RESPIRATORY PROTECTION
PROGRAM FOR AIR POLLUTION
CONTROL INSPECTORS
STUDENT'S MANUAL
Prepared by:
Pacific Environmental Services, Inc.
560 Herndon Parkway, Suite 200
Herndon, Virginia 22070
(703) 471-8383
Prepared for:
U. S. Environmental Protection Agency
Air Pollution Training Institute
Manpower and Technical Information Branch
MD-17
Research Triangle Park, NC 27711
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RESPIRATORY PROTECTION
PROGRAM FOR AIR POLLUTION
CONTROL INSPECTORS
STUDENT'S MANUAL
Prepared by:
Pacific Environmental Services, Inc.
560 Herndon Parkway, Suite 200
Herndon, Virginia 22070
(703) 471-8383
Prepared for:
U. S. Environmental Protection Agency
Air Pollution Training Institute
Manpower and Technical Information Branch
MD-17
Research Triangle Park, NC 27711
-------
DISCLAIMER
This Student Manual was furnished to the Environmental Protection
Agency by Pacific Environmental Services, Inc., Herndon, Virginia 22070,
in partial fulfillment of Contract No. 68-02-4464, Work Assignment No.
91-125. The opinions, findings, and conclusions expressed are those of
the authors and not necessarily those of the Environmental Protection
Agency or the cooperating agencies. Mention of company or product names
is not to be considered as an endorsement by the Environmental Protec-
tion Agency. The guidance provided in this manual does not create any
rights for defendants nor responsibilities for the Environmental
Protection Agency. The Agency reserves the right to act at variance
with these procedures at any time without notice to the regulated
community. Nothing contained in this manual can be used as a defense in
an enforcement action. The safety precautions set forth in this manual
are general in nature. The precise safety precautions required for any
given situation depend upon and must be tailored to the specific
circumstances. Pacific Environmental Services, Inc. does not assume
liability for any personal health problems, death, or economic loss
arising from any actions taken in reliance upon this manual.
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TABLE OF CONTENTS
Page
LECTURE 1 INTRODUCTION
Purpose and Scope of Course
Pretest
Course Agenda
LECTURE 2 CONSEQUENCES OF EXPOSURE TO AIR POLLUTION HEALTH
AND SAFETY RISKS
Dose-Response Relationships
Respiratory System
Routes of Entry
LECTURE 3 IMPORTANCE OF PERSONAL PROTECTIVE EQUIPMENT AND
ADMINISTRATIVE CONTROLS TO MINIMIZE RISKS
LECTURE 4 INTRODUCTION TO THE USE OF RESPIRATORS
Regulatory Requirements
Types of Respirators
LECTURE 5 USES AND LIMITATIONS OF RESPIRATORS
RELs, PELs, TLVs
Care and Maintenance
Fit-Testing Requirements
LECTURE 6 RESPIRATOR "HANDS-ON" EXERCISES
LECTURE 7 INTRODUCTION TO SELF-CONTAINED BREATHING
APPARATUS RESPIRATORS
LECTURE 8 COURSE CONCLUSION
Course Critique
Final Test
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HANDOUT SUMMARY STATEMENTS
Handout 1
Handout 2
Handout 3
Handout 4
Handout 1 contains a listing of acronyms
and definitions of key terms used through-
out this manual.
Handout 2 contains EPA Orders 1440.2 and
1440.3. EPA Order 1440.2 establishes
policy, responsibilities and mandatory
requirements for occupational health and
safety training, certification, and occu-
pational medical monitoring of EPA employ-
ees engaged in field activities. EPA
Order 1440.3 establishes EPA policy, re-
sponsibility, and basic requirements for
protection of employees whose jobs require
the use of respiratory protection devices.
This document also provides background
information of respiratory hazards and
protection factors.
Handout 3 contains a guideline which pro-
vides management with sufficient informa-
tion to establish and operate an respira-
tory protection program as required under
EPA Order 1440.3, Respiratory Protection,
and by the OSHA regulation 29 CFR 1910.
134. This guideline describes elements of
a respirator protection program and in-
cludes the following: administration of
the program, selection and use of respira-
tors, training and fitting of employees,
inspection and maintenance of respirators,
and medical surveillance.
Handout 4 contains a revision of NIOSH'
initial Respirator Decision Logic first
developed in 1975 as part of the NIOSH/-
OSHA Standards Completion Program, the
NIOSH Decision Logic provides a logical
series of step by step questions designed
to assist the reader in the selection of
the proper respirator based upon the haz-
ards of the work environment. This docu-
ment also incudes information on such
topics as oxygen-deficient atmospheres,
warning properties, and protection fac-
tors.
iv
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Handout 5
Handout 6
Handout 7
Handout 8
Handout 9
Handout 5 contains the OSHA respiratory
protection regulations as found in 29 CFR
1910.134. These regulations establish the
minimum requirements under the law regard-
ing employee protection from respiratory
hazards. Areas covered by the standard
include respirator selection, distribu-
tion, and maintenance. Medical and work
area surveillance along with specific
requirements for respirators are also
reviewed.
Handout 6 contains the ANSI standard prac-
tices for respiratory protection. This
standard sets forth accepted practices for
respirator use, provides information and
guidance on the proper selection, use, and
care of respirators, and contains recom-
mended requirements for establishing and
regulating respirator programs. These
guidelines are directed at persons respon-
sible for establishing, maintaining, and
administering an acceptable respirator
program.
Handout 7 is the ANSI standard for respi-
ratory protection, respirator use, and the
physical qualifications of personnel re-
quired to use respiratory protection.
This standard provides examiners with
guidelines for medical examination of
those persons required to use respiratory
protection.
Handout 8 contains the OSHA permissible
exposure levels (PELs) for substances
found in 29 CFR Part 1910.1000. This
standard lists the maximum concentrations
of substances to which an employee can be
exposed to over an 8 hour work shift. The
standard also lists short term exposure
limits (STELs) and ceiling limits for
substances.
Handout 9 contains the chemical resistance
chart for selected protective gloves.
This chart provides guidance is selecting
thee proper glove based upon the physical
and chemical conditions to be encountered.
The chart compares each glove with certain
chemicals, and glove ratings are deter-
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Handout 10
Handout 11
Handout 12
Handout 13
mined by the effect the chemical has on
the glove.
Handout 10 contains the EPA's Health and
Safety Guidelines for EPA Asbestos Inspec-
tors. These guidelines are designed to
reduce the likelihood of injury or illness
to EPA asbestos inspectors. This guide-
line provides information on respiratory
and personal protection. This guideline
also assists inspectors in assessing an
asbestos abatement for compliance with
OSHA asbestos standards. Attachment 1 to
Handout 10 is Chapter 3 of the Occupation-
al Health and Safety Manual. This docu-
ment establishes uniform require-
ments for collecting and compiling occupa-
tional health and safety accident and ill-
ness data for the EPA's Management Infor-
mation System. Attachment 2 to Handout 10
is the non-mandatory Appendices E and F of
the Construction Industry Standards for
asbestos removal, renovation, and demoli-
tion operations. This guideline provides
guidance in the proper equipment, methods
and procedures that should be used in
asbestos removal projects.
Handout 11 is OSHA's proposed safety re-
quirements for entry into confined spaces.
This proposed standard will minimize the
dangers involved in confined space entry
by stating employer responsibilities when
employees work in confined spaces.
Handout 12 is OSHA's proposed guidelines
on occupational exposure to bloodborne
pathogens such as Hepatitis B Virus (HBV)
and the Human Immunodeficiency Virus
(HIV). This proposal provides discussions
on the health risks of occupational expo-
sure to bloodborne pathogens. Health
effects of exposure to bloodborne patho-
gens and control methods which can be
utilized to reduce the possibility of ex-
posure are also provided.
Handout 13 is a copy of Title 30, Mineral
Resources. This document contains the
MSHA regulations, established procedures
and prescribed requirements which must be
met by manufacturers filing for joint
VI
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approval by MSHA and NIOSH of respirators
or modifications to respirators. This
document establishes set fees to be
charged each applicant for inspections,
examinations, and testing conducted by
NIOSH. This section also provides for the
issuance of certificates of approval for
respirators meeting NIOSH criteria.
Handout 14 Handout 14 contains the introduction to
the NIOSH Pocket Guide to Chemical Haz-
ards. This handout summarizes how NIOSH
develops recommendations and how to use
the pocket guide. This section also con-
tains the introduction to OSHA permissible
exposure limits and the ACGIH's 1990-91
introduction to Threshold Limit Values for
Chemical Substances in the Work Environ-
ment .
VI 1
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LECTURE 1
INTRODUCTION
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LECTURE 1
INTRODUCTION
WELCOME AND REGISTRATION
Objectives
The students will know why they are receiving the
training, the background of the instructors, and course
scheduling. The pretest is designed only to provide the
instructor with a general idea of the knowledge of the
students with regards to respiratory protection.
Background
This section of the course provides the students with
the topics which will be covered when they are assembled for
the first time.
COURSE PURPOSE AND SCOPE Handout 1, 2 & 3
A critical element of the air pollution control program
is the State enforcement system. These programs are direct-
ly responsible for the attainment and maintenance of the
ambient air quality through the enforcement of construction
and operating limits for each source.
States are required by the Clean Air Act and regula-
tions to develop and maintain a system to control emissions
from stationary sources. Inspectors are required to make
inspections in and around equipment which may require respi
ratory protection.
The purpose of this training course for state, local,
and federal inspectors is to ensure that they know when,
where, and how to use the appropriate respiratory protec-
tion. This course will provide attendees with information
on the consequences of exposures to air pollution sources
and the importance of minimizing health and safety risks
during air pollution field activities. Attendees are also
provided with a description of available personnel protec-
tive equipment, including the uses and limitations of respi-
rators. Equipment familiarization is accomplished by a
"hands-on" session during the qualitative and quantitative
fit-testing of the respirators.
1 1
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COURSE AGENDA
RESPIRATORY PROTECTION PROGRAM
DAY 1
1:00 p.m. WELCOME AND REGISTRATION
A. Registration
B. Purpose and Scope of Course
C. Speaker's Background and Experience
D. Course Administration
E. Description of Handouts
F. Pretest
G. Correction of Pretests
1:45 p.m. THE CONSEQUENCES OF EXPOSURE TO AIR POLLUTION
SOURCE HEALTH AND SAFETY RISKS
A. Dose-Response Curve Relationships
1. General effect of dose on the probabili-
ty of disease
2. Threshold and no-threshold agents
3. Synergistic actions
a. Cigarette smoking and asbestos
b. Carbon black and polycyclic aro
matics
4. Hypersensitivity
2:30 p.m. Break
2:45 p.m. THE CONSEQUENCES OF EXPOSURE TO AIR POLLUTION
SOURCE HEALTH AND SAFETY RISKS (CONTINUED)
B. The Respiratory System
1. Function and protective systems
a. Basic physiology
b. Sites of contaminant deposition
(1) Soluble and insoluble gases and
vapors
(2) Dust particles and fume parti-
cles
(3) Fibers
c. Contaminant translocation to other
organs
1-2
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Agenda
Day 1 (Continued)
3:05 p.m. THE CONSEQUENCES OF EXPOSURE TO AIR POLLUTION
SOURCE HEALTH AND SAFETY RISKS (CONTINUED)
2. Lung defense mechanisms
a. Nasopharyngeal filtration
b. Mucociliary removal pathway
c. Phagocyte cell s
3. Respiratory diseases
C. Other Routes of Entry
1. Skin
2. Eyes
3. Ingestion
3:20 p.m. Break
3:30 p.m. THE FUNDAMENTAL IMPORTANCE OF PERSONAL PROTEC-
TIVE EQUIPMENT AND ADMINISTRATIVE CONTROLS TO
MINIMIZE HEALTH AND SAFETY RISKS DURING AIR
POLLUTION CONTROL FIELD ACTIVITIES
A. General Procedures and Guidelines
1. Inspection preparation
a. Source file review
b. Selection of personal protection
equipment
2. Inspection/testing conduct
a. Working at a controlled pace
b. Exercising safety judgement
c. Limiting scope
3. Personal hygiene
a. Avoiding contact with contaminated
surfaces and materials
b. Avoiding eye, nose, and mouth
contact
c. Washing hands
d. Eating in uncontaminated areas
4:30 p.m. Adjourn
1-3
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Agenda
DAY 2
8:30 a.m. INTRODUCTION TO THE USE OF RESPIRATORS
A. Videotape: "Respiratory Protection"
B. Importance of Equipment
1. Minimize risk of illness
2. Minimize severity of illness
3. Conform with plant safety requirements
C. Summary of Respirator Regulatory Require-
ments and Certification Procedures
1. Role of OSHA and NIOSH
2. OSHA Regulation 29 CFR 1910.134
D. Fundamental Principles of Respirator Use
1. Engineering and administrative controls
2. Written procedures
3. Selection principles
10:00 a.m. Break
10:15 a.m. E. Types of Respirators
1. Half-mask cartridge respirators
2. Full facepiece cartridge respirators
3. Full facepiece canister respirators
4. Powered air purifying respirators
5. Escape respirators
F. General Fit Testing Requirements and Proce-
dures
11:15 a.m. USES AND LIMITATIONS OF RESPIRATORS
A. General Concepts
1. Exposure limits
a. NIOSH RELs
b. OSHA Revised PELs
c. ACGIH TLVs
2. Respirator limits
a. Respiratory protection factor limits
b. Maximum use concentration
c. Cartridge and canister limits
3. Service life during air pollution field
activities
a. Breakthrough times for various pol-
lutants
b. Effect of air temperature and humid-
ity
c. Estimating service life and using
end-of-service-1ife indicators
12:00 Lunch
1-4
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Agenda
DAY 2
1:00 p.m. USES AND LIMITATIONS OF RESPIRATORS (CONTINUED)
B. Videotape: "Proper Use & Care of Air Purify-
ing Respirators"
1:45 p.m. RESPIRATOR "HANDS-ON" EXERCISES
A. Comfort of Various Styles of Half-Mask, Full
Facepiece, and Powered Air Purifying Respi
rators
B. Half-Mask, Full Facepiece, and Powered Air
Purifying Respirator Pre-inspection Checks
and Replacement of Components
C. Half-Mask, Full Facepiece, and Powered Air
Purifying Respirator Cleaning, Disinfection
and Storage
D. Positive and Negative Pressure Fit Checks
for Air Purifying Respirators
E. Qualitative Fit Test Procedure for Air Puri
fying
Respirators
3:00 p.m. Break
4:30 p.m. Adjourn
DAY 3
8:30 a.m. RESPIRATOR "HANDS-ON" EXERCISES
(Continuation of exercises started on Day 2,
conducted concurrently with fit testing program)
8:30 a.m. QUANTITATIVE FIT TESTING FOR HALF-MASK, FULL
FACEPIECE AND
POWERED AIR PURIFYING RESPIRATORS
A. Videotape: "Fit Test Procedures"
B. Explanation of Procedures
C. Individual Fit Testing
1-5
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Agenda
DAY 3
11:00 p.m. INTRODUCTION TO SELF-CONTAINED BREATHING APPARA-
TUS RESPIRATORS (SCBAs)
A. Videotape: "Confined Space Entry"
B. Types of SCBAs
C. Uses and Limitations of SCBAs
12:00 Break
1:00 p.m. INTRODUCTION TO SELF-CONTAINED BREATHING APPARA-
TUS RESPIRATORS (CONTINUED)
D. Inspection, Cleaning, and Disinfection
1. Routine inspection requirements
2. Cleaning and disinfection procedures
3. Recharging
E. Storage
F. Other Safety Considerations
1. Buddy system
2. Lower Explosive Limits (LELs)
3. Monitoring equipment
4. Accessories
G. Hands-on Exercises
1:30 p.m. RESPIRATOR SCENARIOS
2:15 p.m. COURSE CRITIQUE AND FINAL TEST
3:30 p.m. Adjourn
1-6
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PRETEST
U.S. EPA REGION IV RESPIRATORY PROTECTION WORKSHOP
1. Negative pressure air-purifying respirators should be
used in oxygen deficient environments.
A. True
B. False
2. OSHA has promulgated legal standards for employee expo-
sures to airborne contaminants known as:
A. Permissible Exposure Limits (PELs)
B. Threshold Limit Values (TLVs)
C. Recommended Exposure Limits (RELs)
D. Legal Exposure Standards (LESs)
3. The type of respirator which should be selected when
entering an area which is determined to be immediately
dangerous to life and health (IDLH) is:
A. Half-mask negative pressure air-purifying
respirator with organic vapor cartridges.
B. Powered-air purifying respirator with Type-H
cartridges.
C. Self-contained breathing apparatus.
D. Any of the respirators listed above will
adequately protect an inspector in an IDLH
environment.
4. When conducting inspections at asbestos abatement sites,
a disposable dust mask respirator should be used because
it does not interfere with the wearer's vision.
A. True
B. False
1-7
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5. A worker shall be issued a respirator when:
A. He has been examined by a physician and
deemed medically fit to wear a respirator.
B. He asks for it.
C. He has been properly trained and fit test
ed.
D. A and B
E. A and C
6. The three general classifications of airborne contami-
nants which may be present in industrial environments
are:
A. Particulates, gases, and vapors.
B. Dusts, mists, fumes.
C. Fumes, aerosols, vapors.
D. Gases, dusts, and mists.
7. List the two types of hazardous environments, from a
respiratory standpoint, which may be encountered in
industrial settings.
A.
B.
8. Although normal air contains approximately 21% oxygen,
OSHA defines an oxygen deficient atmosphere as one
containing less than 19.5%.
A. True
B. False
9. Powered-air purifying respirators have a protection
factor of:
A. 10
B. 50
C. 100
D. 1000
1-8
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10. Medical examinations are not necessary before respira-
tors are issued to workers. If a person can work,
he/she can wear a respirator.
A. True
B. False
11. Which of the following is the largest organ of the human
body?
A. Skin
B. Liver
C. Kidney
D. Spleen
12. What size particle would be removed in the nasal chamber
(upper respiratory system)?
A. 1 micron
B. 5 microns
C. 10 microns
D. 50 microns
13. Inhaled particles which penetrate to and are deposited
in the pulmonary air spaces are sized between:
A. 5 10 microns
B. 1 2 microns
C. 10 15 microns
D. 20 50 microns
14. LD50 is defined as:
A. Latent Deficient, 50%.
B. Elevated Distress Factor.
C. Leak Detection, 50%
D. Lethal Dose, 50% probable.
1-9
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15. Factor(s) which influence toxic action are:
A. Route of exposure.
B. Age.
C. Hereditary.
D. All of the above.
16. The ACGIH TLVs are well-documented values which can be
used as "fine lines" between safe and dangerous concen-
trations.
A. True
B. False
17. Lung clearance is achieved by which of the following
mechanisms?
A. Phagocytosis
B. Nasopharyngeal filtration
C. Mucociliary escalator
D. All of the above
18. Which USEPA Order specifies the requirements for respi-
ratory protection?
A. Order 1440.2
B. Order 1440.3
C. Order 1910
D. Order 1926
19. What does LEL stand for?
A. Latent escalatory levels
B. Lower expulsive limit
C. Lower explosive limit
D. Lipid extraction level
1-10
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20. The OSHA law which addresses respiratory protection (in
general) is found in:
A. 29 CFR 1926.153
B. 29 CFR 1926.134
C. 29 CFR 1910.134
D. 29 CFR 1910.101
1-11
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LECTURE 2
CONSEQUENCES OF EXPOSURE
TO AIR POLLUTION HEALTH
AND SAFETY RISKS
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LECTURE 2
CONSEQUENCES OF EXPOSURE TO AIR
POLLUTION
HEALTH AND SAFETY RISKS
DOSE-RESPONSE RELATIONSHIPS
Objectives
Student understanding that the toxic potency of a
chemical is defined by the dose (amount) of the chemical and
the response produced in a biological system. Discussion of
the concepts of threshold and no-threshold agents and
NIOSH's interpretation of certain types of exposures.
Background Transparency 2-1
The dose-response relationship is expressed as the
product of a concentration (C) multiplied by the time dura-
tion (T) of exposure. All toxicological considerations are
based on the dose-response relationship. By using test
animals, data is collected and used to create a dose-re-
sponse curve relating percent mortality to dose adminis-
tered.
LECTURE NOTES
The toxic potency of a chemical is defined by the dose
(amount) of the chemical and the response produced in a
biological system.
LABORATORY TESTING
A dose of a particular contaminant is given to test ani-
mals and increased or decreased until a range is found where
at the upper end all animals die and at the lower end all
animals survive. The dose (amount) is expressed as amount
per unit of body weight, such as mg/Kg. A dose-response
curve is developed from the upper and lower data.
2-1
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LD is defined as lethal dose. LD50 is the calculated
dose of a substance which is suspected of causing the death
of 50% of a substance which is suspected of causing the
death of 50% of a defined experimental animal population, as
determined from the exposure to the substance, by any route
other than inhalation.
LC is defined as lethal concentration. LC50 is used for
airborne materials, since LD50 is not useful for inhalation
exposures. Laboratory animals are put in an exposure cham-
ber and exposed to a concentration of a substance. LC50 is
the point where half of the animals die. LC values should
state the species, length of time exposure was given and
length of time the animals were observed after being ex-
posed. There must be a post-exposure time, since an observ-
able response sometimes occurs after a long post-exposure
period, not just immediately after exposure.
DOSE RESPONSE RELATIONSHIP Transparency 2-2
The slope of a dose-response curve gives an index of the
margin of safety of a substance, given the range of doses
from a non-effective dose to a lethal dose. If the slope of
the curve is steep, the margin of safety is low. One sub-
stance may be more toxic than another because of the shape
and slope for the dose response curves.
In general, as the dose of a substance increases, the
probability of disease increases. Different substances have
different exposure concentrations in which adverse effects
occur. Also, certain substances will produce the same
effect if exposed to at high concentrations for a short time
as a lower concentration would for a longer time. Dose
response relationships may be useful in predicting safe
limits for airborne contaminants in respect to environmental
exposures.
THRESHOLD AND NO THRESHOLD AGENTS
Threshold agents are substances in which a "safe" expo-
sure level has been determined. Threshold limit value (TLV)
is defined as the exposure level for which most people can
be exposed to 8 hours per day over extended periods of time
without adverse effects.
2-2
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Transparency 2-3
NIOSH has established a "No Threshold" approach to
respiratory protection for suspected and known carcinogens.
NIOSH recommends that air-purifying respirators should not
be used for these substances. Only the most reliable and
protective respirators should be utilized. These respi-
rators are:
- self-contained breathing apparatus (SCBA) with full
facepiece operated in positive pressure mode, or
supplied-air respirator with full facepiece operated
in pressure-demand or other positive-pressure mode in
combination with an auxiliary SCBA operated in pres-
sure-demand or other positive-pressure mode
Some no-threshold agents that air pollution agency
personnel may be exposed to include formaldehyde, flyash
(inorganic arsenic) and asbestos.
SYNERGISTIC ACTIONS
Synergism is defined as the cooperative action of sub-
stances whose total effect is greater than the sum of their
separate effects. Two examples of synergism are cigarette
smoking and asbestos exposure/and carbon black and polycy-
clic aromatics exposure.
Cigarette Smoking and Asbestos Exposure
Cigarette smoking and asbestos exposure produce a syner-
gistic effect in developing lung cancer. The airways of the
upper respiratory tract are lined with cilia (hair-like
protrusions) covered with a sheet of mucous. The cilia
constantly sweep upward, bringing particles caught in the
mucous into the back of the mouth. These particles are
either swallowed or expelled. Cigarette smoking temporarily
paralyzes the cilia, delaying the cleansing mechanism.
Smoking several cigarettes paralyzes the cilia for several
hours, sometimes taking an overnight period for the cilia to
begin working again. The natural defense to expel asbestos
fibers is hindered, creating a greater potential for asbes-
tos fibers to get into the lungs.
Employees exposed to industrial concentrations of asbes-
tos have a 5 times (5x) increased risk of developing lung
cancer than the normal non-smoking population. Cigarette
smokers have a 22 times (22x) risk. A cigarette smoker who
works with asbestos has a 80 times (80x) chance to develop
lung cancer than the normal non-smoking population.
2-3
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Carbon Black and Polvcvclic Aromatics
Carbon black has a 10 hour TWA of 3.5 mg/m3 (NIOSH). In
the presence of polycyclic aromatic hydrocarbons, the 10
hour TWA is 0.1 mg/m3 (NIOSH). NIOSH considers carbon black
to be carcinogenic when in the presence of polycyclic aro-
matic hydrocarbons. NIOSH suggests a "No-Threshold" ap-
proach to be taken in this situation.
HYPERSENSITIVITY
Hypersensitivity is defined as an adverse reaction to a
substance resulting from a previous sensitization to the
substance or to a structurally similar substance. Pre-
exposure to the substance is required to produce a toxic
effect. Hypersensitivity is also called an allergic reac-
tion and sensitization reaction. Exposure to the particular
substance results in an antigen-antibody interaction, which
produces the typical symptoms of an allergy. It is dose
related, an example being the allergic response to pollen in
sensitized individuals which is related to the concentration
of pollen in the air.
2-4
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REVIEW QUESTIONS
DOSE-RESPONSE RELATIONSHIPS
1. LD50 is defined as:
a. Latent Deficient, 50%
b. Elevated Distress Factor
c. Leak Detection
d. Lethal Dose, 50% probable
2. Which compound is more toxic than the other?
21
20
5 11
§.
I 10
Ol_u=
DOM
3. LC50 is used for which type of entry?
a. Inhalation
b. Skin
c. Eyes
d. Ingestion
4. Explain the synergistic effect of cigarette smoking and asbestos
exposure.
2-5
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THE RESPIRATORY SYSTEM
Objective
Student understanding of the basic physiology of the
respiratory system and its defens'e mechanisms. Review of
other routes of entry by toxicants into a biological system.
Background
Without oxygen, you would die within a very few minutes.
Your lungs take in this vital oxygen from the air you
breathe. This makes them well worth protecting. In order
to understand the importance of the respiratory system, an
understanding of their basic function and how respiratory
hazards such as oxygen-deficiency and contaminants can cause
abnormal affects on the respiratory system and other organs
of the body.
LECTURE NOTES
THE RESPIRATORY SYSTEM
The most essential input to the human system is oxygen.
Oxygen is supplied by the respiratory system and eventually
to the cells by the circulatory system, which also removes
the carbon dioxide resulting from cell metabolism. Without
food, one can exist for weeks, and without water, for many
days, but without oxygen, for only a very few minutes.
BASIC PHYSIOLOGY
The primary function of the respiratory system is to
supply body cells with oxygen and to excrete carbon dioxide.
In addition, the respiratory organs filter particles from
incoming air, help control the temperature and water content
of the air, aid in producing the sounds used in speech, and
play important roles in the sense of smell and regulation of
pH.
The organs of the respiratory system include the nose,
nasal cavity, sinuses, pharynx, larynx, trachea, bronchial
tree, and lungs. See Diagram A.
Slide 2-4
2-6
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Diagram A
THE RESPIRATORY SYSTEM
Sinus
Masai cavity
Nostnl
Moutn cavity
Larynx
Tracnea
Right
broncnus
Secondary
broncm
Broncnioles
Lung
Diaonragm
2-7
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Air normally enters the body through the nostrils and
passes through a web of nasal hairs and then flows through
the narrow passages around the turbinates. The "inspired
air" proceeds down the trachea which divides into branches
or primary bronchi, leading in turn to upper and lower lobar
bronchi to the right and left. The airway diameter and
velocity decreases, but the number of tubes increases. Gas
exchange occurs in the acini of the lung parenchyma. The
respiratory bronchioles, alveolar ducts, atria, alveolus
sacs, and the alveoli is referred to as the acinis. The
system of airways leading to the acini does not participate
in the gas exchange and is called the "dead space". In
normal lungs, both the oxygen and carbon dioxide pass the
membranes of the microscopic air sacs without difficulty.
The blood carries oxygen from the lungs to the other organs
of the body, where it picks up carbon dioxide to be returned
to the lungs, and ultimately exhaled.
Gas exchange occurs between the air of the alveolus
and the blood of the capillary as a result of differences in
partial pressures. Gas molecules diffuse from regions where
they are in higher concentrations toward regions where they
are in lower concentration. Similarly oxygen will diffuse
from higher pressure (in the alveolus) to lower pressure (in
the capillary), at the same time carbon dioxide will diffuse
from higher pressure (in the capillary) to lower pressure
(in the alveolus). This movement will tend to equalize the
partial pressures in the two regions. See Diagram B.
SITES OF CONTAMINANT DEPOSITION
Transparency 2-5
Inhalation of harmful materials may irritate the upper
respiratory tract and lung tissue. Agents that enter the
lungs may pass directly into the bloodstream and be carried
to other parts of the body. The size, type, and solubility
of an agent determines the site of deposition.
Soluble Gases and Vapors
Vapors are the volatile form of a substance that is
normally in the solid or liquid state at room temperature
and pressure. Solvents with low boiling points will volat-
ize readily at room temperature. Gases are formless fluids
that expand to occupy the space or enclosure in which they
are confined. Examples are welding gases, exhaust gases,
and air.
2-8
-------
Diagram B
TERMINAL AIRWAY UNIT OF THE HUMAN LUNG
ALVEOLI
PULMONARY
ARTERY
BRONCHIOLE II
PULMONARY
VEIN
CAPILLARY
NETWORK
2-9
-------
If a compound is very soluble, such as ammonia, formal-
dehyde, sulfuric acid, or hydrochloric acid, it is rapidly
absorbed in the upper respiratory tract during the initial
phases of the exposure and does not penetrate deeply into
the lungs. Consequently the nose and throat may become very
irritated. Vapors of low solubility can produce an immedi-
ate irritation and inflammation of the respiratory tract and
pulmonary edema.
Insoluble Gases and Vapors
Compounds that are insoluble in body fluids cause con-
siderably less throat irritation than the soluble ones, but
may penetrate deeply into the lungs. A very serious hazard
can be present and not immediately recognized because of a
lack of warning that the local irritation would otherwise
provide. Examples of such gases are nitrogen dioxide and
ozone. The immediate danger of these compounds in higher
concentrations is acute lung irritation or possibly chemical
pneumonia. Other examples are:
Carbon monoxide, a toxic gas, passes into the blood
stream without harming the lungs. The carbon mon-
oxide passes through the alveolar walls into the
blood, where it ties up the hemoglobin so that it
cannot accept oxygen thus causing oxygen starva-
tion.
Cyanide gas prevents enzymic utilization of molecu-
lar oxygen by cells.
Dust and Fume Particles
Dusts are solid particles generated by handling, crush-
ing, grinding, rapid impact, detonation, and decrepitation
of organic or inorganic materials such as rock, ore, metal,
coal, wood, and grain. Airborne solid particle range in
size. 0.1 to 25 micrometers. See Diagram C.
To evaluate dust exposure, knowledge of the chemical
composition, particle size, concentration in air, how it is
dispersed, and many other factors need to be known. Large
particles, more than 10 micrometers in aerodynamic diameter,
can be deposited in large ducts before reaching the very
small sacs (alveoli). This can cause a person to choke or
cough. Depending on the chemical composition, dust can
cause an a", iergic reaction. Dust also c-.n damage the vital
internal tissues.
2-10
-------
Diagram C
Norm
Toba<
Necra
Vin
M
Spr
Ci
il Impurities
Zink Oxic
CO
sis Virus &
s Protein
Carbc
Tobacc
ignesiun (
ly Dried ^
>mbustion
n Qu
Met
Ai
e Fu
n Blc
o Snr
)xide
Rosi
ilk
Nucl
Aerosols
et Outdoor
illurgicai I
imonium Chi
Alkc
Ties
ck
oke
)il Smoke
Smoke
i Smoke
P
ei
*JT
>USt c
Sme
oride Fi
li Fur
Su
Con
Zin
Inse
gmer
nd Fumes
ter Dust e
jmes
ies
Sulp
furic Acid
tensed
: Dust
-^
cticide Du
Bacteria
ts
Silver loc
Fog
nd Fi
Foi
Floi
D
lide 0
Mist
Cerr
sts
ide
jmes
jndry Dus
r Mill
JSt (
~^T "
re, Pulps for
ent Dust
Pulver
Plant
Spores
Polleni
_ Sm
Ry Ash
San
Sea S<
Hu
Mi
sible
roun
Float
zed '
ezes
dTai
ilt Ni
nan
st
To Eye
d Limesto
tion
:oal
ings_
Washed
clei
Hair Diam
Rain
^
ne
^
:oun(
ster
Drops ^
ry J3and
in
O
O
O
6
in
q
d
in
d
in
o
in
O
O
O
O
in
o
o
o
PARTICLE SIZE (Microns)
SIZES OF VARIOUS AIR-BORN CONTAMINANTS
o
o
o
in
2-11
-------
Fumes are materials from a volatilized solid condensed
in cool air. The solid particles make up a fume that is
extremely fine. Solid particle sizes are usually less than
1.0 micron in diameter.
In most cases, hot vapor reacts with the air to form an
oxide. Welding and other operations involving vapors from
molten metals may produce fumes which may be harmful under
certain conditions. Other toxic fumes, such as those formed
when welding structures that have been painted with red
lead, or when welding galvanized metal, may produce severe
symptoms of toxicity unless the fumes are controlled with
adequate, local exhaust ventilation, or the welder is pro-
tected by respiratory protective equipment.
Fibers
Fibrous materials, smaller than 5 micrometers in length
penetrate to the alveoli or inner recess of the lungs.
Asbestos fibers cause fibrotic growth in the alveolar
tissue, plugging the ducts or limiting the effective area of
the alveolar 1ining.
CONTAMINANT TRANSLOCATION TO OTHER ORGANS
The initial site where a chemical localizes is depen-
dent on the blood flow to the area, the permeability of the
tissue to the toxicant, and the availability of binding
sites.
A toxic agent may pass through membranes of a number of
cells before achieving a sufficient concentration in the
target organ. A toxicant may pass through a membrane by one
of two processes: 1) diffusion or passive transfer of the
chemical, in which the cell expands no energy in its trans-
fer; and 2) specialized transport, in which the cell takes
an active part in the transfer of the toxicant through the
membranes.
Small water soluble molecules are diffused through
aqueous channels or pores in the cell membrane. Lipid-
soluble molecules and ions of moderate size cannot enter
cells easily except by special transport mechanisms. After
a chemical enters the plasma by absorption, a toxicant is
available for distribution (translocation) throughout the
body. Translocation usually occurs rapidly, and the rate of
distribution to the tissues of each organ is determined by
2-12
Transparency 2-6
-------
the blood flow through the organ and the ease with which the
chemical crosses the capillary bed and penetrates the cell
of the particular tissue.
Toxicants are often concentrated in a specific tissue
(see Diagram D). Some toxicants achieve their highest
concentrations at their site of toxic action, such as carbon
monoxide, which has a very high affinity for hemoglobin, and
paraquat, which accumulates in the lung. Other agents
concentrate at sites other than the site of toxic action.
The compartment where the toxicant is concentrated can be
thought of as a storage depot. While stored, the toxicant
seldom harms the organism. The storage depot, therefore,
could be considered as a protective mechanism, preventing
the accumulation of high concentrations of the toxicant at
the site of toxic action. As the chemical is biotransformed
or excreted from the body, more of the toxicant is released
from the storage depot, as a result the biologic half-life
of stored compounds can be very long.
Major storage sites of toxicant are the plasma pro-
teins, liver, kidney, fat, and bone.
Lung Defense Mechanisms
The respiratory system has a unique set of mechanisms
for protecting against insults. See Diagram E.
The upper respiratory tract acts
for the lungs. This is important for
designed to filter inspired gases
complex helps in detecting odors.
or vapors, a muscular contraction
occur. This
mizes intake
as an air conditioner
humidification and is
The nasopharyngeal
Upon irritation of gases
of the bronchial tubes may
sneezing, also
contaminants.
reaction restricts the air flow and thus mini-
of the irritating substance. Coughing and
tends to rid the upper respiratory tract of
The mucous membrane lining the nasal cavity contains
pseudostratified ciliated epithelium that is rich in mucus-
secreting goblet cells. The sticky mucous secreted by the
mucous membrane entraps dust and other small particles
entering with the air. As the cilia move, a thin layer of
mucus and any entrapped particles are pushed toward the
pharynx for expulsion or swallowing. Any microorganism in
the mucus that is swallowed is likely to be destroyed by the
action of gastric juices.
Transparency 2-7
2-13
-------
Diagram D Areas of Toxic Concentration
INQEST1ON
1
INHALATION
INTRAVENOUS INTRAPERfTONEAL
SUBCUTANEOUS
GASTROINTESTINAL
TRACT
INTRAMUSCULAR
DERMAL
FAT
2-14
-------
Diagram E Your Body's Natural Protection
Your body has a wonderfully designed respiratory system to carry
air and oxygen into your lungs and carry waste products out. Even
when you're in clean, fresh air, your body's natural defenses con-
stantly work to cleanse and purify the air.
Your Itrst line of defense are the coarse hairs
(vlbrissae) Inside your nose. These trap large
particles as you Inhale.
Cilia are tiny hairs lining your entire respira-
tory tract. Cilia beat rapidly to move mucus
and small particles to the back of your throat
o be swallowed or expelled by coughing.
Mucus Blanket
A mucus blanket lines your entire respiratory
tract. Particles that pass the nose hairs are
trapped and moved toward the_back ol your
throat by the mucus blanket
Normal breathing. Your no*« warms,
cool*, and humidifies the air you breathe. Your
upp«r airway carries air to your lungs. Your
lowntr airway branches out Ilk* a tree and
ends In tiny air sacs called alveoli, where oxy-
gen passes Into your blood and waste* ar* re-
turned to your lungs to be exhaled.
Cough Reflex
Coughing I* a protective reflex that helps expel
mucus and foreign particles that build up In
your respiratory system.
2-15
-------
Mobile phagocyte cells descend on aerosols that are not
removed from the alveolar lining. These cells are white
blood cells capable of ingesting particles. Once laden with
foreign matter they migrate to the small bronchioles, where
the mucous lining carries them out of the system; or they
pass through the alveolar membrane into the lymph vessels
associated with the blood capillaries. They can also be
destroyed (if contaminant is cytoxic) and break up, releas-
ing the particles into the alveolar sac.
Respiratory Disease
Lungs, bloodstream, and the heart are closely inter-
related elements of the entire oxygen-supply system. Dis-
ease or blockage in any part can result in serious illness
or death. The skin, lungs and alimentary canal are the main
barriers that separate humans from toxic substances. Howev-
er these are not complete barriers, and toxicants do enter
the body, resulting in potential injury. See Table 1.
Other Routes of Entry
Toxic materials can enter the body primarily in three
ways: by ingestion, through the gastrointestinal tract; by
absorption through the skin via cuts and punctures; and
eyes.
Ingestion
A person can unknowingly eat or drink harmful chemi-
cals. Inhaled toxic dust can also be ingested in amounts
that may cause trouble. If toxic dust is swallowed with
food or saliva and is not soluble in digestive fluids, it is
eliminated directly through the intestinal tract. Toxic
materials that are readily soluble in digestive fluids can
be absorbed into the blood from the digestive system.
Absorption
Chemicals can absorb through the skin rapidly if the
skin is abraded. Some substances are absorbed by way of
openings for hair follicles and others dissolve in the fat
and oil of the skin. Compounds that are good solvents for
fats (such as toluene and xylene) also may cause problems by
being absorbed through the skin. Many organic compounds can
produce systemic poisoning by direct contact with the skin.
The skin's defense mechanisms against primary irritants are
the buffered acid mantle, the stratum corneum, thickening of
the keratin material, and sweating.
2-16
-------
TABLE 1
HAZARDOUS SUBSTANCES ASSOCIATED
DISEASES AND HEALTH EFFECTS
Hazardous Substance
Chromium
Beryllium
Cadmium
Mercury
Copper
Manganese
Zinc
Lithium Carbonate
Uranium
Cobalt
Ozone
Formaldehyde
Fluorides
Toluene
Phenol
Lead
Sulfur dioxide
Selenium
Disease/Health Effect
Hexavalent lung cancer; chromoholes
Beryl 1osis
Silver brazing
Gingivitis; shifty eyes
Wilson's disease; hardening of arteries
Fibrotic lung disease
Oxide pox
Manic depression
Leukemia
Heart muscle decay
Pulmonary edema; chronic respiratory disease
Pulmonary irritation; broncho spasm; carcinogen
ic; dermatitis
Calcification of 1igaments,ribs, pelvis
Lacrimation; photophobia; dermatitis; paresthe-
sia
Cyanosis; dermatitis; anorexia
Colic; anemia; gingival lead line
Bronchoconstriction; rhinorrhea
Garlic breath; skin discoloration
2-17
-------
Of all the major body organs prone to occupational
injuries, the eye is perhaps the most vulnerable. Contami-
nation of a chemical substance or foreign matter can cause
minor irritation or complete loss of sight. In some in-
stances, a chemical which does no damage to the eye can be
absorbed in a sufficient amount so as to cause systemic
poisoning. The eye does have a few natural defenses to
protect itself. The eye has a blink reflex. The eye is
also equipped with an automatic "windshield wiper and washer
combination". The washers are the tear ducts, and the wiper
is the blinking action. The function of the teary blink is
to wash foreign bodies from the corneal or conjunctival
surfaces before they can become imbedded. The triggering
mechanism is irritation caused by the contaminant.
2-18
-------
REVIEW QUESTIONS
THE RESPIRATORY SYSTEM
1. Label all the organs associated with the respiratory
system on the diagram.
2. Explain the pathway of inspired air.
3. Explain the gas exchange mechanism in the alveolus.
4.
Define:
gas
vapor
dust
fume
fiber
2-18
-------
5. Would a soluble or an insoluble gas/vapor cause an
almost instantaneous reaction?
6. What effect does carbon monoxide have on oxygen?
7. Can dust particles > 10 micrometers reach the alveolar
sacs?
8. What are a few controlled conditions that can decrease
a fumes toxic effect?
9. Fibers < micrometers can penetrate to the alveo-
lus.
10. Explain the two processes by which a toxic agent passes
through a membrane in order to reach a target organ?
11. How would a lipi-soluble molecule and ions of moderate
size enter a cell?
12. Name a factor that could affect the rate of transloca-
tion.
13. Using Diagram C, name three hazardous substances that
translocate to the heart?
14. What is meant by a storage depot?
15. Give two examples of a storage depot.
a.
b.
16. Name two mechanisms that occur in the upper respiratory
tract that act as defense mechanisms.
a.
b.
2-20
-------
17. The mucus lining flows upward by
action.
18. Define phagocyte.
19. Give one example of what can occur to foreign matter en
gulfed by a phagocyte.
20. What are a few defense mechanisms of the skin?
21. Through what openings does a toxicant enter the skin?
22. If a toxicant is ingested, what is its fate?
23. What are the defense mechanisms of the eye?
2-21
-------
LECTURE 3
IMPORTANCE OF PERSONAL PROTECTIVE
EQUIPMENT AND ADMINISTRATIVE CONTROLS
TO MINIMIZE RISKS
-------
LECTURE 3
IMPORTANCE OF PERSONAL PROTECTIVE
EQUIPMENT AND ADMINISTRATIVE CONTROLS
TO MINIMIZE RISKS
INSPECTION PREPARATION
Objective
Student understanding that a source file review, the
selection appropriate personal protective equipment, and the
practice of personal hygiene can substantially minimize
health and safety risks.
Background
The air pollution control inspector can minimize health
and safety risks during air pollution control field activi-
ties by performing certain tasks before and during the
inspection process.
LECTURE NOTES
INSPECTION PREPARATION Handout 10 & 12
Source File Review A source file contains information
about the company, chemicals and processes used, and amounts
of chemicals. This file can be found at the local EPA
office or county agency for hazardous materials. The compa-
ny should also have Material Safety Data Sheets (MSDS) for
on-site chemicals.
Transparency 3-1
Selection of Personal Protection Equipment (PPE) From
the information found in the source file, determinations on
the correct PPE to be utilized may be made.
1) Respirator: Information on each type of respirator
will be discussed during this course. See Figure A.
3-1
-------
Figure A Respiratory Selection for Routine Use of
Respirators
Toxic contaminant
Immediately
dangerous to
life or health
Not immediately
dangerous to
life or health
Gas or vapor
Power air-purifying
respirator
Gas or vapor
and
paniculate
Chemical cartridge
respirator
Combination cartridge
plus filter
respirator
3-2
-------
2)
Hearing Protection: See Figure B for typical noise
levels. Exposure above 90 dbA per 8 hour shift will
require the use of hearing protection depending on
the time spent in the high noise area. There are
various types of hearing protection available.
Aural Insert Types
a. Formable Type disposable, expandable form or
cotton plugs which fit into the ear canal.
b. Custom Molded made for each individual person.
c. Molded Type soft silicone rubber inserted into
the ear canal.
Ear Muffs
a. Covers the entire face. The attenuation provid-
ed by the muff is dependent on size, shape, and
muff material.
3)
Attenuation:
Most commercial earplugs if properly
worn, will provide a 25-30 dB reduc-
tion of sound level. Combinations
of earmuffs and earplugs offer the
greatest protection.
Head Protection: Head protection may need to be
considered in logging operations, construction,
steel mills and other sites with overhead opera-
tions. All helmets should meet ANSI standards.
4) Eye Protection and Foot Protection: Eye protection
and foot protection should also be worn. All equip-
ment should meet ANSI standards.
Transparency 3-2
5) Gloves:
Light Work: Canvas gloves are satisfactory and
inexpensive.
Rough Work: Leather or cut-proof gloves are the
best protection.
For chemicals and hazardous materials, use Figure C
to determine the proper glove to use.
Handout 9
3-3
-------
FIGURE B - Sound Pressure and Decible Values for Some
Typical Sounds
Sound Pressure
(microbars)
0.0002
0.00063
0.002
0.0063
0.02
0.063
0.2
0.63
1.0
2.0
6.3
20
63
200
2000
200.000
Overall Sound Pressure Level
(dB re 0.0002 microOar)
0
10
20
30
40
50
60
70
74
80
90
100
110
120
140
180
Example
Threshold of hearing
Studio for sound pictures
Soft whisper (5 feet)
Quiet office
Audiometric testing booth
Average residence
Large office
Conversational speech (3 feet)
Freight tram (100 feet)
Average automobile (30 feet)
Very noisy restaurant
Average factory
Subway; Printing press plant
Looms in textile mill
Electric furnace area
Woodworking
Casting shakeout area
Hydraulic press
50 hp siren (100 feet)
Jet plane
Rocket launching pad
Not* mat doubling any sound pressure corresponds to an increase of 6 dB in the sound pressure level. A change of sound
pressure oy a (actor ol 10 corresponds to a change in sound pressure level of 20 dB.
3-4
-------
FIGURE C - Choosing The Right Glove
his table snows the relative resistance ratings ol van- tnus insuring the protection o( tne wearer
inoust0"* male"a" lo some «>iu"ons commonly used in 2 Chemical composition ol the solution
Th , 3 Degree ol concentration
ne listings were gleaneo Irom various glove manutac- 4 Abrasive effects ol mater
lurer guioes When se.ectmg one tor an application not 5 Temperature conditions
itenals being handled
ion not emperature c
shown you are urgea to write tne manulacturer ol your 6 Time cycle ol usage
cnoosmg giving as mucn detailed mlormation as possible 7 Specify m purcnase order wnat materials are lo be
according to tne following points- ^^
1 Ability ol glove lo resist penetration ol the chem.cal 8 Cost.
Glove
Material
CHEMICAL RESISTANCE CHART
Natural Rubber
Hydrochloric Acetic Sodium Metnanol
Hydroxide
Methyl
Toluene Naphtha Ethyl Perch/or-
Ketone ethylene
G
NR
Neoorene
Buna-N
Butyl
Polyvmyi Chlonae
Polyvmvl Alconol
Polyethene
NBR'
E
E
G
G
P
G
E
E
E
E
E
F
E
G
E
E
E
G
P
E
G
E
G
E
E
F
E
E
F
F
F
P
P
E
E
E
E
F
P
P
E
E
G
F
E
NR
F
G
F
F
F
NR
NR
E
G
G
MISCELLANEOUS
Glove
Material
Natural Rubber
Neoprene
Buna-N
Butyl
Polyvmyi Chloride
Polyvmvl Alconol
Polyethene
NBR'
Coaling
Natural Rubber
Neoprene
Buna-N
Butyl
Polyvmvl Chlonoe
Polyvmvl Alcohol
Polyetnene
NBR'
Lacquer
Thinner
F
NR
NR
F
F
E
F
F
Abrasion
Resist-
ance
F
G
G
G
G
E
E
Benzene
NR
P
G
NR
F
E
F
G
Formal-
dehyde
E
E
E
E
E
P
E
F
Ethyl
Acetate
F
G
F
G
P
F
G
F
PHYSICAL PERFORMANCE
Cut Puncture Heat
Resist- Resist- Resist-
ance ance ance
'•i
E
E
G
F
E
F
E
E
E
G
G
F
E
E
E
E
E
F
P
P
f
P
F
Vegelaoie
Oil
G
E
E
G
G
E
E
E
CHART
2Flex-
ibility
F
G
F
G
F
F
G
G
Animal
Fat
P
E
E
G
G
E
E
E
Dry
Grip
E
G
G
F
E
E
G
G
Turpen-
tine Phenol
F F
G E
E G
F G
F G
E P
G E
E NR
Wei
Grip
G
F
G
F
E
E
G
F
KEY TO CHARTS
E—E»C«««nl G—GOOO F_F»ir P—Poor NH—Not R»
3-5
-------
INSPECTION/TESTING CONDUCT Transparency 3-3
Working at Controlled Pace
Working in cold or hot temperature extremes can
place a strain on the human body. Physiological
changes occur in hot and cold weather. Internal
body temperature, heart beat, respiration rate, and
the body's need to heat or cool it itself is
changed. The American Conference of Governmental
Industrial Hygienists (ACGIH) have a guide for heat
and cold stress. The information provided explains
monitoring, work time limits, human response to heat
buildup, and a wind speed index chart for wind chill
factors.
Exercising Safety Judgement
Safety judgement is quite often common sense. Do
not do or try anything that seems unsafe. Always
follow safety procedures at all times. When in
doubt, ask questions.
Limiting Scope
Before the job begins, a plan should be made on how
the inspection is to be done. Do not attempt to
finish in a hurry. A rushed job will result in a
less accurate survey and more chances of an injury.
Decide on what is to be done during the day and
judge your time accordingly.
PERSONAL HYGIENE
Avoid contact with contaminated surfaces and materi-
als. If the proper respirator, protective clothing,
gloves, and eye protection are properly utilized,
the chances of exposure will be greatly reduced. If
any spills, leaks, puddles are present, avoid them,
and have them cleaned up as soon as possible.
Eye, nose and mouth contact can be avoided with the
proper use of full .facepiece respirators. When
respiratory protection is not utilized, do not touch
your mouth, face, or eyes; or eat food or smoke
cigarettes until you are out of the area. Wash your
hands thoroughly.
3-6
-------
Washing Hands
Washing hands should be done before eating, smoking,
going to the bathroom, or leaving the work site.
Many commercial hand cleaners are available. Grease
cleaners, anti-biological cleaners, and soaps with
skin conditioners are available for use.
Eating in Contaminated Area
Eating in contaminated areas should not be done at
any time.
3-7
-------
INSPECTION PREPARATION
1. What is a Source File Review?
2. If the noise measured in an area where a source inspec
tion is to take place is known to be 95 dBA, how long
can an inspector remain in the area without hearing
protection?
3. An inspector is going to inspect an operation which
uses chlorinated solvents. The inspector plans to use
the butyl rubber gloves for hand protection.
3-8
-------
LECTURE 4
INTRODUCTION TO THE USE OF
RESPIRATORS
-------
LECTURE 4
INTRODUCTION TO THE USE OF RESPIRATORS
INTRODUCTION TO RESPIRATORS (Video Tape)
Objectives
Student understanding of the evolution of respiratory
protection standards and guidelines and the importance of
utilizing the appropriate respiratory protection when its
use is indicated in the field.
Background
The use of respiratory protection is not a recent
development. It has evolved over many years and has under-
gone many changes.
SUMMARY OF RESPIRATOR REGULATORY REQUIRE-
MENTS AND CERTD7ICATION PROCEDURES
Objective
Student understanding of respirator regulatory require-
ments.
Background
The Occupational Safety and Health Administration
(OSHA) jurisdictions include promulgation and enforcement of
respiratory standards. The National institute for Occupa-
tional Safety and Health (NIOSH) is responsible for research
and for making recommendations concerning respirator use.
4-1
-------
LECTURE NOTES
ROLE OF THE OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION Transparency 4-1
(OSHA)
OSHA has developed maximum exposure standards for many
airborne toxic materials. OSHA has regulations that require
engineering or work-practice controls be used to reduce
exposures as low as possible. If these controls are not
feasible , or while they are being instituted, appropriate
respirators shall be used. OSHA views respirators as the
least satisfactory means of exposure control, because they
provide good protection only if they are properly fitted,
worn by employees, and replaced when their service life is
over. Also, some employees may be unable to wear a respira-
tor.
OSHA has the authority to inspect and evaluate the
effectiveness of respirator protection programs. Citations
may be issued for inadequacy of written procedures.
The OSHA Respiratory Protection Standard, 29 CFR 1910-
.134 will be discussed later in this section.
ROLE OF THE NATIONAL INSTITUTE FOR OCCUPATIONAL SAFETY AND
HEALTH (NIOSH)
Transparency 4-2
NIOSH is the testing agency for respirator approval.
Under authorization of the Coal Mine Health and Safety Act
of 1969 and the Federal Mine Safety and Health Act of 1977,
NIOSH has established an evaluation and certification pro-
gram for respirators. All certifications are issued jointly
with the Mine Safety and Health Administration (MSHA).
NIOSH certification evaluations include: laboratory evalua-
tion of the respirator, evaluation of the manufacturer's
quality control (QC) program, audit testing of certified
respirators and investigations of problems with NIOSH/MSHA
certified respirators.
Respirators must meet the minimum performance require- Handout 13
ments which are in Title 30, Code of Federal Regulations,
Part II (30 CFR 11). This is found in Handout 13.
4-2
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NIOSH will approve only if the entire respirator assem-
bly, including cartridges, filters and hoses, passes the
test. Then NIOSH and MSHA will issue a joint approval
number for that specific respirator assembly. NIOSH lists
approved respirators and cautions and limitations for spe-
cific respirator classes in the NIOSH Certified Equipment
List.
NIOSH also monitors respirators over the lifetime of
their certification. Respirators are evaluated after a
period of time in NIOSH
laboratories in order to see if they still meet applicable
minimum performance requirements.
NIOSH recommendations are based on the Respirator
Decision Logic, found in Handout 4. This was developed
jointly in 1975 by NIOSH and OSHA and has been updated to
reflect new developments. The latest decision logic (1987)
differs from the original in five areas: odor warning
properties with respect to air-purifying cartridge/canister
respirators, recognition of the problems in assigning pro-
tection factors, changes in protection factors for certain
respirator classes, respirator recommendations for carcin-
ogens, and medical recommendations. NIOSH also performs in-
plant QC audits of respirator manufacturers.
Handout 4
OSHA REGULATION 29 CFR 1910.134
This regulation is OSHA's Respiratory Protection Stan-
dard. It states when respirators should be used, require-
ments for a minimal acceptable respiratory program, selec-
tion of respirators, air quality (breathing air from cylin-
ders or air compressors), use of respirators, maintenance
and care of respirators, and identification of gas mask
canisters. 29 CFR 1910.134 is found in Handout 5.
Handout 5
4-3
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REVIEW QUESTIONS
RESPIRATOR REGULATORY REQUIREMENTS
1. Certifications for respirators are issued by which
agency?
a. NIOSH
b. OSHA
c. MSHA
d. NIOSH and MSHA
e. NIOSH and OSHA
2. The OSHA law which addresses respiratory protection (in
general) is found in:
a. 29 CFR 1926.153
b. 29 CFR 1926.134
c. 29 CFR 1910.134
d. 29 CFR 1910.101
3. Minimum performance requirements for respirators are
found in:
a. 29 CFR 1910.134
b. 29 CFR 1926.153
c. 29 CFR 1910.101
d. 30 CFR 11
e. 30 CFR 15
4. Respirators are the best means of exposure control.
a. True
b. False
4-4
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FUNDAMENTAL PRINCIPLES OF RESPIRATOR USE
Objectives
Student understanding that respiratory protection
should be the third option behind engineering controls and
administrative controls when protecting against inhalation
hazards. Discussion of varying types of controls.
Background
Respiratory protection is considered to be the third
option behind engineering controls and administration con-
trols when controlling employee exposures.
LECTURE NOTES
Transparency 4-3
The order of preference for minimizing respiratory
hazards is engineering controls, administrative controls and
respiratory protection.
After hazards have been identified and evaluated and
information for informed decisions has been provided, the
next process involves the actual installation of control
measures. Controls are of two kinds; administrative (i.e.,
through personnel management, monitoring, limiting worker
exposure, measuring performance, training and education,
housekeeping and maintenance, purchasing) and engineering
(i.e., isolation of source, design, process or procedural
changes, monitoring and warning equipment, chemical or
material substitution).
There are three areas where hazards can be controlled;
the source of the hazard; the path between the hazard source
and the worker; and at the area of the worker. Engineering
controls attempt to either eliminate the hazard at its
source, or cut off its path to the worker. This can be done
through ventilation, isolation or chemical substitution.
Administrative controls attempt to allow as little
worker exposure to the source as possible. This can be done
by setting up job procedures which limit the amount of time
a worker can spend in the hazardous area, training, and
educating the employees in the hazards they work with.
4-5
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Respiratory protection attempts to control the hazard
in the area of the worker, or in the worker's "breathing
zone". One of the most important aspects of administering a
Respiratory Protection Program is the development of written
guidelines describing all facets of the selection, use and
maintenance of respirators. In addition, contingency plans
should be included to minimize confusion and provide in-
struction in emergency situations.
The formula for implementation is practical and will
work for any personal safety equipment program in any size
organization. The program consists of:
• Thorough evaluation of the hazard and need for
protection.
• Strong management support.
• Local union support.
• The mandatory involvement of supervision.
• A complete and honest personal communication with
all personnel involved.
• A comprehensive training and educational program in
the use, care and maintenance of the safety equip-
ment.
• An effective system of evaluating the program.
Once a respiratory protection program begins, a major
part of the program involves respirator selection. Among
the many factors to be considered in the selection of the
proper respiratory protective device for any given situation
involving air contamination are the following:
• The nature of the hazardous operation or process.
• The type of air contaminant, including its physical
properties, chemical properties, physiological
effects on the body, and its concentration.
• The period of time for which respiratory protection
must be provided.
• The location of the hazard area with respect to a
source of uncontaminated respirable air.
• The state of health of personnel involved.
• The function and physical characteristics of respi-
rators.
Transparency 4-4
Handout 6&7
Transparency 4-5
4-6
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HALF-MASK RESPIRATORS Transparency 4-6
Objectives
Student understanding of limitations, care, and fit-
testing procedures for half-mask respirators.
Background
The half-mask respirator is the simplest form of an
airpurifying respirator device. Its small compact size
makes it ideal for compact work areas, but its lower protec-
tion factor against hazardous elements limits its use.
LECTURE NOTES
INTRODUCTION TO THE HALF-MASK RESPIRATOR
The basic purpose of any respirator is to protect the
respiratory system from inhalation of hazardous atmospheres.
There are three families of respirators: air-purifying
respirators, air-line or supplied-air respirators, and self-
contained breathing apparatus.
The half-mask respirator is an air-purifying respira-
tor. It covers half the face from under the chin to the
bridge of the nose. The half-mask respirator removes con-
taminants from the breathing air before it is inhaled. See
Figure A.
1. Selection
The proper selection of a respirator involves two
steps:
a. Identification and evaluation of the hazard.
b. Selection of approved respirator based on the
first consideration.
The half-mask respirator has many uses and limitations.
The half-mask does not protect the wearer from eye irri
tants. Facial hair lying between the sealing surface of a
respirator facepiece and the wearer's skin will prevent a
good seal. A poor seal will permit contaminated air to
enter the facepiece. These respirators remove limited
concentrations of air contaminants from the breathing air,
therefore they can only be used where air contaminants do
not exceed the specified range of the respirator and car-
tridge. These types of respirators should not be used in
operations where the air might be oxygen-deficient such as
4-7
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Figure A
TYPICAL HALF MASK RESPIRATOR
4-8
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fire fighting rescue work. The half-mask respirator can
protect against low concentrations of organic vapors, pesti-
cides, alkaline gases, acid gases, mercury vapors, organic
vapors or gases combined with acid or alkaline gases, and
any of the above materials combined with dust, fumes, or
mist. In general, half-mask units can be used up to 10
times the substance PEL or 1000 ppm, whichever is lower.
The half-mask respirator does not restrict wearer's mobili-
ty.
2. Maintenance and Care
In order to keep your respirator operating at its
optimum level, a certain amount of care and maintenance
needs to be exercised by the user.
as
to use the
Routine inspection:
OSHA requires that all respirators be leak checked
part of an inspection program. The person who is to usc m
respirator is responsible for inspecting it. Respirators
for normal, non-emergency work must be inspected before and
after each use. Emergency respirators must be inspected
after each use and at least once a month.
During a routine inspection the facepiece should be
checked for excessive dirt, distortion from improper stor-
age, cracks, tears, or holes. The head strap should also be
checked for loss of elasticity, broken or malfunctioning
buckles or attachments, or tears. The inhalation valves and
exhalation valves should be checked for dust particles or
dirt; cracks, tears or distortion in the valve seat; and
missing or distorted valve covers. Filter elements should be
checked for approval designation (TC X X X ID# X X X ),
missing or worn gaskets, worn threads, and cracks or dents
in filter housing.
Cleaning and disinfecting:
When cleaning and disinfecting your respirator:
* Remove excess contaminants
* Remove filters, screens, and head band.
* Scrub the respirator in detergent and warm wa-
ter. Use any good detergent or mild cleaning
solution containing a bactericide.
* Submerge facepiece and scrub gently with soft
brush or sponge.
* Rinse cleaned and disinfected respirator thor-
oughly in plain water to remove all detergent
and disinfectant.
4-9
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* If reusing filters, clean outer surfaces with a
damp cloth or sponge saturated with mild clean-
ing solution.
* Air dry at room temperature on clean surface.
Do not dry rubber parts under heat or sunlight.
* Never use solvents to clean plastic or rubber.
Inspection of the respirator should be done before and
after cleaning. Follow the same procedures discussed under
routine inspection.
Respirator storage:
Respirators should be stored in a heat-sealed or reus-
able plastic bag inside a rigid container, keeping facepiece
away from dust, sunlight, extreme cold, excessive moisture
and damaging chemicals. Facepieces should be placed in a
normal position to prevent the rubber or plastic from being
permanently distorted.
Respirator repair:
OSHA standards state that "replacement or repair shall
be done by experienced persons with parts designated for the
respirator". Parts should never be substituted from a
different brand or type of respirator. Faulty equipment
should never be accepted.
3. Different Styles
There are basically two different styles of the half-
mask respirator. One is the mechanical-filter respirator.
It is designed specifically for removing particles out of
the air (e.g., dust). The second type of half-mask respira-
tor is the chemical-cartridge respirator. This type of
respirator can be used for such hazards as low concentra-
tions of organic gases, paint vapors, and pesticides. It
also has cartridges available for hazardous fiber condi-
tions, such as asbestos.
4. Types of Cartridges (Discussed in Lecture 5).
5. Fit Testing
Pre-inspection:
Before each use of a respirator, OSHA requires a pre-
inspection be performed. The inspection outlined under the
routine inspection section should be performed. Also check
that the proper cartridge for the hazardous element has been
selected.
4-10
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Field inspection:
After a pre-inspection has been performed, the field
inspection can be conducted. This involves a negative and
positive pressure check. To perform a negative pressure
check, the wearer must close off the inlet of the facepiece;
inhale so that the facepiece collapses against face; and
hold breath for approximately ten seconds. If facepiece
does not remain collapse, readjust headstraps and repeat the
above steps. If adjusting headstraps does not give proper
seal, check facepiece for leaks. To perform a positive
pressure check the wearer must close off the exhalation
valve, and gently exhale into facepiece. The fit test
passes if positive pressure builds up inside the facepiece
without air leaking from around the facepiece. (See Figure
B).
Post inspection:
After a respirator has been used in the field, a post-
inspection should be performed. OSHA requires that all
respirators be inspected after each use. Follow the same
procedures discussed under routine inspection.
4-11
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Figure B - Respirator Field Inspection
NEGATIVE PRESSURE
..U _)..
ft * tTWT^ - 'ft
NEGATIVE PRESSURE TEST
POSITIVE PRESSURE
4-12
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REVIEW QUESTIONS
HALF-MASK RESPIRATORS
1. The half-mask respirator is a supplied air respirator.
T or F
2. The half-mask respirator removes contaminants from the
breathing air after it is inhaled. T or F
3. Name two steps involved in respirator and cartridge
selection.
a.
b.
4. Name two limitations of the half-mask respirator.
a.
b.
5. Half-mask respirator can protect against high concen-
trations of gases and vapors. T or F
6. Half-mask units can be used up to times the sub
stance PEL or 1000 ppm, whichever is lower.
4-13
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FULL FACEPIECE RESPIRATORS Transparency 4-7
Objectives
Student understanding of limitations, care,and fit-
testing procedures for full facepiece respirators.
Background
Full facepiece, air purifying respirators can be uti-
lized for protection against low concentrations of organic
vapors, acid gases, dusts, mists and fumes. The type and
level of protection depends on the rating of the cartridges
or canister used in conjunction with the full facepiece
respira-tor. Advantages of utilizing the full facepiece
respirator instead of the half-mask respirator are 1) a
higher protection factor and 2) eye protection.
LECTURE NOTES
The basic purpose of any respirator is to protect the
respiratory system from inhalation of hazardous atmospheres.
There are three families of respirators: air-purifying
respirators, air-line or supplied-air respirators, and self-
contained breathing apparatus.
The full facepiece is an air purifying respirator. It
covers the whole face from under the chin to the top of the
forehead. The full facepiece respirator removes contami-
nants from the breathing air before it is inhaled.
1. Selection
The proper selection of a respirator involves two
steps:
• Identification and evaluation of the hazard.
• Selection of an approved respirator based on the
first consideration.
The full facepiece respirator can restrict the users
peripheral vision. The full facepiece respirator has
many uses and limitations. Facial hair lying between
the sealing surface cf a respirator facepiece and the
wearer's skin will pr /ent a good seal. A poor seal
will permit contaminated air to enter the facepiece.
Full facepiece respirators remove limited concentra-
tions of air contaminants from the breathing air,
therefore they can only be used where air contaminants
4-14
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do not exceed the specified range of the respirator and
cartridge. These types of respirators should not be
used in operations where the air might be oxygen-defi-
cient such as fire fighting rescue work. Full face-
piece respirators should not be used for exposures to
contaminants easily detected by odor or irritations.
The full facepiece respirator provides eye protection
unlike the half-mask respirator. The full face respi-
rator can protect against low concentrations of organic
vapors, pesticides, alkaline gases, acid gases, mercury
vapors, or gases combined with acid or alkaline gases,
and any of the above materials combined with dust,
fumes, or mist. In general, full facepiece units can
be used up to 50 times the substance PEL or 1000 ppm,
whichever is lower. The full facepiece respirator does
not restrict the wearer's mobility.
2. Maintenance and Care
In order to keep your respirator operating at its
optimum level, a certain amount of care and maintenance
needs to be exercised by the user. If properly per-
formed, inspections will identify damaged or malfunc-
tioning respirators before they can be used.
Routine inspection
OSHA requires that all respirators be leak checked as
part of an inspection program. The person who is to
use the respirator is responsible for inspecting it.
Respirators for normal, non-emergency work must be
inspected before and after each use. Emergency respi-
rators must be inspected after each use and at least
once a month.
OSHA requires that respirators be inspected before and
after each use. During a routine inspection the face-
piece should be checked for excessive dirt, distortion
from improper storage, cracks, tears, or holes. The
head straps should also be checked for loss of elastic-
ity, broken or malfunctioning buckles or attachments,
or tears. The inhalation valves and exhalation valves
should be checked for dust particles or dirt; cracks,
tears or distortion in the valve seat; and missing or
distorted valve covers. Filter elements should be
checked for approval designation (TC XXX ID# XXX),
missing or worn gaskets, worn threads, and cracks or
dents in the filter housing(s).
4-15
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Cleaning and disinfecting:
When cleaning and disinfecting your respirator:
• Remove excess contaminants
• Remove filters, screens and head band.
• Scrub the respirator in detergent and warm wa-
ter. Use any good detergent or mild cleaning
solution containing a bactericide.
• Submerge facepiece and scrub gently with soft
brush or sponge.
• Rinse and clean and disinfect respirator thor-
oughly in water to remove all detergent and
disinfectant.
• If reusing filters, clean outer surfaces with a
damp cloth or sponge saturated with a irrld clea-
ning solution.
• Air dry at room temperature on a clean surface.
Do not dry rubber parts under heat or sunlight.
• Never use solvents to clean plastic or rubber.
Inspection of the respirator should be performed before
and after cleaning. Follow the same procedures dis-
cussed under routine infection.
Respirator storage:
Respirators should be stored in a heat-sealed or reus-
able plastic bag inside a rigid container, keeping the
facepiece away from dust, sunlight, extreme cold,
excessive moisture, and damaging chemicals. Respira-
tors should be placed in a normal position to prevent
the rubber or plastic from being permanently distorted.
Respirator repair:
OSHA standards state that "replacement or repair shall
be done by experienced persons with parts designated
for the respirator". Parts should never be substituted
from a different brand or type of respirator. Faulty
equipment should never be accepted.
3. Different Styles
There are basically two different styles of the full
facepiece respirator. One is the mechanical-filter
respirator. It is designed specifically for removing
particles out of the air (e.g., dust), the seconc type
of full facepiece respirator is the chemical-cartridge
respirator. This type of respirator can be used for
such hazards as low concentrations of organic gases,
paint vapors, and pesticides. It also has cartridges
4-16
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available for hazardous fiber conditions, such as
asbestos.
4. Types of Cartridges (Discussed in Lecture 5).
5. Fit Testing
Pre-Inspection:
Before each use of a respirator, OSHA requires a pre-
inspection be performed. The inspection outlined under
the routine inspection section should be performed.
Also check that the proper cartridge for the hazardous
element has been selected.
Field Inspection:
After a pre-inspection has been performed, the field
inspection can bed conducted. This involves a negative
and positive pressure check. To perform a negative
pressure check, the wearer must 1) close off the inlet
of the facepiece, 2) inhale so that the facepiece
collapses against face, and 3) hold breath for approxi-
mately ten seconds. If facepiece does not remain
collapse, readjust headstraps and repeat the above
steps. If adjusting headstraps does not give proper
seal, check facepiece for leaks. To perform a positive
pressure check, the wearer must close off the exhala-
tion valve, and gently exhale into facepiece. The fit
test passes if positive pressure builds up inside the
facepiece without air leaking from around the face-
piece.
Post Inspection:
After a respirator has been used in the field, a post-
inspection should be performed. OSHA requires that all
respirators be inspected after each use. Follow the
same procedures discussed under routine inspection.
4-17
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REVIEW QUESTIONS
FULL FACEPIECE RESPIRATORS
1. The full facepiece respirator is a suppl ied-air respi
rator. T or F.
2. Name two limitations of the full facepiece respirator.
a.
b.
3. Full facepiece respirators can be used up to times
the substance PEL or 1000 ppm, whichever is lower.
4. What is one major advantage that the full facepiece
respirator offers over the half-mask respirator, not
including the advantage of an increased PF?
4-18
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POWERED AIR PURIFYING RESPIRATORS
Transparency 4-8
Objective
Student understanding of the limitations, care, and
fit-testing of PAPRs. Discussion of NIOSH's studies on
PAPRs PFs.
Background
A powered air purifying respirator (PAPR) uses a blower
and portable, rechargeable battery pack to pass contaminated
air through an element that removes the contaminants and
supplies the purified air to a respiratory inlet covering.
PAPRs were considered positive pressure devices until re-
cently. Field studies conducted by NIOSH and others have
shown that PAPRs are not positive pressure respirators and
that their assigned protection factors are too high. NIOSH
now recommends much lower protection factors.
LECTURE NOTES
USES AND LIMITATIONS OF POWERED AIR PURIFYING RESPIRATORS
Uses
PAPRs protect the wearer against particulates and/or
gases and vapors. The air purifying element may be a filter
to remove particulates, a cartridge to remove vapors and
gases, or a combination filter and cartridge, canister, or
canister and filter. The decreased inhalation resistance
makes PAPRs more comfortable to wear than normal negative
pressure air purifying respirators. In addition, the air-
stream through the mask provides a cooling effect in warm
temperatures. PAPRs with loose fitting hoods or helmets are
advantageous for people who cannot wear a tight-fitting
facepiece. This type of respirator is used in operations
involving abrasive blasting, grinding, pesticide spraying,
and asbestos.
Limitations
PAPRs cannot be used in oxygen deficient atmospheres
(less than 19.5% oxygen) or in atmospheres immediately
dangerous to life or health (IDLH). They should not be used
for protection against gases or vapors with poor warning
properties except for escape only or where permitted by a
regulatory agency, and the respirator is equipped with an
4-19
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end of service life indicator for the particular substance.
The respirator user should always read the NIOSH/MSHA ap-
proval label concerning cartridge and canister limitations.
PAPR filters do not remove poisonous gases or vapors from
the air supply. No filter is designed for all substances.
The filter element may be degraded by extreme humidity and
temperature and the cost of replacement elements can be
high.
The nickel-cadmium battery packs must be recharged
periodically. These batteries have a limited useful life
and battery replacement cost may be expensive. The blower
has a high speed motor which will eventually wear out and
must be replaced periodically.
If hot or very cold air is in working area, there is
the problem of this air blowing into the respiratory inlet
covering, making it uncomfortable for the wearer.
CARE AND MAINTENANCE OF PAPRs
Routine Inspection
The facepiece should be checked for excessive dirt,
cracks, tears, or holes; distortion from improper storage;
cracked, scratched, or loose fitting lens; and broken or
missing mounting clips.
Headstraps should be checked for breaks or tears; loss
of elasticity; broken or malfunctioning buckles or attach-
ments; and excessively worn serrations of the head harness
which might allow the facepiece to slip.
Inhalation and exhalation valves should be checked for
detergent residue; dust particles or dirt on the valve seat;
cracks, tears, or distortion in the valve material or valve
seat; and missing or defective valve cover.
The filter elements should also be checked for the
following: proper filter for the hazard; approval designa-
tion (TC _X_ JL X ID# X X X ); missing or worn gas-
kets; worn threads; and cracks or dents in the filter hous-
ing.
If the PAPR includes a hood or helmet, the headgear
suspension should be checked, and adjusted, if required.
The facepiece should be inspected for cracks and breaks.
Cracks or other damage to the flexible air hose and
clamps should also be checked.
4-20
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Cleaning and Disinfecting
Before cleaning, remove any excess contaminant from the
respirator. Disconnect the breathing tube from the face-
piece. The facepiece may be washed by hand or in a commer-
cial dishwasher or clothes washer with a rack installed to
hold the facepieces in a fixed position. Domestic dishwash-
ers are not preferred because they do not immerse the face-
piece. When handwashing, submerge the facepiece and scrub
gently until clean with a soft brush or sponge. Use any
good detergent or mild cleaning solution with water or a
detergent containing a bactericide. The cleaning water
should be between 120°F and HOT to ensure adequate clean-
ing. If a dishwasher is used, eliminate the drying cycle,
because the extreme temperature may damage the facepiece.
After cleaning, follow with a disinfecting rinse.
Disinfectant must be added to the rinse cycle if a dish or
clothes washing machine is used. Rinse the cleaned and
disinfected respirator thoroughly in plain water (140°F
maximum) to remove all detergent and disinfectant, as it may
irritate the wearer's face.
Separate the motor-blower, battery pack and filters.
Use a damp cloth or sponge saturated with a mild cleaning
solution to wipe the breathing tube, motor-blower, and
battery pack cases clean. If reusing filters, clean the
outer surfaces with a damp cloth or sponge saturated with a
mild cleaning solution. Wash the support belt with a soft
brush or sponge and mild cleaning solution.
Air dry the respirator at room temperature on a clean
surface. Take care not to damage or distort the facepiece
when hanging to dry. A commercial, electrically heated
steel storage cabinet, with a built in circulating fan may
be utilized to dry respirators. If using this cabinet,
replace the shelves with steel mesh.
Inspect the entire PAPR during and after cleaning.
Since the respirator is usually disassembled during clean-
ing, it is a good time to inspect each part. Follow the
procedures for routine inspection. Inspect all parts of the
PAPR following cleaning and reassembly. OSHA requires that
all respirators be leak-checked as part of an inspection
program. Do this after cleaning and reassembly is complete.
This procedure will show if the complete reassembly is air
tight.
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Storage
The clean facepiece should be stored in a heat-sealed
or reusable plastic bag inside a rigid container, keeping
the facepiece away from dust, sunlight, extreme cold, exces-
sive moisture, and damaging chemicals. Store in a clean,
dry location away from direct sunlight. The facepiece and
exhalation valve should be placed in a normal position to
prevent rubber or plastic from being permanently distorted.
Store the charged PAPR battery pack within a tempera-
ture range suggested by the manufacturer for maximum battery
life. Storing at higher temperatures will shorten the
battery life. Lower temperatures will decrease the capaci-
ty, and the operating time will be reduced.
Maintenance and Repair
OSHA standards state that "replacement or repair shall
be done by experienced persons with parts designed for the
respirator." Parts must not be substituted from a different
brand or type of respirator for the following reasons: it
is contrary to OSHA standard; invalidates NIOSH/MSHA approv-
al; and wearer may be improperly protected.
The battery pack requires special attention. Nickel -
cadmium batteries may develop a "memory" when they are
partially discharged and then recharged continuously. The
battery pack should be used for the rated time, then re-
charged. Do not charge indefinitely; run down battery
periodically and fully recharge it. Follow the manufactur-
er's recommendations for the entire PAPR (including battery
pack).
DIFFERENT STYLES
There are three main types of powered air-purifying
respirators. The first type is with the air-purifying
element(s) attached to a small blower which is worn on the
belt and connected to the respiratory inlet covering with a
flexible tube. The second is with the air-purifying element
attached to a stationary blower, powered by a battery or an
external power source and connected by a long flexible tube
to the respiratory inlet covering. The third type of PAPR
is a helmet or facepiece to which the air-purifying element
and blower are attached, with the battery worn on the belt.
4-22
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The respiratory inlet covering can be a tight fitting
half-mask or full facepiece, or a loose fitting hood or
helmet. A PAPR with a tight fitting mask must deliver at
least 6 f3/min (170 1/min).
TYPES OF CARTRIDGES
(Discussed in Lecture 5.)
FIT TESTING
Pre-Use Inspection
OSHA requires that all respirators be inspected before
each use. This inspection should be performed as outlined
under routine inspection. Check the battery pack to make
sure it is fully charged. Check for proper connection of
the breathing tube to the facepiece. The air-purifying
element must also be checked. Make sure it is the proper
element for the hazard and that it is connected correctly.
Field Checks (done without breathing tube connected to the
facepiece)
One of the field checks that must be done is the nega-
tive pressure check. The inlet must be closed off first.
Inhale so that the facepiece collapses against the face and
hold breath for approximately ten seconds. If the facepiece
does not remain collapsed, readjust the headstraps and
repeat the above steps. If adjusting the headstraps does
not give a proper seal, check the facepiece. Do not use a
facepiece that does not seal properly.
After Use Inspection
OSHA requires that all respirators be inspected after
each use. Perform the inspection as outlined under routine
inspection and follow the procedures listed in inspecting
the respirator during and after cleaning.
4-23
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REVIEW QUESTIONS
POWERED AIR PURIFYING RESPIRATORS
1. According to NIOSH, powered air purifying respirators
have a protection factor of:
a. 10
b. 25
c. 50
d. 100
e. 1000
2. PAPRs can be worn in oxygen deficient atmospheres
a. True
b. False
3. PAPR filter will remove poisonous gases or vapors from
the air supply
a. True
b. False
4. Why does one need to run down a nickel-cadmium battery
pack periodically and recharge it?
5. What is the minimum air flow a tight fitting half-mask
or full-facepiece must deliver?
a. 2 ftVmin
b. 4 ft3/min
c. 6 ft3/min
d. 10 ft3/min
6. One must perform a positive and negative pressure check
with a PAPR before going into a contaminated area.
a. True
b. False
4-24
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ESCAPE RESPIRATORS
Transparency 4-9
Objective
Student understanding of limitations, care, and styles
of escape respirators.
Background
Escape respirators are respirators whose single func-
tion is to allow a person working in a normally safe envi-
ronment sufficient time to escape from suddenly occurring
respiratory hazards.
LECTURE NOTES
USES AND LIMITATIONS OF ESCAPE RESPIRATORS
Uses
The single function of an escape respirator is to allow
a person working in a normally safe environment sufficient
time to escape from suddenly occurring respiratory hazards.
Limitations
Escape respirators are not to be used for entry into
contaminated
atmospheres. The appropriate escape respirator must be
selected for the anticipated respiratory hazard (each type
is designed for a specific use only). SCBA escape respira-
tors only provide 5 to 15 minutes of respiratory protection.
Air-purifying escape respirators cannot be used in oxygen
deficient atmospheres (less than 19.5% oxygen). Mouthpiece
respirators are only good for short periods of escape from
low concentrations of organic vapor or acid gas. Gas masks
and other air-purifying respirators cannot be used if the
exposure concentration is above the limitations of the
canister or cartridge.
4-25
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CARE AND MAINTENANCE
Inspection
Routine procedures should be followed after each use.
OSHA
requires that escape respirators be inspected once a month
and that "a record shall be kept of inspection dates and
findings for respirators maintained for emergency use."
NIOSH recommends that inspections be conducted at least
weekly, in order that loss of breathing gas from emergency
SCBAs does not go undetected.
Escape Gas Mask (Canister) and Mouthpiece Respirators
The facepiece should be checked for excessive dirt,
cracks, tears, or holes; distortion from improper storage;
cracked, scratched, or loose fitting lens; and broken or
missing mounting clips. Check the headstraps for breaks or
tears; loss of elasticity; broken or malfunctioning buckles
or attachments; and excessively worn serrations of the head
harness which might allow the facepiece to slip. The inha-
lation and exhalation valves should be checked for detergent
residue; dust particles or dirt on the valve seat; and
missing or defective valve cover. Examine the filter ele-
ments for proper filter for the hazard (proper air-purifying
element or chemical canister); approval designation (TC X
X X_ ID# _X X_ X ); missing or worn gaskets; worn
threads; and cracks or dents in the filter housing.
Self-Contained Breathing Apparatus (SCBA). Open-Circuit
The facepiece should be checked for excessive dirt;
cracks, tears, or holes; distortion from improper storage;
cracked, scratched or loose fitting lens; and broken or
missing mounting clips. Examine the headstraps for breaks
or tears; loss of elasticity; broken or malfunctioning
buckles or attachments; and excessively worn serrations of
the head harness which might allow the facepiece to slip.
Check the inhalation and exhalation valves for detergent
residue; dust particles or dirt on the valve seat; cracks,
tears, or distortion in the valve material or valve seat;
and missing or defective valve cover.
Hood-type SCBA: Examine the hood for rips and tears,
seam integrity, etc.
4-26
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Examine the air supply systems for integrity and condi-
tion of the air supply lines and hoses, including at-
tachment and fittings; good working order of regula-
tors and gauges; and check to ensure that the cylinder
is fully charged. The charging of a cylinder depends
on the model.
DIFFERENT STYLES OF ESCAPE RESPIRATORS
Mouthpiece Respirators
Mouthpiece respirators consist of a mouthpiece held in
the teeth (lips seal around it) and a clamp that closes the
nostrils (see Figure C). Communication is eliminated and
mouthpiece respirators may cause fatigue. They provide no
eye protection. Mouthpiece respirators are designed specif-
ically for use in the chemical industry, pulp and paper
industries, or other industries where acid gas contamination
may occur. They must be equipped with a cartridge or canis-
ter for specific contaminants, and may not be used in oxy-
gen-deficient atmospheres. These respirators are available
for carbon monoxide, chlorine, ammonia, organic vapors, and
acid gases.
Escape Gas Mask (Canister) Respirator
An escape gas mask respirator consists of a facepiece
or mouthpiece, canister, and associated connections. They
are certified under 30 CFR 11, Subpart I. These respirators
may not be used in oxygen-deficient atmospheres. An example
of an escape gas mask respirator is the "filter" self rescu-
er. It is a mouthpiece device designed to protect specifi-
cally against less than 1% carbon monoxide. These respira-
tors are used in escaping from mines.
Escape-Only Self-Contained Breathing Apparatus (ESCBA). Open
Circuit. 5 to 15 Minutes Supply
This is a small sized, low weight SCBA. The com-
pressed-air container is usually hip- or back-mounted with
the air valve in an accessible position. The facepiece may
be put on quickly by tightening the headband straps. The
different styles are full mask, half-mask, and mouthpiece
styles. They also are available in a hood-style for quick
donning.
4-27
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Figure C - Typical Mouthpiece Respirator
Nose Clamp
Air-Purifying Element
Respirator Body
4-28
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Self-Contained Self-Rescuer fSCSR). Closed Circuit
These respirators are certified for use in underground
mines in emergency situations. There are compressed-oxygen
and oxygen-generating types. Most SCSR have a one hour
duration. They feature a mouthpiece instead of a facepiece
and have no structural breathing bag protection. SCSR with
pressure vessels use active pressure gauge indicators.
Chemical SCSR use passive storage life color indicators and
inspection procedures. MSHA has strict enforceable storage
and location requirements for SCSR, indicating specific
daily and 90 day required SCSR inspection periods and proce
dures.
4-29
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REVIEW QUESTIONS
ESCAPE RESPIRATORS
1. How often does OSHA require inspections to be performed
for escape respirators?
a. once per week
b. daily
c. once per month
d. twice per year
2. How often does NIOSH recommend escape respirators to be
inspected?
a. once per month
b. once per week
c. twice per month
d. twice per year
3. Escape respirators are designed for a broad range of
hazards.
a. True
b. False
4. Air-purifying escape respirators can be worn in oxygen
deficient atmospheres.
a. True
b. False
5. Escape respirators are respirators which are worn into
IDLH atmospheres.
a. True
b. False
4-30
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LECTURE 5
USES AND LIMITATIONS
OF RESPIRATORS
-------
LECTURE 5
USES AND LIMITATIONS OF RESPIRATORS
EXPOSURE LIMITS Transparency 5-1
Objective
Student understanding of the origin and current use of
the RELs, PELs, and TLVs.
Background
Prior to 1970, State agencies used the Threshold Limit
Value (TLV) recommended by the American Conference of Gov-
ernmental Industrial Hygienists (ACGIH) as guidelines for
exposures to toxic materials. After 1970, Congress enacted
several new safety and health laws, one of which was the
"OSHA Act" under which NIOSH was established.
LECTURE NOTES
GENERAL CONCEPTS Transparency 5-2
Prior to 1970, governmental regulations of safety and
health matters were concerns of state agencies. Most states
adopted as guidelines the Threshold Limit Values (TLV) for
exposure to toxic materials as recommended by the American
Conference of Governmental Industrial Hygienists (ACGIH).
Enforcement of those guidelines were minimal. In 1970
Congress enacted new safety and health laws, one of which
was the Public Law 91-596, the Occupational Safety and
Health Act of 1970 or "OSHA Act". One of the key provisions
was the establishment of the National Institute of Occupa-
tional Safety and Health (NIOSH).
NIOSH RELs Handout 14
The National Institute for Occupational Safety and
Health (NIOSH) is the principle government agency engaged in
the national effort to eliminate on-the-job hazards to the
health and safety of workers. Acting under the Occupational
5-1
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Safety and Health Act 1970 (Public Law 91-596), NIOSH devel-
ops and periodically revises recommended exposure limits to
potentially hazardous substances and conditions in the work
place.
OSHA Revised PELs Handout 8
The Occupational Safety and Health Administration
(OSHA) is amending its existing Air Contaminants standard
1910.1000 including Tables 2-1, 2-2, 2-3. This amendment is
lowering 212 Permissible Exposure Limits (PELs) listed for
these three tables; setting new PELs for 164 substances not
currently regulated by OSHA; and maintaining other PELs un-
changed. The changes also include inclusion of Short Term
Exposure Limits (STELs) to complement the 8 hour time-weigh-
ted average (TWA) limits, where applicable. Many of OSHAs
PELs were promulgated initially from the American Conference
of Governmental Industrial Hygienists (ACGIH) 1968 Threshold
Limit Values (TLV) list; PELs are not updated annually as is
the TLV list. As law, however, they represent the legal
maximum levels of contaminants in work room air. Section 17
contains the 1989 revision of the OSHA PELs.
ACGIH TLVs
The American Conference of Governmental Industrial
Hygienists (ACGIH) developed a list of Threshold Limit
Values (TLVs) that refer to airborne concentrations of
suostances and represent conditions under which it is be-
lieved that nearly all workers may be repeatedly exposed day
after day without adverse effect. Because of wide variation
in individual susceptibility, a small % of workers may
experience discomfort from some substances at concentrations
at or below the threshold limit.
Cartridge Life
Areas of high humidity and temperature can substantial-
ly reduce cartridge life by tying up the activation sites of
the adsorbent material in the cartridge. Some cartridge and
canister manufacturers have engineered "sight devices" into
the cartridge which change color when its effectiveness is
substantially reduced or totally eliminated. These devices
are also known as end-of-service of life indicators. These
indicators can also be audible in nature, such as the warn-
ing bell on a SCBA indicating that the air cylinder needs
replacing or recharging. Different air contaminants will
have varying breakthrough times. The user must utilize the
manufacturer's recommendations, possible olfactory warning
properties, and other information to determine when car-
tridges or canisters require replacement.
5-2
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REVIEW QUESTIONS
EXPOSURE LIMITS
1. What agency develops and periodically revises recommend-
ed exposure limits to potentially hazardous substances
and conditions in the work place?
2. What agency was NIOSH formed under?
3. What does PEL stand for?
4. Prior to 1970, what did state agencies use as guidelines
for recommended exposures to toxic materials?
5. What does ACGIH stand for?
5-3
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USES AND LIMITATIONS OF RESPIRATORS
Objectives
Student understanding of the differing levels of protec-
tion offered by different respiratory protection devices.
Calculations of PFs and MUCs.
Background
Respirators offer varying degrees of protection against
different contaminants. One must understand the differences
between different types of respirators. Comparisons of
respirators can be done by using the concept of protection
factors (PFs). Maximum Use of Concentration (MUC) is deter-
mined by TLV x PF.
LECTURE NOTES
PROTECTION FACTORS (PFs) Transparency 5-3
Protection factor (PF) is defined as the concentration
of a contaminant measured outside the respirator divided by
the concentration found inside the respirator. It is a
measure of the degree of protection provided to the wearer.
The protection factor depends greatly on the fit of the
respirator to the wearer's face. The PF offered by any one
respirator will be different for each individual. The
protection constantly changes depending on the worker's
activities and shaving habits.
Protection factors, based on extensive research, have
been developed for different categories of respirators. See
Table 1. PF are based on quantitative fit testing of respi-
rators, and not based on a sufficient amount of workplace
testing.
The range of all potential exposures should be deter-
mined for all workers and for all circumstances that can be
reasonably anticipated. The highest anticipated exposure
for each respirator wearer should be used to compute the
protection factor required for each wearer. One can deter-
mine the PF needed by using the following formula:
5-4
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Table 1 Respiratory Protection Factors
Type of Respirator
AIR PURIFYING
Single-use, dust, dust/mist,
and dust/mist/fume
Half-mask
Protection
Factor
5
10
Full facepiece 50
Powered air purifying, tight fitting 50
Powered air purifying, loose fitting 25
Facepiece
Pressure
Negative
Negative
Negative
Negative
Negative
ATMOSPHERE-SUPPLYING
Self-Contained Breathing Apparatus 10,000
(SCBA) : Open-circuit, pressure-demand,
full facepiece
Positive
5-5
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PF needed = Concentration of contaminant outside mask
Concentration of contaminant desired inside
mask
Required PF should be used with caution. The following
tables show Protection Factors for different types of respi-
rators.
MAXIMUM USE CONCENTRATION (MUC) Transparency 5-4
Maximum Use Concentration (MUC) is defined as the maxi-
mum ambient air concentration of an air contaminant in which
a respirator can be used. It is determined by the following
formula:
MUC = TLV x PF
See Table 2 for an example of the use of this formula.
The MUC cannot be applied if the calculation yields a
value close to or exceeding an IDLH level for a particular
air contaminant.
5-6
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TABLE 2 Example of Maximum Use Concentration Determination
What Is the MUG for a half-mask respirator with dust/mist
filters for copper dust?
TLV for copper dust: 1 rng/m3
PF for half-mask respirator with dust/mist filter: 10
MUG = TLV x PF
= 1 mg/m3 x 10
= 10 mg/m3
If air-samping indicates an ambient concentration greater than
10 mg/m3, this resptator does not provide sufficient protection!
5-7
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REVIEW QUESTIONS
USES AND LIMITATIONS OF RESPIRATORS
1. What is the formula used to determine the protection
factor of a respirator?
2. Are protection factors based on qualitative or quantita-
tive fit testing of respirators?
3. What is the protection factor of a half-face respirator?
a. 5
b. 10
c. 20
d. 50
e. 100
4. Is the protection factor for a certain respirator going
to be the same for all individuals?
a. Yes
b. No
5. What is the MUC for a full facepiece respirator with
organic vapor cartridges for methyl chloroform?
5-8
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PROPER USE AND CARE OF AIR-PURIFYING RESPIRA-
TORS (Video Tape)
Objectives
Student understanding of the general maintenance and
storage requirements for respirators.
Background
To prepare the student for Lecture 6, the general re-
quirements and procedures in maintaining respirator's is
discussed.
5-9
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LECTURE 6
RESPIRATOR "HANDS-ON" EXERCISES
-------
LECTURE 6
RESPIRATOR "HANDS-ON" EXERCISE
RESPIRATOR EXERCISE
Objectives
Student familiarization with different types of respira-
tors. Student practice performing field checks and respira-
tor inspections.
Background
It is important for students to be thoroughly familiar
with the respirators to ensure comfort and acceptance of the
devices.
FIT-TESTING (Video Tape)
Objective
Student understanding of the necessity for, and the
procedures for, qualitative and quantitative fit-testing.
Background
OSHA requires that the seal of the respirator facepiece
with the face of the wearer be verified with standard fit-
testing procedures.
6-1
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LECTURE 7
INTRODUCTION TO SELF-CONTAINED
BREATHING APPARATUS RESPIRATORS
-------
LECTURE 7
INTRODUCTION TO SELF-CONTAINED
BREATHING APPARATUS RESPIRATORS
SELF-CONTAINED BREATHING APPARATUS (SCBA)
Objective
Student understanding of the limitations, care, use, and
types of SCBAs.
Background
A self-contained breathing apparatus (SCBA), while
providing the greatest protection to the wearer, is by far
the most complex respirator in use today. SCBA training is
essential. SCBAs can provide respiratory protection in
oxygen deficient environments and in situations where high
or unknown concentrations of toxic gases, vapors or particu-
late are present. When using a SCBA, the wearer is indepen-
dent of the surrounding atmosphere, because he/she is brea-
thing within a closed system. The type of SCBA that will be
addressed and used in this class is a pressure demand, open
circuit system supplied by cylinder-stored compressed air.
LECTURE NOTES
USES AND LIMITATIONS Handout 11
All SCBAS may be used in oxygen deficient environments.
However, if used in a IDLH environment only a positive
pressure unit can be used. Demand devices have protection
factors no greater than air purifying devices with the same
facepiece.
Under emergency conditions. Any SCBA may be used for
escape and rescue.
The pressure-demand unit that we will use in this class
can provide up to 30 minutes of breathing time, much less
under extreme exertion.
7-1
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SCBA with less than 15 minute air supply may be used for
emergency escape only.
All SCBA equipment must have a functioning warning
device that alarms when only 20-25% of service time remains.
SCBA are approved as systems. The interchanging of
parts from one manufacturer's unit to another will void the
approval as in all other types of respirators.
Oxygen must not be used to fill SCBA tanks. Tanks must
be filled by qualified personnel.
When using SCBA equipment, the use of a buddy system
and/or other safety considerations are required when working
in IDLH environments.
Where contaminants pose a hazard through skin absorp-
tion, precautions must be taken to cover all exposed skin
surfaces with impermeable clothing.
Always follow manufacturers' instructions for SCBA use
and cylinder recharging and testing.
SCBAs should not be worn in areas in which explosive
contaminants are potentially present at concentrations equal
to or above 10% of the lower explosive limit (LEL).
Only trained persons should wear a SCBA as the equipment
is bulky and the air cylinders' service life is dependent on
the individual wearer's physical conditioning and ability to
perform the work required when wearing a SCBA.
COMPONENT(S) CHECKLIST Transparency 7-1
Facepiece Assembly
The facepiece assembly consists of a facepiece, rubber
mask assembly, speaking diaphragm, exhalation valve and a
breathing tube. Lens fogging is reduced by the flow of
cool, dry air directed across the lens +hrough inlet ducts
located in the facepiece. A speaking diaphragm may be
mounted in the front of the facepiece; its housing may
contain the exhalation valve or the exhalation valve may be
mounted separately.
Fastened to the facepiece, by a threaded connector, is a
corrugated breathing tube. The other end of which attaches
to the regulator by means of a coupling nut.
7-2
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The facepiece must seal on the wearer to ensure safety
in hazardous atmospheres. The head band must be tight to
maintain that seal. The seal may be broken by head move-
ment, facial movement, exhalation valve not seating, speak-
ing diaphragm in poor condition, damage to the facepiece,
facial structure, missing gaskets, and any facial or head
hair that comes in contact with any part of the facepiece
that seals against the face and forehead. This seal can be
checked by a negative pressure test by placing palm over the
end of the corrugated breathing tube and inhaling. If this
does not create negative pressure in the mask, try to adjust
it or do not use that facepiece.
Carrier and Harness Assembly
The carrier is the means of mounting the cylinder on the
apparatus. It consists of a metal back plate against which
the cylinder rests, and which has an opening at the bottom
for insertion of the cylinder neck and valve. The cylinder
is held in place by a curved, metal bank fitted to the back
plate.
The harness is the means by which the apparatus is worn.
It consists of two shoulder straps, a chest strap, and a
waist strap. The carrier and harness should be checked for
loose belts and worn straps.
Audible Alarm
The audible alarm rings to indicate low cylinder air
pressure. It is a warning device that is connected between
the cylinder and demand regulator on the high pressure hose.
A loud ringing sound indicates a low air pressure below 540
psi or 1,000 psi depending on the model. They will ring
continuously when the cylinder pressure reaches the preset
pressure for approximately 4 to 6 minutes rated time.
Operational time would be approximately 2 to 3 minutes or
less. This is the amount of air remaining. This alarm
should be checked before every use or during the monthly
check.
Remember, the audible alarm is indicating low air pres-
sure, and it is imperative, when it does ring, that the
wearer leave the area to obtain another cylinder. Do not
remain in the area.
Pressure-Demand Regulator
The pressure-demand regulator reduces the cylinder
pressure to a breathable pressure and supplies the wearer
with air in direct response to breathing requirements. All
7-3
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entry or re-entry into immediately dangerous or hazardous
atmospheres require the use of the pressure-demand regula-
tor. The regulator is the heart of the SCBA and should only
be worked on by trained personnel. The pressure-demand
regulator can be checked by putting on the SCBA and breaking
the seal between the rubber mask assembly and your face.
There should be a flow of air coming through the break in
the seal to demonstrate positive pressure in the facepiece.
In the event that the automatic mechanism of the regula-
tor fails, an emergency bypass valve, which is distinguished
by its red handwheel and octagon shape, can be used. This
valve, which is usually tapped into the inlet side of the
regulator, routes the flow of air through a special passage-
way in the regulator, so that it enters the breathing tube
and facepiece independent of the automatic phase of the
regulator.
Since the bypass valve is a constant flow device, it
should be used only when the demand regulator fails to
operate. When the bypass valve is used the supply of air
will be reduced to approximately ten minutes duration with a
full cylinder. This bypass valve should be checked before
using a SCBA.
High Pressure Flexible Hose
The high-pressure hose is a flexible hose that routes
the compressed air from the cylinder to the regulator. The
connection to the cylinder is made with a fitting that is
hand-tightened or tightened with a wrench. The connection
is made in a brass cone fitting using an 0-ring gasket as
the seal between the male and female sections. This gasket
should be checked periodically and spare parts kept for
replacement as needed.
Cylinder
The cylinder has a 45 cubic feet capacity at 2216 psi
and a 30 minute duration rating when full. The rated dura-
tion of the SCBA is determined by NIOSH/MSHA in their test-
ing procedures. The true time duration of the cylinder will
depend on several operational factors.
1. Physical activity of the user.
2. Physical condition of the user.
3. The user's training or experience with the SCBA.
4. The emotional cor ition of the user, (e.g., excite-
ment or fear).
5. The condition of the SCBA and the amount of air in
the cylinder.
7-4
-------
The cylinder should be charged only by qualified person-
nel. The cylinder should also have a hydrostatic test
performed every five years by a qualified person. Extra
cylinders should be available to deal with emergency situa-
tions. No cylinder should be used below 1500 psi. Only
Grade D air should be used when refilling cylinders.
Routine Inspection
Inspection for Defects
The most important part of a respirator maintenance
program is the continual inspection of the devices. If
properly performed, inspections will identify damaged or
malfunctioning respirators before they can be used. The
OSHA standard outlines two types of inspections.
a. While the respirator is in use.
b. While it is being cleaned.
In plants where the workers maintain their own respira-
tors, the two types of inspections become essentially one.
Frequency of Inspection
OSHA requires that "All respirators be inspected before
and after each use" and that those not used routinely, i.e.,
emergency escape and rescue devices, "shall be inspected
after each use and at least monthly ..." Obviously, emer-
gency escape and rescue devices do not require inspection
before use. Records of inspections should be kept on appro-
priate Forms. See Figure I.
Inspection Procedures Transparency 7-2
The OSHA standard states that the respirator inspection
shall include checking of:
a. Tightness of the connections.
b. Facepiece.
c. Valves.
d. Connecting tubes.
e. Canisters, filters, and cartridges.
In addition, the standard also states that the regulator
and warning devices on a SCBA shall be checked for proper
functioning.
Field inspection of respirators should be checked as
follows before and after each use:
7-5
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1. Examine the facepiece for:
a. Excessive dirt.
b. Cracks, tears, holes or physical distortion of shape
from improper storage.
c. Inflexibility of rubber facepiece.
d. Cracked or badly scratched lenses in full facepieces.
e. Incorrectly mounted full facepiece lenses, or broken
or missing mounting clips.
f. Cracked or broken air-purifying element holder(s) and
badly worn threads or missing gasket(s).
2. Examine the head straps or head harness for:
a. Breaks.
b. Loss of elasticity.
c. Broken or malfunctioning buckles and attachments.
d. Excessively worn serrations on the head harness,
which might permit slippage (full facepieces only).
3. Examine the exhalation valve for the following after
removing its cover:
a. Foreign material, such as detergent residue, dust
particles or human hair under the valve seat.
b. Cracks, tears or distortion in the valve material.
c. Improper insertion of the valve body in the face-
piece.
d. Cracks, breaks or chips in the valve body, particu-
larly in the sealing surface.
e. Missing or defective valve cover.
f. Improper installation of the valve in the valve body.
4. If the device has a corrugated breathing tube examine it
for:
a. Broken or missing end connectors.
b. Missing or loose hose clamps.
c. Deterioration, determined by stretching the tube and
looking for cracks.
5. Examine the air supply systems for:
a. Integrity and good condition of air supply lines and
hoses, including attachment and end fittings.
b. Correct operation and condition of all regulators and
other air flow regulators.
6. The high pressure cylinder of compressed air or oxygen
is sufficiently charged for the intended use, preferably
fully charged.
7. On osed circuit SCBA, a fresh canister of C02 (carbon
dio, de) sorbent is installed.
8. On open circuit SCBA, the cylinder has been recharged if
less than 25% of the useful service time remains.
7-6
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9. All SCBAs are required to have a warning device that
indicates when the 25% level is reached. However, it is
recommended that an open-circuit SCBA be fully charged
before use.
NON-ROUTINE USE OF AIR-PURIFYING OR ATMOSPHERE SUPPLYING
DEVICES
When air-purifying or atmosphere supplying devices are
used non-routinely, all the above procedures should be
followed after each use. OSHA requires that devices for
emergency use be inspected once a month and that "a record
shall be kept of inspection dates and findings for respira-
tors maintained for emergency use."
Defects Found in Field Inspection
If defects are found during any field inspection, two
remedies are possible. If the defect is minor, repair
and/or adjustment may be made immediately. If it is major,
the device should be removed from service until it can be
repaired. A spare unit should replace the unit removed from
service. Under no circumstances should a device that is
known to be defective remain in the field.
Cleaning and Disinfecting
OSHA 1910.134 states "routinely used respirators shall
be collected, cleaned, and disinfected as frequently as
necessary to ensure that proper protection is provided . ."
and that emergency use respirators "shall be cleaned and
disinfected after each use".
The actual cleaning may be done in a variety of ways.
It is recommended that a commercial dishwasher be used. A
standard domestic clothes washer may also be used if a rack
is installed around the agitator to hold the facepieces in
fixed positions. If the facepieces are placed loose in the
washer, the agitator may damage them. A standard domestic
dishwasher may be used, but is not preferred, because it
does not immerse the facepieces. Any good detergent may be
used followed by a disinfecting rinse or a combination
disinfectant-detergent for a one stop operation. However,
where individual issue is not practical, disinfection is
strongly recommended. Reliable, effective disinfectants may
be made from readily available household solutions, includ-
ing :
7-7
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a. Hypochlorite solution (50 ppm of chlorine) made by
adding approximately two milliliters of bleach (such
as Chlorox) to one liter of water, or two teaspoons
of bleach per gallon of water. A two minute immer-
sion disinfects the respirators.
b. Aqueous solution of iodine (50 ppm of iodine) made by
adding approximately 0.8 milliliters of tincture of
iodine per liter of water, or one teaspoon of tinc-
ture of iodine per gallon of water. A two-minute
immersion is sufficient to disinfect the respirators.
If the respirators are washed by hand, a separate disin-
fecting rinse may be provided. If a washing machine or
dishwasher is used, the disinfectant must be added to the
rinse cycle. The amount of water in the machine at that
time will have to be measured to determine the correct
amount of disinfectant.
To prevent damaging the rubber and plastic in the respi-
rator facepieces, the cleaning water should not exceed 140°
F, but it should not be less than 120°F to ensure adequate
cleaning. In addition, if commercial or domestic dishwash-
ers are used, the drying cycle should be eliminated, since
the temperatures reached in these cycles may damage the
respirators.
Rinsing
The cleaned and disinfected respirators should be rinsed
thoroughly in water (140°F maximum) to remove all traces of
detergent and disinfectant. This is very important for
preventing dermatitis to the wearer.
Drying
The respirators may be allowed to dry in room air on a
clean surface. They may also be hung from a horizontal
wire, but care must be taken not to damage or distort the
facepieces. Another method is to equip a standard steel
storage cabinet with an electric heater that has a built-in
circulating fan, and to replace the solid steel shelves with
steel mesh.
Reassembly and Inspection
The clean, dry respirator facepieces should be reassem-
bled and inspected in an area separate from the disassembly
area to avoid contamination. The inspection procedures have
been discussed. Special emphasis should be given to in-
specting the respirators for detergent or soap residue left
by inadequate rinsing. This appears most often under the
7-8
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seat of the exhalation valve and can cause valve leakage or
sticking.
The facepiece should be combined with the tested regula-
tor and the fully charged cylinder, and an operational check
performed.
Inspection During Cleaning
Because respirator cleaning usually involves some disas-
sembly, it presents a good opportunity to examine each
respirator thoroughly. The procedures outlined above for a
field inspection should be used. Respirators should be
inspected after cleaning operations and reassembly have been
accomplished.
OSHA requires, as part of an inspection program, that
all respirators be leak checked to determine that the com-
plete assembly is air tight. Follow field inspection proce-
dures to examine the freshly cleaned, reassembled respira-
tor.
Respirator Storage Transparency 7-3
OSHA requires that respirators be stored to protect
against:
a. Dust
b. Sunlight
c. Heat
d. Extreme cold
e. Excessive moisture
f. Damaging chemicals
g. Mechanical damage
Damage and contamination of respirators may take place
if they are stored on a workbench, or in a tool cabinet or
toolbox, among heavy tools, greases and dirt.
Freshly cleaned respirators should be placed in heat-
sealed or reusable plastic bags until reissued. They should
be stored in a clean, dry location away from direct sun-
light. They should be placed in a single layer with the
facepiece and exhalation valve in an undistorted position to
prevent rubber or plastic from taking a permanent distorted
"set".
7-9
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Air-purifying respirators kept ready for non-routine or
emergency use should be stored in a cabinet with individual
compartments. The storage cabinet should be readily acces-
sible, and all workers should be made aware of its location.
Preventing serious injury from the inhalation of a toxic
substance depends entirely on how quickly workers can get to
the emergency respirators.
A chest or wall-mounted case may be purchased from the
respirator manufacturer for storing SCBAs for use in emer-
gencies. Again, the location of SCBAs should be well known
and clearly marked. They should be located in an area that
will predictably remain uncontaminated. Putting on a SCBA
in a highly contaminated atmosphere such as might be created
by a massive release of a toxic material, may take too long
a time to perform safely in that area. Therefore, the first
reaction should be to escape to an uncontaminated area, then
put on the SCBA, and re-enter the hazardous area for whatev-
er task must be done. Exceptions to this rule may be en-
countered, and only a thorough evaluation of the process and
escape routes, will permit a final decision about the cor-
rect storage location for SCBAs.
Respirators should be stored in a plastic bag inside a
rigid container.
If the worker is trained adequately, he/she should
develop a respect.for respirators which will be an automatic
incentive to protect them from damage. Besides providing an
assurance of adequate protection, this training will lower
maintenance costs by decreasing damage.
Maintenance and Repair
The OSHA standard states that "replacement or repair
shall be done by experienced persons with parts designed for
the respirator." Besides being contrary to OSHA require-
ments, substitution of parts from a different brand or type
of respirator invalidates approval of the device.
Maintenance personnel must be thoroughly trained. They
must be aware of the SCBA's limitations and never try to
replace components or make repairs and adjustments beyond
the manufacture's recommendations, unless they have been
specially trained by the manufacturer.
These restrictions apply primarily to maintenance of the
more complicated devices, especially closed and open-circuit
SCBA, and more specifically, regulator valves and low pres-
sure warning devices. These devices should be returned to
the manufacturer or to a trained technician for adjustment
or repair.
7-10
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Types of SCBAs
Transparency 7-4
There are two categories of SCBAs. The first category
is the closed circuit SCBA. Another name for the closed-
circuit SCBA is the "rebreather" device which is indicative
of the mode of operation. The breathing gas is rebreathed
after the exhaled carbon dioxide has been removed and the
oxygen content restored by a compressed or liquid oxygen
source or an oxygen generating solid substance. This cate-
gory of SCBA can be used for one to four hours. There are
some positive pressure closed-circuit SCBA that can be used
in IDLH environments. Most closed-circuit SCBAs are nega-
tive pressure and should be used in atmospheres Immediately
Dangerous to Life or Health (IDLH) only where their long
term use is necessary as in mine rescue. All closed-circuit
SCBAs can be used in oxygen deficient atmospheres.
Two basic types of closed-circuit SCBA are presently
available. One uses a cylinder of compressed oxygen and the
other a solid oxygen generating substance. On a typical
closed-circuit SCBA with a small cylinder of compressed
oxygen breathing air is supplied from an inflatable bag.
The exhaled air passes through a granular solid adsorbent
that removes the carbon dioxide, thereby reducing the flow
back into the breathing bag. The bag collapses so that a
pressure plate bears against the admission valve which opens
and admits more pure oxygen that reinflates the bag. Thus
the consumed oxygen is replaced.
The second type of closed-circuit SCBA uses an oxygen-
generating solid, usually potassium superoxide (K02). The
H20 and C02 in the exhaled breath react with the K02 to
release 02. Oxygen is continually released at a high flow
rate into the breathing bags which act as a reservoir to
accommodate breathing fluctuations. A pressure relief valve
and saliva trap, release the excess pressure created in the
facepiece by oxygen flow and nitrogen buildup. This type of
SCBA is lighter and simpler than the cylinder type. Howev-
er, it is useful for only about one hour and once initiated,
cannot be turned off.
An open-circuit SCBA is the other category of SCBA.
They are SCBAs that exhaust the exhaled air to the atmo-
sphere instead of recirculating it. Most of these SCBAs are
filled with compressed air and some have compressed oxygen.
Compressed oxygen can never be used in a device unless it is
specifically designed for that purpose. A cylinder of high
pressure (2000-4500 psi) compressed air, supplies air to a
regulator that reduces the pressure for delivery to the
7-11
-------
facepiece on demand. Because it has to provide the total
breathing volume requirements, since there is no recircu-
lation, the service life of the open-circuit SCBA is usually
shorter than the closed-circuit SCBA. Most open-circuit
SCBA have a service life of 30 to 60 minutes based on NIOSH
breathing machine tests as prescribed in 30 CFR 11. Open-
circuit SCBA are widely used in firefighting and for indus-
trial emergencies.
Fit-Testing of SCBAs
The full facepiece of the SCBA can be qualitatively and
quantitatively fit-tested as previously discussed in this
manual.
Other Safety Considerations Transparency 7-5
1. Buddy System
OSHA requires in CFR 29 1910,134 (e)(3) (ii) that
when SCBAs are used in atmospheres immediately dan-
gerous to life and health (IDLH), standby men must be
present with suitable rescue equipment. One method of
the buddy system consists of first attaching a life
line to the person entering the IDLH area. The other
end of the life line is manned by a standby person
outside of the IDLH area with an unobstructed view of
the person inside the IDLH area. This way if the
person in the IDLH area is overcome he can be pulled
to safety. Another method is to have a standby
person wearing and SCBA stationed outside the en-
trance to the IDLH area ready for immediate emergency
rescue.
2. Lower Explosion Limits (LEL)
The lower explosion limit is the minimum volume
percentage of a material in air that can be ignited
to cause self-sustaining flame. Concentrations in
excess of LEL are considered to be immediately dan-
gerous to life or health. When concentration of a
substance are at or above the LEL, respirators must
provide maximum protection. See Figure A.
3. Monitoring Equipment
Mixtures of combustible gas and air cannot be ignited
to cause self sustaining flame unless the concentra-
tion o* gas exceeds the LEL. Explosimeters or com-
bustible gas indicators are usually battery powered,
portable direct reading instruments used to detect
the presence of explosive or combustible gases in the
7-12
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Figure A Exposure Limits
8
7.5
I 6
CJ
cc.
LU
^
Z>
_l
o
>
1.4
0.7
UFL
UFL - UPPER FLAMMABLE LIMIT
LFL - LOWER FLAMMABLE UMIT
FP - FLASH POINT
•-45
-100 -50 0 50 100
TEMPERATURE IN DEGREES FAHRENHEIT
7-13
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air. Normally a probe is used to draw in the air to
be sampled. Most models provide either a direct
reading, or have an audible alarm. Most instruments
do not distinguish between different types of gases
or vapors, however, it is usually not necessary to
know the exact identity of a gas to evaluate its fire
and explosion risk.
4. Accessories
Corrective goggles or spectacles worn inside the
facepiece the respirator should be mounted to the
facepiece or bridge of the nose. Corrective specta-
cles must not affect the fit of the facepiece.
Safety harnesses or safety lines used for lifting or
removing persons from hazardous atmospheres should be
sturdy and in good condition.
7-14
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REVIEW QUESTIONS
SELF-CONTAINED BREATHING APPARATUS (SCBA)
1. The rated duration of the SCBA cylinder is tested and
determined by:
A. OSHA
B. ACGIH
C. NIOSH/MSHA
D. EPA
E. All of the above
2. The operational duration of the SCBA cylinder is depen-
dent on which of the following factors?
A. The emotional status of the user
B. Physical activity of the user
C. User's experience with the SCBA
D. Physical condition of user
E. All of the above
3. A hydrostatic test should be performed every:
A. 2 years
B. 1 year
C. 10 years
D. 5 years
4. The cylinder should not be used if it is:
A. Less than 2217 psi
B. Less than 1500 psi
C. Filled with Grade D Air
D. Colored yellow
5. Which components reduces the cylinder pressure to a
breathable pressure and supplies the wearer with air in
direct response to breathing requirements?
A. High pressure hose
B. Pressure-demand regulator
C. Audible alarm
D. Cylinder
7-15
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RESPIRATOR SCENARIOS
Objectives
Student use of concepts learned during this training
program.
Background
These six scenarios allow the students to utilize previ
ously learned concepts.
7-16
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SCENARIOS
Question 1: Transparency 7-6
An inspection is to be made at a hazardous waste site
containing drums with organics which have been partially
identified and the ground is contaminated. The work being
done on the site is removing contamina-ted earth. When
going into the exclusion zone, the inspector should wear:
a. Only an SCBA.
b. Only a powered air purifying respirator with an
organic vapor cartridge.
c. Whatever respirator is called for in the existing
site safety plan prepared by a CIH with adequate
training under OSHA standards.
d. Cannot enter the exclusion zone until all the unknown
contaminants are identified.
e. Can enter the site with less protective respiratory
protection than called for in a site safety plan, if
inspector has evaluated all the data and determines
that it is safe to do so.
7-17
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Question 2: Transparency 7-7
An inspection is to be made in an oil refinery where the
inspector observes a process stream leak from a vacuum
distillation tower. The small stream is shooting out about
! foot laterally at a rate of about a gallon every 20 min-
utes and is spreading out over the cement ground. The leak
appears to be very recent and the temperature is 60°F and a
nice breeze is present at this outdoor location. What
respiratory protection should the inspector wear in docu-
menting the leak?
a. SCBA.
b. Full facepiece air purifying respirator with organic
vapor cartridges.
c. Full facepiece air purifying gas mask with an organic
vapor canister.
d. No respiratory protection would be necessary if the
inspection will take less than 15 minutes.
e. Either B or C depending on the professional judgement
of the inspector of potential exposures.
7-18
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Question 3: Transparency 7-8
An inspection is going to be made at an outdoor pesti
cide manufacturing plant that uses phosgene (in large com-
pressed cylinders) to make organophosphate pesticides. The
plant safety designee hands the inspector a mouth breather
escape respirator in case there is a phosgene release (this
is plant policy and part of their written respirator pro-
gram). What should the inspector do?
a. Can't use that particular respirator because he or
she was not fit tested for that type of respirator.
b. After checking to make sure the cartridge is correct
for phosgene, the inspector should accept it and
carry it with him or her into the plant knowing other
respiratory protection may be necessary.
c. Mouth breathing escape respirators offer no protec-
tion, and the inspector should refuse to accept and
must use an escape type SCBA.
d. If the plant is running normally and no phosgene
leaks have occurred in the past five years, the
inspector does not need an escape respirator for
phosgene.
e. None of the answers is correct.
7-19
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Question 4: Transparency 7-9
In making an inspection of an underground tank, an
inspector will have to enter and travel through an under-
ground crawl space. There are no provisions to check air
quality and the inspector is alone. What respiratory pro-
tection should the inspector use to enter the crawl space?
a. SCBA.
b. Full facepiece gas mask with canister for protection
against gases and vapors.
c. Any supplied air respirator in case there is lack of
oxygen.
d. Cannot enter the space with any type of respiratory
protection because not all requirements for entering
a confined space have been met.
e. Cannot enter the space with any type of respiratory
protection because the space was not checked for
adequate amounts of oxygen.
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Question 5: Transparency 7-10
You are going to conduct a NESHAP inspection of an
asbestos removal project. You will be entering the envelope
during active removal. You notice that there is no shower
r.-iua... __ negative pressure systems, and debris is seen
lirlock. What respiratory protection would you
facility, no ..
outside the ai
select?
a. SCBA.
b
c
d
SCBA.
Full face, HEPA cartridges, air purifying respirator.
Powered air purifying respirators with HEPA filters.
No respiratory protection is required if the time
spent in the enclosure is 15 minutes or less.
A supplied air positive pressure type C respirator
using the removal firm's air supply hoses and mani-
folds.
7-21
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Question 6: Transparency 7-11
You are inspecting a chemical plant in a remote area by
yourself when you see an employee enter a tank through a
hatch on top of the tank. You climb on top of the tank and
see that the man has collapsed and is lying on the bottom of
the empty tank about 10 feet below the hatch. You are
carrying an organic cartridge full facepiece gas mask. You
should:
a. Put on the gas mask, enter the tank, and rescue the
employee.
b. Ignore the situation because the tank was not part of
your inspection.
c. Close the hatch so that whatever caused the employee
to collapse will not contaminate the environment.
d. Run and get help.
e. Check the tank from the outside to make sure all
lines to the tank are shut, open any other hatches
you see on the tank, and then go get help.
7-22
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LECTURE 8
COURSE CONCLUSION
-------
LECTURE 8
COURSE CONCLUSION
COURSE CRITIQUE AND FINAL TEST
Objectives
Provide students the opportunity to critique the
strengths and weaknesses of the program materials and the
course instructors. Students take the final test and obtain
their grades before leaving the classroom.
Background
To determine program and instructor effectiveness, a
feedback mechanism is required.
8-1
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STUDENT COURSE CRITIQUE
Course No. Date: Student name (optional):
For each statement circle the response(s) that is (are) the closest to
your opinion.
1. The course objectives were:
1. clearly stated or written
2. stated or written, but not all of them were clear to me
3. stated or written, but most of them were not clear to me
4. neither stated nor written
2. Course content was:
1. useful for my professional growth
2. too complex
3. too simple
4. what I had expected
3. Course contained a sufficient amount of practice exercises.
1. agree
2. disagree
3. no opinion
4. The amount of time allotted for this course was:
1. sufficient
2. too long, should be days
3. too short, should be days
5. Overall, I think the course was:
1. excellent
2. good
3. fair
4. poor
6. Generally, the course was presented in an interesting manner.
1. agree
2. disagree
3. no opinion
7. The course content was well-coordinated among the instructors.
1. agree
2. disagree
3. no opinion
8. The instructors wee well prepared for most class sessions.
1. agree
2. disagree
3. no opinion
8-2
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9. The instructors were quite knowledgeable about their subject areas
1. agree
2. disagree
3. no opinion
10. The questions raised during the lectures (and laboratories) were
usually answered to my satisfaction.
1. agree
2. disagree
3. no opinion
11. The teaching methods used int his course were effective for my
learning.
1. agree
2. disagree
3. no opinion
12. the audio-visual materials aided my understanding of the topics
presented.
1. agree
2. disagree
3. no opinion
13. The classroom environment and facilities were:
1. excellent
2. adequate
3. poor
Please comment:
14. Overall, the course instructors were:
1. excellent
2. good
3. fair
4. poor
Please comment:
The most needed improvements in this course are:
The "best" parts of this course were:
Additional comments:
8-3
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