Table 2.

Chemical-Specific Parameters used in the Rat and Human CFD/PBPK Model

Parameter	Acrolein	Source	Acetaldehyde	Source	Formaldehyde	Source
Diffusivity (D—cm2/s)
Air (Dair)	0.105	a	0.124	b	0.150	c
Tissue (Dt)	1.22 x 10−5	a	3.33 x 10−6	d	8.08 x 10−6	e
Blood (Db)	1.22 x 10−5	a	3.33 x 10−6	d	1.62 x 10−5	e
Partition coefficients (P)
Tissue:air (Pta)	88.0	a	224.0 (rat),	d	101.5	f
			190.0 (human)	d
Tissue:blood (Pbt)	1.0	a	1.0	a	1.0	a
Metabolism—Rat
Km1 (µg/l)	0.5	a, g	2.39 x 106	d, h, i	2.13 x 103	j
Vmax1C (µg/l/s)	572.9	a, g	3910	d, h, i	1.0 x 105	h, f, j
				(3050, Olfactory Subepithelium)
Km2 (µg/l)	-	-	441	d, h, i	-	-
Vmax2C (µg/l/s)	-	-	881	d, h, i	-	-
Kf (s−1)	5.0 x 10−2	a	-	-	1.8 x 10−2	j
Metabolism—Human
Km1 (µg/l)	0.5	a, g	3.3 x 106	d	201	h, j
Vmax1C (µg/l/s)	112	a, g	766	d, h	1.96 x 104	h
Km2 (µg/l)	-	-	441	d, h	-	-
Vmax2C (µg/l/s)	-	-	173	d, h	-	-
Kf (s−1)	2.0 x 10−2	a, g	-		1.8 x 10−2	j
VmaxC region-specific adjustment factor
Nose	1.0	g	1.0	g	1.0	g
Mouth, Pharyx, Larynx, Trachea,
Bronchi	0.25	g	0.25	g	0.25	g
Bronchioles	0.5	g	0.5	g	0.5	g
Non-specific binding
Kb (s−1)	–	–	–	–	1.07 × 10−7 (rat and human)	j
Mass-transfer coefficients for non-mucus-coated squamous epithelium (e.g. vestibule)
Ks (cm/s)	7.1 × 10−4	a	1.6 × 10−3	d	0.41	f

^aSchroeter et al. (2008).

^bhttp://www.gsi-net.com/en/publications/gsi-chemical-database.html.

^cEPA (1998)

^dTeeguarden et al. (2008).

^eGeorgieva et al. (2003).

^f Calculated from Kimbell et al. (2001) as described in Methods.

^gFranks (2005) as described in Corley et al. (2012).

^hRecalibrated and rescaled by body weight and respective tissue volumes as described in Methods.

ⁱMorris and Blanchard (1992).

^jConolly et al. (2008).