Respiratory Protection

An Overview

Respiratory Protection

• When respirators are needed

• Types of respirators and their limitations

• What you must do when respirators are required

• What you must do when respirators are optional (wearing voluntarily)

When Are Respirators Needed?

• In an oxygen-deficient atmosphere

• When chemical “Permissible Exposure Limits” are exceeded

• When required by a pesticide label

• When you require it by company policyNormally, an oxygen deficiency will only be found in a confined space or a major chemical leak or spill. Permissible exposure limits are covered in following slides.There are only a few pesticides that have label requirements for respirators. Some employers require their employees to wear respirators as a safety precaution.

Oxygen Deficiency

Oxygen deficiency can occur in confined or enclosed spaces, during fires or large chemical releases.

Normal air contains 21% oxygen. An area with oxygen content below 19.5 % is considered “oxygen deficient”.

Only a supplied air respirator can protect against the effects of oxygen deficiency.

21%0%

19.5%

Oxygen deficiency exists

Oxygen content

21%8%

Immediate death

Permissible Exposure Limits (PELs)

Most chemicals and dusts have limits in the air that will cause adverse health effects if exceeded.

If airborne levels cannot be reduced below these limits by other means, respirators must be provided to protect exposed employees.

Toxic chemicals and dusts

There are about 600 chemicals with listed permissible exposure limits in regulations. Most of these limits are based on 8-hour average exposures, but some have short-term exposure limits based on 15 minute exposures. A few have ceiling limits, which can’t be exceeded even for an instant. The limits are based on the levels at which harmful effects are first know to occur.

Why Respirators Are the Last Choice

Respirators have major limitations:

They can leak, wear out, or be the wrong kind

They can be hot, uncomfortable and make it hard to see or communicate

They can be hard to breathe through

They are easily removed in contaminated air

The first choice is to reduce chemical exposure by other means. Most people do not like wearing respirators and may remove them to talk to another worker. Tight-fitting respirators are especially inclined to leaking.

How to Avoid Using Respirators

Use one or more of the following controls to reduce exposure to airborne chemicals:

Ventilation

Dust suppression with water

Eliminate use of chemical

Substitute with a less toxic chemical

Isolate or enclose the chemical processes

Other processing changes

Respirators should be used only if these methods are not feasible or don’t reduce exposure.

Types of Respirators

Air-purifying respirators – filters air through cartridges or filtering facepieces (dust masks)

Powered air-purifying respirators – filters air through cartridges with assistance of a blower.

Airline respirators – provides unlimited clean air from a compressor.

Self-contained breathing apparatus (SCBA) – provides 30- 60 minutes of clean air from a tank.

Escape respirators – provides air for escape only from a small bottle.

Types of Air-purifying Respirators

Filtering facepiece (dust mask) Half-face cartridge respirator

Full-face cartridge respirator Powered air-purifying respirator

Air-Purifying Respirators

Air-purifying respirators trap air contaminants in a cartridge or filter when the wearer inhales.

Particulate respirators capture dusts, mists and welding fumes.

Chemical cartridge respirators capture gases and vapors.

Combination cartridges are available.

These type of respirators have many limitations and restrictions and cannot be used where air contaminant levels are extremely high or when there is an oxygen deficiency.

Air inhaled in Air inhaled inAir exhaled out

How Cartridge Respirators Work

This picture shows how air moves in and out of the respirator. The act of breathing creates a negative pressure inside the mask, which is why these and dust masks are sometimes called “negative pressure respirators”. If the mask does not fit properly along the edges, contaminated air can enter during inhalation.

Air-purifying Respirator Limitations

Cartridges must be changed periodically to provide protection.

The right cartridge for the contaminant of concern must be chosen.

Air-purifying respirators provide protection up to 10 or 100 times the PEL.

Will not provide adequate protection in confined spaces, major leaks or spills or for certain highly toxic chemicals.

Respirator Protection Factor

Half-face cartridge and dust mask respirators only provide protection to levels 10 times above the chemical or dust permissible limit.

Ammonia Permissible Limit – 25 ppm

Respirator Protection Factor for ammonia – 250 ppm

ppm = parts per million

Example

Limits of Chemical Cartridges

Chemical cartridges can absorb only so much chemical.

When their capacity is reached, breakthrough will occur.

You can’t always tell if a respirator leaks by a chemical odor.

Some chemicals have no odor, or can only be smelled at high levels.

Breakthrough means the chemical goes through the cartridge into the facepiece. If a worker smells the chemical with their respirator on, they will know it is not working. But if the chemical has no odor, or it can only be detected at high levels above the permissible limit, they may not know if your respirator is working properly. For these reasons, cartridges must be changed regularly.

Supplied Air Respirators

Airline Respirator SCBAClean air comes from a compressor or tank and provides the highest protection to users.

Supplied air respirators can provide protection up to 1000 to 10,000 above the permissible exposure limit, depending on the type of respirator. The two types of respirators shown here have tight-fitting facepieces. Loose fitting respirators are also available.

Loose-fitting supplied air respirators

Hood Helmet

facepiece Full Body Suit

Air is supplied from these respirators by means of a hose from an air compressor. These are the only type of respirators that do not require fit-testing. Their protection varies depending on the type. The loose-fitting facepiece is the least protective of this type.

Oxygen deficiency

High levels of toxic chemicals in the air – above “IDLH” levels

Other conditions of high levels of highly toxic chemicals in the air

Firefighting

When Are Supplied-air Respirators Required?

Unlike air-purifying respirators (cartridge-type respirators or dust masks), supplied air respirators provide a high degree of protection for the user in these life-threatening situations. If air contaminant or oxygen levels are unknown and testing can’t be done in confined spaces, emergency spills or leaks or at hazardous waste sites, it must assumed that IDLH levels are exceeded and supplied air respirator must be worn. Assume the worst case, unless you have evidence otherwise.

What is “IDLH”?

“IDLH” means immediately dangerous to life or health

Most chemicals have a listed IDLH level link to NIOSH IDLH Table

Oxygen deficiency is also IDLH

IDLH conditions can occur in confined or enclosed spaces, large chemical spills or leaks and firesIn most workplaces, IDLH conditions rarely occur. Confined spaces are the exception - IDLH conditions are much more common in sewers or tanks where welding is done or which contained chemicals or fuel.

Escape Respirators

Escape bottle attached to airline respirator system Carried escape respirator

These can’t be used for entry – going in a room to turn off a valve or make a repair. They only contain 5 -10 minutes supply of air, enough time to exit a room or building where there has been a major chemical leak or spill, or when the supplied air respirator fails.

Air Quality for Supplied Air Respirators

Air for tanks or from compressors must be “Grade D” air.

Tank air is purchased from vendors.

Compressors supply air for airline respirators.

Compressor air must be equivalent to Grade D air.

Low pressure compressors may not provide adequate amount of air.

Link to Grade D air requirements

Construction & Plant Air Compressors

Be careful – these do not provide clean air without a filter system!!

Oil-lubricated compressor are especially hazardous. You must test for carbon monoxide or have a high temperature alarm.

Locate air intake away from engine exhaust which can contaminate breathing air.

Use these compressors with caution

Respirator Selection

One of the most important task is selecting the correct respirator for the hazard.

Knowledge of chemical identity, extent of use, levels in the air and permissible limits is needed.

You must conduct a workplace hazard assessment – air sampling may be necessary.

                                                                      

Personal air sampler

Respirator Selection

Conditions Type of Respirator

IDLH conditions or oxygen deficiency

SCBA or airline respirator with escape bottle

Dust/chemical levels up to 1000 times PEL

Airline respirator with full facepiece or hood

Dust/chemical levels up to 100 times PEL

Air-purifying respirator with full facepiece

Dust/chemical levels up to 50 times PEL

Powered air purifying respirator with half facepiece

Dust/chemical levels up to 10 times PEL

Air-purifying respirator with half facepiece

Respirator Fit

Respirators Must Fit Properly

Fit-testing must be done before first wearing a respirator.

Tight-fitting respirators must fit properly to prevent leaks around the edges.

Beards are not allowed when wearing a tight-fitting respirator because they will leak.

Respirator Fit-testing

Required for all tight-fitting respirators.

Four qualitative methods and three quantitative – your choice.

Quantitative methods are more accurate.

Fit-testing methods are covered in detail in the Respirator Rule.

Checking fit of respirator on individual employees

Link to fit-testing methods

Medical Evaluations

Medical evaluations are required for anyone wearing respirators.

Respirator use places a burden on the body.

Respirators can be hazardous to people with heart or lung problems.

Air-purifying respirators restrict breathing, particularly during heavy exercise. They also can add to heat stress in hot conditions. Tank-type respirators (SCBAs) are heavy. Airline respirators are less of a burden to the body.

Respirator cleaning & maintenance

Respirators must be cleaned, inspected and maintained regularly.

Respirator maintenance and repair are essential for proper functioning.

Store in a clean, dry place.

Don’t store like this!

Employee Training

Training is required for any employee wearing respirators.

Training must cover why respirators needed, their limitations, how to clean and maintain and how to use.

Hands-on training is especially important for emergencies and SCBA use.

Link to respirator training modules

What is required in a respirator program?

Respirator program administrator

Written procedures and records

Proper respirator selection

Medical evaluation of respirator users

Fit-testing of respirators to each user

Respirator maintenance, repair & storage

Assured air quality for supplied-air respirators

Employee training

Written Respirator Program

Prepared materials:– from manufacturers– From WISHA sample program– Other boiler plate programs

Must be workplace-specific Link to sample written respirator program

Much of your written program can be composed of compiled procedures from several sources. But some procedures will need to reflect your specific workplace practices. Be careful of “boiler plate” programs which may not describe your workplace’s selection considerations or its specific emergency procedures. The purpose of a written procedure is to get a specific, consistent outcome by giving instructions that can be applied in your actual work area.

Voluntary Respirator Use

If you allow employees to wear respirators:

– Provide the mandatory handout,

– ensure safe use,

– provide medical evaluations

– ensure proper cleaning, storage and maintenance

Link to mandatory handout

These requirements apply to voluntary use of all respirators including dust masks. Fit-testing is not required.