Table 4.

Exposures to a PFOS and PFHxS mixture were prepared to replicate the contribution of these compounds in AFFF dilutions.

Combined PFOS and PFHxS (mg/L)	PFOS contribution (mg/L)	PFHxS contribution (mg/L)	Relative % AFFF
0	0	0	0	0
5.11	4.41	0.70	0.0014	$1.41\times {10}^{-3}$
10.23	8.82	1.41	0.0028	$2.81\times {10}^{-3}$
20.46	17.64	2.81	0.0056	$5.63\times {10}^{-3}$
40.91	35.29	5.63	0.0113	$1.13\times {10}^{-2}$
81.83	70.58	11.25	0.0225	$2.25\times {10}^{-2}$
163.65	141.15	22.50	0.0450	$4.50\times {10}^{-2}$
327.30	282.30	45.00	0.0900	$9.00\times {10}^{-2}$

Note: These dilutions were made keeping the PFOS:PFHxS ratio (6.27:1) as defined in the legacy 3% AFFF sample. Single exposures to PFOS and PFHxS at these defined concentrations were completed alongside the mixture exposures. AFFF, aqueous film-forming foam; PFOS, perfluorooctanesulfonic acid; PFHxS, perfluorohexanesulfonic acid.