Table 5.

FFR media layer hydrophobicity

FFR model	Total layers	Outer layer	Middle layers	Inner layer
N95 FFRs
N95-A	4	—	Second, —	+
			Third, —
N95-B	2	+/—	No middle layer	—/+
N95-C	5	Plastic webbing	Second, —	—
			Third, —
			Fourth, plastic webbing
Surgical N95 respirators
SN95-D	5	—	Second, —	—
			Third, —
			Fourth, —
SN95-E	5	—	Second, —	—
			Third, —
			Fourth, —
SN95-F	4	—	Second, —	+
			Third, —
P100 FFRs
P100-G	5	—	Second, —	+
			Third, —
			Fourth, —
P100-H	12	Plastic webbing	Second, —	—
			Third, —
			Fourth, —
			Fifth, —
			Sixth, plastic webbing
			Seventh, —
			Eighth, —
			Ninth, —
			10th, —
			11th, plastic webbing
P100-I	6	+	Second, —	+
			Third, —
			Fourth, —
			Fifth, —

—, both sides of layer are hydrophobic; +, both sides of layer are hydrophilic; +/—, outer side of layer is hydrophilic and inner side of layer is hydrophobic; —/+, outer side of layer is hydrophobic and inner side of layer is hydrophilic; plastic webbing, not tested.