DEQ-CFW_00022512

Questions and Answers Regarding Potential Health Effects Related to GenX
(GenX is also known as 2,3,3,3 -tetrafluoro-2-(heptafluoropropoxy)propionic acid, ammonium salt, CAS# 62037-80-
3)
I I a I . a I . 0 a 0 .
The goal of the North Carolina Department of Health and Human Services (NC DHHS) is to provide timely
health information to residents and others who are concerned about potential health effects ofGenX.
When there is not a federal standard and sufficient scientific information is available, NC DHHS can
develop and issue a health assessment. This assessment can include establishing a health goal,
sometimes referred to as a health screening level. A health goal is a non -regulatory, non -enforceable
level of a contaminant below which no adverse health effects would be expected over a lifetime of
exposure. Although health information is limited for many of the newer or "emerging" perfluorinated
compounds, NC DHHS has determined that there is sufficient scientific information to provide a
preliminary health assessment for GenX.
It is important to note that as new information becomes a
with federal agencies (EPA and
researchers to better understa
� preliminary assessments are based on available data and are updated
ailable. DHHS continues to review all available health data and work
:he U.S. Centers for Disease Control and Prevention [[D[])and academic
d the health risks associated with GenX.
in their initialpreliminary assessment?
In the absence of health guidance values published by U.S. federal agencies, NC DHHS used GenX
toxicity information available from the European Chemicals Agency (ECHA) to calculate a health goal of
71,000 nanograms per liter (ng/L, also referred to as parts per trillion or ppt). See Appendix 1 for the
calculation of the initial preliminary assessment using the information from ECHA.
Since sharing the initial health assessment, NC DHHS has continued to review all available health
information about 6enX. Based on this review and continuing discussions and a more recent consensus
with EPA, NC DHHS has determined that sufficient, additional data are available to update our initial
assessment.
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The revised health goal is14Ona/Lfor the most vulnerable population- ie.bottle-fed infants, the
population that drinks the largest volume ofwater per body weight. Additional goals were also
established for older children, breastfeeding women, pregnant women and adults, and their respective
health goals range from 38U-64Uno/L All five categories and goals are presented inAppendix 4.
This revised level is lower than the level in the initial assessment for several reasons, including the
This revised health assessment is based on evolving toxicological data; therefore, it is still considered
provisional and issubject tofurther updates based onanongoing review, consultation with federal
agencies and other partners, and the introduction of new research and scientific information.
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Additionally, the initial health goal was based upon combined cancer and noncancer endpoints.The
revised health goal is based on animal studies that included non -cancer endpoints only. Based on
conversations with EPA, we concluded there is not enough information at this time to identify a specific
level ofGenXthat might beassociated with anincreased risk for cancer.
NCDHHS is not recommending that people stop using the municipal
purposes. That's because there is not enough information about t[
related chemicals to make such a recommendation ag for the gener
group at this time. Individuals are encouraged to consider informati
when making decisions about water use. The potential health effecl
balanced against the health benefits of municipal water, including r
microbial and known chemical contaminants that could be present
sources. NC DHHS supports all efforts to eliminate sources of GenX
vater for drinking orother
! human health effects ofGenXor
| population or for any specific
n in the health risk assessment
from these chemicals should be
itine monitoring for a variety of
private other unregulated
id related chemicals in the water
rous" level of a chemical. Rather, hisa
health effects would be
In discussions with EPA and other partners, there is not sufficient, identified data that can be used to
deve|opapreUminaryhea|thriskaoeomentfortheothernew/eror"emeqJing"perMuorinated
compounds mentioned in the 2016 paper by Sun et al (PF02HxA, PFMOAA, PFMOBA, PF030A,
PFK4OPrAand PFO4PA). Scientific information such as animal toxicology studies and laboratory testing
standards are needed by these agencies to conduct further health assessment on the other
perf|uorinatedcompounds.
North Carolina Department of Health and Human Services DRAFT [ DATE \@ "M/d/yyyy h:mm am/pm" ]
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Health information about 1,4-dioxane is available at http://deq.nc.gov/about/divisions/water-
resources/water-resources-data/water-sciences-home-page/1-4-dioxane.
Yes. NC DHHS has been in close contact with officials at EPA and the CDC to gather and review all health
information related to GenX. EPA isworking to develop a health risk assessment for Gen>; however, the
timeframefor that assessment is not known. N[ DHHS staff are also in contact with academic
researchers with knowledge and experience with these compounds.
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The European Chemical Agency (ECHA) information included a Derived No Effect Level (DNEL) of 0.01
mg/kg body weight (bw)/day for oral exposures. The ECHA assessment was performed using a no -
observed -adverse-effect-I evel (NOAEL) from a 2-year rat chronic toxicity/carcinogenicity study as the
point ofdeparture (POD) and applying default uncertainty factors, as described below:
* No-observedadveoe-effect-|eve|(NOAEU=l.0mg/kg body ight(bw)/day
w Total default uncertainty factors (UF) = 100 (interspecies variability= 10; intraspecies
* variability =1O)
NC DHHS calculated a drinking water equivalent level (DWEL) for GenX as fol
NO expressed osparts per trillion orApt
The values used for body weight and drinking water intake were based on infants in order to be
maximally protective, since infants consume the highest amount of water in relation to their body
weight. The initial calculation assumed that 100% of GenX exposure (relative source contribution) was
from water consumption. DWEL is the same as a health goal or health screening level.
North Carolina Department of Health and Human Services DRAFT [ DATE \@ "M/d/yyyy h:mm am/pm" ]
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After consultation with EPA, the following were updated:
* Sufficient data are available to support the use a lower no'observed'adverse'efhect |eve|
(NOAEU as point of departure for the assessment. This NOAEL(O.1 mg/kg/day) is 10-foN lower
than the NOAEL used in the initial assessment and is based on effects on the liver in mice.
* Since this point of departure is based on a subchronic toxicity study rather than a chronic
study,toxicity dd | uncertainty factor of 10 is includedcalculations.
* Arelative source contribution (R3C)utZOY6is used to account for potential exposure toGenX
from other routes like air and food. The RSC lowers the acceptableconcentration inwater due
to the potential for other exposure routes.
Revised calculation:
w
w Total default uncertainty factors
* Formula: muaE4ur=Reference Dose \RrD&�
31
weight(bvv)/c
�
iabi|ky=10 i
Ufor GenXasfollows:
ies
X body weight (kg)/intake (L/day) X RSC X Unit Conversion =
NOTE: noILcan also beexpressed osparts per trillion orApt
The values used for body weight and drinking water intake were based on bottle-fed infants in order to
bemaximally protective, since infants consume the highest amount of water in relation to their body
weight. See Appendix for other age groups see table below. DVVEL is the same as a health goal or
health screening level.
North Carolina Department of Health and Human Services DRAFT [ DATE \@ "M/d/yyyy h:mm am/pm" ]
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Beekman M,Zm/eeoP,Muller A,deVries W,Janssen P,Zei|makerK4.2U16.R|VMReport 2D16-D174:
Evaluation of substances used in the GenX technology by Chemours, Dordrecht.
http://w/w/w/.rivmo|/Documenten_en_pub|icabes/VVetenschappe|�k/RappoMLen/2U16/december/Eva|ua
don_of_substances_used_in_the_GenX_techno|ogy_by_[hemours_Dordrecht.
E[HAToxicological Summary for Ammonium J,3,3,3'Tetraf Iuoro-J-(Heptaf Iuoropr000xv)Pro panoate.
Ferreira etal. Comparing the potency invivo of PFAS alternatives and their predecessors. March 2U17.
(heptafluoropropoxy)propanoic acid ammonium slalt following a single closeth rat, mouse, and
Sun et al.
the Cape Fear River Watershed of
2016 DOI: 10,1021/acs.est|ett.6b�
eamentfor ammonium ��3,3'
9(2016)336'342.
iu-- 3,3,3-tetrafuoro'2'
rReports.]une2Ol5.
lkyl Substances Are ImportantDrinking Water Contaminants in
anu|ina. Environmental Science /& Technology Letters. Nov
es for PFOA and PFOS. https://www.epa.gov/ground-water-and-
idvisories-pfoa-and-pfos
ness Information for 8EHQ-06-16478.
North Carolina Department of Health and Human Services DRAFT [ DATE \@ "M/d/yyyy h:mm am/pm" ]
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GenX
Point of Departure
UFtota|
D8AFTRfD
Relative Source Contribution (RS[)
0.1
mg/kg/day
1000
unidess
0.0001
mg/kg/day
0.2
unidess
Assumes 20% of
NOAELfor uubch
Screening level =[(RefenenceDose (mo/ko/dav)*RS[*Body w/eig
Acronyms:
UF=Uncertainty Factor
RfD = Reference Dose
mo/ko/day=milligram ofcompound per kgofbc
NOAEL=NoObserved Adverse Effect Level
EPA =U.8.Environmental Protection Agency
RAGS = Risk Assessment Guidance for Superfund
parnm/aysIntake rate (L/day
�
0
�
studies
from drinking water to account for other potential
Only: [:EPA 201:11
able:8 S. eighted:average of 5 percentile body weight for females 15-45 years of age + 5kg retained
centile for consumers only from birth to 12 months [EPA 2011, ATSDR 2016b]
North Carolina Department of Health and Human Services DRAFT [ DATE \@ "M/d/yyyy h:mm am/pm" ]
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OSVVER = Office of Solid Waste and Emergency Response
EFH = Exposure Factor Handbook
ATSDR = Agency for Toxic Substances and Disease Registry
[EPA 20111 US Environmental Protection ARencv. 2011. EXDOsure Factors Handbook:
uidance for Body Weight. Atlanta, GA: U.S. Department
for Water Ingestion, Version 2. Atlanta, GA: U.S.
011 Final. Waship2ton DC: National Center for
North Carolina Department of Health and Human Services DRAFT [ DATE \@ "M/d/yyyy h:mm am/pm" ]