SAFETY EQUIPMENT CATALOGUE - Eoss.com

Air Purifying RespiratorsIDLH (Immediately Dangerous to Life or Health)characterizes an atmosphere that posesan immediate threat to life, would causeirreversible adverse health effects, or wouldimpair an individual’s ability to escape froma dangerous atmosphere.It is important to note that exposure limits andother exposure standards are constantlychanging as more data is gathered aboutspecific chemicals and substances. As such,you must be certain that you are using themost recent data when determining allowableexposure levels for employees.3Hazard ControlHazard control should start at the process,equipment, and plant design levels wherecontaminants can be controlled effectivelyat the outset.With operating processes, theproblem becomes more difficult. In all cases,however, attention should be given to the useof effective engineering controls to eliminateand/or reduce exposures to respiratory hazards.This includes consideration of process encapsulationor isolation; use of less toxic materialsin the process’ and suitable exhaust ventilation,filters, and scrubbers to control the effluents.Because it is sometimes not practical tomaintain engineering controls that eliminateall airborne concentrations of contaminants,proper respiratory protective devices shouldbe used whenever such protection is required.4Respirator SelectionSelecting respirators entails knowing whatlevel of respiratory protection employeesneed, as well as which size respirator is rightfor any face and facial contours.Respiratory protective devices vary indesign, application, and protective capability.Thus, the user must assess the inhalationhazard and understand the specific uselimitations of available equipment to assureproper selection.If your calculation shows that exposureconcentrations exceed recommended limitsand engineering/administrative controls donot reduce exposure below the permissiblelimit, tailor your respiratory protectionprogram to your specific conditions based on:• Toxicity (TLV or TWA)• Maximum Expected Concentration• Oxygen level• IDLH concentration• Warning properties (adequate or not)• Sorbent limitations• Facepiece fit• Mobility requirements• Type of use(routine, escape, or emergency entry)Types of RespiratorsRespirators fall under two classifications:air-purifying and air-supplied. Air-purifyingrespirators are used against particulates,gases, and vapors. These are categorizedas negative-pressure respirators that usechemical cartridges and/or filters; gas masks;and positive-pressure units such as poweredair-purifying respirators (PAPRs). Air-supplieddevices rely on a primary air source todeliver a steady flow of respirable air tothe user’s facepiece. These consist ofSelf-Contained Breathing Apparatus (SCBA)and air-line devices.Air-Purifying Respirators (APRs) rangefrom simple disposable cup masks tolow-maintenance halfmask facepieces withcartridges and/or filters to the more complexPAPRs with full- facepieces, or hoods.• APRs for particulates use filters to capturedusts,mists, and fumes. Filters do notprotect against gases or vapors, andgenerally become less effective as particlesaccumulate on the filter and plug spacesbetween the fibers. Filtering APRs requirefilter replacement when the user finds itdifficult to breathe through them.• Gas and vapor APRs employ chemicalcartridges or canisters to remove hazardousgases or vapors from the air. They do notprotect against airborne particles. Made toprotect against specific gases or vapors,they provide protection only as long as thecartridge’s absorbing capacity is notdepleted.The service life of a chemical cartridgedepends upon many factors and can beestimated in various ways. Cartridges andcanisters require an end-of-service-lifeindicator (ESLI) or a change schedule, basedon objective information or data that willensure that canisters and cartridges arechanged before the end of their useful life.In the respirator program, the employer mustdescribe the information and data relied uponand the basis for the canister and cartridgechange schedule as well as the basis forreliance on the data.• Combination APRs, fitted with bothparticulate filters and gas/vapor cartridges,are worn in atmospheres that containhazards of both particulates and gases.Supplied-Air Respirators (SARs), compriseair-line respirators, SCBA, and combination(supplied-air) respirators.• Air-Line Respirators are used for extendedperiods in non-IDLH atmospheres. They usean air-line hose to deliver clean breathingair from a stationary source of compressedair for prolonged periods of time. Althoughcomparatively lightweight, air-linerespirators can limit users’ mobility becauseof the air-line hose that must be attached.• Self-Contained Breathing Apparatus (SCBA)have an open-circuit design that providesair rated for 30 to 60 minutes. They consistof a wearable, clean-air supply and atight-fitting facepiece, and are used forshortduration entrance or escape fromatmospheres that are or may be IDLH.They offer relatively unrestricted movement.• Combination SARs are air-line devices usedfor extended work periods in atmospheresthat are or may be IDLH. They have anauxiliary self-contained air cylinder thatcan be used if the primary air supply fails.The air cylinder can also be used for entryinto or escape from IDLH atmospheres,such as confined spaces.Employers are required to provideemployees using SARs with breathing gasesof high purity.5TrainingFor proper use of any respiratory protectiondevice, it is essential that the user beproperly instructed in its selection, use, andmaintenance. Both supervisors and workersmust be so instructed by competent persons.Minimum training must include:• Methods of recognizing respiratory hazards• Instruction in the hazards and an honestappraisal of what could happen if the properrespiratory protection device is not used27 Customer Service: 1300 728 672 • Website: www.msa.net.au • New Zealand Customer Service 0800 441 335