Figure 4-3. Half-face air-purifying respirator.
PERSONAL PROTECTIVE EQUIPMENT
TRAINEE OBJECTIVES
After completing Section 4, you will be able to:
Maximum use concentration
Protection factor
Quantitative fit test
Qualitative fit test
Tested and certified
APR
IDLH
NIOSH
PAPR
PPE
SAR
SCBA
TC
INTRODUCTION
Personal protective equipment (PPE) is any protective clothing or device used to prevent contact with, and exposure to, hazards in the work place. Hazards may be chemical or nonchemical although lead exposed workers are most concerned with respiratory PPE. Examples of PPE include respirators, gloves, protective suits, boots, hard hats, and safety glasses.
PPE is critical to the safe performance of lead abatement work. Therefore, workers need an appreciation of the types of PPE, their limitations, and what goes into the selection process. The PPE issue is made more complicated because no one type protects against all exposure situations. As a result, there are many types of protective gear. Choosing the correct type requires that the industrial hygienist have a detailed knowledge of the chemical exposure(s) at hand. This section discusses the following areas of PPE:
Respiratory Protection
A respirator is a piece of equipment that reduces chemical exposures by preventing contaminant's from being inhaled. There are many different types of respirators, all useful in specific situations. Respirators are composed of a facepiece that seals out contaminant's, and a device that provides clean air. Two types of respirators are used for obtaining clean air:
Respirators differ in how much protection they afford. A paper mask is less protective than a firefighter's respirator with an air tank. But how much difference is there? Industrial hygienist have developed a scoring system to rank different types of respirators. Each respirator is given a score based on the amount of protection it can provide. This score is known as a protection factor (PF).
Protection Factors
The key to understanding respirator protection is to realize that all respirators leak to a certain degree. The amount of leakage depends on how well the facepiece seals to the face. A leak in the facepiece means that contaminated air can enter the facepiece. The act of inhaling creates negative air pressure inside the facepiece that results in a slight suction effect. The suction can draw in contaminated air. These leaks compromise the protection given by the respirator. Breathing contaminated air can lead to adverse health effects depending on the type and amount of chemical.
Respirators are tested for leakage
by measuring the contaminant levels both outside and inside the respirator.
Using the ratio of these two measurements, a PF is assigned. A PF is based on
the assumption that the respirator is working properly, is worn correctly, and
fits the wearer. Respirator PFs range from 5 to 10,000. The lower the PF,
the lower the protection. The higher the PF, the higher the protection.
Figure 4-1 shows the calculation for determining the PF.
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The goal of a respirator is to reduce the amount of hazardous chemical inside the mask to below the Occupational Safety and Health Administration (OSHA) permissible exposure limit (PEL). Respirators must be chosen to ensure that workers are never overexposed while wearing the respirator. The practical application of PF for the asbestos worker can be summed up as: How much of the outside contaminant level is reduced by the respirator? Examples follow:
Remember: The lower the PF, the lower the protection. The higher the PF, the higher the protection.
Maximum Use Concentration
Maximum use concentration (MUC) is that level of contaminant's which, if exceeded, will cause a worker to be exposed above the PEL because of leakage into the respirator. The MUC is the highest concentration of contaminant's in which a respirator can be used safely. At no time should a respirator be used in an environment that exceeds the MUC.
The MUC is calculated by multiplying PF times PEL. Figure 4-2 gives an example of calculating the MUC for nitric acid.
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AIR PURIFYING RESPIRATORS
Air purifying respirators (APRs) clean the air a worker breathes by removing or filtering a contaminant from the air before it enters the wearer's lungs. APRs have two components-the facepiece and the filter or cartridge. When a worker inhales, contaminated air is pulled into the respirator through a filter or cartridge attached to the facepiece. The filter or cartridge removes the contaminant from the air before it enters the inside of the respirator through the inhalation valve. When the wearer exhales, air from the lungs reverses the airflow through the facepiece and out a separate valve called the exhalation valve.
Negative Pressure Respirators
APRs are commonly called negative pressure respirators. They depend on lung power to pull the air through the filters. The suction created when a worker inhales draws air into the respirator. This suction creates a momentary negative pressure. During inhalation, the negative pressure brings contaminant's into the facepiece through leaks and improper seals. During exhalation air is blown out and a positive pressure is created in the facepiece. It's important to remember that negative pressure respirators must only be used if the oxygen level in the work place is above 19.5%.
Disposable Paper Masks and Quarter Masks
Many workers are familiar with the disposable paper masks. They are the throwaway type, and do not seal to the face well enough to provide a good fit. Laboratory tests done with mannequins show PFs of 5 to 10. However, studies done under actual work conditions show even lower PFs. The leakage for this type of mask is too severe. Furthermore, the paper of a disposable mask is only effective for large-particle dusts. Gases, vapors, fumes, and fine dusts, such as asbestos, may pass right through the paper. These masks are not to be used for asbestos abatement operations.
The quarter mask is normally a rubber mask, which fits from the top of the nose to the top of the chin. It uses cloth or cartridge filters. The PF is rated at 5. This type of mask it is not to be used for asbestos abatement work.
Half-Face APRs
The half-face APR is made of rubber or plastic. It fits from the top of the nose to under the chin. Figure 4-3 shows a typical half-face APR.
Figure 4-3. Half-face air-purifying respirator.
A half-face APR uses one or two filter cartridges attached to the facepiece to filter the air. The fit given by the respirator rates a fairly low PF of 10. These respirators can be used in some situations, but the industrial hygienist must be confident in his or her knowledge of the level of asbestos exposure that will occur, and how high the levels can potentially get.
Other limitations of the half-face APR are:
Half-face respirators are the minimum type used for asbestos abatement work.
Table 4-1 is a list of some chemicals that can't be safely protected against by APRs. Table 4-2 lists general MUCs for chemical cartridges that have hazardous breakthrough problems.
Table 4-1. Chemicals not suited for air purifying respirators.
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Table 4-2. Maximum use concentrations for chemical cartridges with hazardous breakthrough problems.
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Full-Face APRs
A full-face APR is made of rubber or plastic. It covers the whole face, starting at the forehead, down over the temples and the eyes, and under the chin (Figure 4-4). The full-face APR has a PF of 50 because it's easier to get a good seal across the forehead than across the nose. Also, the respirator is held more securely in place because it has a harness instead of straps. The full-face APR uses the same types of filters as the half-face APR, so it also carries the same limitations. It does protect the eyes, although it has a tendency to fog up.
Figure 4-4. Full-face air-purifying respirator.
Some full-face APRs can use larger chin, chest, or back-mounted canister-type filters. These filters are larger, and have fewer limitations. There are several filters available in larger sizes for full-face APRs that are not available for half-face APRs. Since canisters are larger than cartridges, they have higher capacities. Even though full-face APRs protect more than half-face APRs, they still do not offer enough protection to be used in IDLH conditions.
Powered Air Purifying Respirator
The powered air purifying respirator (PAPR) uses the same type of facepiece and filters as the full-face APR (Figure 4-5). However, the full-face APR is a negative pressure APR and the PAPR is a positive pressure APR. The PAPR uses a small lightweight battery-operated blower to draw air through filters and into the facepiece. This makes it more comfortable to use because less work is required to breath. Also air is blown across the face to provide some degree of cooling. Because the PAPR seals the face in the same manner as the full-face negative pressure APR, the protection factor assigned by OSHA (for exposure to lead) is 50.
Figure 4-5. Powered air-purifying respirator.
Although the PAPR is an improvement over the negative pressure full-face APR, it has two limitations:
Some PAPRs have loose-fitting hoods and helmets instead of face masks. While these hoods are comfortable, they provide less protection. OSHA assigns a PF of only 25 for loose-fitting PAPRs.
Filtering Devices
Air purifying respirators are manufactured with two basic types of filtering devices:
Particulate Filters
Particulate filter respirators use a filter made of a fibrous material to capture contaminant particles before the air reaches the wearer's lungs. The particles are pulled through the filter as the worker inhales, and become trapped by the fibers of the filter. Particulate filter respirators are used for protection against particles of dusts, fumes, and/or mists. Typical examples include welding fumes, oil mists, silica,asphalt fumes, and asbestos.
42 CFR Part 84 for Particulate Filters
Respirator certification regulations 30 CFR 11 were first promulgated in 1972 and are commonly referred to as Part 11. Since 1972 new research, testing, and advances in technologies have required that changes be made in the certification regulations. NIOSH will be revising all of the certification requirements for all classes of respirators. These changes will take place in modules. The first change is the certification requirements for non-powered, air-purifying particulate-filtering respirators. Modules for all respirators will eventually be revised, but the process isn't expected to be completed for many years.
In July of 1995, the certification requirements in the Part 11 standard were re-titled as 42 CFR 84 or Part 84. Since the effective date of the Part 84 standard, July 10, 1995, NIOSH will only approve new non-powered, air-purifying particulate-filter respirators based on Part 84 performance testing procedure. Manufacturers may still produce and sell the old filters until July 10, 1998.
There are two changes in the particulate filter labels. The changes are listed below:
Approval labels are normally found on the respirator box, cartridge box, or in the booklet supplied with the respirator. Figures 4-6 shows the label for MSHA approved respirators, and Figure 4-7 shows the label for non-powered, air-purifying particulate filters.
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Figure 4-6. NIOSH Approval label showing MSHA as an approving agency.
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Particulate Filter Efficiency
Particulate filters are not designed to be 100% efficient in removing particulates from the air. It would be too hard for a worker to pull air through the filters when inhaling. Filters are manufactured to create maximum filter efficiency while keeping the resistance to breathing low. As contaminated air is drawn through the filter, the particles are captured by the filter, plugging up the holes between the fibers of the filter. This increase breathing resistance for the wearer.
Particulate filter efficiencies are classified into two groups, high efficiency and lower efficiency. High efficiency filters are capable of capturing 99.97% of particles 0.3 micrometers or larger in diameter from air pulled through the filter. Filters of this type are commonly called high efficiency particulate air (HEPA) filters. HEPA filters are used for dusts, fumes, and mists having an exposure limit less than 0.05 milligrams per cubic meter of air (0.05 mg/m3 ). Particulates with exposure limits this low are the most hazardous to workers' health, which explains why high efficiency filters are to be used. For example, HEPA filters must be used for exposures to asbestos or lead.
Lower efficiency filters are less efficient than HEPA filters and capable of capturing approximately 99% of dust, fume, and mist particulates 0.3 micrometer or larger in diameter . Lower efficiency filters are used for particulates that have exposure limits greater than 0.05 mg/m3 . These substances are not as hazardous to the health of exposed workers.
Particulate Filter Classification
The new Part 84 regulation creates nine classes of particulate filters. The nine classes are made up of three levels of filter efficiency and three categories of resistance to filter efficiency degradation. The three levels of efficiency are 95%, 99%, and 99.97%. The three categories of resistance are labeled N, R, and P, respectively.
Each filter series must pass a test using a particle with a diameter of 0.3 microns. (A particle that is 0.3 microns can penetrate into the deepest parts of the lungs and cause the most damage.) All three classes of filters are limited in that they must be replaced whenever there is a hygiene concern, damage, or increased breathing resistance detected by the wearer.
N Series The N series is tested against sodium chloride (NaCl) and is used with water-based particulates. It's not resistant to oil and cannot be used in an atmosphere that contains an oil or an oil-based particulate. An N series filter can be used for more than one work shift as long as there are no problems with hygiene, damage, or breathing resistance.
R Series The R series is tested with an oil called dioctyl phthalate (DOP) and is used for filtering any solid or liquid particles. It's resistant to oil, but not oil proof. Therefore, an R series filter has a limited use time if used in an environment containing an oil mist or oil-based particulate. It can be used for one 8-hour shift or a combined total of 8 hours. However in an oil-free environment, the R series filter can be used for an extended period of time.
P Series The P series is also tested with DOP and is used for any solid or liquid particles, both oil-based and non-oil-based. It is oil proof. So a P series filter can continue to be used as long as a worker has no breathing problems.
An easy way to remember the filter series is:
There are three filter efficiencies associated with each of filter series. The minimum efficiency levels are 95%, 99%, and 99.97%. These efficiency levels are identified by the following designations:
Table 4-3 summarizes the nine classes of particulate filters. Figure 4-8 illustrates the decision process for choosing the appropriate filter.
Vapor and Gas Removing Cartridges and Canisters
Vapor and gas removing cartridges and canisters are used with APRs to protect workers from exposures to air that is contaminated with toxic vapors and gases.
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While particulate filters are effective for nearly all types of particles, gas and vapor removing cartridges and canisters are designed to protect against specific individual contaminant's. Examples include carbon monoxide, ammonia gas, or combinations of gases and vapors, such as acid gases or organic vapors.
Contaminant's are removed as inhaled air enters the cartridge or canister and passes through a granular material called a sorbent. The sorbent absorbs contaminant's from the air, and provides protection to the wearer from the toxic effects of the gas or vapor.
Materials used as sorbents include activated charcoal, silica gel, and various mixtures of specific chemicals that will capture the contaminant. Initially a gas and vapor sorbent is 100% efficient in capturing a contaminant. As the sorbent is used up, the efficiency decreases. When the sorbent is exhausted, the contaminant passes completely through the sorbent and into the facepiece where it is inhaled by the wearer. This loss of capturing efficiency is opposite to particulate filters which become more efficient as particles collect on the filter.
Sorbents for gases and vapors are packaged into either cartridges or canisters. The only difference between a cartridge and a canister is the amount of sorbent they contain. Cartridges are designed to be used singly or in pairs on quarter-, half-, and full-facepieces. The amount of sorbent contained in a cartridge is small, making their useful lifetime short in duration. This limitation restricts the use of cartridges to low concentrations of gases and vapors.
Canisters contain larger amounts of sorbent material than cartridges. Therefore, they can be used in situations where the workplace air concentration of gases or vapors is high. Canisters are designed as chin, front, or back-mounted devices. When a canister is used with a facepiece, the respirator is called a gas mask.
Cartridges or canisters are designed for either one specific type of gas or vapor, or a combination of gases and vapors together. In addition, some cartridges and canisters are manufactured to protect against both gases and vapors, as well as particulates by combining particulate filters with sorbent materials. When filters are combined with gas and vapor sorbents, the filter is located in the inlet side of the cartridge. It is either built into the cartridge itself or held to the outside of the cartridge by a snap-on cover.
Both canisters (gas masks) and chemical cartridges are available for the following specific gases and vapors:
Only chemical cartridges are available for these additional substances:
Likewise, only canisters (gas masks) are available for:
A color coding scheme has been established to identify the contaminant's that a gas and vapor canister or cartridge protects against. The color coding is assigned to either individual contaminant's or combinations of contaminant's as shown in Table 4-4.
When the sorbent becomes exhausted or used up, breakthrough will occur. Warning signs include odor, taste, or throat irritation. If the wearer notices any warning signs, follow these steps:
Gas and vapor cartridges have short useful service times. Therefore, it is recommended workers discard their cartridges or canisters at least daily, even if no odor, taste, or irritation is detected. Some canisters are designed for use against substances with poor warning properties (no odor or taste). These canisters have end of service life indicators (ESLIs) that show the canister is exhausted and needs to be replaced. For example, cartridges used for mercury have ESLIs because mercury has poor warning properties that are not readily noticed by a worker being exposed.
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ATMOSPHERE SUPPLYING RESPIRATORS
There are two types of atmosphere supplying respirators -air line respirators and self-contained breathing apparatus (SCBA).
Both types of respirators supply clean breathable air to the wearer and do not depend on filters. With an air line respirator, air is delivered by a hose connected to a compressor. The compressor is equipped with a filtering system that purifies the air. The air for an SCBA is contained either in a compressed air tank or cylinder. The air in the tank or cylinder is under pressure. Regulators are used to reduce the pressure and control the flow of air into the facepiece.
There are two types of regulators:
Demand Flow vs. Pressure Demand Regulators
A demand flow regulator uses the suction force of inhalation to open the regulator valve and let air flow into the facepiece. In other words, when the worker "demands" the air, he or she gets it. When the wearer exhales, the flow of air into the facepiece stops. The advantage of the demand flow regulator is that the air supply is not wasted, so the time allowed by the tank is maximized. The disadvantage is that the regulator depends on negative air conditions during inhalation. Because of this, the PF for demand type atmosphere supplying respirators is only 50.
Pressure demand regulators are similar to demand flow regulators in that airflow into the facepiece occurs mainly during inhalation. However, there is also a constant flow of air into the mask that keeps it pressurized. So, negative pressure conditions never exist, even during inhalation. Instead, positive pressure conditions exist at all times, and leakage is minimized. This regulator is used most often in hazardous waste operations.
Air Line Respirators
Air line respirators supply air to a facepiece through a length of hose. The hose is connected to either a compressed air cylinder or a compressor that is equipped with equipment to purify the air. The air supply can be used to pressurize the respirator to achieve a high PF. With a pressure demand regulator, a PF of 1,000 can be typically obtained. The air line respirator, shown in Figure 4-9, is being used more and more for lead removal. It does however have the following limitations :
Due to the limitations of air line respirators, they are often used with a small bottle of air for escape purposes. The bottle contains a 5 to 10 minute air supply. When this escape bottle is provided, OSHA assigns the unit a PF of 2,000. Escape bottles are required for air line respirators being used in IDLH atmospheres.
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Figure 4-9. Air line respirator.
Self-Contained Breathing Apparatus
A self-contained breathing apparatus (SCBA) consists of a facepiece and regulator mechanism connected to a cylinder of compressed air that is worn by a worker (Figure 4-10). SCBAs are commonly used during the most hazardous aspects of waste site jobs because they have a high PF. With an SCBA, a worker doesn't have air line problems. Worker training is essential to the safe use of SCBAs. There are different types of SCBAs with their own set of limitations. They include:
Open Circuit vs. Closed Circuit SCBAs
With an open circuit SCBA, exhaled air goes through valves directly into the outside air. The system comprises a tank of breathing quality air containing between 19.5% and 23.5% oxygen, a regulator, and the respirator. Open circuit tanks usually are rated at 30 to 60 minutes.
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Closed circuit SCBAs are called rebreathers because the exhaled air goes back into the system to be recycled. A closed-circuit system consists of a scrubber device to remove exhaled carbon dioxide, a tank of pure oxygen, and a breathing bag to blend the mixture. The closed circuit unit supplies enough breathing air for up to four hours.
Rebreathers work in the following manner. The air for breathing is mixed in a flexible breathing bag. As the wearer inhales and deflates the bag, oxygen flows into the bag from the oxygen tank. The oxygen tank can contain either compressed or liquid oxygen. The exhaled air goes through a filter known as an alkaline scrubber, which removes the carbon dioxide from the exhaled breath. The scrubbed air then mixes with the oxygen in the bag, so that a breathing quality mixture is available for the next inhalation.
One problem for rebreathers is that they typically use demand regulators, which means that they have a lower PF. This demand type rebreather is not recommended for hazardous waste work. There are a few companies that make rebreathers with pressure demand regulators which can be used on a hazardous waste site. NIOSH has given them a PF of 10,000.
Escape vs. Entry SCBAs
The typical pressure demand SCBA is an open circuit unit with a large cylinder. It provides enough air for 30 to 60 minutes and weighs about 25 or 30 pounds. This SCBA is called an entry SCBA and is good for any type of work. Escape SCBAs are small cylinders capable of providing 5 to 10 minutes worth of breathable air. They do not provide enough air for entry to do work, but are only used for emergency evacuation. Some air line respirators have attached escape SCBAs which provide additional protection (PF is 10,000). Other escape SCBAs use hoods and workers wearing non-SCBA respirators use them for emergencies.
Pressure-demand, open-circuit, entry SCBAs are the work-horse respirators used on waste sites when hazards are severe or unknown. They provide excellent protection to the worker. The chief drawbacks to these respirators are their weight and a limited air supply. These limitations greatly affect the work schedule because the work day is broken up into many smaller segments. Also, some workers feel uncomfortable and confined in the respirator. It's important that workers be able to familiarize themselves with SCBA equipment, as well as practice using it before going in a hazardous area.
Protection Factors for Respirators
All respirators differ in the amount of protection they provide since all facepieces leak to a certain degree. The amount of leakage depends on how well the facepiece seals (fits) around the face. If the seal is not good, contaminated air enters, which can lead to adverse health effects.
Industrial Hygenist (IH) use a scoring system called protection factor (PF) for ranking the different types of facepieces. Facepieces are tested for leakage by measuring the contaminant levels both outside and inside the facepiece. A ratio of these two measurements provides the PF. Respirator PFs range from 5 to 10,000. The lower the PF, the lower the protection. The higher the PF, the higher the protection. In other words, low PFs provide the lowest protection, and high PFs provide the highest protection.
A PF of 10 means that if the exposure level is 100 µg/m3 (micrograms per cubic meter) outside the facepiece, the inside level would be 10 µg/m3 due to the facepiece leakage (the ratio of 100/10 = 10). In other words, any respirator with a PF of 10 doesn't eliminate exposure; it cuts the exposure by a factor of 10. Therefore, workers can be exposed above OSHA's permissible exposure limit (PEL), even though they are wearing a respirator. This is not acceptable. IH must take air samples to ensure that the respirator is appropriate for the exposure levels on the job.
Facepieces that have a PF of 10 can only be used in exposures up to 10 times over OSHA's PEL; use in higher levels of exposure cause overexposure.
According to OSHA's Lead in Construction Standard, the contractor may select the respirator that maintains the concentration inside the respirator below 50 µg/m3 (micrograms per cubic meter) of air.
All facepieces have an acceptable level of concentration use. This level is referred to as maximum use concentration (MUC).
If workers know the PF and OSHA's PEL, they can determine the highest level that a facepiece can be safely used by multiplying the PEL.
MUC = (PF)(PEL)
Note: Workers must not remove their respirator mask while in a contaminated area because even brief exposures can reduce the PF significantly. The PF provided by SCBAs is 10,000. If a worker's mask is taken off 5% of the time (3 minutes out of an hour), it's like reducing the PF from 10,000 down to 100. If a worker's mask is taken off 10% of the time (6 minutes out of an hour), the PF would decrease to 10.
Air Purifying Respirators
The PFs for air purifying respirators follow.
Half-Face Air Purifying Respirators
Half-face air purifying respirators can't be used with lead levels exceeding 500 µg/m3 (micrograms per cubic meter). When the µg/m3 exceeds the MUC, workers are exposed above OSHA's PEL.
In the following example, workers can use a half-face respirator because the MUC didn't exceed 500 µg/m3.
| PEL for Lead | = | 50 µg/m3 |
| PF of Half-Mask | = | 10 |
| MUC = (50)(10) | = | 500 µg/m3 |
Reusable half-face air purifying respirators (with HEPA filters) are approved for concentrations up to 500 µg/m3 (10 times the PEL).
Full-Face Air Purifying Respirators
Full-face air purifying respirators are approved for concentrations up to 2,500 µg/m³ or 50 times the PEL. This type of respirator provides a higher PF of 50, because it is easier to get a good seal across the forehead, than it is across the nose. (Half-face air purifying respirators seal across the nose.)
Powered Air Respirators
PAPRs with HEPA filters have a PF of 50 (for lead), which permits lead exposures up to 2,500 µg/m³. OSHA assigns a PF of 25 for loose-fitting hoods or helmets PAPRs (with a flow rate of 6 cfm). Loose-fitting hood or helmet PAPRs with HEPA filters are permitted to be used in lead exposures up to 1,250 µg/m³ (25 times the PEL). Often, OSHA assigns much higher PFs to PAPRs than NIOSH. This is the case with asbestos (OSHA assigns a PF of 100, NIOSH recommends a PF of 50); thus, there are some disagreement between agencies. Because NIOSH is the testing and certification branch of OSHA (they make recommendations to OSHA), and OSHA is a regulatory agency (they make the laws), always follow OSHA's protection factor ratings. These may be found within specific standards for specific hazardous occupations such as lead abatement (29 CFR 1926.62), asbestos abatement (29 CFR 1926.1101), and hazardous waste remediation (29 CFR 1926.65).
Supplied Air Respirators
The PFs for supplied air respirators used for lead exposures follow.
A PF of 1,000 can be, typically, obtained with a regulator known as a "Pressure-Demand." NIOSH recommends a higher rating of 2,000.
There are some supplied airline masks which include an escape SCBA tank. The tank, containing a 5- to 10-minute air supply, is much smaller than the large tank used with the SCBA. When this back-up tank is provided, OSHA assigns the unit a PF of 2,000 (for lead). Only supplied air respirators with back-up tanks can be used in imminent dangerous to life and health (IDLH) atmospheres.
Type CE Continuous Flow Positive Pressure Respirators (Abrasive Blasting Hood or Helmet)
These loose fitting respirators are approved up to 1,250 µg/m3 for lead. This type of respirator has the same MUC as the loose-fitting PAPR because they both provide the wearer air at a constant rate. Therefore, they both have the same limitation of being out breathed (breathing more air than the respirator can provide).
Type CE Positive Pressure, Pressure Demand
A type CE positive pressure, pressure demand respirator may be used for concentrations up to 100,000 µg/m3. With a compressed-air cylinder back-up, they may be used in concentrations greater than 100,000 µg/m3 or unknown concentrations.
Self-Contained Breathing Apparatus
Because of the limitations in using this type of respirator (30 minute air tank and weight of the unit), this type of respirator is not often used for lead abatement jobs. SCBAs have a high PF (2,000 + for lead) assigned to them and may be used in concentrations of lead greater than 100,000 µg/m3 or unknown concentrations.
Table 4-5 shows the type of respirator required for the airborne concentrations of lead aerosols. (Notes: PFs for the powered air purifying respirators are from the most recent data available. Quick referencing materials for Protection Factors, Maximum Use Concentration, and Respirator Profiles are found in Appendix 4-1, 4-2, and 4-3 at the end of this chapter.)
Table 4-5. Respiratory protection for lead aerosols.
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RESPIRATOR SELECTION CRITERIA
Employers are responsible for selecting the appropriate
respirators for their workers. Many employers use industrial hygienist for this purpose. The industrial hygienist evaluates the information gathered about the site and conditions and applies it to a selection process. The selection process is based upon NIOSH's Respirator Decision Logic and involves answering a series of questions to determine the specific respirator needed.
Therefore, the information gathered is critical in order to use the selection process logic, and must include the following:
General Use Conditions/Determination of Contaminants
General use conditions include the following:
Determination of the contaminant's includes the identity of the substances present in the air and the actual measured exposure level of the contaminant on the job. If possible, an estimate of the highest level of exposures that workers are likely to encounter should be included. An industrial hygienist will be necessary to determine the the concentration of chemicals.
Properties of the Contaminants
Information is needed on the physical, chemical, and toxic properties of the contaminant. This information includes:
Odor Threshold Data
Information on odor threshold is essential to determine whether the contaminant has warning properties at or below the exposure limit that will allow APRs to be selected. If the odor threshold exceeds the exposure limits, the contaminant is not considered to have good warning properties and APRs (except those with end of service life indicators) are not recommended for use. Data on odor thresholds will have to be obtained from industrial hygienist or other experts, such as NIOSH or OSHA.
Exposure Limits
Exposure limits include OSHA's PEL or NIOSH's recommended exposure limit (REL). This information is necessary if maximum use concentration (MUC) are to be calculated for the types or classes of respirators, using their assigned PFs. The NIOSH Pocket Guide to Chemical Hazards is an excellent source for this information for many chemicals.
IDLH Concentrations
Contaminant concentrations that are IDLH are life threatening and call for the use of the most protective respirators for the wearer. The NIOSH Pocket Guide to Chemical Hazards provides IDLH concentrations for many chemicals that are found in the workplace. The IDLH concentration for a substance must be compared to the actual concentration measurement of the substance on the job.
Eye Irritation
If a contaminant has the potential to cause eye irritation, a full facepiece, hood, or helmet should be selected instead of a half mask. This is to provide the worker with adequate protection from eye irritation.
Service Life Information
Collect any service life information that is available for cartridges and canisters used in APRs. Service life will help to determine the length of time that a cartridge/canister could provide protection to the worker and can be used to establish cartridge replacement schedules.
RESPIRATOR DECISION LOGIC SEQUENCE
After criteria information is gathered and evaluated, the industrial hygienist follows a sequence of questions to identify the NIOSH recommended class of respirators for the airborne contaminant's. The questions listed below are summarized from the Respirator Decision Logic document. They should be followed in sequence, while using the criteria information that has been gathered to select the proper respirator.
Divide the measured exposure concentration of the contaminant by its OSHA or NIOSH exposure limit. For escape respirators, determine the potential for a hazardous condition to occur caused by an accident or equipment failure. Go to step 9.
10.2 Determine the type of filter that should be used
for the particulate contaminant. Go to step 10.3
10.3 Select a particulate respirator with a PF equal to
or greater than the minimum PF calculated in step 8.
11.2 Are the warning properties for the gas/vapor contaminant adequate at or below the exposure limit (PEL or REL)?
11.3 An APR chemical cartridge/canister respirator is recommended. Go to step 11.4.
11.4 Select a gas/vapor respirator with a PF equal to or greater than the minimum PF calculated in step 8.
12.3 Use an APR with chemical cartridge/canister that has a particulate pre-filter. Go to step 12.4.
12.4 Select a combination gas/vapor and particulate respirator with a PF equal to or greater than the minimum PF calculated in step 8.
The respirator decision flow chart shown in Figure 4-11 helps the selector organize the information and keep track of the flow of questions in the sequence.
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Figure 4-11. Respirator decision flow chart.
RESPIRATOR PROGRAM REQUIREMENTS
The safe use of a respirator is more than just knowing how to put it on. OSHA Standard 1910.134 governs general requirements for respirator usage (Appendix C). The standard requires that employers establish a written respirator program to cover all aspects of respirator use. This program is called the Minimal Accepted Respirator Program (MARP) and includes 11 requirements:
Air Quality
OSHA regulation 29 CFR 1910.134 (d) addresses air quality, an important issue for atmosphere supplying respirators. Respirator air quality must, as a minimum, meet Grade D standards. Grade D air has the following limits:
Other issues addressed by section 1910.134 (d) include the following:
Note: Compressors used for pneumatic tools must not be used for air line systems. The air contains carbon monoxide and is unbreathable and dangerous.
Use of Respirators
Section 1910.134(e) of the OSHA Standards address usage questions. It includes the requirement that additional standby workers shall be present in areas where the atmosphere is toxic or oxygen deficient and workers might be overcome if their respirators failed. The purpose of the standby worker is to assist co-workers in case of an emergency. It also deals with properly wearing, adjusting, and fitting respirators.
Fit Checks
Respirators need to be selected and adjusted each time they are put on to ensure the best possible seal. There are two common procedures a worker must perform to check a facepiece seal:
Positive Pressure Check
To perform a positive pressure check, follow these steps:
If the respirator fits, a slight pressure should build up inside it. If air leaks out, the respirator does not fit properly and the seal is inadequate. Figure 4-12 illustrates a positive pressure check.
Figure 4-12. Positive pressure fit check.
Negative Pressure Check
To perform a negative pressure check, follow these steps:
If the facepiece fits correctly, it should collapse slightly inward. If the facepiece does not fit correctly, it will not collapse and an air leak will be felt. This test is done on SCBAs by covering the hose with the hand and inhaling (Figure 4-13).
Figure 4-13. Negative pressure fit check.
QUALITATIVE FIT TESTING
A qualitative fit test (QLFT) involves introducing a harmless, odorous, or irritating substance into the breathing zone of the wearer. If the wearer doesn't detect the substance, the respirator fits properly. Three testing agents are used for a QLFT:
Qualitative fit testing addresses the following issues:
A QLFT is simple and inexpensive, which makes it the most common type of fit testing done for respirators. However, a QLFT relies upon a wearer's subjective response to the testing media. In other words, the wearer must inform the tester if he/she can smell or taste the substance. Because of the subjectivity of the QLFT, a respirator should never be assigned a PF higher than 10 when using this type of test.
Note: Before performing any test, make sure the correct respirator cartridges have been installed.
Fit Testing Protocols
A specific procedure or protocol has been provided by OSHA for the performance of all qualitative fit tests. By following this protocol for each qualitative a fit test, the test results will be consistent from one test to another. A fit test chamber is used to ensure that the concentration of the testing agent is at the same level for the entire fit test. A sample fit test chamber is shown in Figure 4-14.
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Figure 4-14. Fit test chamber for isoamyl acetate.
The American National Standards Institute (ANSI Z88.10 Respirator Fit Test Methods) has created protocols for fit testing respirators. OSHA has adopted ANSI's fit testing protocols as their own, and specifies them as the only allowable qualitative fit test protocols permissible for compliance. They may also be referenced through other specific OSHA regulations that require the use of a respirator.
When and Who Should Do the Fit Testing and When
A fit test must be given to any worker who is issued a respirator prior to entering a hazardous atmosphere. A fit test is generally good for 6 months to 1 year. It must be retaken if a worker gains or loses 20 pounds, or has facial or oral surgery. Fit tests must be given by a trained and competent person who has a thorough understanding of respirator use and testing protocols.
Isoamyl Acetate Protocols
Isoamyl acetate (IAA) is also known as banana oil. Before using IAA as a fit testing agent, OSHA requires an odor threshold screening to be conducted. The screening determines if a worker can smell the IAA at low concentrations or 1 part per million (PPM). If the worker can detect the banana oil, he or she will be allowed to use this protocol.
Note: In some individuals, exposure to IAA may cause the following health effects:
Irritant Smoke Test
Another fit testing agent is irritant smoke. It is very irritating to the eyes, nose, and throat, and usually causes the subject to cough. The worker being tested must keep his or her eyes closed during the fit test when wearing a half facepiece. This test requires combination filters for both acid gases and particulates. They are color-coded white and purple or white and magenta.
Saccharin Test
The saccharin test uses a saccharin aerosol. If saccharin leaks into the facepiece, the worker will have a sweet taste on the lips and tongue. Workers must take a taste test before using this testing agent because some people can't taste saccharin. A small nebulizer is used to create a saccharin aerosol inside the test chamber. This test uses HEPA cartridges, which are color-coded magenta.
QUANTITATIVE FIT TESTING
A quantitative fit test (QNFT) measures the actual amount of leakage into the respirator. It is the most sophisticated type of fit test. An aerosol generator is used to create an atmosphere of corn oil, salt, or other harmless aerosol inside a fit chamber or booth. Air monitoring instruments measure both the concentration inside the booth and the concentration inside the actual mask. (A measurement probe inserted into the mask samples the air inside the mask.)
OSHA has a procedure for quantitative fit testing. This is the same type of test that is done in research labs to develop the protection factors which were described early in this section.
OSHA REQUIREMENTS
OSHA also requires that workers be trained to perform positive and negative pressure checks and receive fit tests on a regular basis. In addition, OSHA does not permit respirators to be worn when conditions prevent a good seal. These conditions include the following:
This is the reason beards are prohibited for workers who must rely on respirators. A beard prevents the mask from sealing against the face, and results in a high rate of leakage.
Eyeglasses are another big fit problem. The temple bars on eyeglasses prevent a respirator from sealing against the side of the head. To go without eyeglasses creates vision-related problems, such as tripping hazards. Respirator manufacturers make fittings which hold the lenses in place in the mask without temple bars. It is an OSHA requirement that this type of fitting be made available to workers with glasses at the employer's expense.
Cooling Garments
Heat stress is a hazard when wearing PPE in warm weather and/or doing vigorous work. There are two different types of cooling devices that have been developed for use in special situations.
USING PERSONAL PROTECTIVE EQUIPMENT
Training is critical to the safe and proper use of PPE for the following reasons:
Even though this course provides experience with PPE, site specific training is important. There may be important differences between manufacturers.
Personal Use Factors
Several items can affect the protection provided by PPE. It's important that workers are aware of these items. They include the following:
Facial Hair
A beard or long sideburns prevent a good seal between the face and the respirator. Studies have shown that any facial hair reduces the protection received from a respirator. This includes a full beard, as well as a few days growth. A mustache is acceptable if it fits under the mask without affecting the seal.
Long Hair
Long hair may interfere with a good seal in some situations. The hair must be contained under the protective suit.
Eyeglasses
The temple bars that extend from the ear to the lens prevent the respirator from fitting up against the side of the head. Spectacle kits take care of this situation quite easily. They are inexpensive, and must be provided by the employer. Under no condition should workers hesitate to request a spectacle kit. To work without eyeglasses creates a serious potential for accident and injury.
Contact Lenses
Contact lenses cannot be used with a respirator in a containment for the following reasons:
Gum and Tobacco Chewing
Gum and tobacco chewing are prohibited when wearing a respirator. The chewing action puts a strain on the respirator seal. It could also lead to ingestion of contaminant's.
Donning PPE
Donning is the act of putting on PPE. It's not difficult to put on the equipment. However, a specific routine must be followed for the best results.
Before entering the work area (Figure 4-15), personal protective
clothing should be donned (put on) in the following sequence
Figure 4-15. Typical decon layout.
While in the clean change room:
While in the equipment/dirty room:
While in the work area:
Once inside the work area, workers must never leave without going through the decontamination process (doffing personal protective clothing), unless it's an extreme emergency. Common problems include workers "stepping out" for a cigarette or workers "stepping in" the work area to deliver messages or equipment. These type of actions defeat the purpose of protecting workers and others from lead exposure.
Doffing PPE
Doffing is the act of removing PPE. Again, it is important to follow the specific steps when removing PPE. Doffing is made more complicated by the fact that the PPE may be contaminated.
Before workers leave the work area for any reason, they should doff (take off) their personal protective clothing in the following sequence.
While in the Work Area or Equipment/ Dirty Room:
With the respirator still on:
While in the clean change room:
FALL PROTECTION SYSTEMS
As with any construction site, falls are a hazard on bridge repair or renovation projects. However, wearing PPE can increase the risk of falls or make a fall more dangerous. For example, the added weight of an SCBA can cause a worker to lose balance more easily or make it harder to recover from a trip or stumble. OSHA requires that fall protection systems be used to protect workers when working at heights. These systems include:
Guardrail Systems
If an employer chooses to use guardrail systems to protect workers from falls, the systems must meet the following criteria:
Structure
The highest part of the toprail shall be 42 inches, ±3 inches above the working surface. When midrails are used, they must be installed at a height midway between the toprail and the working level.
Projections
Guardrail systems shall be smooth to protect workers from punctures or lacerations and to prevent PPE from snagging. In addition, the ends of toprails and midrails must not overhang terminal posts, except when the overhang does not create a projection hazard.
Walking/Working Surfaces
In hoisting areas, a chain, gate, or removable guardrail section must be placed across the opening when hoisting operations aren't taking place.
At holes, guardrail systems must be set up on all unprotected sides or edges. When holes are used for passing materials, they shall have no more than two sides with removable guardrail sections. When the hole is not in use, it must be covered or provided with guardrails along all unprotected sides or edges.
Guardrail systems can be used around holes that are access points, such as ladderways. In this situation, the guardrail must have gates, or the point of access must be offset to prevent workers from accidentally walking into the hole.
If guardrails are used at unprotected sides or edges of ramps and runways, they must be erected on each unprotected side or edge.
Personal Fall Arrest
A personal fall arrest system consists of an anchorage, connectors, and a body belt or body harness. It may also include a deceleration device, lifeline, or suitable combinations. If a personal fall arrest system is used for fall protection, it must do the following:
Note: As of January 1, 1998 the use of body belts for fall arrest is prohibited.
Personal fall arrest systems must be inspected prior to each use for wear damage and other deterioration. Defective components must be removed from service.
Self-retracting life lines and lanyards that do not limit free fall distance to 2 feet or less shall be capable of sustaining a load of 3,000 pounds applied to the device in the fully extended position. Ripstitch lanyards that tear apart when a load is place on them shall be capable of sustaining a minimum load of 5,000 pounds. Lanyard ropes, lifeline straps, and body belt and harness components shall be made of synthetic fibers.
Anchorages used to attach personal fall arrest systems shall be independent of any anchorage being used to support or suspend platforms. Personal anchorage points, lanyards, and vertical life lines must be capable of supporting at least 5,000 pounds per person attached.
Positioning Device Systems
These body belt or body harness systems are to be set up so that a worker can free fall no farther than 2 feet. They shall be secured to an anchorage capable of supporting at least twice the potential impact load of an employee's fall or 3,000 pounds, whichever is greater.
Safety Net Systems
Safety net systems must be installed as close as possible under the working surface, but never more than 30 feet below such levels. Defective nets shall not be used. Safety nets shall be inspected at least once a week for wear, damage, and other deterioration. The maximum size of each safety net mesh opening shall not exceed 6 inches x 6 inches. All mesh crossing shall be secured to prevent enlargement of the mesh opening. Each safety net or section shall have a border rope for webbing with a minimum breaking strength of 5,000 pounds.
Connections between safety net panels shall be as strong as integral net components and be spaced no more than 6 inches apart.
Safety nets shall be installed with sufficient clearance underneath to prevent contact with the surface or structure below. They shall be capable of absorbing the impact of a 400 pound drop test. Items that have fallen into safety nets, such as scrap, equipment, and tools, must be removed as soon as possible or at least before the next work shift.
Safety Monitoring Systems
When no other alternative fall protection has been
implemented, the employer shall implement a safety monitoring system. The safety monitoring system is a system in which a competent person is responsible for recognizing and warning workers of fall hazards. This safety monitor shall:
Other provisions of the safety monitoring system include the following:
A controlled access zone is an area in which certain work may take place without the use of guardrail systems, personal fall arrest systems, or safety net systems. Entry (access) to the zone is controlled.
Training
Employers must provide a training program that teaches workers who might be exposed to fall hazards how to recognize such hazards and how to minimize them. In addition, they must issue written certification that identifies the worker as trained with the date of the training. The employer or trainer must sign the certification record. Retraining also must be provided when necessary.
INSPECTIONS
Inspection are an important part of a good PPE program. Checklists and written records are needed to verify and maintain the effectiveness and safety of the PPE. There are different types of inspections.
The responsibility to inspect PPE must be assigned to a specific qualified person. However, it is a good practice for workers to know how to do a basic equipment inspection. Inspection guideline are provided in Appendix 4-2.
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ASSIGNMENT SHEET
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Appendix
RESPIRATOR PROFILES
Half-face Mask
Other Common Names: Cartridge Mask, Type A Mask, Negative Pressure Mask, APR
Assigned Protection Factor: 10
Limitations: Can only be used at low exposure levels, where contaminant's are known and adequate filters are available. Can't be worn in an O2 deficient atmosphere. Contaminate should have adequate warning properties.
Full-face Mask
Other Common Names: Cartridge Mask, Canister Mask, Negative Pressure Mask APR
Assigned Protection Factor: 50
Limitations: Limited protection. Can only be used when exposure levels are fairly low, (less than 50 x PEL) and contaminant's are known. Limited selection of filters. Can't be worn in an oxygen-deficient atmosphere.
Powered Air-Purifying
Other Common Names: PAPR
Assigned Protection Factor:
50......... OSHA
50......... NIOSH
25......... OSHA (for loose-fitting hood models)
Limitations: Protection depends on charged battery. Use restricted by considerations as other full-face masks. Can't be worn in an oxygen-deficient atmosphere.
Supplied Air Respirator
Other Common Names: Hose Masks, SAR Masks, Type CE Respirators
Assigned Protection Factor:
1,000 - OSHA 1/2-face positive pressure, pressure demand (pppd)
1,000 + - NIOSH Full-face pppd equipped with auxiliary escape tank SCBA operated in pppd mode.
Limitations: Problems with hose (prone to tangling and damage).
Self-Contained Breathing
Other Common Names: SCBA
Apparatus Assigned Protection Factor: 50 for demand units
2,000 for pressure demand units.
Limitations: Very Heavy. Air supply limited 30 or 60 minutes in 2200 or 4500 psi cylinders.
STANDARD OPERATING PROCEDURE 1
A. Inspect the half-face APR. Check all parts for signs of dirt, wear, tears, and integrity. Ensure that all parts can and will work properly by using the following steps:
1. Check general appearance (no deformities).
2. Check harness and strap assemblies.
3. Check nose cup.
4. Check facepiece seal area.
5. Check inhalation valves.
6. Check exhalation valve, valve seats, and cover.
7. Check cartridge or filter holder and gaskets.
8. Check cartridges or filters.
B. Don a half-face APR using the following steps:
1. Inspect the respirator (8 steps from A., Standard Operating Procedure 1).
2. Loosen the harness assembly completely.
3. Hang the facepiece around your neck using the neck strap (if available).
4. Raise the facepiece upward and open, exposing your chin and nose cup.
5. Place your chin in the chin cup and pull the harness over the top of your head. (Make sure there is no hair or other obstructions between your face and facepiece.)
6. Tighten the bottom two harness straps (not too tight).
7. Tighten the top strap slightly.
8. Adjust the mask if needed. The mask should be centered on your face.
C. Perform a negative pressure check with the half-face APR.
1. Inspect the respirator (8 steps from A., Standard Operating Procedure 1).
2. Don the respirator (8 steps from B., Standard Operating Procedure 1).
3. Cover the filter/cartridge inlet openings. (Use the palms of your hands, duct tape, plastic wrap, or surgeon's gloves.)
4. Inhale, so the facepiece collapses inward, and hold for ten seconds.
5. If the facepiece stays collapsed, continue with Step 7.
6. If there is leakage, readjust the facepiece and try again. If there is still leakage, reinspect the respirator and try again. If you still can't get a seal, try a different size and/or respirator.
7. Remove the coverings from the filter or cartridge inlets.
D. Perform a positive pressure check with the half-face APR.
1. Inspect the respirator (8 steps from A., Standard Operating Procedure 1).
2. Don the respirator (8 steps from B., Standard Operating Procedure 1).
3. Cover the exhalation outlet. (Use the palms of your hands, duct tape, plastic wrap, or surgeon's gloves.)
4. Exhale, so the facepiece is enlarged slightly, and hold for ten seconds.
5. If the facepiece stays enlarged, continue with Step 7.
6. If there is leakage, readjust the facepiece and try again. If there is still leakage, reinspect the respirator and try again. If you still can't get a seal, try a different size and/or respirator.
7. Remove the coverings from the exhalation outlet.
E. Clean, sanitize, and maintain a half-face and/or full-face APR using the following steps:
1. Remove and properly discard filters and/or cartridges.
2. Immerse the respirator in a warm (about 120º) solution of germicidal or disinfecting detergent.
3. Scrub the respirator body and parts gently with a cloth or soft brush.
4. Rinse in clean, warm water (about 120º F).
5. Shake gently to remove excess water. It may be necessary to tip the respirator in several directions.
6. Wipe the respirator with a soft, clean cloth (if available) or allow to air dry away from direct heat or sunlight.
7. Inspect the respirator (8 steps from A., Standard Operating Procedure 1).
8. Replace all damaged or missing parts according to the manufacturer's instructions.
9. Loosen harness straps.
10. Place respirator in a clean bag, box, or storage area in a cool, dry place. Do not place any weight on the respirator.
STANDARD OPERATING PROCEDURE 2
Complete an Isoamyl Acetate (IAA) Qualitative Fit Test using the following steps:
1. Read the following instructions. These instructions will be typed on a card and placed on the table in front of the two test jars (1 and 2).
"The purpose of this test is to determine if you can smell banana oil at a low concentration. The two jars in front of you contain water. One of these jars also contains a small amount of banana oil. Be sure the covers are on tight, then shake each jar for two seconds. Unscrew the lid of each jar, one at a time, and sniff at the mouth of the jar. Indicate to the test conductor which jar contains banana oil."
2. Make sure each of the covers are on tight, and shake each jar for two seconds.
3. Unscrew the lid of each jar one at a time, and sniff at the mouth of the jar.
4. Indicate to the person conducting the test which jar contains the banana oil.
5. If you are unable to correctly identify the jar containing the odor test solution, the IAA QLFT may not be used.
6. If you correctly identify the jar containing the odor test solution, proceed to Step 7.
7. Select the most comfortable respirator from the various sizes and manufacturers by holding each facepiece up to your face, and eliminating the ones that don't fit comfortably. Normally, selection will begin with a half-mask. If a half-mask respirator can't be found, look for a full-facepiece respirator. (A small percentage of users will not be able to wear any half-mask). Each respirator represents a different size and shape. If the respirator fits properly, it will provide adequate protection. The selection process shall be conducted in a room separate from the fit test chamber to prevent odor fatigue. A mirror shall be available to assist you in the evaluation of the fit and positioning of the respirator.
8. Inspect the chosen respirator, make sure that it is equipped with an organic vapor cartridge. Don and wear the most comfortable mask for at least five minutes to assess comfort. Assess comfort by discussing and reviewing the following points with your instructor(s).
9. If you are not familiar with using a particular respirator, your instructor(s) will help you inspect and don the mask several times. Adjust the straps each time, so that you set the proper tension on the straps.
10. After selecting, donning, and properly adjusting a respirator, "seat" the mask by rapidly moving the head side to side and up and down, taking a few deep breaths.
11. Conduct the conventional negative and positive pressure fit checks (e.g. see ANSI Z88.2-1980 - see Standard Operating Procedure 1 - A. and B.)
12. Wear the respirator for at least 10 minutes before starting the fit test.
13. Enter the fit test room, get the 6-inch by 5-inch piece of paper towel or other porous absorbent single ply material. Fold the paper towel in half, and wet it with three-quarters to one cc of pure IAA from the instructor. Hang the wet towel on the hook at the top of the chamber.
14. Allow two minutes for the IAA test concentration to be reached before starting the fit-testing exercises. Read the test exercises that are taped to the inside of the test chamber. Use this time to ask the instructor(s) any questions or to have them demonstrate exercises.
15. Perform the following test exercises for at least one minute each.
a. Breath normally.
b. Breathe deeply. Be certain that breaths are deep and regular.
c. Turn head from side to side. Be sure movement is complete. Do not bump the respirator on your shoulders. Inhale when the head is at either side.
d. Nod head up and down. Be certain motions are complete and made about every second. Do not bump the respirator on your chest. Inhale when your head is in the full up position.
e. Talk aloud and slowly for several minutes. Read the following Rainbow Passage. Reading this passage results in a wide range of facial movements; and thus, useful to satisfy this requirement.
"When the sunlight strikes raindrops in the air, they act like a prism and form a rainbow. The rainbow is a division of white light into many beautiful colors. These take the shape of a long round arch, with its path high above, and its two ends apparently beyond the horizon. There is, according to legend, a boiling pot of gold at one end. People look, but no one ever finds it. When a man looks for something beyond reach, his friends say he is looking for the pot of gold at the end of the rainbow."
f. Breath normally.
16. If at any time during the test, you detect the banana-like odor of IAA, quickly exit the test chamber and leave the test area to avoid olfactory fatigue.
17. If you have detected the odor, return to the selection room and remove the respirator. Repeat the odor sensitivity test and select another respirator. If you can't be fitted with the selection of half-mask respirators, include full facepiece models in your selection process. Return to the test by starting at Step 8 above.
18. If you complete the test without detecting the banana-like odor, break the face seal and take a breath before exiting the chamber. This demonstrates the efficiency of the respirator.
19. Remove the saturated towel from the hook, leave the test chamber, and return the towel to the instructor(s).
20. If you successfully passed this fit test, you may be assigned the use of the tested respirator in atmospheres with up to 10 times the PEL. In other words, this IAA protocol may be used to assign a protection factor no higher than 10.
21. After passing the fit test, assess the comfort of the respirator using the steps outlined above. If the respirator becomes uncomfortable, try another respirator model and conduct a fit test.
STANDARD OPERATING PROCEDURE 3
A. Complete an irritant smoke or Isoamyl Acetate Qualitative Fit Test using the following steps:
1. Smell a weak concentration of the test agent.
2. Inspect the respirator (8 steps from A., Standard Operating Procedure 1).
3. Don the respirator (8 steps from B., Standard Operating Procedure 1).
4. Perform a negative pressure check (5 steps from C., Standard Operating Procedure 1).
5. Perform a positive pressure check (5 steps from D., Standard Operating Procedure 1).
6. Wear the respirator for at least 5 minutes.
7. Step into the test chamber or bag.
8. Close your eyes.
9. Breathe normally.
10. Breathe deeply. (Breaths must be deep and regular.)
11. Turn your head from side to side.
12. Nod your head up and down.
13. Read the Rainbow Passage.
14. Jog in place.
15. Breathe normally.
16. If the test agent is detected, get out of the test chamber and readjust the mask. Repeat Steps 4 through 15.
17. If the test agent is still detected, select another size and/or type respirator and repeat Steps 2 through 15.
18. Clean, sanitize, and maintain the respirator (10 steps from E., Standard Operating Procedure 1).
STANDARD OPERATING PROCEDURE 4
A. Inspect a full-face APR using the following steps. Check for signs of wear, dirt, and integrity. Check to ensure that all parts work properly.
1. Overall general appearance (no deformities).
2. Harness assembly and connections.
3. Lens and lens gasket.
4. Face to facepiece seal area.
5. Inner nose cup.
6. Inhalation valves and their seating surfaces.
7. Exhalation valves and their seating surfaces.
8. Filter or cartridge assembly.
9. Filter or cartridge.
10. Install proper filter or cartridge.
B. Don a full-face APR using the following steps:
1. Inspect the respirator (10 steps from A., Standard Operating Procedure 3).
2. Loosen the harness assembly completely.
3. Hang the facepiece around your neck using the neck strap (if available).
4. Raise the facepiece upward and open to expose the your chin and nose cup.
5. Place your chin in the chin cup and pull the harness over the top of your head. Make sure there is no hair or other obstructions between your face and facepiece.
6. Tighten the bottom harness straps (not too tight).
7. Tighten the middle two harness straps.
8. Tighten the top strap slightly.
9. Adjust the mask if needed. (The mask should be centered on your face.)
C. Perform a negative pressure check with a full-face APR.
1. Inspect the respirator (10 steps from A., Standard Operating Procedure 3).
2. Don the respirator (9 steps from B., Standard Operating Procedure 3).
3. Cover the filter or cartridge inlet openings. (Use the palms of your hands, duct tape, plastic wrap, or surgeon's gloves.)
4. Inhale, so that the facepiece collapses and hold for ten seconds.
5. If the facepiece stays collapsed, go to Step 7.
6. If there is leakage, readjust the facepiece and try again. If there is still leakage, reinspect the respirator and try again. If you still can't get a seal, try a different size and/or respirator.
7. Remove the coverings from the filter or cartridge inlets.
D. Perform a positive pressure check with the full-face APR.
1. Inspect the respirator (10 steps from A., Standard Operating Procedure 3).
2. Don the respirator (9 steps from B., Standard Operating Procedure 3).
3. Cover the exhalation outlet. (Use the palms of your hands, duct tape, plastic wrap, or surgeon's gloves.)
4. Exhale, so that the facepiece is enlarged slightly and hold for ten seconds.
5. If the facepiece stays enlarged go to Step 7.
6. If there is leakage, readjust the facepiece and try again. If there is still leakage, reinspect the respirator and try again. If you still can't get a seal, try a different size and/or respirator.
7. Remove the coverings from the exhalation outlet.
STANDARD OPERATING PROCEDURE 5
A. Don and doff the following personal protective equipment:
Donning:
1. Remove all street clothes, including undergarments. Store street clothes in a clean, convenient location. (Bins or lockers work well.)
2. Put on disposable undergarments.
3. Put on disposable coveralls.
4. Put on disposable foot coverings (if separate disposable foot coverings are used).
5. Tape ankles to take up the slack in the suits and to reduce the chance of tripping. (Tape pants over foot coverings, if separate.)
6. Put on the respiratory equipment. (Respirator equipment should have been inspected and fit checked.)
7. Put on the hood and head covering over the respirator head straps.
8. Pass through airlock and shower into the work area.
9. Put on safety shoes/boots as required.
10. Put on gloves. (Cotton or leather gloves can be used during most types of abatement work. However, when working with caustic pastes, use rubber gloves or gloves that the chemical can't pass through. Gloves used with caustic paste or chemical strippers should also be long enough to protect the lower part of the arm, as well as the hand.)
11. Put on the hard hat and/or safety glasses (if a half-face respirator is used) or any other protective equipment.
Doffing:
1. Clean off the gross debris using a HEPA vacuum inside the work area.
2. Remove all protective garments and equipment (except respirators) in the "dirty" or work area. Place all disposable clothing in plastic bags, and label as "lead-contaminated waste."
3. Clean reusable protective equipment, such as boots/shoes, safety glasses, hard hats, etc., as they are removed.
4. Proceed through the airlock to the clean area with respirator still on. Remove and clean respiratory protection. Change the filters on a regular basis and discard filters as "lead-contaminated waste." Showers are recommended as part of good work practices after all the protective equipment is removed. In lieu of a shower, wash your face and hands prior to going to the bathroom, smoking, drinking, eating, or chewing gum or tobacco, etc. Upon leaving the work area, you should take a shower as soon as possible to help remove any lead contamination. Small amounts of lead on the hands or in the hair can result in a major route of exposure through ingestion.
5. Get dress in your street clothes. Disinfect, clean, and inspect the respirator. If cartridges are discarded, new cartridges should be placed in the respirator. Store respirator in a clean and dry environment.
PERFORMANCE TEST
FOR
INSPECTING AND DONNING AIR PURIFYING RESPIRATORS
Instructions:
Equipment and Supplies Needed:
1. Half-face and full-face respirators (enough for everyone)
2. Variety of canisters and cartridges
3. Copy of the Observation Scale for each laborer
Time: About 10 minutes per laborer.
Directions:
1. Demonstrate, practice, coach, and talk through the task as a training exercise.
2. Divide laborers into pairs to work together.
3. Require each to take the test with the second laborer as observer.
4. Require each laborer to talk through his/her thinking, inspection, and decision-making process while he/she performs the test.
5. Rate each laborer on each task, using Observation Sheet.
6. Discuss score with laborer. Have laborer sign and date form, together with your signature as an instructor.
7. File forms for future reference.
8. Retest, as necessary.
