1. Respiratory Protection in Workplace
A. H. Mehrparvar, MD
Occupational Medicine department
Yazd University of Medical Sciences

2. Airborne contaminants
Particulate (aerosol)
Dust
Mist
Smoke
Gas
Vapor

3. Methods of controlling airborne contaminants
Engineering controls (elimination of the hazard)
substitution
Isolation
vetilation
Administrative controls
Personal protective devices

4. Respiratory personal protective devices (respirators)
used to protect against inhaled agents or to improve the quality of inhaled air
An effective component of a worker protection program
Used for protection against chemical agents (e.g., asbestos, lead), and biologic agents

5. Use of Respirators not the method of choice for controlling exposures
completely dependent on voluntary compliance by the worker
requires an ongoing multifaceted program to ensure proper maintenance and utilization

6. When respirators are needed?
when the work is of a varied nature, preventing the construction of adequate engineering controls
during maintenance and repair operations when ventilation controls are disengaged or nonoperative.
when relatively infrequent operations are conducted (e.g., transfers of liquid raw materials).
for emergency and unplanned events (e.g., as part of the emergency response to a spill) or when the agent is unknown.
when product substitutions or engineering controls are not financially feasible.

7. Different kinds of respirators
(a) air-purifying respirators use ambient air and filter or adsorb the contaminants
(b) atmosphere-supplying
Most respirators in use are air-purifying respirators.
Generally, atmosphere-supplying respirators provide a higher level of protection.

8. Air-purifying respirators
decrease contaminant levels by several mechanisms:
Filtration
Electrostatic characteristics
Sorbent respirators

9. Air- purifying respirators
Mechanical filter
Chemical-cartridge respirator
Gas mask
Powered air-purifying respirator

10. Mechanical-filter respirator
For particulates
3 kinds:
N (Not resistant to oil)
R (Resistant to oil)
P (oil Proof)
efficacy 95 99
100

11. Chemical-cartridge respirator
For vapors and gases
Cartridge contains chemical to absorb gases and vapors

12. Gas mask Designed for: Full face
Organic vapors and gases
Alkaline gases
Acid gases
Pesticides
Paint vapors
Radioactive particulates
Dusts
Fumes
Mists
Full face
Use a canister (sorbent: 2-10 times a cartridge)

13. Powered air-purifying respirator (PAPR)
Used for particulates, gases and vapors

14. Atmosphere -supplying
Self-contained breathing apparatus (SCBA)
Air line: air via a hose
Combined air line with backup tank

15. SCBA

16. Airline

17. Combination

18. Atmosphere -supplying
Continuous flow
Demand: air flow only during inspiration
Pressure demand: attempts to maintain mask pressure positive throughout respiration

19. Mask type Quarter mask Half mask Full-face mask Other (e.g., air hat)

20. Half Mask
Full Face

21. Fit type
Tight fitting
Loose fitting

22. Tight-fitting
respirator

23. Loose fitting- PAPR helmet

24. Respirator efficacy
The overall efficacy of the respirator is described by protection factor.
Protection factor: the ratio of the contaminant concentration outside the mask to the concentration inside the mask.
Assigned protection factor (APF)
Measured protection factor (MPF)
Workplace protection factor (WPF)
Usually MPF>APF>WPF

25. Fit Testing and Checking
Every time a user dons a respirator, should perform a fit check
Typically for the first time
Qualitative and quantitative fit tests
Qualitative: detection of a tracer material by the subject.
Quantitative: concentration of a marker substance inside and outside the mask is measured under laboratory conditions for the specific user.

26. Occupational Respiratory Protection Program
Assessment of whether respirators are needed
Exposure assessment
Respirator selection
Medical assessment of users
Training
Cleaning and maintenance
Program audit

27. Respirator Selection Two factors inform respirator selection:
exposure situation per se
worker medical condition
Worker preferences

28. Sequence of activities
Should respirators be used at all?
What are the exposures of concern?
What degree of contaminant reduction is necessary?
permissible exposure level (PEL).
The ratio of the actual workplace exposure level to the permissible exposure defines the degree of reduction that the respirator must afford.
the 8-hour time-weighted average (TWA)
short-term exposure limits (STEL)

29. What safety factor is necessary?
A safety factor of tenfold is added
Greater safety factors are needed with highly toxic agents on unpredictable exposures.
single-use disposable respirators have a maximum assigned protection factor of 10 ppm
The fit test may misestimate the actual workplace protection by a factor of ten.
Meaningful fit testing for single-use respirators may not feasible since their protection factor is only ten at most.

30. Does the agent have good warning properties?
Is there an immediately dangerous to life and health‌ (IDLH) situation?
an atmosphere-supplying rather than an air-purifying respirator is generally required.
In particularly hazardous situations, dual protection is necessary to ensure safety
a full-face mask with positive pressure mode operation is employed to avoid inward movement of contaminants during inspiration.
Does the agent have good warning properties?
End-of-service-life indicators (if available) are necessary if air-purifying respirators are employed with agents with poor warning properties.
What respirator types are compatible with the work situation?
Air-line respirators cannot be used where considerable mobility is necessary.

31. Can the individual worker safely and effectively use the respirator?
Will the worker actually use the device when needed?
What can be afforded?
How do respirators integrate with other protective measures (e.g., protective suits)?
Respirator programs must be periodically evaluated and adjusted to be effective in real-life situations.

32. ratio of workplace air concentration to the occupational exposure level (e.g., PEL) defines the minimum degree of protection to be afforded, and greater respiratory protection may be needed occasionally.
physical state of an inhaled agent
Particle size
greater degree of respiratory protection for small-size particles (e.g., fumes)
For fibers, the dimensions and charge affect uptake and clearance
Greater degrees of respiratory protection for longer duration of exposure
The level of exertion
Personal susceptibility

33. Medical evaluation for respirator use
Prior to respirator use
Periodically during use
Upon change in health status
When respirator use problems are suspected

34. A questionnaire about respiratory and other health conditions, prior to use of respirators
Medical examination
In some circumstances, a limited exercise test
In marginal cases, observation of the worker using the respirator in the workplace or during work simulation may be needed.

35. Periodic evaluation of users is also advisable.
For special examinations of selected individuals who have expressed difficulty with respirator use, more intensive assessment of the user is warranted.

41. Negative pressure respirators
Half-face cartridge respirator
Full-face cartridge respirator

42. N95 Particulate respirator

43. Filters and cartridges

44. What are the ten parts of a respirator program?
1. Administrator of the Program
2. Medical Evaluation
3. Selection of Respiratory Protection-
Choose the right respirator to protect from contaminant-consult with EH&S.
Respirators must be NIOSH approved.
Evaluate workplace exposure, assume IDLH if contaminant is not known.
Air purifying respirators cannot be used in IDLH atmospheres.

45. 4. Training
Initial training required with periodic refresher training every year. The training shall encompass the following:
Why the respirator is necessary and how improper fit, usage, or maintenance can compromise the protective effect of the respirator;
What the limitations are
Use of respirator effectively in emergencies, including situations in which the respirator malfunctions;
How to inspect, put on and remove, use, check the seals of the respirator
Maintenance and storage procedures
How to recognize medical signs and symptoms that may limit or prevent the effective use of respirators

46. 5. Fit testing 6. Inspection & care
for all tight fitting respirators annually, or if changes occur to facial features, weight gain/loss, eyewear changes, fitcheck fails
6. Inspection & care
inspect before each use
replace defective parts immediately

47. 7. Cleaning
after each use, disassemble and thoroughly clean and disinfect respirator
8. Use
inspect before using, proper storage, positive/negative fit check before each use,

48. 9. Review
Periodic audits of the UR Respiratory Protection Program
10. Record Keeping
Medical certifications
Training records
Fit test records
Air monitoring records

50. Types of Fit Tests Qualitative: Quantitative:
Test agent directed around the head of the respirator wearer
If user can detect agent, test is failed
Quantitative:
Test atmosphere
Quantifies respirator fit using instrumentation to determine the amount of leakage into the respirator facepiece

51. Qualitative Fit Test Quantitative Fit Test Banana oil Irritant smoke
Saccharin challenge
Bitrex solution
Quantitative Fit Test
Expensive machinery
Fit Factors
Outside to inside concentration
Standard prohibits facial hair which interferes with face - to - facepiece seal or valve function

52. ASSIGNED PROTECTION FACTOR TABLE Air-Purifying Respirators
Quarter Mask
APF=5
Filtering Facepiece
APF=10
Elastomeric Half Mask
APF=10
Full-Face Respirator APF=50

53. ASSIGNED PROTECTION FACTOR TABLE Powered Air-Purifying Respirators
Half Mask
APF=50
Hood/Helmet
APF=25/1,0004
Full-Face
APF=1,000
4Must be proven to provide APF of 1,000 or be treated as Loose-fitting Facepiece PAPR with APF=25.
Loose-fitting Facepiece
APF=25

54. ASSIGNED PROTECTION FACTOR TABLE
Demand Supplied-Air Respirators
Full Face
APF=50
Half Mask
APF=10

55. ASSIGNED PROTECTION FACTOR TABLE
Pressure Demand Supplied-Air Respirators
Half Mask
APF=50
Full Face
APF=1,000

56. ASSIGNED PROTECTION FACTOR TABLE
Continuous Flow Supplied-Air Respirators
Hood/Helmet
APF=25/1,0004
Half Mask
APF=50
Full Face
APF=1,000
4Must be proven to provide APF of 1,000 or be treated as Loose-fitting Facepiece SAR with APF=25.
Loose-fitting Facepiece APF=25

57. ASSIGNED PROTECTION FACTOR TABLE
Demand Self Contained Breathing Apparatus
Half Mask APF=10
Full Face APF=50
Helmet/Hood
APF=50

58. ASSIGNED PROTECTION FACTOR TABLE
Hooded Demand Self Contained Breathing Apparatus
The demand unit is Draeger’s Air Boss Guardian, which consists of a hood with an inner nose cup with 30 minute air supply. Neck seal forms gas-tight seal.
Per NIOSH, fit testing requirements apply.
Fit Test adapter, P/n for fit testing with PortacountTM Plus

59. ASSIGNED PROTECTION FACTOR TABLE
Pressure Demand Self Contained Breathing Apparatus
Helmet/Hood
APF=10,000
Not NFPA compliant
Full Face APF=10,000
Includes closed circuit SCBA

60. ASSIGNED PROTECTION FACTOR TABLE
Pressure Demand Self Contained Breathing Apparatus
NIOSH certified the tight-fitting hooded Survivair Puma respirator as a pressure-demand SCBA with 30, 45, or 60 min air supply. Has a nosecup.
Inappropriate Marketing
NIOSH warns that facial hair cannot
interfere with neck or nosecup seal.
Fit test adapter for qualitatively fit testing Puma

61. Combination Respirators
Not in APF Table
When using a combination respirator ensure that the APF is appropriate to the mode of operation in which the respirator is being used [paragraph (d)(3)(i)(A)].
Full Face PD Airline APF = 1,000
Full Face Air-purifying APF = 50
Preamble states: “…the combination pressure- demand full facepiece SAR with auxiliary SCBA respirator is equivalent to an SCBA, and, therefore, the APF for an SCBA applies.