PERFLUOROOCTANOIC ACID 1. Exposure Data 1.1 Identification of the agent

1.1.2 Structural and molecular formulae, and relative molecular mass of the straightchain isomer

1.1.1 Nomenclature

F F

F

F

F

F

F

F

O

Chem. Abstr. Serv. Reg. No.: 335-67-1 OH F F F F F F F Chem. Abstr. Serv. Name: Perfluorooctanoic acid Molecular formula: C8HF15O2 IUPAC Name: 2,2,3,3,4,4,5,5,6,6,7,7,8,8,8Relative molecular mass: 414 pentadecafluorooctanoic acid Synonyms: PFOA; pentadecafluoro-1-octan­ - 1.1.3 Chemical and physical properties of the oic acid; pentadecafluoro-n-octanoic acid; pure substance (straight-chain isomer) pentadecaflurooctanoic acid; perfluorocaprylic acid; perfluoroctanoic acid; From HSDB (2014), unless otherwise perfluoroheptanecarboxylic acid; APFO; indicated ammonium perfluorooctanoate Description: White to off-white powder Isomers and Salts: There are 39 possible strucBoiling point: 192.4 °C tural isomers of pentadecafluorooctanoic Melting point: 54.3 °C acid (1 with chain length 8, 5 with chain Density: 1.792 g/cm3 at 20 °C length 7, 13 with chain length 6, 16 with chain length 5, and 4 with chain length 4). These Solubility: 9.5 g/L in water at 25 °C isomers can also exist as the ammonium, Vapour pressure: 0.0023 kPa at 20 °C (extrapsodium, or potassium salt (Nielsen, 2012). olated); 0.127 kPa at 59.25 °C (measured) Fig. 1.1 presents the few isomers and salts (ATSDR, 2009); 0.070 kPa at 25 °C that have Chemical Abstracts Service (CAS) Stability: When heated to decomposition it references. emits toxic vapours of hydrogen fluoride Conversion factor: Assuming normal temperature (25 °C) and pressure (101 kPa), 1 mg/m3 = 16.9 ppm.

1

IARC Monographs – 110 Fig. 1.1 Structures of isomers and salts of perfluorooctanoic acid (PFOA) registered by the Chemical Abstracts Service (CAS) a. PFOA isomers

b. Ammonium salts of PFOA isomers

Carbon chain length and structure COOH

8

CAS registry number

Carbon chain length and structure -

335-67-1

8

COOH NH 4

+

COO -NH 4+

7

COOH

207678-51-1

7

7 7

7

COOH

COOH

705240-04-6 6

COO -NH 4+

COO -NH 4+

CAS registry number 3825-26-1 207678-62-4

19742-57-5

13058-06-5

1144512-18-4 c. Sodium salts of PFOA isomers

7

COOH

7

COOH

909009-42-3

15166-06-0

Carbon chain length and structure 8

COO -Na + COO -Na +

7 6

COOH

COOH

1192593-79-5 7

6

6

COOH

COOH

1144512-36-6

1144512-34-4

6

COO -Na + COO -Na +

COO -Na +

COOH

35605-76-6

8 7

7

Adapted from Nielsen (2012)

2

207678-72-6

646-84-4

18017-22-6

1195164-59-0

d. Potassium salts of PFOA isomers Carbon chain length and structure

6

335-95-5

1144512-35-5 7

6

CAS registry number

COO -K + COO -K +

COO -K +

CAS registry number 2395-00-8 207678-65-7

29457-73-6

Perfluorooctanoic acid

Table 1.1 Selected methods for the analysis of perfluorooctanoic acid (PFOA) Sample matrix

Sample preparation

Assay procedure

Limit of detection

Reference

Drinking-water

Adsorb on polystyrene divinylbenzene; elute methanol; reconstitute in water/methanol with 13C-PFOA internal standard