Table 1.

Specifications of test products and parameters for aqueous smoke extracts (AqE) generation.

	3R4F	e-cig	HTP	nic
Product	3R4F reference cigarette	VYPE ePen 2.0	iQOS	nicotine solution
Manufacturer	University of Kentucky, Lexington, KY, USA	British American Tobacco, London, UK	Philip Morris International, Lausanne, Switzerland	Sigma-Aldrich, Munich, Germany
Consumables	n/a	Blended Tobacco e-liquid	Marlboro Essence HeatSticks	n/a
Nicotine content	0.73 mg/cig	18.00 mg/ml	0.37 mg/stick	1.00 g/ml
Puff Regime	HCI	CRM No. 81	HCIm	n/a
Puff Volume	55 ml	55 ml	55 ml	n/a
Puff Duration	2 s	3 s	2 s	n/a
Puff Frequency	30 s	30 s	30 s	n/a
Puff Profile	Bell	Square	Bell	n/a
Vent Blocking	Yes	n/a	No	n/a
Number of Puffs	10 puffs	10 puffs	10 puffs	n/a
Capture Solvent	M199 w/o Phenol red	M199 w/o Phenol red	M199 w/o Phenol red	n/a
Volume of Capture Solvent	20 ml	20 ml	20 ml	n/a
Settings	90° vaping angle	High power (4.4 W); 4 s Button activated (1 s pre-activation followed by 3 s activation during puffing); 45° vaping angle	4 s Button activated followed by 20 s pre-heating (no button pressed) prior 1st puff; 90° vaping angle	n/a