DEQ-CFW_00080379

Risk Assessment for GenX (Perfluoro-2-propoxypropanoic acid)
This document contains osummary ofpreliminary information and is shared with local health departments as
means 4fproviding awareness o/currently available information, and osotool uomaintain consistency /n
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 of GenX.
When there is not a federal standard and sufficient scientific information available, the NC DHHS can
develop and issue ahealth assessment. This assessment can include establishing ahealth goal,
sometimes referred to as a health screening goal. A health goal is a non -regulatory, non -enforceable
level of contamination below which no adverse health effects would be expected over a lifetime of
The NC DHHS shared a preliminary assessment for GenX with local partners on June 8,2017 in an
attempt to provide some context for understanding the health risks that could be associated with levels
found inthe Cape Fear River during ZOl3-IOl4.
Since sharing the preliminary health assessment, NC DHHS has continued to review all available health
information about 6enX.Based onthis review, continuing discussions, and consensus with EPA, NC
DHHS has determined that sufficient data are available to make changes to the preliminary assessment.
The updated health goal is 140 ng/L for the most vulnerable population- i.e. bottle-fed infants, the
population that drinks the largest volume ofwater per body weight.
This updated level is lower than the level in the preliminary assessment for several reasons, including
the following:
0 After consultation with EPA, a different set of animal studies was identified as an appropriate
starting point for the assessment. This change lowered the health goal by10-fo|d.
= Since the new starting point was based on intermediate (sub -chronic) rather than long-term
(chronic) animal studies, an additional uncertainty factor was added, which lowered the level by
� While the preliminary assessment assumed that drinking water was the only source of exposure,
the updated value includes an assumption that only 20% of a person's GenX exposure comes
from drinking water, lowering the level anotherS4o|d. EPA's practice is to use this 2UY6default
factor as a generic assumption when information is lacking about other sources of exposure in

the environment asiscurrently the case with GenX. N[DHHS'suse ofthe JOY6factor was
included based on additional review and consultation with EPA.
Details of the specific updates and calculations for the updated health screening goal are presented in
Appendix3.
As with the preliminary assessment, it is important to note that this updated risk assessment is not final
and is likely to be updated as new information becomes available or when standards are made available
by the EPA.
For the most vulnerable population (bottle-fed infants) the updated health risk assessment means that
there could be an increased risk ofadverse health effects over a lifetime ofconsuming water with levels
greater than 14On8/L.
Because this goal/level bcalculated based onthe most vulnerable population, histhe most
conservative and is protective of other groups, including pregnant women, nursing mothers, children, as
well asother adults.
This updated 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.
Although the preliminary assessment was based upon a study with combined cancer and non -cancer
endpoints, the updated health goal considers non -cancer endpoints only. There are nostudies in
humans on cancer related to GenX. Only one animal study is available for cancer analysis, and it has
shown increases in certain cancers. Based on conversations with EPA, there is not enough information at
this time to identify a specific level of GenX that might be associated with an increased risk for cancer.
purposes if levels are above 140 ng/L ?
NC DHHS will not be making a blanket recommendations about water use, but will work with local
partners about health risks and messaging regarding sampling results. Individuals are encouraged to
consider information in the health risk assessment when making decisions about water use.
The potential health effects from these chemicals should bebalanced against the health benefits of
municipal water, including routine monitoring for avariety ofmicrobial and known chemical
contaminants that could be present in private wells orother unregulated sources. There are many
sources of contamination of groundwater, including naturally -occurring chemicals and minerals (for

example, arsenic, radon, and uranium),local land use practices (ferd|izers,pesticides, |ivestod,anima|
feeding operations, biosolids applications), manufacturing processes, and sewer overflows.
Studies to determine if any filtration systems could remove GenX and other perfluorinated chemicals
are underway and DHHS will share new information as it becomes available.
4LDoes this mean nmywater is unsafe if levels are over 14Ong/L?
Thishea|thassessmentisnotaboundary|inebetw/eena"safe"and"dan8erous"|eve|ofachemica|.
Rather, it is a level that represents the concentration ofGenX at which no adverse non -cancer health
effects would be anticipated over an entire lifetime to the most sensitive population.
/Udhou8hheakhinformadonis|imitedformanyofthenevveror^emergin8"perMuohnatedcompounds,
N[ DHHS has determined that there issufficient scientific information to provide preliminary health
assessment for GenX.
The U.S. Environmental Protection Agency (EPA) is working to provide more health risk information for
this chemical. However, the timeliness of that process is not sufficient to address the urgent public
concerns raised by identification of GenX in the public drinking water supply.
In the absence of health guidance values published by U.S. federal agencies, N[DHHSused GenX
toxicity information available from the European Chemicals Agency (ECHA) to calculate a provisional
health protective level of71,OOU nano8rams per liter (no/L also referred to as parts per trillion). See
Appendix l for the calculation of the preliminary assessment using the information from ECHA.
There are nostudies regarding human health effects ofGenX. However, animal studies demonstrate
liver and red blood cell non -cancer effects and pancreas, liver, and testicular cancer effects. Whether or
not animal effects will be the same in humans is not known. There is no health information about other
pe/f|uorinatedchemica|s.
There are no fish advisories related to GenX. Preliminary information from EPA suggests that GenX is not
anticipated tobioaccumu|ateinfish. Alist ofstatewide and location -specific fish advisories related to
other contaminants is available at http://epi.publichealth.nc.gov/oee/fish/advisories.htmi.
OEQ-CFVV_00080381

Fear River?
In discussions with EPA and other partners, there is not sufficient identified data that can be used to
develop a preliminary health risk assessment for the other newer or "emerging" perUuorinated
compounds mentioned in the 2016 paper by Sun et al (PF02HxA, PFIVIOAA, PFMOBA, PF030A,
PFK4OPrAand PFO4PA). This applies for exposure to these compounds individually and in combination.
Scientific information such as animal toxicology studies and laboratory testing standards are needed by
these agencies toconduct further health assessment on the other perf|uorinated compounds. NC DHHS
will continue to work with the EPA and CDC to identify and share any health risk information about
these compounds asitbecomes available.
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, along with NC DEQ, 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 health risk assessment
forGen); however, the dmefnsmefor that assessment iu not known. N[ DHHSstaff are also in contact
with academic researchers with knowledge and experience with these compounds.

The European Chemical Agency (ECHA) information included a Derived No Effect Level (DNEL) of 0.01
mg/kg body weight (bw/)/dayfor oral exposures. The DNELreported byECHAwas calculated using ano-
observed 'adverse-effect'|eve|(NOAEL)fromaJ-yearratchronictoxicity/cardno8enidtystudyasthe
point of departure (POD) and applying default uncertainty factors, as described below:
w No-observed-adverse-effest-|eve|(NOAEU=1.Omg/kg body weight (bvv)/day
• Total default uncertainty factors (UF) = 100 (interspecies variability = 10; intraspecies
variability =1O)
NC DHHS calculated a drinking water equivalent level (DWEL) for GenX as follows:
* Dose (DNEU=(lO1mg/kg bw/day
* Body Weight =7.8kB(infant)
w Intake = 1.1 L/day(infant)
* Unit Conversion =1D«nu/m8
* Formula: dose (mu/kBbm/day)Xbody weight (kg)/intake(L/day)XR8CXUnit Conversion
=
DVVEL
k10 X7DkofiYJ/6avXl.DXl06no/mo=7l000noIL
NOTE: nanograrns per liter (moIL)can also beexpressed maparts per trillion orppt
The values used for body weight and drinking water intake were based on infants(in order tobe
maximally protective) since they consume the highest amount of water in relation to their body weight.
from water consumption. The DWEL was used as our preliminary assessment.

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 preliminary assessment and is based on effects on the liver in mice.
w Since this point of departure is based on a subchronic toxicity study rather than a chronic
toxicity study, an additional uncertainty factor of 10 is included in the calculations.
* A relative source contribution (RSC) of 20% is used to account for potential exposure to GenX
from other routes like air, soil, dust, and food. The RS[lowers the acceptable concentration in
water due tothe potential for other exposure routes.
w No-observed-adverse-effest-|eve|(NOAEU=O.1mg/kg body weight (bvv)/day
* Total default uncertainty factors (UF) = 1000 (inteopeciesvariability = 10; intnaupecies
variability = 10; and subchronicto chronic extrapolation = 10)
w Formula: NOAEL/UF= Reference Dose(RfD)
NC DHHS calculated a drinking water equivalent level (DWEL) for GenX as follows:
• Body Weight = 7.8 kg (bottle-fed infant)
* Unit Conversion =1D«nu/m8
* Formula: dose (mu/kBbm/day)Xbody weight (kg)/intake(L/day)XR8CXUnit Conversion
=
DVVEL
k1000X7.Rko1(?.2/6avX(l2X2D«no/mo=24DnoIL
NOTE: nanograrns per liter (moIL)can also beexpressed maparts per trillion orppt
The values used for body weight and drinking water intake were based on bottle-fed infant (in order to
be maximally protective) since infants consume the highest amount of water in relation to their body
weight. The DWEL was used to set a provisional health goal for the most sensitive population (bottle-
fed

Beekman K4,IvveeoP,Muller A,deVries N,Janssen P,Zei|makerK4.JO16.R|VMReport Z016-0174:
Evaluation of substances used in the GenX technology by Chemours, Dordrecht.
tion of substances used in the GenX technology by Chemours Dordrecht.
E[HAToxicological Summary for Ammonium 2,3,3,3'Tetnaf Iuuro-Z-(Heptaf Iuoropr000xv)Pro panoate.
Ferreira et al. Comparing the potency in vivo of PFAS alternatives and their predecessors. Abstract.
K4archZU17.
S2SS#shash]ofaSrDn.dobs
(heptafluoropropoxy)propanoic acid ammonium salt following a single dose in rat, mouse, and
Hoke etal. Aquatic hazard, bioaccumu|adon and screening risk assessment for ammonium 2,3,3,3-
tetrafluoro-2-(heptafluoropropoxy)-propanoate. Chemosphere 149 (2016) 336-342.
http://dx.doi.org/10.1016/­­i.chemosphere.2016.01.009
Rae et al. Evaluation of chronic toxicity and carcinogenicity of ammonium 2,3,3,3-tetrafluoro-2-
(heptafluoropropoxy)-propanoate
Sun et al. Legacy and Emerging Perfluoroalkyl Substances Are Important Drinking Water Contaminantsin
the Cape Fear River Watershed of North Carolina. Environmental Science & Technology Letters. Nov
USEPA. Drinking Water Health Advisories for PFOA and PFOS. https://www.epa.gov/ground-water-and-
drinking-water/drinking-water-health-advisories-pfoa-and-pfos
USEPA.TS[ANon-Confidential Business Information for OEHCFO6'16478.

7/14/2017 3:06 PM
DEQ-CFW 00080386