Facial Sealing of Respiratory Protection Equipment

Introduction to Respiratory Protection

• The Centers for Disease Control and Prevention recommends that facial hair, especially beards, be completely removed before using negative-pressure respirators, as it critically compromises the facial seal; for individuals who cannot shave, positive-pressure respirators (PAPR) should be used, which reduce facial seal leakage to less than 2-4% 1, 2

Critical Factors Compromising Facial Sealing

• The facial seal is the critical point of failure in respirators, as the efficiency of the HEPA filter is effectively 100%, so virtually all particle leakage occurs at the facial seal interface 1, 3

Anatomical and Personal Factors Causing Leaks

• Facial hair (beards) causes a 246-fold reduction in protection with half-face masks and 330-fold with full-face masks, increasing leakage from 0.03% to 8% 2
• Incorrect size or shape of the facepiece results in greater leakage in individuals with smaller or harder-to-fit faces 4, 3
• Sweating or facial oils cause the facepiece to slip 1, 5

Operational Factors

• Not using all head straps 1, 2
• Incorrect positioning of the facepiece on the face 1, 2
• Incorrect tension or positioning of the straps 1
• Inadequate maintenance or damage to the respirator 1, 2

Mandatory Fit Testing Strategy

• Formal fit testing is mandatory according to OSHA and must be performed by qualified personnel before initial use of the respirator 4, 6
• Quantitative fit testing (QNFT) uses detectors to objectively measure leakage and is more reliable than qualitative fit testing 6
• Qualitative fit testing (QLFT) is based on the worker's subjective response using aerosol substances that can be tasted 4, 6

Algorithm for Respirator Selection Based on Facial Characteristics

• For individuals without facial hair, formal fit testing with multiple models and sizes should be performed to find one with an adequate fit factor 4, 6
• For individuals with facial hair, options include shaving completely before using negative-pressure respirators or using PAPR, which reduce facial seal leakage to less than 2-4% 2, 4

Comparison of Respirator Types

• Negative-pressure respirators have a facial leakage of 0-20% in disposable cup-shaped respirators 4, 5
• Positive-pressure respirators (PAPR) have a facial leakage of less than 2% with an adjusted facepiece and less than 4% with a loose facepiece or hood 4, 3

Essential Components of the Respiratory Protection Program

• Medical evaluation to identify conditions that may limit safe use 2
• Mandatory formal fit testing required by OSHA to identify the respirator that fits adequately 6, 2
• Specific training on the nature and extent of hazards 2
• Instruction on proper inspection and use, including placement, adjustment, and verification 2

Respirator Fit Testing Guidelines

Introduction to Respirator Fit Testing

• The Centers for Disease Control and Prevention (CDC) recommends that workers be retrained in the correct placement of the respirator and/or change to a different model or size if a leak greater than 10% is detected during the qualitative fit test 7, 8

Respirator Selection and Fit Testing

• The CDC recommends trying different sizes of the same model (respirators should be available in at least three sizes) if retraining does not resolve the issue 7, 8
• The Occupational Safety and Health Administration (OSHA) requires that respirators be fitted to achieve a facial seal leak of ≤10% 7, 8

Documentation and Record Keeping

• The CDC recommends registering the results of each fit test 7
• The American Conference of Governmental Industrial Hygienists (ACGIH) suggests that fit testing should be repeated annually or when there are changes in the worker's facial characteristics 7