&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
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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).
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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).
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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
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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.
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