Table 1.

Ten fluoroethers and 10 legacy PFAS measured for in serum samples in the GenX exposure study.

Short name	U.S. EPA registry name	Formula	CASN (hyperlinked to U.S. EPA Chemicals Dashboarda)	DTXSIDb	Monoisotopic mass, deprotonated	# of fluorinated carbons	Chain lengthc
Fluoroethers
HFPO-DA (GenX)	Hexafluoropropylene oxide dimer acid	${\mathrm{C}}_6{\text{HF}}_{11}{\mathrm{O}}_3$	13252-13-6	70880215	328.9677	5	7
PMPA	Perfluoro-2-methoxypropanoic acid	${\mathrm{C}}_4{\text{HF}}_7{\mathrm{O}}_3$	13140-29-9	80528474	228.9741	3	5
PEPA	Perfluoro-2-ethoxypropanoic acid	${\mathrm{C}}_5{\text{HF}}_9{\mathrm{O}}_3$	267239-61-2	60896486	278.9709	4	6
PFO2HxA	Perfluoro-3,5-dioxahexanoic acid	${\mathrm{C}}_4{\text{HF}}_7{\mathrm{O}}_4$	39492-88-1	50892351	244.9691	3	6
PFO3OA	Perfluoro-3,5,7-trioxaoctanoic acid	${\mathrm{C}}_5{\text{HF}}_9{\mathrm{O}}_5$	39492-89-2	20892348	310.9608	4	8
PFO4DA	Perfluoro-3,5,7,9-butaoxadecanoic acid	${\mathrm{C}}_6{\text{HF}}_{11}{\mathrm{O}}_6$	39492-90-5	90723993	376.9525	5	10
PFO5DoA	Perfluoro-3,5,7,9,11-pentaoxadodecanoic acid	${\mathrm{C}}_7{\text{HF}}_{13}{\mathrm{O}}_7$	39492-91-6	50723994	442.9442	6	12
NVHOS	1,1,2,2-Tetrafluoro-2-(1,2,2,2-tetrafluoroethoxy)ethanesulfonic acid	${\mathrm{C}}_4{\mathrm{H}}_2{\mathrm{F}}_8{\mathrm{O}}_4\mathrm{S}$	801209-99-4	80904754	296.9473	4	6
Nafion by-product 1	Perfluoro-3,6-dioxa-4-methyl-7-octene-1-sulfonic acid	${\mathrm{C}}_7{\text{HF}}_{13}{\mathrm{SO}}_5$	29311-67-9	30892354	442.9264	7	10
Nafion by-product 2	Perfluoro-2-{[perfluoro-3-(perfluoroethoxy)-2-propanyl]oxy}ethanesulfonic acid	${\mathrm{C}}_7{\mathrm{H}}_2{\mathrm{F}}_{14}{\mathrm{SO}}_5$	749836-20-2	10892352	462.9327	7	10
Legacy PFAS
PFBA	Perfluorobutanoic acid	${\mathrm{C}}_4{\text{HF}}_7{\mathrm{O}}_2$	375-22-4	4059916	212.9792	3	4
PFPeA	Perfluoropentanoic acid	${\mathrm{C}}_5{\text{HF}}_9{\mathrm{O}}_2$	2706-90-3	6062599	262.9760	4	5
PFHxA	Perfluorohexanoic acid	${\mathrm{C}}_6{\text{HF}}_{11}{\mathrm{O}}_2$	307-24-4	3031862	312.9728	5	6
PFHpA	Perfluoroheptanoic acid	${\mathrm{C}}_7{\text{HF}}_{13}{\mathrm{O}}_2$	375-85-9	1037303	362.9696	6	7
PFOA	Perfluorooctanoic acid	${\mathrm{C}}_8{\text{HF}}_{15}{\mathrm{O}}_2$	335-67-1	8031865	412.9664	7	8
PFNA	Perfluorononanoic acid	${\mathrm{C}}_9{\text{HF}}_{17}{\mathrm{O}}_2$	375-95-1	8031863	462.9632	8	9
PFBS	Perfluorobutane sulfonic acid	${\mathrm{C}}_4{\text{HF}}_9{\mathrm{SO}}_3$	375-73-5	5030030	298.9429	4	5
PFHxS	Perfluorohexane sulfonic acid	${\mathrm{C}}_6{\text{HF}}_{13}{\mathrm{SO}}_3$	355-46-4	7040150	398.9366	6	7
PFOS	Perfluorooctane sulfonic acid	${\mathrm{C}}_8{\text{HF}}_{17}{\mathrm{SO}}_3$	1763-23-1	3031864	498.9302	8	9
6:2 FTS	6:2 fluorotelomer sulfonate	${\mathrm{C}}_8{\mathrm{H}}_5{\mathrm{F}}_{13}{\mathrm{SO}}_3$	27619-97-2	6067331	426.9679	6	9

Note: CASN, Chemical Abstracts Services Number; EPA, Environmental Protection Agency; GenX, hexafluoropropylene oxide dimer acid.

^a U.S. EPA CompTox Chemistry Dashboard (https://comptox.epa.gov/dashboard).

^b DTXSID is a unique substance identifier used in the U.S. EPA CompTox Chemistry Dashboard (Williams et al. 2017).

^c Includes carbon, oxygen, and sulfur atoms in the fluoroalkyl chain but does not include oxygen atoms in the anionic group (i.e., does not include O in carboxylic acid).