Manikin-based performance evaluation of elastomeric respirators against combustion particles

Area of Science:

• Occupational Health and Safety
• Respiratory Protection
• Firefighter Safety

Background:

• Firefighters face exposure to combustion particles.
• Elastomeric respirators, including P-100 half and full facepiece models, are crucial protective equipment.
• Understanding factors influencing respirator performance is vital for ensuring adequate protection.

Purpose of the Study:

• To investigate the impact of faceseal leakage, breathing flow dynamics, and combustion material on particle penetration into P-100 respirators.
• To evaluate the effectiveness of current respirator testing protocols, specifically the NIOSH total inward leakage (TIL) test.

Main Methods:

• Respirators were tested on a breathing manikin exposed to combustion aerosols (wood, paper, plastic).
• Testing involved various cyclic and constant breathing flow rates and four faceseal conditions.
• Particle penetration was measured by comparing concentrations inside and outside the respirator.

Main Results:

• Faceseal leakage, breathing flow, and combustion material significantly affected respirator performance.
• P-100 filter efficiency met NIOSH criteria and was unaffected by aerosol type or flow.
• Increased leak size led to higher particle penetration, particularly in unsealed or partially sealed half mask respirators.

Conclusions:

• While P-100 filters are highly efficient, faceseal integrity is critical for overall respirator protection.
• The current NIOSH TIL test may underestimate protection levels for half mask respirators with imperfect seals.
• Further refinement of testing protocols is needed to accurately predict real-world respirator performance.