Table 4.

Comparison of free concentrations as a percent of total concentration (μg/L) for select phenols and parabens within complete study sample and subgroups [n (%)].^a

Percentage of free/total	Bisphenol A			Butyl paraben			Methyl paraben			Propyl paraben			Benzophenone-3
	Complete sample (n = 45)	Random sample (n = 30)	High-BPA subgroup (n = 15)	Complete sample (n = 45)	Random sample (n = 30)	High-BPA subgroup (n = 15)	Complete sample (n = 45)	Random sample (n = 30)	High-BPA subgroup (n = 15)	Complete sample (n = 45)	Random sample (n = 30)	High-BPA subgroup (n = 15)	Complete sample (n = 45)	Random sample (n = 30)	High-BPA subgroup (n = 15)
Missing	2 (1.5)	1 (1.1)	1 (2.2)	2 (1.5)	1 (1.1)	1 (2.2)	2 (1.5)	1 (1.1)	1 (2.2)	2 (1.5)	1 (1.1)	1 (2.2)	2 (1.5)	1 (1.1)	1 (2.2)
Free < LOD	0 (0.0)	0 (0.0)	0 (0.0)	0 (0.0)	0 (0.0)	0 (0.0)	0 (0.0)	0 (0.0)	0 (0.0)	0 (0.0)	0 (0.0)	0 (0.0)	120 (88.9)	80 (88.9)	40 (88.9)
0–5%	0 (0.0)	0 (0.0)	0 (0.0)	6 (4.4)	5 (5.6)	1 (2.2)	130 (96.3)	87 (96.7)	43 (95.6)	71 (52.6)	51 (56.7)	20 (44.4)	9 (6.7)	6 (6.7)	3 (6.7)
> 5–10%	1 (0.7)	1 (1.1)	0 (0.0)	18 (13.3)	10 (11.1)	8 (17.8)	2 (1.5)	1 (1.1)	1 (2.2)	31 (23.0)	17 (18.9)	14 (31.1)	2 (1.5)	2 (2.2)	0 (0.0)
> 10–20%	2 (1.5)	1 (1.1)	1 (2.2)	21 (15.6)	16 (17.8)	5 (11.1)	1 (0.7)	1 (1.1)	0 (0.0)	16 (11.9)	12 (13.3)	4 (8.9)	1 (0.7)	1 (1.1)	0 (0.0)
> 20–50%	16 (11.9)	13 (14.4)	3 (6.7)	38 (28.2)	28 (31.1)	10 (22.2)	0 (0.0)	0 (0.0)	0 (0.0)	7 (5.2)	3 (3.3)	4 (8.9)	1 (0.7)	0 (0.0)	1 (2.2)
> 50%	114 (84.4)	74 (82.2)	40 (88.9)	50 (37.0)	30 (33.3)	20 (44.4)	0 (0.0)	0 (0.0)	0 (0.0)	8 (5.9)	6 (6.7)	2 (4.4)	0 (0.0)	0 (0.0)	0 (0.0)
LOD, limit of detection. aComplete sample (n = 45 participants, 135 samples); random sample: randomly selected participants with no previously measured BPA concentrations (n = 30 participants, 90 samples); high-BPA subgroup: participants with high BPA concentrations in a previous random selection (n = 15 participants, 45 samples).