Using CO2 to Determine Inhaled Contaminant Volumes and Blower Effectiveness in Several Types of Respirators

Table 1

Summary of results.

Respirator	Blower flow rate (L/min)	Exhaled volume (L)	CO2  ratio	Wearer protection factor	Leakage volume (L)	Inhaled volume (L)	Blower contribution  (L)	Total blower volume  (L)	Blower effectiveness
Racal PAPR	191–200	2.41	0.84	1.2	2.02	2.66	0.43	2.42	0.18
Centurion PAPR	88–101	2.37	0.25	4	0.60	2.66	1.99	1.17	1.70
3M hood PAPR	157–161	2.39	0	∞	0	2.63	2.63	1.87	1.41
3M PAPR	121–278	2.42	0	∞	0	2.62	2.62	2.51	1.04
SE 400 PAPR	64–322	2.32	0	∞	0	2.58	2.58	2.90	0.89
SE 400 APR (blower off)	(0–284)	2.37	0.048	21	0.11	2.58	2.46	2.50	0.98
FRM 40 APR	0–289	2.37	0.057	18	0.14	2.62	2.47	2.51	0.99