Personal Protective Equipment

Respirator Selection Principles

1)Select appropriate respirator based on the respiratory hazard 2)The work atmosphere must be evaluated: • Reasonable estimate of employee exposures • Identify contaminant chemical state and physical form • Atmosphere is considered IDLH where the employer cannot identify or reasonably estimate exposure 3) Respirators for IDLH • Full facepiece pressure demand SCBA , minimum 30 minute service life, or • Combination full facepiece pressure demand supplied-air respirator (SAR) with auxiliary self-contained air supply. • Escape-only respirators where appropriate

Estimating a Cartridge's Service Life

1. Conduct Experimantal Tests 2. Use Manufacturer's Recommendation 3. Use Modeling

Cartridge Change-out

1)Change filters when breathing resistance increases 2)Previously, gas/vapor cartridges were changed when the user sensed "breakthrough" • Contaminant must have good "warning properties 3) Now, cartridges must be changed before breakthrough (OSHA 1910.134) • A few cartridges have an End-of-Service Life Indicator (ESLI) • Use a cartridge change schedule

5 Respirator Selection Principle

1)Oxygen Deficiency IDLH 2)Respirators for non-IDLH 3)Respirators for IDLH 4)Select appropriate respirator based on the respiratory hazard 5)The work atmosphere must be evaluated

Air-Purifying Respirators • Filter types

1)Previously, particulate filters were classified by use and efficiency • Dust,fume,mist • High efficiency (HEPA) 2)Now, filters are classified by efficiency and resistance to oil • Prompted by need to protect health care workers from TB

Fit Testing

1)Qualitative Fit Tests • Simple to conduct • For PF<100 2)Quantitative Fit Tests • Fit testing booth and associated equipment • For PF>100

Respirator Programs

• OSHA requires written programs defining the procedures by which respiratory protective equipment is selected, stored, maintained, and repaired • Procedures for determining if persons required to wear respiratory protective equipment are medically fit, trained in its use, and evaluated

Use and Misuse of PPE

• Personal protective equipment is widely used • Frequently inappropriate application or wrong equipment • Specification of wrong PPE may result in higher exposure than use of no PPE • Must know proper uses and limitations

Respiratory Protective Equipment

• Protect the respiratory system from inhalation of airborne contaminants by removing contaminants from the air before they are inhaled • Supplying an independent source of "clean" air • Viewed as control method of last resort in the hierarchy of controls

Fit-Testing Procedures two types of testing :

• Qualitative fit-testing • Quantitative fit-testing

Medical Evaluation

• Required before PPE use • Evaluation by physician or licensed health care professional • Questionnaire or examination as specified in 29 CFR 1910.134(e) • Mandatory exam for positive response to specified questions

Protection Factors

• Respirator performance rated by protection factor • Determined for respirator type PF = [contaminantout]/[contaminantin]

Atmosphere Supplying Respirators

• Self-contained breathing apparatus • Air-line respirators

OSHA User Seal Check Procedures, part 1 • OSHA User Seal Check Procedures (Mandatory)

• The individual who uses a tight-fitting respirator is to perform a user seal check to ensure that an adequate seal is achieved each time the respirator is put on. • Either the positive, negative, or manufacturer's recommended user seal check method shall be used. User seal checks are not substitutes for qualitative or quantitative fit tests.

OSHA User Seal Check Procedures, part 4 Manufacturer's Recommended User Seal Check Procedures

• The respirator manufacturer's recommended procedures for performing a user seal check may be used instead of the positive and/or negative pressure check procedures provided that the employer demonstrates that the manufacturer's procedures are equally effective.

PPE Limitations, part 2

• Training in proper use of PPE is required to achieve maximum possible protection • PPE designed to pass certification test • Need to know limitations of tests • If PPE isn't used, it doesn't work

What doe medical evaluations determine?

• limitations of respirator use by the worker • additional or follow-up medical evaluations • that the worker can use the type of respirator being provided by the employer • that the employer must provide an additional type of respirator • whether the employee is medically fit to use a respirator

True/False • Use NIOSH-certified respirators • NIOSH also certifies a range of PPE

true

Vapor and Gas Removal Mechanisms

• Adsorption • Absorption • Catalyst

Air Purifying Respirator

• Air-purifying elements appropriate to contaminant (filter or adsorbent) • Operates under negative pressure (seal/leaks) • Determination of service life

Powered Air-Purifying Respirator

• Air-purifying elements appropriate to contaminant (filter or adsorbent) • Operates under positive pressure (seal/leaks) • Determination of service life (and associated limitations) • Cannot be used in IDLH environments

Types of Respirators, part 1

• Air-purifying respirators • Particulate-removing • Positive or negative pressure within the mask • Gas-and-vapor-removing • Positive or negative pressure within the mask • Single or multiple use

Fit Testing

• All tight fitting respirators must be fit-tested • Workers must be clean shaven • Qualitative or Quantitative fit test • Pass/fail • Test response to test substance

Training

• Annual; "comprehensive and understandable" • Selection of respirator • Inspection of respirator • Use of respirator • Cleaning of respirator • Storage of respirator

Types of Respirators, part 2

• Atmosphere-supplying respirator • Higher level of protection than air-purifying respirator • Types: • Hose mask

2. Use Manufacturer's Recommendation

• Can result in a more accurate estimate for your particular brand of respirator • Relies on the manufacturer's broad knowledge and expertise • May not be possible if the manufacturer is unable to provide a recommendation • May not account for all workplace and user factors adequately

Conduct Experimental Tests

• Can save money by providing a more accurate service life value instead of relying on conservative assumptions made by other methods • Most reliable method, especially for multiple contaminants • Can be used to validate an existing change schedule • Will likely take time and money to perform the tests

Cartridge Selection

• Cartridges for specific contaminants • Acid gas, organic vapor, ammonia, mercury, • Available in combination w/filters • "Type N" Universal gas mask canister removes a wide range of contaminants

Maintenance and Care

• Cleaning and disinfection • Storage • Inspection • Emergency use • Routine use • Repair

OSHA User Seal Check Procedures, part 2 Positive pressure check

• Close off the exhalation valve and exhale gently into the facepiece. The face fit is considered satisfactory if a slight positive pressure can be built up inside the facepiece without any evidence of outward leakage of air at the seal.

OSHA User Seal Check Procedures, part 3 Negative pressure check

• Close off the inlet opening of the canister or cartridge(s) by covering with the palm of the hand(s) or by replacing the filter seal(s), inhale gently so that the facepiece collapses slightly, and hold the breath for ten seconds. • If the facepiece remains in its slightly collapsed condition and no inward leakage of air is detected, the tightness of the respirator is considered satisfactory.

Air-Purifying Respirators

• Disposable air-purifying respirators • Reusable quarter-face, half-face, or full-face Respirators • Mouthpiece respirator

Legitimate Uses of Respiratory Protection

• Emergency situations • Spill clean-up • Short-term solutions where engineering controls not feasible • Asbestos removal jobs • While controls being installed

Self-Contained Breathing Apparatus

• Flow regime: • Demand • Pressure demand • Continuous flow

Cartridge Change-out • Rule of Thumb is:

• If the chemical's boiling point is > 70 °C and the concentration is less than 200 ppm you can expect a service life of 8 hours at a normal work rate. • Service life is inversely proportional to work rate. • Reducing concentration by a factor of 10 will increase service life by a factor of 5. • Humidity above 85% will reduce service life by 50%

3. Use Modeling

• Inexpensive and takes little time • Modeling support availale, for example Advisor Genius (CDC software) • Not as accurate as experimental testing. May result in a service life estimate that is shorter than it needs to be due to conservative assumptions • Generally limited to single contaminant situations

PPE Limitations, part 1

• Must match PPE to the hazard • Actual performance is always less than that claimed by manufacturer or indicated by testing • Considerable variability among manufacturers • Comfort and ease of use is important

Fit-Testing Procedures

• Normal breathing • Deep breathing • Turning head side to side • Moving head up and down • Talking (reciting the rainbow passage) • Grimace (making faces) • Bending over or jogging in place • Normal breathing

Air-Purifying Respirators • Gas and Vapor Removing Mechanisms

1) Adsorption • Contaminant molecules retained on surface • Activated charcoal, for organic vapors • May be treated with other substances 2)Absorption • Contaminant penetrates sorbent • Hydroxides with lime, for acid gases 3)Catalysis 4)Chemical reaction

Respirator Selection Principles • Respirators for non-IDLH

1) Atmosphere supplying respirators are suitable for gases, vapors or particulates • May be used for non-IDLH oxygen deficiency 2) Air-purifying respirators have more limitations • Not for oxygen deficiency • More information is needed about the contaminants • Cartridge selection and changeout is based on contaminant type and concentration

Air-Purifying Respirators • 42 CFR part 84 Filter Classification

1) Oil Resistance • N = Not Oil Resistant • R = Oil Resistant • P = Oil Proof 2)Efficiency(for"mostpenetrating"particle) • 95 (95%) • 99 (99%) • 100 (99.97%), the same as HEPA • Example: • N-95 = most filtering facepiece "dust masks"

Air-Purifying Respirators • Filter Selection

1)Before 42 CFR 84, filters were selected according to particulate size • HEPA filters used for Mass Median Aerodynamic Diameter (MMAD) < 2 micrometers 2)Now, select filters according to oil resistance • Specific OSHA standards may specify HEPA (P-100), although objective data suggests HEPA filters are not effective • Increased filtration efficiency does not compensate for increased facepiece leakage

PPE Certification Tests

A primary influence on the design and performance of PPE is conformance with the requirements of the certification tests

Maximum use concentration (MUC)

MUC = (EL)(APF) EL: exposure limit APF: assigned protection factor

Respirator Selection Principle

Oxygen Deficiency IDLH 1) Normal oxygen conditions • 20.9% "normal" @ sea level • 159 mm pO2, partial oxygen pressure (.209x760mm) 2)ANSI limit based on pO2 • 122 mm pO2 = oxygen deficient • 95 mm pO2 = IDLH 3)OSHA defines oxygen deficiency < 19.5% as IDLH • Conditional exception based on altitude and percent O2 (see Table II):