Face Masks and Respirators: Protection Factors, Selection, Fit Testing, and Respirator Demonstrations

Course Presenters (alphabetical order) Dr. Paul A. Jensen Centers for Disease Control and Prevention USA Dr. Grigory V. Volchenkov Vladimir Oblast TB Dispensary Russian Federation

Hierarchy of Infection Control

Personal Protective Equipment Respirators vs. Masks

Surgical Masks

Personal Protective Equipment Masks (patients and HCWs for large droplets) Respirators (HCWs)

Negative Pressure Respirator A respirator in which the air pressure inside the facepiece is negative during inhalation with respect to the ambient air pressure outside the respirator

Air-Purifying Respirator (APR) A respirator with an air-purifying filter, cartridge, or canister that removes specific air contaminants by passing ambient air through the air-purifying element

Filter A component used in respirators to remove solid or liquid aerosols from the inspired air. Also called air purifying element

High Efficiency Particulate Air (HEPA) Filter Filter that is at least 99.97% efficient in removing particles of 0.3 micrometers in diameter Equivalent CDC-NIOSH 42 CFR 84 particulate filters are the N100, R100, and P100 filters

CDC-NIOSH Standards

Selection of N-, R-, and P- Series Filters If no oil particles are present in the work environment, use a filter of any series. If oil particles are present, use and R- or P- series filter Selection of filter efficiency depends on size of particulate and how much filter leakage is acceptable

N95 Respirators N95 disposable respirators are generally acceptable for most TB situations Higher level of protection may be prudent during high risk procedures Sputum induction Bronchoscopy Autopsy

CEN Standards Initial filter penetration (NaCl & paraffin oil) Total inward leakage Maximum breathing resistance Loading test

CEN Standards (Initial Filter Penetration) NaCl < 20% = P1 < 6% = P2 < 3% = P3 Paraffin Oil NA = P1 < 2% = P2 < 1% = P3

CEN EN 1822 Filter Filtration Class Efficiency (%) Penetration (%) H10 85 15 H11 95 5 H12 99,5 0,5 H13 99,95 0,05 H14 99,995 0,005 U15 99,999 5 0,000 5 U16 99,999 95 0,000 05 U17 99,999 995 0,000 006

CEN Standards Total inward leakage < 25% = FFP1 < 11% = FFP2 < 5% = FFP3

CEN Respirators FFP2 or FFP3 disposable respirators are generally acceptable for most TB situations Higher level of protection may be prudent during high risk procedures Sputum induction Bronchoscopy Autopsy

http://www.cdc.gov/niosh/npptl/topics/respirators/disp_part/respsource.html#sect1

Other Classes of Respirators Powered air-purifying respirator Atmosphere-supplying respirators Supplied air respirator Self-contained breathing apparatus Emergency escape

Respirator Program Elements Training Medical evaluation Fit testing Selection Use Maintenance and care Program evaluation

Why fit testing? Ensure that each person receives an adequate fit while wearing a respirator Determine appropriate make/model Determine appropriate size Ensure proper seal between respirator and wearer

Fit Testing Uses a challenge agent to evaluate the fit of a respirator on an individual

Fit Testing Employees should pass an appropriate qualitative fit test or quantitative fit test: prior to initial use whenever a different respirator facepiece (size, style, model or make) is used, and periodically thereafter Additional fit test whenever changes in physical condition or job description that could affect respirator fit are noticed or reported

Physical Factors Contributing to Poor Fitting Respirators Weight loss/gain Facial scarring Changes in dental configuration (dentures) Facial hair Cosmetic surgery Excessive makeup Mood of worker (smiling/frowning) Body movements

Sources of Facepiece Leakage Through air-purifying element Through exhalation valve Around facepiece/skin interface

Qualitative Fit Tests A pass/fail fit test to assess the adequacy of respirator fit that relies on the individual s response to the test agent

Qualitative Fit Tests Began with US Bureau of Mines respirator certification program Coal dust test Subject donned respirator Coal dust blown into face of subject Subject removed respirator Respirator failed if dust streaks were noticed

Coal Dust Test

Qualitative Fit Tests Two methods commonly recognized and accepted Saccharin Bitrex (Denatonium benzoate)

Saccharin and Bitrex Can be used for all particulate respirators (i.e., 95-, 99-, 100-series, FFP2, and FFP3) Uses subject s sense of taste aerosolized saccharin (>2μm) Requires the use of small test hood

Qualitative Fit Tests Advantages No expensive equipment Tests easy to conduct Disadvantages Rely on subject s subjective response May not be reliable

Quantitative Fit Tests An assessment of the adequacy of respirator fit by numerically measuring the amount of leakage into the respirator

Qualitative Fit Factor An estimated/assumed value used to assess the quality of respirator fit Fit Factor C FIT TEST SOLUTION C SENSITIVITY SOLUTION

TSI PortaCount Plus

Particle Counting Instrument Subject wears probed respirator at ambient conditions Aerosol generator (NaCl) can be used as supplement Counts particles inside and outside facepiece Care must be taken to ensure no particles generated by subject

Quantitative Fit Tests Advantages Does not rely on subject response More reliable Disadvantages Expensive equipment needed Requires trained personnel Requires probes/adapters (not CNP)

Fit-Test Comparison Results Method Alpha Error Beta Error Accuracy Goal <= 50% <=5% Bitrex 51% 11% Saccharin 56% 9% N95 Companion 57% 9% CDC/NIOSH 75% 4% Proposed Method 1 1 Not for general use

Achieving APF Cummulative Distribution of PFs With & Without Fit Testing Percentage of PFs < PF Shown 100% 80% 60% 40% 20% 0% 1 10 100 1000 Protection Factor, PF

Design versus Fit-Testing 100 Percentage of subjects achieving SWPFs < SWPF indicated 80 60 40 20 0 Three poorest designed models with all subjects passing Bitrex Fit-Test Three best designed 3 models without Bitrex Fit-Test 1 10 100 1000 Simulated Workplace Protection Factor (SWPF)

Selection of Respirators Provide an appropriate respirator based on: Respiratory hazards to which the worker is exposed and Workplace and user factors that affect respirator performance and reliability Design to fit!

Selection of Respirators

3M 1860 Use Instructions Before use for respiratory protection, a written respiratory protection program must be implemented... Respirator may be used until damaged, breathing becomes difficult, or contaminated with blood or body fluids Filtering facepieces are to be inspected prior to each use...

Reuse of Respirators The Russian experience Three-month study Fit tested all participants Unlimited supply of respirators HCWs recorded hourly and calendar time-of-use ~20% of HCWs failed the fit test with used respirator(s) 1 of 200+ respirators failed >95% and all passed >94% test

What Can You Do? Be proactive Research and select well-designed respirators Take care of your respirator Decontamination Cleaning Storage No! No! Clean & dry place! Take care when reusing respirator closely monitor service life Dispose of respirator if you question its performance

Summary Good-fitting respirators better than poor after fit-testing Most protection provided by: Well-designed respirators Performing fit-testing Comfort and usability issues critical! Reuse with caution

Thank you! PJensen@cdc.gov vlchnkv@yahoo.com