011).
What detection and site characterization methods are available
for PBDE and PBB?
   Analytical methods used for PBDE detection
   include gas chromatography (GC)-mass
   spectrometry (MS) for air, sewage, fish, and animal
   tissues; GC/electron capture detector (ECD) for
   water and sediment samples; GC/high resolution
   MS (HRMS) for fish tissue; and liquid
   chromatography (LC)/GC-MS-flame ionization
   detector (FID) for sediments (ATSDR 2004).
Analytical methods for PBB detection include GC-
ECD for commercial samples, soil, plant tissue,
sediment, fish, dairy, and animal feed; HRMS/GC
for fish samples; GC-FID/ECD for soil; and LC-GC-
MS/FID for sediment (ATSDR 2004).

-------
 Technical Fact Sheet - PBDEs and PBBs
What technologies are being used to treat PBDE and  PBB?
    Research is being conducted at the laboratory
    scale on potential treatment methods for media
    contaminated with PBDEs and PBBs.
    A laboratory study investigated the degradation of
    a mixture of decaBDE and octaBDE using
    anaerobic bacteria (He et al. 2006).
    Another laboratory study investigated ZVI as a
    treatment method for decaBDE. Secondary
treatment using cationic surfactants may be
required to increase the availability of PBDE
molecules for reactions with ZVI (Keum and Li
2005).
The use of activated carbon has also been
investigated in a laboratory study for the treatment
of PDBE in sediment (Choi et al. 2003).
Where can I find  more information about PBDE and PBB?
   Agency for Toxic Substances and Disease
   Registry (ATSDR). 2004. Toxicological Profile
   for Polybrominated Diphenyl Ethers and
   Polybrominated  Biphenyls.
   www.atsdr.cdc.gov/toxprofiles/tp68.pdf.

   ATSDR. 2010. Minimal Risk Levels for
   Hazardous Substances.
   www.atsdr.cdc.gov/mrls/index.htmltfbookmarkQ2

   Birnbaum, L. S. and D. F. Staskal. 2004.
   Brominated Flame Retardants: Cause for
   Concern? Environmental Health Perspectives.
   Volume 112, No.1. Pages 9 to 13.

   California Environmental Protection Agency
   (Cal/EPA) Office of Environmental Health and
   Hazard Assessment. No Significant Risk Levels
   for Carcinogens and Maximum Allowable Dose
   Levels for Chemicals Causing Reproductive
   Toxicity. 2006. http://www.oehha.ca.gov/prop65/
   pdf/Aug2006StatusReport.pdf

   Choi, J., Onodera, J., Kitamura, K., Hashimoto,
   S., Ito, H. Suzuki, N., Sakai, S., and Morita, M.
   2003. Modified clean-up for PBDD, PBDF and
   PBDE with an active carbon column—its
   application to sediments. Chemosphere. Volume
   53 (6). Pages 637-643.

   De Wit, C. A. 2002. An Overview of Brominated
   Flame Retardants in the Environment.
   Chemosphere. Volume 46. Pages 583 to 624.

   He, J., K. R. Robrock, and L. Alvarez-Cohen.
   2006. Microbial Reductive Debromination of
   PBDEs. Environmental Science & Technology.
   Volume 40. Pages 4429 to 4434.

   Hooper, K., and  T.A. McDonald. 2000. The
   PBDEs: An Emerging Environmental Challenge
   and another Reason for Breast-Milk Monitoring
   Programs. Environmental Health Perspectives.
   Volume 108 (5). Pages 387 to 392.

   Keum, Y-S., and Q. X. Li. 2005. Reductive
   Debromination of PBDEs by Zero-Valent Iron.
 Environmental Science & Technology. Volume
 39. Pages 2280 to 2286.

 McDonald, T. A. 2002. A Perspective on the
 Potential Health Risks of PBDEs. Chemosphere.
 Volume 46. Pages 745 to 755.

 Occupational Safety and Health Administration
 (OSHA).Permissible Exposure Limits. 2011.
 Web site accessed on November 3.
 http://osha.gov/SLTC/pel/index.htmltfstandards

 Streets, S. S., S. A. Henderson, A. D. Stoner, D.
 L. Carlson, M. F. Simcik, and D. L. Swackhamer.
 2006. Partitioning and Bioaccumulation of
 PBDEs and PCBs in Lake Michigan.
 Environmental Science & Technology. Volume
 40. Pages 7263 to 7269.

 U.S. Department of Health and Human Services
 (DHHS). 2011. Report on Carcinogens, 12th
 Edition - Substance Profile on Polybrominated
 Biphenyls (PBB).
 http://ntp.niehs.nih.gov/ntp/roc/twelfth/roc12.pdf

 U.S. Environmental Protection Agency (EPA).
 2010. DecaBDE Phase-out Initiative.
 www.epa.gov/oppt/existingchemicals/pubs/actio
 nplans/deccadbe.html

 EPA Integrated Risk Information System (IRIS).
 1990a. "Octabromodiphenyl ether (CASRN
 32536-52-0)."
 www.epa.gov/ncea/iris/subst/0180.htm.

 EPA IRIS. 1990b. "Pentabromodiphenyl ether
 (CASRN 32534-81-9)."
 www.epa.gov/iris/subst/0184.htm

 EPA IRIS. 2008a. Toxicological review of
 decabromodiphenyl ether (BDE-299) in support
 of summary information on the Integrated Risk
 Information  System. EPA 635-R-07-008F.
 www.epa.gov/ncea/iris/toxreviews/0035tr.pdf

-------
 Technical Fact Sheet - PBDEs and PBBs
Where can I find more information about PBDE and PBB? (continued)
   EPA IRIS. 2008b. "Decabromodiphenyl ether
   (BDE-209) (CASRN 1163-19-5)."
   www.epa.gov/IRIS/subst/0035.htm

   EPA IRIS. 2008c. "2,2',4,4',5,5'-
   Hexabromodiphenyl ether (BDE-153) (CASRN
   68631-49-2)." www.epa.gov/iris/subst/1009.htm

   EPA IRIS. 2008d. "2,2',4,4'-Tetrabromodiphenyl
   ether (CASRN 5436-43-1)."
   www.epa.gov/iris/subst/1010.htm

   EPA Office of Pollution Prevention and Toxics
   (OPPT). 2010. Polybrominated Diphenylethers.
   Web site accessed on November 7.
   www.epa.gov/oppt/pbde/
Washington State Department of Labor and
Industries (WDLI). 2011. Workplace Exposure to
PBDEs. Web site accessed on November 7.
www.lni.wa.gov/Safetv/Topics/AtoZ/polybrom/defa
ult.asp.

World Health Organization International Agency for
Research on Cancer (IARC). 2011. Agents
Reviewed by the IARC Monographs: Volumes 1-96
(Alphabetical Order).
http://monographs.iarc.fr/ENG/Classification/index.
php
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.

-------