Table 2.

Summary of test matrix production methods.

	Test exposure matrix
	Total particulate matter	Aqueous extract		Whole aerosol
Aerosol generator	Borgwaldt RM2001 (3R4F cigarette)	Borgwaldt RM20H1	Borgwaldt RM20S1 (3R4F cigarette)	Vitrocell® VC 102
	Cerulean CETI83 (IS1.0(TT) e-cig)		Borgwald LM4E1 (IS1.0(TT) e-cig)
Preparation procedure	TPM/ACM was captured on a Cambridge filter pad from 3R4F and IS1.0(TT) e-cig products.	Aerosol from 8 puffs of a 3R4F cigarette, or 24 puffs of IS1.0(TT) e-cig, was bubbled through 20 mL of cell culture medium in a glass impinger.	WA cytotoxicity assay - for 3R4F exposures, WA was diluted with air, while undiluted aerosol was used for IS1.0(TT) e-cig assessment. Aerosols were delivered to purpose-built Perspex chambers for exposure of H292 lung epithelial cells at the air-liquid interface.	Ames test - WA was undiluted and delivered to a Vitrocell® AMES 4 exposure module for exposure of bacteria at the air–agar interface
	Pads were extracted with DMSO to a concentration of 24 mg/mL (3R4F cigarette), and 60 mg/mL (IS1.0(TT) e-cig).	AqE was made fresh for each individual experiment and diluted in the appropriate culture medium for specific assays
	TPM/ACM was frozen at −80 °C until use.
	Extracts were diluted with cell culture medium to a range of test concentrations

Abbreviations: ACM, aerosol collected mass; AqE, aqueous extract; DMSO, dimethyl sulfoxide; TPM, total particulate matter; WA, whole aerosol.

¹Borgwaldt KC, Hamburg, Germany.

²Vitrocell® systems, Waldkirch, Germany.