DEQ-CFW_00080065

When there is not a federal standard and there is sufficient scientific information available, the North
Carolina Department of health and Human Services (NC DHHS) can develop and issue a health
assessment. 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.
NCDHHSshared apreliminary assessment withlocal partners un] some context for understanding the health risks that could be associ
in the Cape Fear River during 2013-2014. The U.S. Environmental Pri
provide more comprehensive health risk information for this chemic
process is not sufficient to address the urgent public concerns raised
public drinking water supply.
It is important to note that these preliminary assessments are ba
change as new information becomes available. DHHS continues,
work with federal agencies (EPA and the U.S, Centers for Disease
academic researchers to better understand the health risks asso(
ZU17inanattempt tuprovide
tedwith GenXatthe levels found
tectionAgency (EPA)iuworking to
1. However, the timeliness ofthat
mv identification ofGenXinthe
on available data and are subject to
Mew all available health data and
trol and Prevention [CDC]) and
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
screening level of 71,000 nanograms per liter (ng/L, also referred to as parts per trillion). See Appendix
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 GenX. Based on this review and continuing discussions and consensus with EPA, NC
DHHS has determined that sufficient data are available to make changes to the initial assessment.
The current revised health screening level is 140 no/Lforthe most vulnerable population- i.e. bottle-fed
infants, the population that drinks the largest volume of water per body weight. Details ofthe specific
updates and calculations for the revised health screening level are presented in Appendix 3.
Aawith the initial preliminary assessment, kisimportant tonote that this updated risk assessment is
not final and is likely to change as new information becomes available. Provisional screening levels for
other populations are presented inAppendix 4.

The revised health risk assessment means that there could be an increased risk of adverse health effects
for the most vulnerable people in the population over a lifetime of consuming water with levels greater
than 140 ng/L. This revised health screening level is lower than the level in the initial risk assessment.
Because this level is based on the most vulnerable population (bottle-fed infants), it is also protective of
adults, pregnant women, nursing mothers, and children. See Appendix 4for age group calculations and
provisional screening levels for other population This revised health assessmentisbased onevolving
toxicological data; itisstill considered provisional and is subject change based onanongoing review
and onconsultation with federal agencies and other partners.
There isnot enough inform
DHHStomake a recommen
any specific group atthis tit
assessment when making d
should be
variety of microbial and kn
unregulated sources. NC D
the water supply.
6. Does this mean the wat
A health screening level is not a boundary line between a"uafe"and "dangerouu"level ofachemical.
Rather, itisagoal that represents the level ofGenXatwhich noadverse non -cancer health effects
would be anticipated over an entire lifetime of exposure to the most sensitive population.
There are no fish advisories related to GenX. Preliminary information from EPA suggests that GenX is not
anticipated tobivaccumu|ateinfish. Alist ofstatewide and location -specific fish advisories related to
other contaminants is available at http://epi.publichealth.nc.gov/oee/fish/advisories.htmi.

Fear River?
In discussions with EPA and other partners, there is no identified data that could be used to determine a
preliminary health risk assessment for the other newer or "emerging" perfluorinated compounds
mentioned in the 2016 paper by Sun et al (PFO2HxA, PFMOAA, PFMOBA, PFO3OA, PFMOPrA and
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 perfluorinated
compounds.
Health information about 1,4-dioxane is available at'http://deq.nc.gov/ab
resources/water-resources-data/water-sciences-home-page/1-4-dioxane.
DHHS DRAFT FAQ [ DATE \@ "M/d/yyyy h:mm am/pm" ]
ivisions/water-
ie CDC to gather and review all health
evelop a health risk assessment for
NC DHHS has also requested a public
S staff are also in contact with
compounds.
DEQ-CFW 00080067

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:
w No-observed-adverse-effest-|eve|(NOAEU=1.Omg/kg body weight (bvv)/day
w Total default uncertainty factors (UF) = 100 (interspecies variability= 10; intraspecies
* variability =1O)
* Formula: NOAEL/UF=DNEL
NC DHHS calculated a drinking water equivalent
0NEUfor GenXas
)XRS[XUnit Conversion =
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 screening level.

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 =
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 ofwater inrelation totheir body
weight. For other age groups see table below. DVVEListhe same asa health screening level.

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
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.

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 = [(Reference Dose (mg/kg/day) * RS[ * Bodym/ei8
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
Intake rate (L/day
parnm/ays
�
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]
OEQ-CFVV_00080071

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
ysiological and behavioral changes during pregnancy and