Technical Fact Sheet Polybrominated Biphenyls (PBBs)


vvEPA	Technical Fact Sheet -
United States
is:—p° Polybrominated Biphenyls (PBBs)
November 2017
TECHNICAL FACT SHEET - PBBs
Introduction
This fact sheet, developed by the U.S. Environmental Protection Agency
(EPA) Federal Facilities Restoration and Reuse Office (FFRRO), provides
a summary of the contaminant group polybrominated biphenyls (PBBs),
including physical and chemical properties; environmental and health
impacts; existing federal and state guidelines; detection and treatment
methods; and additional sources of information. This fact sheet provides
basic information on PBBs to site managers and other field personnel who
may encounter these contaminants at cleanup sites.
The manufacture of PBBs was banned in the United States in 1976 after an
agricultural contamination incident in 1973 when PBB was accidentally
mixed into animal feed, exposing millions of Michigan residents to
contaminated dairy products, eggs and meat (ATSDR 2004; NTP 2014).
What are PBBs?	
~	PBBs are a class of brominated hydrocarbons. They contain a central
biphenyl structure surrounded by up to 10 bromine atoms (ATSDR
2004).
~	PBBs were formerly used as additive flame retardants in synthetic
fibers and molded plastics. They are no longer used in the United
States (ATSDR 2004; NTP 2014).
~	Three types of commercial PBB mixtures were: hexabromobiphenyl
(hexaBB), octabromobiphenyl (octaBB) and decabromobiphenyl
(decaBB) (ATSDR 2004).
~	There are no known natural sources of PBBs (ATSDR 2004).
~	PBBs are structurally similar to polychlorinated biphenyls (PCBs).
~	PBBs are fat-soluble and hydrophobic (NTP 2014).
Disclaimer: The U.S. EPA prepared this fact sheet using the most recent
publicly-available scientific information; additional information can be obtained
from the source documents. This fact sheet is not intended to be used as a
primary source of information and is not intended, nor can it be relied upon, to
create any rights enforceable by any party in litigation with the United States.
Mention of trade names or commercial products does not constitute endorsement
or recommendation for use.
At a Glance
~	Class of brominated
hydrocarbons that serve as
flame retardants for electrical
equipment, electronic
devices, furniture, textiles and
other household products.
~	Structurally similar and exhibit
low to moderate volatility.
~	Exposure in rats and mice
caused neuro-developmental
toxicity and other symptoms.
~	The U.S. Department of
Health and Human Services
states that PBBs are
reasonably anticipated to be
human carcinogens.
~	EPA has calculated screening
levels for PBBs in air, soil and
tap water.
~	Detection methods include
gas chromatography, mass
spectrometry and liquid
chromatography.
United States
Environmental Protection Agency
Office of Land and Emergency
Management (5106P)
1
EPA 505-F-17-016
November 2017

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Technical Fact Sheet - PBBs
Exhibit 1: Physical and Chemical Properties of PBBs (ATSDR 2004)
Property

PBBs

HexaBB
OctaBB
DecaBB
Chemical Abstracts Service (CAS) number
36355-01-8
27858-07-7
13654-09-6
Physical description (physical state at room
temperature)
White solid
White solid
White solid
Molecular weight (g/mol)
627.4
785.2
943.1
Water solubility at 25°C (pg/L)
11
20 to 30
Insoluble
Boiling point (°C)
Not available
Not available
Not available
Melting point (°C)
72
200 to 250
380 to 386
Vapor pressure (mm Hg)
5.2 x 10"8 (at 25°C)
7 x 10"11 (at 28°C)
Not available
Octanol-water partition coefficient (log K0w)
6.39
5.53
8.58
Soil organic carbon-water coefficient (log Koc)
3.33 to 3.87 a
Not available
Not available
Henry's law constant at 25°C (atm-m3/mol)
3.9 x 10-®
Not available
Not available
Abbreviations: g/moi - gram per mole; |jg/L - micrograms per liter;
atmosphere-cubic meters per mole.
a- Estimated value
'C - degrees Celsius; mm Hg - millimeters of mercury; atm-m3/mol -
Existence of PBBs in the environment
PBBs have been detected in air, sediments,
surface water, fish and other marine animals
(ATSDR 2004).
PBBs do not dissolve easily in water and bind
strongly to soil or sediment particles. This reduces
their mobility in soil, sediment, surface and
groundwater, but increases their mobility in the
atmosphere, where they are attached to airborne
particulate matter (ATSDR 2004).
Volatilization from soil surfaces is expected to be
low to moderate, depending on the number of
bromine atoms. More brominated congeners
(higher numbers of bromine atoms) tend to exhibit
lower volatilities (NTP 2014).
Even though PBBs are stable, they are
susceptible to photolytic debromination when they
are exposed to ultraviolet light (ATSDR 2004).
As of 2016, PBBs had been identified at few sites
on the EPA National Priorities List (NPL);
however, the number of sites evaluated for PBBs
is not well documented (EPA 2016a).
What are the routes of exposure and the potential health effects of PBBs?
Routes of potential human exposure to PBBs are
ingestion, inhalation or dermal contact (NTP
2014).
Since PBBs are not produced or used in the
United States, the general population can only be
exposed from historical releases or products
(ATSDR 2004).
The U.S. Department of Health and Human
Services (DHHS) states that PBBs are reasonably
anticipated to be human carcinogens based on
sufficient evidence of carcinogenicity from
experimental animal studies (NTP 2014).
The International Agency for Research on Cancer
(IARC) classified PBBs as "probably carcinogenic
to humans" (IARC 2016).
Studies on mice and rats, and evidence from cows
exposed via feed show that PBBs cause
neurotoxicity, weight loss, skin disorders, liver
toxicity, kidney toxicity, thyroid toxicity
immunotoxicity and cancer (ATSDR 2004;
Birnbaum and Staskal 2004).
Studies on animals and humans show that some
PBBs can act as endocrine system disruptors,
have been found in human breast milk, and tend
to deposit in human adipose tissue (ATSDR 2004;
Birnbaum and Staskal 2004; NTP 2014).
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Technical Fact Sheet - PBBs
Are there any existing federal and state guidelines and health standards for
PBBs?
EPA has not derived chronic oral reference doses
(RfDs) for PBBs.
EPA has calculated the following screening levels for
residential soil, industrial soil and tap water (EPA
2017b):
Various states have adopted screening values or
cleanup goals for PBBs in drinking water or
groundwater, ranging from 0.0001 to 5 |jg/L:

Residential
Industrial
|
Chemical
Soil
Soil


(mg/kg)
(mg/kg)

I PBBs |
0.018 |
0.077 |
0.0026 |
For PBBs, EPA has also calculated a residential air
screening level of 3.3 x 10 4 micrograms per cubic
meter (|jg/m3) and an industrial air screening level
of 1.4 x 10"3 jjg/m3 (EPA 2017b).
The Agency for Toxic Substances and Disease
Registry (ATSDR) has established a minimal risk
level (MRL) of 0.01 mg/kg/day for acute-duration
(14 days or less) oral exposure to PBBs (ATSDR
2016).
State
Guideline (|jg/L)
Source
Indiana
0.026
IDEM 2016
Michigan
0.03
MDEQ 2015
Mississippi
0.00752
MS DEQ 2002
Nebraska
0.0022
NE DEQ 2012
New York
5
NYDEC 2016
Texas
0.0001
TCEQ 2016
West Virginia
0.0022
WV DEP 2009
Some states have established soil standards or
guidelines for PBBs, including Michigan,
Mississippi, Nebraska, North Carolina, Texas,
West Virginia and Wisconsin. The California
Environmental Protection Agency (Cal/EPA) has
established a No Significant Risk Level of 0.02 jjg
per day for PBBs (Cal/EPA 2017).
What detection and site characterization methods are available for PBBs?
~ Analytical methods for PBB detection include gas
chromatography-electron capture detector (GC-
ECD) for commercial samples, soil, plant tissue,
water, sediment, fish, dairy and animal feed; high
resolution GC (HRGC)/high resolution mass
spectrometry (HRMS) for fish samples; GC-flame
ionization detector (FID)/ECD for soil; and liquid
What technologies are being used to treat PBBs?
chromatography (LC)-GC-MS/FID for sediment
(ATSDR 2004).
Research is being conducted at the laboratory
scale on potential treatment methods for media
contaminated with PBBs.
Where can I find more information about PBBs?
~	Agency for Toxic Substances and Disease
Registry (ATSDR). 2004. "Toxicological Profile for
Polybrominated Biphenyls."
www. atsd r. cdc.gov/toxprofiles/tp6 8. pd f.
~	ATSDR. 2016. "Minimal Risk Levels (MRLs)."
www.atsdr.cdc.gov/mrls/index.html
~	Birnbaum, L.S., and D.F. Staskal. 2004.
"Brominated Flame Retardants: Cause for
Concern?" Environmental Health Perspectives.
Volume 112 (1). Pages 9 to 13.
~	California Environmental Protection Agency
(Cal/EPA) Office of Environmental Health and
Hazard Assessment. 2017. "Proposition 65 No
Significant Risk Levels for Carcinogens and
Maximum Allowable Dose Levels for Chemicals
Causing Reproductive Toxicity."
oehha.ca.gov/media/downloads/proposition-
65/general-info/regsart7.pdf
~	Indiana Department of Environmental Management
(IDEM). 2016. "IDEM Screening and Closure
Levels." www.in.gov/idem/landgualitv/
files/rise screening table 2016.pdf
~	International Agency for Research on Cancer
(IARC). 2016. "Agents Classified by the IARC
Monographs, Volumes 1-107."
monographs.iarc.fr/ENG/Classification/index.php
~	Michigan Department of Environmental Quality
(MDEQ). 2015. "Rule 57 Water Quality Values."
www.michigan.gov/documents/deg/wrd-swas-
rule57 372470 7.pdf
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Technical Fact Sheet - PBBs
Where can I find more information about PBBs? (continued)
Mississippi Department of Environmental Quality
(MS DEQ). 2002. "Risk Evaluation Procedures for
Voluntary Cleanup and Redevelopment of
Brownfield Sites." www.deg.state.ms.us/
MDEQ.nsf/pdf/GARD brownfieldrisk/$File/Proced.
pdf?OpenElement
National Toxicology Program. 2014. "Report on
Carcinogens, Fourteenth Edition." Research
Triangle Park, NC: U.S. Department of Health and
Human Services, Public Health Service.
https://ntp.niehs.nih.gov/pubhealth/roc/index-1 .html
Nebraska Department of Environmental Quality.
2012. Voluntary Cleanup Remediation Goals.
deg.ne.gov/Publica.nsf/xsp/.ibmmod res/domino/Op
enAttachment/Publica.nsf/D243C2B56E34EA8486
256F2700698997/Bodv/ATTIY3JX.pdf
New York Department of Environmental
Conservation (NYDEC). 2016. Water Quality
Standards, www.dec.nv.gov/chemical/23853.html
Texas Commission on Environmental Quality.
2016. "Texas Risk Reduction Program (TRRP)
Protective Concentration Levels (PCLs)."
www.tceg.texas.gov/remediation/trrp/trrppcls. html
EPA. 2016a. Superfund Information Systems.
Superfund Site Information, cumulis.epa.
g o v/s u pe rcpad/cu rs ites/s rchs ites. cf m
EPA. 2017b. Regional Screening Level (RSL)
Summary Table, https://www.epa.gov/risk/regional-
screening-levels-rsls-generic-tables-iune-2017
West Virginia Department of Environmental
Protection (WV DEP). 2009. "Voluntary
Remediation and Redevelopment Rule."
www.dep.wv.gov/dlr/oer/voluntarvmain/Documents
/60CSR3%20VRRA%20rule%206-5-09.pdf
Contact Information
If you have any questions or comments on this fact sheet, please contact: Mary Cooke, FFRRO, at
cooke.marvt@epa.gov.
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