Respiratory Protective Equipment

Types of RPE

1. Respirators Designed to purify respirable air by

inhaling it through a medium which removes the contaminants

2. Breathing Apparatus Supplies pure respirable air from an

uncontaminated source

Types of Respirator

Filtering Facepiece RespiratorHalf-mask RespiratorFull-face RespiratorPowered Clean-air RespiratorPowered Visor Respirator

Filtering Facepiece Respirator

Piece of filtering material worn over the nose & mouth and secured by twin elastic headbands (MEMS)

Cheap & disposableFace seal cannot be fully achieved

over facial hair

Half-mask Respirator

Flexible facepiece which covers nose & mouth, to which is fixed a replaceable cartridge capable of removing airborne contaminants during inhalation

Single or twin cartridgesFacial hair reduces efficiencyBreathing is not easySpeech and vision are slightly reduced

Full-face Respirator

Cover mouth, nose & eyesReplaceable canisters which are

either fitted to the facepiece or connected via a flexible corrugated rubber breathing tube

Canisters are for specific hazards

Powered Clean-air Respirator

Respirator air is pumped into facepiecePositive pressure which reduces

fatigue, allows longer work periods and reduces risk of leaks

Designs are either half or full-face, or helmets with a fabric skirt

Cannot be used in oxygen deficient areas

Powered Visor Respirator

Purified air is blown down over the user’s face behind a protective visor

Contaminated air is drawn through a pre-filter and then into a filter bag before it is directed over the face

It is powered by nickel cadmium batteries

Types of Breathing Apparatus

Fresh Air Hose ApparatusCompressed Airline Apparatus

Constant flow Demand flow

Self-Contained Apparatus Escape BA General BA Oxygen BA

Nominal Protection Factor

Npf=Concentration of atmospheric contaminant

Concentration of contaminant in facepiece

The higher the npf, the greater the the degree of protection

Typical NPFs

Filtering face piece 5Half-mask 10Full-facepiece 500-1000Powered Clean Air 500Powered Visor 10-20Fresh Air Hose 50Compressed Airline 1000-2000Self Contained 2000

Selection

Selection of RPE is based on: Type of hazard; Contaminant concentration safely

tolerated by user; and Contaminant concentration

The concept of NPF is based on the fact that ingress of contaminant into RPE may (and can) occur

Face-fit Test

Stated NPF value is not reached in practice, due to poor fit

User should carry out test each time RPE is put on: Close inlet to facepiece Inhale gently to create negative pressure Hold breath for 10-15 seconds If pressure is lost, then headbands may need

tightening to increase seal