PMID- 24148765
OWN - NLM
STAT- MEDLINE
DCOM- 20150810
LR  - 20140214
IS  - 1475-3162 (Electronic)
IS  - 0003-4878 (Linking)
VI  - 58
IP  - 2
DP  - 2014 Mar
TI  - Contribution of breathing frequency and inhalation flow rate on performance of 
      N95 filtering facepiece respirators.
PG  - 195-205
LID - 10.1093/annhyg/met051 [doi]
AB  - The investigation of particle penetration through filtering facepiece respirators 
      under cyclic flows is very necessary because cyclic flows represent actual 
      breathing flow patterns. This article reports the development of a procedure to 
      investigate the individual impact of breathing frequency and flow rate on the 
      performance of N95 filtering facepiece respirators. Experiments were performed 
      for two peak inhalation flows (PIFs; 135 and 360 l min(-1)) and two breathing 
      frequencies [24 and 42 breaths per minute (BPM)] for a total of four cyclic flows 
      (Flow A: 135 l min(-1) and 24 BPM; Flow B: 135 l min(-1) and 42 BPM; Flow C: 360 
      l min(-1) and 24 BPM; and Flow D: 360 l min(-1) and 42 BPM). Each experiment was 
      performed using two different set-ups: the first set-up included both inhalations 
      and exhalations through the filter media and test chamber, while with the second 
      set-up, only inhalation flows were considered. The results showed that, for the 
      most penetrating particle size range, an increase in both PIF and breathing 
      frequency could potentially enhance the penetration with both set-ups; however, 
      the effect of PIF was observed to be much more pronounced than that of frequency. 
      The results indicated that with both set-ups, when the PIF was increased from 135 
      to 360 l min(-1) (for the given frequency: 24 or 42 BPM), an increase of up to 
      139-152% in penetration was observed. On the other hand, only a 10-16% increase 
      in penetration occurred when the frequency was changed from 24 to 42 BPM (for a 
      given PIF: 135 or 360 l min(-1)). This suggests that, from low to high 
      respiratory efforts, a huge portion of penetration enhancement is due to PIF 
      variations and only a small portion is contributed by frequency variations.
FAU - Mahdavi, Alireza
AU  - Mahdavi A
AD  - Department of Building, Civil and Environmental Engineering, Concordia 
      University, Montreal, Quebec H3G 1M8, Canada;
FAU - Bahloul, Ali
AU  - Bahloul A
FAU - Haghighat, Fariborz
AU  - Haghighat F
FAU - Ostiguy, Claude
AU  - Ostiguy C
LA  - eng
PT  - Journal Article
DEP - 20131022
PL  - England
TA  - Ann Occup Hyg
JT  - The Annals of occupational hygiene
JID - 0203526
RN  - 0 (Air Pollutants, Occupational)
SB  - IM
MH  - Air Pollutants, Occupational
MH  - Algorithms
MH  - Filtration/*instrumentation
MH  - Humans
MH  - Inhalation
MH  - Inhalation Exposure/prevention & control
MH  - Manikins
MH  - Materials Testing/methods
MH  - Occupational Exposure/prevention & control
MH  - Particle Size
MH  - Respiratory Protective Devices/*standards
MH  - *Respiratory Rate
OTO - NOTNLM
OT  - breathing frequency
OT  - cyclic flow
OT  - filtering facepiece respirators
OT  - peak inhalation flow
OT  - penetration
OT  - ultrafine particles
EDAT- 2013/10/24 06:00
MHDA- 2015/08/11 06:00
CRDT- 2013/10/24 06:00
PHST- 2013/10/24 06:00 [entrez]
PHST- 2013/10/24 06:00 [pubmed]
PHST- 2015/08/11 06:00 [medline]
AID - met051 [pii]
AID - 10.1093/annhyg/met051 [doi]
PST - ppublish
SO  - Ann Occup Hyg. 2014 Mar;58(2):195-205. doi: 10.1093/annhyg/met051. Epub 2013 Oct 
      22.