Nanoparticle Leakage Through Staple Punctures in N95 Single Use Filtering Facepiece Respirators

Details

• Personal Author:
  Hammad Y ; Medina D
• Description:
  Objective: NIOSH-approved N95 filtering facepiece respirators (FFPR) are widely used in industry where personnel are exposed to aerosolized particles that can produce adverse health effects. The manufacturing processes for some N95 FFPR attach the head straps by stapling them directly onto to the respirator filter. This method punctures the filter media and creates an open space between the staple and the filter where leakage of particles can occur. This study evaluates the effect of stapled head straps on respirator efficiency using 5 different N95 FFPR models challenged with 30 to 500 nm polystyrene latex spheres when the stapled head straps are left intact, stretched, and the staple punctures sealed. Methods: A polystyrene latex aerosol is generated by a 3-jet Collison nebulizer operating at 20 psi. The aerosol cloud is dried and charge neutralized using a silica gel desiccant and a radioactive beta source (Kr85). The aerosol is introduced and mixed in the top part of the testing chamber above the respirator test assembly. A Scanning Mobility Particle Sizer is used to measure particle concentration inside and outside the respirator test assembly and this ratio is used to determine respirator efficiency. Results: N95 FFPR efficiencies differed by model, particle size, and staple condition. There is significant difference between different models of FFPR and among the efficiencies of a single model when the head straps are left intact, stretched, and when the staple puncture is sealed. The lowest efficiencies were observed when head straps were stretched and at the 50-60 nm particle sizes. For some FFPRs, efficiencies were below 95%. Conclusions: The study suggests that nanoparticle concentrations inside N95 FFPRs with stapled head straps (attached to the filter media) are expected to be higher than models with head straps attached using a method that does not puncture the filter. [Description provided by NIOSH]
• Subjects:
  Aerosols Environmental Exposure Occupational Health Particulate Matter Personal Protective Equipment Respiratory Protective Devices Safety
• Keywords:
  Aerosol Particles Exposure Levels Filters Hazards Health Effects Models N95 Filtering Facepiece Respirators Nanoparticles Particle Size Respirator Testing
• Publisher:
  American Industrial Hygiene Association
• Document Type:
  Text
• Funding:
  Grant
• Genre:
  Abstract or Summary
• Place as Subject:
  Florida ; OSHA Region 4
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Topic:
  Workplace Safety & Health
• Location:
  North America
• NIOSHTIC Number:
  nn:20063356
• Citation:
  AIHce 2013: American Industrial Hygiene Conference and Exposition, May 18-23, 2013, Montreal, Quebec. Falls Church, VA: American Industrial Hygiene Association, 2013 May; :139
• CAS Registry Number:
  Polystyrene (CAS RN 9003-53-6)
• Federal Fiscal Year:
  2013
• Performing Organization:
  Sunshine Education and Research Center, University of South Florida
• Peer Reviewed:
  False
• Start Date:
  20050701
• Source Full Name:
  AIHce 2013: American Industrial Hygiene Conference and Exposition, May 18-23, 2013, Montreal, Quebec
• End Date:
  20290630
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:e645ef5701b491d4f4e71a74a382d900bcc53340d956e5683f146c6372542238d8a3942b18f9808d30230445cbf0923e4f51b8d76619030331805adf3e663d8e
• Download URL:
  https://stacks.cdc.gov/view/cdc/226434/cdc_226434_DS1.pdf
• File Type:
  [PDF - 974.68 KB ]