United States
            Environmental Protection
            Agency
              Office of Emergency and
              Remedial Response
              Emergency Response Division
                                          540R95131
Environmental
Response
Team
vvEPA
Air Monitoring
for Hazardous Materials

Environmental Response
Training Program

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                                                                                    ,(>•.,  .  • ••.,

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                                      FOREWORD
This manual  is for reference use of students enrolled  in scheduled training courses of the U.S.
Environmental Protection Agency (EPA). While it will  be useful to anyone who needs information
on the subjects covered, it will  have its greatest value as an  adjunct to classroom presentations
involving discussions among the  students and the instructional staff.

This manual  has been developed with a goal  of providing the  best available current information;
however, individual instructors may  provide additional material to cover special aspects of their
presentations.

Because of the limited availability of the manual,  it  should not be cited in bibliographies or other
publications.

References to products and manufacturers are for illustration  only; they do not imply endorsement
by EPA.

Constructive  suggestions for improvement of the content and  format of the manual are welcome.

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                                    CONTENTS


                                                                               Section

Acronyms and Abbreviations

Air Monitoring Plans and Strategies	1

Exposure Limits and Action Levels	2

Oxygen Monitors, Combustible Gas Indicators, and
Specific Chemical Monitors	3

Total Vapor Survey Instruments	4

Air Sample Collection  	5

Introduction to  Gas Chromatography  	6

Air Dispersion  Modeling During Emergency Response	7

References  	8

Manufacturers and Suppliers of Air Monitoring Equipment	9

Workbook:  Air Monitoring for Hazardous Materials	 10
10/93                                     v                                   Contents

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             AIR MONITORING FOR HAZARDOUS MATERIALS

                                       (165.4)

                                        5 Days
This course instructs participants in the practices  and procedures  for monitoring and sampling
airborne hazardous materials.  It is designed for personnel  who  evaluate releases of airborne
hazardous materials at hazardous waste sites or accidental hazardous material releases.

Topics that are discussed include air monitoring and sampling programs, air monitoring and sampling
techniques,  air monitoring and sampling equipment, instrument calibration, exposure guidelines, air
dispersion modeling, and health  and safety considerations.   The course will  include operating
procedures  for  specific air monitoring and sampling  equipment,  as well  as  strategies for air
monitoring and sampling at abandoned hazardous waste sites and for accidental releases of hazardous
chemicals.

Instructional methods include a combination of lectures, group discussions, problem-solving sessions,
and laboratory and field exercises with hands-on use of instruments.

After completing the course, participants will be able to:

       •     Properly use the following types of air monitoring and sampling equipment:

                    Combustible gas indicators
                    Oxygen monitors
                    Detector tubes
                    Toxic gas monitors
                    Photoionization detectors
                    Flame  ionization detectors
                    Gas chromatographs
                    Sampling pumps
                    Direct-reading aerosol monitors.

       •     Identify the operational parameters, limitations,  and data interpretation requirements
             for the instruments listed above.

       •     Identify  the factors to be  considered in the development of air monitoring and
             sampling plans.

       •     Discuss  the use of air monitoring data for the establishment  of  personnel and
             operations  health and safety requirements.
                        U.S. Environmental Protection Agency
                     Office of Emergency and Remedial  Response
                            Environmental Response Team

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                     ACRONYMS AND ABBREVIATIONS
ACGIH      American Conference of Governmental Industrial Hygienists
AID         argon ionization detector
AIHA        American Industrial Hygiene Association
ALOHA      areal locations of hazardous atmospheres
ANSI        American National Standards Institute
ASTM       American Society for Testing and Materials

BEI          biological exposure indices

C            ceiling (precedes exposure limit)
cc/min       cubic centimeters per minute
cfm          cubic feet per minute
CFR         Code of Federal Regulations
CGI         combustible gas indicator
Cl           chlorine
CO          carbon monoxide

DNPH       2,4-dinitrophenylhydrazine
DQO         data quality objective

BCD         electron capture detector
EPA         U.S. Environmental Protection Agency
ERT         Environmental Response Team (EPA)
eV           electron volt

FID          flame ionization detector
FM          Factory Mutual Research Corporation

GC          gas chromatography

HC1          hydrogen chloride

ICS          incident command system
IDLH        immediately dangerous to life or health
IP           ionization potential

KOH         potassium hydroxide

LCD         liquid crystal display
LED         light-emitting diode
LEL         lower explosive limit
LFL         lower flammable limit
1pm          liters per minute
JO/93
Acronyms and Abbreviations

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MACs       maximum allowable concentrations
MAKs       maximum concentrations at the workplace (Federal Republic of Germany)
MCE        mixed cellulose ester
mg/m3       milligrams per cubic meter
ml           milliliter
mm          millimeter
MOS        metal-oxide  semiconductor
MSDS       material safety data sheets
MSHA       Mine Safety and Health Administration

NaOH       sodium hydroxide
NEC        National Electrical Code
NFPA       National Fire Protection Association
NIOSH       National Institute for Occupational Safety and Health
NRC        Nuclear Regulatory Commission

OH          hydroxide
OS HA       Occupational Safety and Health Administration
OVA        organic vapor analyzer (Foxboro®)
OVM        organic vapor meter

PAH        polycyclic (or polynuclear) aromatic hydrocarbon
PBK         playback
PCB         polychlorinated biphenyl
PEL         permissible exposure limit
PID          photoionization detector
ppb          parts per billion
PPE         personal protective equipment
ppm         parts per million
ppt          parts per trillion
PUF         polyurethane foam
PVC         polyvinyl  chloride

REL         recommended exposure limits

SA          shift average
SCBA       self-contained breathing apparatus
SEI          Safety Equipment Institute
SOP         standard operating procedure
SOSG       Standard Operating Safety Guides
SS           chemical-specific sensor
STEL       short-term exposure limit

TCD        thermal conductivity detector
TLV         threshold limit values
TWA        time-weighted average
Acronyms and Abbreviations                  2                                       10/93

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UEL         upper explosive limit
UL          Underwriters' Laboratory, Inc.
UV          ultraviolet light

VDC         volts DC

WEEL®      workplace environmental exposure level
70/93                                     3                  Acronyms and Abbreviations

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   AIR  MONITORING  PLANS
         AND  STRATEGIES
PERFORMANCE OBJECTIVES
At the end of this lesson, participants will be able to:

•   List six objectives of air monitoring specified by the EPA
    Standard Operating Safety Guides

•   Identify the OSHA standard and EPA standard that cover
    hazardous waste site operations and emergency response

•   List four situations that initial entry monitoring is designed
    to detect

•   Differentiate between "personal monitoring"  and "area
    monitoring"

•   Define, per 1910.120,  when personnel monitoring is
    required

•   List documents that EPA  has developed as guidance for
    compliance with 1910.120

•   Given  the  Personal Air  Sampling  and Air Monitoring
    Requirements Under 29 CFR 1910.120 fact sheet, define air
    monitoring and air sampling

•   List three uses of meteorological data.

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                                                 NOTES
 AIR MONITORING PLANS
      AND STRATEGIES
        AIR MONITORING
         EPA Objectives
 • Identify and quantify airborne
   contaminants onsite and offsite

 • Track changes in air contaminants that
   occur over the lifetime of the incident

 • Ensure proper selection of work practices
   and engineering controls

Source: EPASOSGs
        AIR MONITORING
          EPA Objectives
  • Determine the level of worker protection
    needed

  • Assist in defining work zones

  • Identify additional medical monitoring
    needs in any given area of the site.
 Source: EPASOSGs
10/93
Air Monitoring Plans and Strategies

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     NOTES
                           WORKER PROTECTION
                            STANDARDS (OSHA)

                           29 CFR 1910.120 (HAZWOPER)

                           Applies to
                           - Federal employees
                           - Private industry employees
                           - State and local employees in
                             OSHA states
                           WORKER PROTECTION
                             STANDARDS (EPA)


                         • 40 CFR Part 311

                         • Applies to state and local employees
                          in non-OSHA states

                         • Wording same as 1910.120
                              MONITORING
                             REQUIREMENTS
Air Monitoring Plans and Strategies
10/93

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                                                   /VOTES
           INITIAL ENTRY
                               or
Monitoring for:

•  Immediately dangerous to life
   health (IDLH) conditions

•  Exposures over permissible
   exposure limits (PELs) or published
   exposure levels
          INITIAL ENTRY
   Monitoring for:

   •  Exposure over a radioactive
     material's dose limits

   •  Other dangerous conditions
     - Flammable atmospheres
     - Oxygen-deficient environments
     PERIODIC MONITORING
  "Periodic monitoring (shall) be done
  when the possibility of a dangerous
  condition has developed or when there
  is reason to believe that exposures
  may have risen above PELs since prior
  monitoring was conducted."
 Source: EPA SOSGs
4/94
                                       Air Monitoring Plans and Strategies

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      NOTES
                                PERSONAL MONITORING


                               Required

                               • During actual cleanup phase

                               • To evaluate high-risk employees
                                 (i.e., employees likely to have
                                 highest exposures)

                               • Evaluation pf other employees
                                 needed if high-risk employees exceed
                                 exposure limits

                             Source: 1910.120(h)(4)
                                PERSONAL MONITORING
                                   AREA MONITORING
                             t&
                                        S = Area samplers
Air Monitoring Plans and Strategies
JO/93

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                                                 NOTES
        SITE SAFETY AND
          HEALTH PLAN
   Minimum requirement

   "Frequency and types of air monitoring,
   personnel monitoring, and environmental
   sampling techniques and instrumentation
   to be used, including methods of
   maintenance and calibration of monitoring
   and sampling equipment to be used."
 Source: 1910.120(b)(4)(ii)(E)
    GUIDANCE DOCUMENTS
    	OSHA	


      • Technical manual

      • Analytical methods manual
     GUIDANCE DOCUMENTS
   	EPA	
    EPA-ERT Standard Operating Safety
    Guides (SOSGs), Publication
    9285.1-03, June 1992

    Personal Air Sampling and Air
    Monitoring Requirements (PASAMR)
    Under 29 CFR 1910.120 fact sheet,
    Publication  9360.8-17FS, May 1993
4/94
Air Monitoring Plans and Strategies

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      NOTES
                                   AIR MONITORING vs.
                                      AIR SAMPLING

                                Air monitoring refers to the use of
                                direct-reading instruments producing
                                instantaneous data

                                Air sampling refers to the use of a
                                sampling pump and collection media
                                that produce samples that must be
                                sent to a laboratory for analysis
                                     AIR MONITORING
                                          Features
                                  "Real time" (direct reading)

                                  Rapid response

                                  Generally not compound specific

                                  Limited detection levels

                                  May not detect certain classes of
                                  compounds
                                      AIR SAMPLING
                                         Features
                                Compound or class specific

                                Greater accuracy

                                Requires more time for results

                                Requires additional pumps, media,
                                and analytical support
Air Monitoring Plans and Strategies
JO/93

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                                                 NOTES
  PERSONNEL AIR SAMPLING
  Elements in Sampling Strategy

        • Employee sampled

        • Tasks performed

        • Duration

        • Hazardous substances

        • Equipment to be used
 Source: PASAMR fact sheet
        AREA SAMPLING
            Locations
      Upwind
      - Establish background

      Support zone
      - Ensure support area is clean
        and remains clean
Source; EPASOSGs
        AREA SAMPLING
            Locations
  Contamination reduction zone
  - Ensure that personnel in zone are
     properly protected
  - Ensure that onsite workers are not
     removing PPE in a contaminated area
 Source: EPASOSGs
10/93
Air Monitoring Plans and Strategies

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      NOTES
                                     AREA SAMPLING
                                         Locations
                              • Exclusion zone
                                - Represents greatest risk of exposure
                                - Requires most sampling
                                - Use data to set boundaries
                                - Use data to select proper levels of
                                  PPE
                                - Provide a record of air contaminants

                             Source: EPASOSGs
                                     AREA SAMPLING
                                          Locations
                                Fenceline/downwind
                                - Determine whether air contaminants
                                  are migrating from site
                              Source: EPA SOSGs
                                     AREA SAMPLING
                              Elements in Sampling Strategy
                              • Locations where air sampling will be
                                performed

                              • Hazardous substances that will be
                                sampled during the task

                              • Duration of the sample

                             Source: PASAMR fact sheet
Air Monitoring Plans and Strategies
10/93

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                                              NOTES
        AREA SAMPLING
  Elements in Sampling Strategy
   Equipment that will be used to sample
   for the different hazardous substances

   Collection of meteorological data
 Source: PASAMR fact sheet
      METEOROLOGICAL
       CONSIDERATIONS
    • Data needed
      - Wind speed and direction
      - Temperature
      - Barometric pressure
      - Humidity
       METEOROLOGICAL
       CONSIDERATIONS
   • Data uses
    -  Placement of samplers
    -  Input for air models
    -  Calibration adjustments

   • Data sources
    -  Onsite meteorological stations
    -  Government or private
       organizations
10/93
Air Monitoring Plans and Strategies

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     NOTES
                               AIR DISPERSION MODELS
                                Public exposure assessment

                                Air monitoring and air modeling
                                should interact
                             LONG-TERM AIR MONITORING
                            	PROGRAMS	

                                   Considerations

                                     Type of equipment
                                     Cost
                                     Personnel
                                     Accuracy of analysis
                                     Time to obtain results
                                     Availability of analytical
                                     laboratories
                            Source: EPA SOSGs
                            LONG-TERM AIR MONITORING
                                      PROGRAMS
                              ERT Approach

                              • Use total vapor survey instruments
                                for organic vapors and gases
                                -  Initial detection
                                -  Periodic site surveys
                                -  Area monitors to track changes

                            Source: EPA SOSGs
Air Monitoring Plans and Strategies
10/93

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                                                   NOTES
 LONG-TERM AIR MONITORING
 	PROGRAMS	

    ERT Approach

    •  Collect air samples
      - Analyze with field gas
        chromatographs
      - Send selected samples to
        laboratories
    •  Use survey instruments or gas
      chromatographs to screen samples
      for laboratory analysis
 Source; EPASOSGs
 LONG-TERM AIR MONITORING

	PROGRAMS	

    ERT Approach

    •  When they are known to be present
      or when there are indications that
      they may be a problem, sample for
      - Particulates
      - Inorganic acids
      - Aromatic amines
      - Halogenated pesticides

Source: EPASOSGs
      ADDITIONAL READING
   Air/Superfund Technical Guidance Study
   Series
   - Volume IV - Guidance for Ambient Air
     Monitoring at Superfund Sites (revised),
     EPA-451/R-93-007, May 1993
   - Compilation of Information on Real-Time
     Monitoring for Use at Superfund Sites,
     EPA-451/R-93-008, May 1993
10/93
Air Monitoring Plans and Strategies

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      NOTES
                                     INSTRUMENT
                                 CHARACTERISTICS
                                      SELECTIVITY
                             • Selectivity is an instrument's ability to
                               differentiate a chemical from others in
                               a mixture

                             • Chemicals that affect an instrument's
                               selectivity are called interferences
                                      SENSITIVITY
                                Sensitivity is the least change in
                                concentration that will register an
                                altered reading of the instrument
                            Source: Air Sampling and Analysis for Contaminants: An
                            Overview
Air Monitoring Plans and Strategies
10/93

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                                                     NOTES
  ACCURACY AND  PRECISION

  •  Accuracy refers to the difference
    between the instrument reading and
    the true or correct value.

  •  Precision is the grouping of the data
    points around a calculated average.
    Precision measures the repeatability
    of data.
  ACCURACY AND PRECISION
   Accurate and Precise
        0
Precise but Inaccurate
         x
     ©
   Accurate but Imprecise     Inaccurate and Imprecise


 Source: The Industrial Environment - Its Evaluation and Control
       RELATIVE RESPONSE

    Relative response is the relationship
    between an instrument's reading and
    the actual concentration
    Calculation
     Relative Response =
Instrument Reading

Actual Concentration
JO/93
                      Air Monitoring Plans and Strategies

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       NOTES
                                          CALIBRATION
                                   Process of checking an instrument to
                                   see if it gives the proper response
                                   and making any necessary
                                   adjustments.

                                   Direct-reading instruments generally
                                   are calibrated to one chemical (the
                                   standard).
                                         RESPONSE TIME
                                    Response time is the time between
                                    initial sample contact and readout
                                    of the full chemical concentration
                                    (usually seconds to minutes)

                                    Turnaround time is the time from
                                    sample collection to receipt of
                                    results (days to weeks)
                                             MOBILITY
                                 • Portable
                                   - Handheld
                                   - No external power supply

                                 • Fieldable
                                   - Particularly rugged
                                   - Easily transported by vehicle
                                   - Limited external power supply

                                 • Mobile
                                   - Small enough to carry in a mobile lab
                                Source: Field Screening Methods Catalog, EPA/540/2-881005,
                                September 7888
Air Monitoring Plans and Strategies
4/94

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                                                       NOTES
       EASE OF OPERATION

  •  How easy is it to operate the
    controls?

  •  How easy is it to learn to operate?

  •  How many steps must be performed
    before an answer is obtained?

  •  How easy is it to repair?
        INHERENT SAFETY
                            32L6

                           LISTED
       APPROVED

      INTRINSICALLY SAFE COMBINATION

      COMBUSTIBLE GAS AND OXYGEN INDICATING

      DETECTOR FOR HAZARDOUS LOCATIONS

      CLASS I, DIVISION 1, GROUPS A, B, C & D



Source; Scoff Model S-105 Certification Label
10/93
Air Monitoring Plans and Strategies

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                AIR MONITORING PLANS  AND STRATEGIES


INTRODUCTION

Airborne contaminants present at a hazardous waste site or a hazardous materials release can present
a risk to human health and the environment. One way to assess that risk is to identify and quantify
these contaminants by air monitoring.  The U.S. Environmental Protection Agency's (EPA) Standard
Operating  Safety  Guides  (SOSGs) state that the  objectives of air monitoring during response
operations  are to:

       •      Identify and quantify airborne contaminants onsite and offsite

       •      Track changes in air contaminants that occur over the lifetime of the incident

       •      Ensure proper selection of work practices and engineering controls

       •      Determine the level of worker protection needed

       •      Assist in defining work zones

       •      Identify additional medical monitoring needs  in any given area of the  site.

Several questions should be addressed when  you develop an air monitoring plan. Why is the air
monitoring being done? How will the monitoring be done? Who will do the monitoring? When and
where will the  air monitoring be done?  What equipment will be used?

The above list gives several reasons why air monitoring is done. Some organizations have developed
guidelines  on the why, how, who, where, when, and what of air monitoring. Some organizations
have procedures that are legal requirements.  These organizations will be discussed.  Also, general
equipment characteristics will be covered in the latter part of this section.


STANDARDS AND GUIDELINES


U.S.  Department of Labor - Occupational Safety and Health Administration  (OSHA)

Since 1971, OSHA has regulated  exposure  to chemicals in industry.  29  CFR Part  1910.1000
specifies limits on exposure to airborne concentrations of chemicals.  See the section on Exposure
Limits and Action Levels for further information.

On March 6, 1990, OSHA's  Hazardous Waste Operations and Emergency Response standard (29
CFR Part 1910.120) went into effect.  This standard addressed the legal requirements  for protecting
workers involved  with hazardous  waste or  emergency responses to  hazardous materials.  Air
monitoring is one of the many activities regulated by this standard.
10/93                                      1           Air Monitoring Plans and Strategies

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The standard requires the site-specific safety and health plan to address:

       Frequency and types of air monitoring, personnel monitoring, and environmental
       sampling  techniques and instrumentation  to  be  used,  including  methods  of
       maintenance  and calibration  of monitoring and  sampling equipment to be used.
Under section (c) Site characterization and analysis is:

       (6) Monitoring.  The following monitoring shall be conducted during initial site entry
       when the site evaluation produces information that shows the potential for ionizing
       radiation or IDLH (Immediately Dangerous to Life or Health) conditions, or when
       the site information is not sufficient reasonably to eliminate these possible conditions:

              (i)  Monitoring with direct-reading instruments for hazardous levels
              of radiation.

              (ii) Monitoring the air with appropriate direct-reading test equipment
              (e.g., combustible  gas meter,  detector tubes)  for IDLH and other
              conditions that  may cause death or serious harm  (combustible or
              explosive atmospheres, oxygen deficiency, toxic substances).

              (Hi) Visually observing for signs of actual or potential IDLH or other
              dangerous conditions.

              (iv)  An  ongoing  air  monitoring  program  in  accordance  with
              paragraph (h)  of  this  section shall  be  implemented  after  site
              characterization has determined the  site is safe for the startup of
              operations.

This section states when monitoring should be done (site entry), why it is done (to  identify IDLH
conditions),  and what kind of equipment to  use.   Additional requirements are  found under (h)
Monitoring.

       (1)  General

              (i)  Monitoring shall be performed in accordance with this paragraph
              where there may be a question of employee exposure to hazardous
              concentrations of hazardous substances  in order  to assure proper
              selection  of  engineering  controls,  work  practices  and personal
              protective equipment  so that employees are not exposed to levels
              which exceed permissible exposure limits or published exposure levels
              for hazardous substances.

              (ii) Air monitoring shall  be used to identify and  quantify airborne
              levels of hazardous substances and safety and health hazards in order
              to  determine the appropriate level of employee protection needed on
              site.


Air Monitoring Plans and Strategies            2                                        10/93

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Here the purpose (why) is to identify and quantify hazardous substances so that proper exposure
controls are used.  The substances are identified  and quantified so that the concentrations can be
compared to an exposure limit.  See the Exposure Limits and Action Levels section for further
information on exposure limits.

       (2) Initial entry. Upon initial entry, representative air monitoring shall be conducted
       to identify any  IDLH  condition, exposure over  permissible  exposure  limits  or
       published exposure levels, exposure over a radioactive material's dose limits or other
       dangerous condition such as the presence of flammable atmospheres or oxygen-
       deficient environments.

This paragraph expands on site characterization and analysis paragraph (c)(6) by including exposure
limits along with IDLH conditions to monitor.

       (3) Periodic monitoring.  Periodic monitoring shall be conducted when the possibility
       of an IDLH  condition or flammable atmosphere has developed  or when there  is
       indication that exposures may  have risen over  permissible  exposure  limits  or
       published exposure levels since  prior monitoring.   Situations  where it shall  be
       considered whether the possibility that exposures have risen are as follows:

              (i) When work begins on a different portion of the site.

              (ii)  When contaminants other than those previously identified are
              being handled.

              (in)   When a different type  of operation is  initiated (e.g.,  drum
              opening as opposed to exploratory well drilling).

              (iv)  When employees are handling  leaking drums or containers  or
              working in areas with obvious liquid contamination (e.g., a spill or
              lagoon).

Again, where, when, and  why are covered.

       (4)  Monitoring of high-risk employees.   After the  actual cleanup phase of any
       hazardous waste operation commences; for  example,  when soil, surface water,  or
       containers are moved or disturbed; the employer shall monitor those employees likely
       to have the highest exposure to hazardous  substances and health hazards likely to be
       present above permissible exposure limits or published exposure levels  by  using
       personal sampling frequently enough to  characterize  employee exposures.  If the
       employees likely to have the highest exposure are over permissible exposure limits
       or  published  exposure  limits,  then  monitoring  shall  continue  to  determine  all
       employees likely to be above those limits.  The employer may utilize a representative
       sampling approach by documenting that  the employees and chemical  chosen for
       monitoring are based on the criteria stated above.

       Note to (h):  It is not required to monitor employees engaged in site characterization
       operations covered by paragraph (c) of this section.


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These paragraphs state that personal monitoring (how) must be done on high-risk employees (who)
during cleanup activities (when).

Section (q) of 1910.120 addresses emergency responses to hazardous substance releases.  It states
in (q)(3)(ii) that

       the individual in  charge of the ICS (Incident Command System) shall identify, to the
       extent possible, all hazardous substances or conditions present and shall address as
       appropriate site  analysis, use of engineering controls,  maximum exposure limits,
       hazardous substances handling procedures, and use of any new technologies.

Air monitoring is not specifically mentioned in section (q), but would be a useful, if not necessary,
tool for assessment.

29 CFR 1910.120 is  a federal regulation. In states where there is an approved state OSHA (state-
plan state), requirements at least as stringent as 1910.120 must be developed.  Thus, in some states
the air monitoring requirements may be more detailed.
U.S. Environmental Protection Agency (EPA)

On June 23,  1989, EPA adopted 40 CFR Part 311,  Worker Protection Standards for Hazardous
Waste Operations and Emergency  Response.   This  standard  is a duplicate  of 1910.120.  The
difference in the standards is to whom they apply.  The OSHA standard applies to federal agencies,
private industries, and public employees in OSHA state-plan states.  The EPA standard applies to
public employees in states that have no OSHA state-plan.

As noted in the previous paragraph, EPA has regulations for monitoring for worker protection.
There are also requirements for monitoring for public  protection.  However, this subject will not be
discussed here in detail.  Additional information is mentioned in this manual in the Exposure Limits
and Action Levels section.

EPA  has published  guidelines for hazardous material  operations  which include air monitoring
procedures. General guidelines can be found in the SOSGs.  The following topics are discussed in
the SOSGs:

       1.     Objectives of air monitoring
       2.     Identifying airborne contaminants
       3.     Air sampling equipment and media
       4.     Sample collection and analysis
       5.     General monitoring practices
       6.     Meteorological considerations
       7.     Long-term air monitoring programs
       8.     Variables in hazardous waste site air monitoring
       9.     Using vapor/gas concentrations to determine level of protection.
Air Monitoring Plans and Strategies            4                                        10/93

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Other EPA guidance documents are:

•      Personal Air Sampling and Air Monitoring Requirements Under 29 CFR 1910.120 fact sheet
•      Guidance for Ambient Air Monitoring at Superfund Sites, Volume IV in the Air/Superfund
       National Technical Guidance Series
•      Compilation of Information on Real-Time Monitoring for use at Superfund Sites
•      Removal Program Representative Sampling:  Air
•      A Compendium of Superfund Field  Operations Methods.

EPA's Environmental Response Team (ERT) has developed standard operating procedures for their
air monitoring equipment and strategies.  These documents provide information on the why, how,
when, where, and what of air monitoring.  Because EPA is concerned with offsite migration and
public exposure along with worker protection, their sampling requirements are broader than OSHA's.
Air monitoring is done  onsite  to determine the type and quantity of chemicals  being released.
Downwind monitoring is done to determine offsite migration.  Upwind sampling is done to determine
what background concentrations may  be contributing to  the downwind and onsite measurements.
This helps determine what the site is contributing to the environment.

Some of the methods use air monitoring equipment to  monitor for the presence of chemicals in media
other than air (e.g., soil  gas sampling  and  water headspace).
Other Organizations

The National  Institute  for Occupational Safety and Health (NIOSH), the American Conference of
Governmental Industrial Hygienists (ACGIH), the American Industrial Hygiene Association (AIHA),
and the American Society for Testing and Materials (ASTM) have publications about air monitoring
strategies. See the References section of this manual for more information.
CHARACTERISTICS OF AIR MONITORING  INSTRUMENTS

The selection of equipment to be used must be part of the air monitoring plan.  There are many
factors to consider when determining the proper equipment to use. Specific instrument characteristics
related to the following factors can be found in later sections of this manual.
Hazard

The proper equipment must be selected to monitor the hazard or chemical at hand.


Selectivity

Selectivity is  the ability of an instrument to detect and  measure a specific  chemical.  If other
chemicals  are detected,  they are called interferences.  Interferences can affect the accuracy of the
instrument reading. In some situations, an instrument (like the combustible gas indicator [CGI]) that


10/93                                       5            Air Monitoring Plans and Strategies

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responds to more than one chemical  is desired.  Again, the purpose of the monitoring must be
considered.
Sensitivity

Sensitivity is important when slight concentration changes can be dangerous. Sensitivity is defined
as the ability of an instrument to accurately measure changes in concentration.  Therefore, 'sensitive"
instruments can detect small changes in concentration.
Accuracy

Accuracy is the measure of how close readings are to true values.  It is expressed as % bias.  For
example,  if  an  instrument is tested  and the  average results are  15% higher  than the true
concentration, ihen the  instrument is said to  have a bias of +15%.  NIOSH recommends that a
portable direct-reading instrument be withi.1. 25% of the true value 95% of the time.
Precision

Precision is the grouping of the data points. It is a quantitative measure of the variability of a group
of measurements compared to their average value.  It is defined by the  standard deviation.  This
value is a ±  qualifier when a value is reported  (e.g.,  10+1 ppm).

Accuracy  and precision  are affected  by factors such as the instrument's calibration and relative
response.
Calibration

An instrument must be properly calibrated, prior to use, in order to function properly in the field.
Calibration  is the process of adjusting the instrument readout so that it corresponds to an actual
concentration.  Calibration involves checking the instrument results with a known concentration of
a gas or vapor to see that the instrument gives the proper response.  For example, if a combustible
gas meter is checked with a calibration gas that is 20% of the lower explosive limit (LEL), then the
instrument should read 20% of the LEL.  If it does not read accurately, it is out of calibration and
should be adjusted until an accurate reading is obtained.

Although an instrument  is calibrated to give a one-to-one  response  for a  specific chemical  (the
calibration gas), its response to other chemicals is usually different (see Relative Response below).
If the calibration is changed for an instrument, its  relative responses will also change.   Also, the
instrument may  not give a  one-to-one response to the chemical for the full range of detection  (see
detection range).

Instruments come from  the manufacturer calibrated to a specific chemical.  The manufacturer
supplies information  about how to  maintain that  calibration.   If the user wants  to change the
calibration gas, the manufacturer can supply  information on how to do so.


Air Monitoring Plans and Strategies            §                                         10/93

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Relative Response

Whereas some instruments may detect more than one chemical, equal concentrations may not give
equal response. The relationship between the instrument's response and the actual concentration of
the chemical is termed the "relative response."  Relative response can be calculated by using the
following formula:

         Relative Response =   Instrument Reading  (x  m% fof % Rekaive R^po^^
                             Actual Concentration


For example, if an instrument reading for a 100 ppm concentration of acetone is 63, then the relative
response for that instrument and  acetone is 0.63  or  63%.   Table  1 gives relative response
information for a particular CGI.

                 TABLE 1.  RELATIVE RESPONSE OF SELECTED CHEMICALS
                           FOR A CGI CALIBRATED TO PENTANE
Concentration
Chemical {% LED
Methane
Acetylene
Pentane
1,4-Dioxane
Xylene
50
50
50
50
50
Meter Response
(% LED
85
60
50
37
27
Relative Response
(%)
170
120
100
74
54
             Source:  Portable Gas Indicator, Model 250 and 260, Response Curves,
             Mine Safety Appliances Company, Pittsburgh, PA.

Relative responses vary with  chemical and instrument.   The same chemical may have a relative
response of 63% for one instrument and 120% response for another. Calibration also affects relative
response.

Instruments come from the manufacturer calibrated to a specific chemical. If the instrument is being
used for a chemical that is not the  calibration standard, then it may be possible to look at the
manufacturer's information to get the relative response of that instrument for the chemical.  Then
the actual  concentration  can be calculated.   For example, if the instrument's relative response for
xylene is 0.27 (27%) and the reading is 100 ppm (parts per million),  then the actual concentration
is 370 ppm (0.27 x actual concentration =  100 ppm; actual concentration = 100/0.27 = 370 ppm).

If there is  no relative response data for the chemical in question, it may be possible to recalibrate
the instrument.  If the instrument has adjustable settings and a known concentration is available, the
instrument may  be adjusted to read directly for the chemical.  Because recalibration takes time, this
is  usually  done  only if the instrument is going to be used for many  measurements of the special
chemical.
10/93                                       7            Air Monitoring Plans and Strategies

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Detection Range

The operating range is the lower and upper use limits of the instrument.  It is defined by the lower
detection limit at one end and the saturation concentration at the other end. The lower detection limit
is the lowest concentration to which an instrument will respond.  It is important to use an instrument
with an operating range that will accurately measure the concentration in the range of concern.  For
example, a CGI could be used to monitor for methane because methane is combustible. However,
the upper limit of the CGI is the lower  explosive limit (LEL) of the chemical.   LEL is the lowest
concentration of gas or vapor (in air) that will burn or explode if an ignition source is present at
ambient temperatures. In this case, that  would be 5 % methane.  If higher concentrations of methane
need to be quantified,  another  type of instrument would be needed.  Also, most CGIs are  not
sensitive to ppm concentrations.  A different instrument would be needed to measure that range.

Some instruments may respond to the chemical for a range of concentrations but not give a consistent
response throughout the range.   The linear  range is the range of concentrations over which  the
instrument gives response proportional to the chemical concentration.
Response Time

Response time is the time between initial  sample contact  and  readout  of the  full chemical
concentration.  In direct-reading instruments, a rapid response time is desired.  Response time for
direct-reading instruments can be from seconds to minutes.  The HNU PI-101 gives 90% of full-scale
concentration in 3 seconds.  Some hydrogen cyanide detectors may take 90 seconds to give a full
concentration reading.   Factors  that affect response time are temperature,  type of detector, and
sample hose length.

For methods  that require air sample collection and analysis, the response time is referred to as the
turnaround time.  In other words, how long was the period of time between collection of the sample
and receipt of results from the laboratory?
Mobility

EPA's Field Screening Methods Catalog uses the following terms:

       •      Portable—Hand-held devices that can be easily carried by one person and require no
              external power source.

       •      Fieldable—Easily transported in a van, pick-up, or four-wheel drive.  Particularly
              rugged and limited external power required.

       •      Mobile—Small enough to carry in a mobile lab.  Power consideration may limit the
              use of many instruments in mobile laboratories. (Size, durability, and power supply
              are the main considerations in determining the mobility of an instrument.)
Air Monitoring Plans and Strategies            g                                       10/93

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Ease of Operation

Because many of these instruments were designed for industrial use, allowances may not have been
made for using the instrument while wearing protective equipment.  One must consider how easy it
is to use the instrument while wearing gloves or how difficult it is to read the meter while wearing
a respirator.   Also, how quickly a user can learn to  operate the  instrument correctly should be
considered.

Preparation time for use of the instrument should be short.  Rapid warm-up, easy attachment of
accessories,  and quick instrument checks shorten preparation time.
Direct-Reading vs. Sample Analysis

Direct-reading instruments are those that give a response to a chemical within seconds or minutes
of contact.  They are also meant to be taken to the location that is to be evaluated. Sample analysis,
however, involves collecting an air sample on a media or in a container and then sending  it to an
analytical laboratory.  This type of analysis involves much more time—sometimes days longer—than
using a direct-reading instrument.
Personal vs. Area Monitor/Sampler

A personal monitor/sampler is one that can be worn by the worker with the intent of obtaining the
exposure for the wearer.  An area monitor/sampler obtains information for the area in which it is
placed.  A personal monitor/sampler must be small enough to be worn by the worker and also must
have a battery supply if it is electronic. A personal monitor/sampler is the ultimate in portability.
They  range in size from  pocket size to a size that can be  clipped to a belt without hindering the
wearer. Area samplers can be much larger and can use AC power. Many of the personal monitors
are equipped with warning alarms and with dataloggers to store and calculate exposures.
Inherent Safety

Many of the instruments used for air monitoring will be used in the atmosphere being monitored.
Therefore, they must be safe to use in that environment.  Electrical devices, including instruments,
must be constructed to prevent the ignition of a combustible atmosphere.  The sources of this ignition
could be an arc generated by the power source itself or the associated electronics, or a flame or heat
source  necessary for function of the instrument.  The National Fire Protection Association (NFPA)
publishes the National Electrical  Code (NEC), which spells out types of areas in which hazardous
atmospheres can be generated and the types of materials that generate these atmospheres. It also lists
design  safeguards acceptable for  use in hazardous atmospheres.
10/93                                       9           Air Monitoring Plans and Strategies

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Hazardous Atmospheres

The term "hazardous atmosphere" causes response workers,  depending on their backgrounds, to
imagine  situations ranging from toxic air contaminants to flammable  atmospheres.   For  NEC
purposes, an atmosphere is hazardous if it meets the following criteria:

       •      It is a mixture of any  flammable material in air whose concentration is within the
              material's flammable range (i.e., between the material's lower flammable limit and
              its upper flammable limit).

       •      There is the potential for an ignition source to  be present.

       •      The resulting exothermic reaction could propagate beyond where it started.

To adequately describe hazardous atmospheres, the NEC categorizes them according to their class, group,
and division.  Class is a category describing the type of flammable material that produces the hazardous
atmosphere:

       •      Class I is flammable vapors and gases, such as gasoline and hydrogen.  Class I is further
              divided into Groups A,  B, C, and D on the basis of similar flammability characteristics
              (Table 2).

       •      Class II consists of combustible dusts like coal or grain and is divided into groups E, F,
              and G (Table 3).

       •      Class III is ignitable fibers  such as those produced  by cotton milling.

                     TABLE 2.  SELECTED CLASS I CHEMICALS BY  GROUP
  Group
               Examples of Chemicals Within Group
  Group A Atmospheres    acetylene

  Group B Atmospheres    1,3-butadiene

  Group C Atmospheres    carbon monoxide
                          diethyl ether
                          dicyclopentadiene
                          ethyl mercaptan
                     ethylene oxide

                     ethylene
                     hydrazine
                     hydrogen sulfide
                     methyl ether
                        hydrogen

                        nitropropane
                        tetrahydrofuran
                        tetramethyl lead
                        triethylamine
  Group D Atmospheres
acetone
ammonia
benzene
ethanol
fuel oils
gasoline
liquified petroleum gas
methane
methyl ethyl ketone
propane
vinyl chloride
xylenes
   Source: NFPA.   1991.  Classification of Gases, Vapors, and Dusts for Electrical Equipment in
   Hazardous (classified) Locations.  National Fire Protection Association, ANSI/NFPA 497M.
 Air Monitoring Plans and Strategies
                    10
                                        10/93

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                    TABLE 3. SELECTED CLASS II CHEMICALS BY GROUP
   Group                          Characteristics of Group
   Group E Conductive Dusts       Atmospheres containing metal dusts, including aluminum,
                                  magnesium, and their commercial alloys, and other metals
                                  of similarly hazardous characteristics

   Group F Semivolatile Dusts      Atmospheres containing carbon black, coal, or coke dust
                                  with more than 8% volatile material

   Group G Nonconductive Dusts   Atmospheres containing flour, starch, grain, carbonaceous,
                                  chemical thermoplastic, thermosetting and molding
                                  compounds.

   Source: NFPA. 1991.  Classification of Gases,  Vapors, and Dusts for Electrical Equipment
   in Hazardous (classified) Locations.   National  Fire Protection Association, ANSI/NFPA
   497M.

Division is the term describing the "location" of generation and release of the flammable material.

       •      Division 1 is a location where the generation and release are continuous, intermittent,
              or periodic  into an open, unconfined area under normal conditions.  Instruments
              certified for Division 1 locations are also called "intrinsically safe."

       •      Division 2 is a location where the generation and release  are only from ruptures,
              leaks, or other failures from closed systems or containers.

Using this system, a hazardous atmosphere can be routinely and adequately defined. As an example,
an abandoned waste site containing intact closed drums of methyl ethyl ketone, toluene and xylene
would be considered a Class I, Division 2, Group D environment.  However, when transfer of the
flammable liquids takes place at the site, or if releases of flammable gases/vapors are considered
normal, those areas would be considered Class  I, Division 1.
Certification

If a device is certified for a given class, division, and group, and it is used, maintained, and serviced
according to the manufacturer's instructions, it will not contribute to ignition.  The device is not,
however, certified for use in atmospheres other than those indicated.  All certified devices  must be
marked to  show  class,  division,  and group  (Figure  1).  Any manufacturer wishing to have an
electrical device certified must submit a prototype to a recognized laboratory for testing.  If the unit
passes, it is certified as submitted. However, the manufacturer agrees to allow the testing  laboratory
to randomly check the manufacturing plant at any time, as well as any marketed units. Furthermore,
any change in the unit requires the manufacturer to notify the test laboratory, which can continue the
certification or withdraw it until the modified unit can be retested.  NFPA does not do certification
testing.  Testing and certification  is done by such organizations as Underwriters' Laboratory, Inc.
(UL) or Factory Mutual Research Corporation (FM).
10/93                                        11           Air Monitoring Plans and Strategies

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                                                                 32L6
                                                              LISTED
                   APPROVED

                INTRINSICALLY SAFE COMBINATION

                COMBUSTIBLE  GAS AND OXYGEN  INDICATING

                DETECTOR FOR HAZARDOUS LOCATIONS

                CLASS I, DIVISION  1, GROUPS A, B, C &  D
               FIGURE 1. CERTIFICATION LABEL FROM SCOTT® MODEL S-105
                          COMBUSTIBLE GAS AND 02 INDICATOR

To ensure personnel safety, only approved instruments can be used onsite and only in atmospheres
for which they have been certified.  When investigating incidents involving unknown hazards, the
monitoring instruments should be rated for use in the most hazardous locations.  The following points
will assist in selection of equipment that will not contribute to ignition of a hazardous atmosphere:
              The mention of a certifying group in the manufacturer's equipment literature does
              suarantee certification.
guarantee certification.
                                                                        not
              Some organizations test and certify instruments for locations different from the NEC
              classifications.    The  Mine  Safety  and  Health  Administration  (MSHA)  tests
              instruments only for use in methane-air atmospheres and in atmospheres containing
              coal dust.

              In  an  area designated  Division 1, there is a greater probability of generating a
              hazardous  atmosphere than in Division 2.   Therefore, the test protocols for
              Division 1  certification are more stringent than those for Division 2. Thus, a device
              approved for Division 1 is also permitted for use in Division 2, but not vice versa.
              For most response work, this means that devices approved for Class 1 (vapors and
              gases), Division 1 (areas of ignitable concentrations), Groups A, B, C,  and D should
              be  chosen whenever possible.  At a minimum, an instrument should be approved for
              use in Division 2  locations.

              There are so many groups, classes, and divisions that it may not be possible to certify
              an  all-inclusive instrument.  Therefore, select a  certified  device based on the
              chemicals and  conditions  most likely  to be encountered.  For example, a device
              certified for a Class II, Division  1, Group  E (combustible metal  dust) would offer
              little protection around a flammable vapor or gas.
Air Monitoring Plans and Strategies
                              12
10/93

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Accessories or Options

Many manufacturers offer accessories or options for their instruments. A useful option is an alarm
to alert the user that a concentration level has been exceeded.  This is a common feature on CGIs
and oxygen meters.

A recent addition to instruments are microprocessors/dataloggers.  This combination can help the
operator calibrate the instrument, store calibration information, make adjustments to the instrument,
store readings so that a readout of concentrations at specific locations or times can be made at the
end of a monitoring period, and report the data.  Some units may even do time-weighted averaging
of the concentrations. Some instruments can transfer this information into an external computer for
storage and data manipulation.

Other accessories and options include special  sample probes, special carrying cases, and the ability
to change detectors in an instrument.
DATA QUALITY

The Characteristics of Air Monitoring Instruments section discussed instrument characteristics (e.g.,
accuracy, selectivity, and sensitivity) that affect the quality of the data from the air  monitoring
instruments.  Data quality is a concern and EPA has published a document entitled Data Quality
Objectives for Remedial Response Activities (U.S. EPA 1987) that discusses how to address this
concern.

The data quality objectives (DQOs) basically state that  the desired quality of data determines the
amount of time and effort needed to produce the result.  There are different levels of data quality.
Table 4 illustrates this point.   The higher the  analytical level,  the better the  quality of data.
However, higher analytical levels usually require more time and money.
CONCLUSION

The desired air monitoring instrument is one that is portable, direct-reading,  easy to  use, and
accurate and precise.  The instrument should also respond quickly, be capable of detecting ppb and
% concentrations, be inherently safe,  identify and give concentrations of all the chemicals and
hazards in an atmosphere,  and do its job while  the operator is sitting at a safe distance  from the
hazardous material site or spill. Unfortunately, no instrument meets these criteria.  Thus,  a variety
of instruments are needed depending on the air monitoring plan.

When preparing an  air monitoring plan, the operator must determine why, how,  when, and where
the monitoring is to  be done and what equipment  is necessary.   In addition, there are legal
requirements to comply with.  Guidance documents are available to assist in complying with these
requirements.   Other  factors must  also be considered when selecting the monitoring equipment.
Additional information on why to sample, or what to  sample for, will be covered in the Exposure
Limits and Action Levels section of the course.  Characteristics of the various types of equipment will
also be  discussed in later sections.
10/93                                        13           Air Monitoring Plans and Strategies

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   EXPOSURE LIMITS  AND
           ACTION  LEVELS
PERFORMANCE OBJECTIVES
At the end of this lesson, participants will be able to:

•    Identify the three sources of exposure limits specified in
     OSHA's 29 CFR 1910.120Hazardous Waste Operations and
     Emergency Response standard

•    Define the terms "time-weighted average (TWA) limit,"
     "short-term exposure limit," and "ceiling limit"

•    Given the identity and concentration of a chemical exposure,
     determine whether an exposure limit is exceeded

•    Calculate an 8-hour TWA exposure when given a chemical's
     exposure concentration and the duration of the exposure

•    List  the  three uses mentioned in  1910.120  for exposure
     limits

•    List three of the five applications for which the American
     Conference of Governmental Industrial Hygienists states the
     threshold limit values should not be used

•    List EPA's action levels for oxygen, combustible gas, and
     radiation and the actions associated  with each level.

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                                             NOTES
 EXPOSURE LIMITS AND
      ACTION LEVELS
      EXPOSURE LIMITS
    (29 CFR Part 1910.120)
   Permissible Exposure Limits (PELs)
   - 29 CFR Part 1910, Subparts G
     and 2, Occupational Safety and
     Health Administration (OSHA)
      EXPOSURE LIMITS
    (29 CFR Part 1910.120)
   Published Exposure Levels
   - NIOSH Recommendations for
     Occupational Health Standards,
     1986
   - American Conference of
     Governmental Industrial Hygienists1
     (ACGIH) Threshold Limit Values
     (TLVs) and Biological Exposure
     Indices (BEIs) for 1987-1988
10/93
Exposure Limits and Action Levels

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     NOTES
                                 EXPOSURE LIMITS
                                       Sources
                            • OSHA
                             -  PELs
                             -  Legal requirements
                             -  1968 TLVs and American National
                                Standards Institute (ANSI)
                             -  29 CFR 1910.1000 (tables)
                             -  Specific standards - benzene
                                 EXPOSURE LIMITS
                                       Sources
                             National Institute for Occupational
                             Safety and Health (NIOSH)
                             - Recommended exposure limits
                                (RELs)
                             - May be legal (1910.120)
                             - Rationale in criteria documents
                             - Immediately dangerous to life or
                                health  (IDLH)
                                 EXPOSURE LIMITS
                                       Sources
                               • ACGIH
                                 - TLVs
                                 - Recommendations
                                 - May be legal (1910.120)
                                 - Yearly booklet
                                 - Documentation
Exposure Limits and Action Levels
10/93

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                                             NOTES
   EXPOSURE GUIDELINES
            Sources
     American Industrial Hygiene
     Association (AIHA)
     - Workplace environmental
        exposure levels (WEELs)
     - Recommendations
     - Yearly updates
     - Documentation
   EXPOSURE GUIDELINES
            Sources
   Other
   -  U.S. Army and U.S. Air Force
   -  Mine Safety and Health
      Administration (MSHA)
   -  Other countries (e.g., Federal
      Republic of Germany maximum
      concentration values in the
      workplace  (MAKs))
      TIME-WEIGHTED AVERAGE
              (TWA)
     c
     o
     c
     Q)
     O
     C
     o
    O
      750	/- r	r\-~
                         TWA-EL
                         3PM
10/93
Exposure Limits and Action Levels

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      NOTES
                                  TIME-WEIGHTED AVERAGE CALCULATION
                                     Exposures: 1500 ppm for 1 hour

                                             500 ppm for 3 hours

                                             200 ppm for 4 hours
                                     (1 hr)(1500 ppm) + (3 hrs)(500 ppm) + (4 hrs)(200 ppm)
                                                  8hrs
                                     1500 ppm + 1500 ppm + 800 ppm


                                             8
                   475 ppm
                                      SHORT-TERM EXPOSURE LIMIT

                                                 (STEL)
                                     c
                                     o


                                     I
                                     +-»
                                     c
                                     0)
                                     o
                                     c
                                     0
                                     o
                                         1000
750 -
                                           6AM
                                                               3PM
                                                  STEL
                                    Excursions to the STEL

                                    •  Should not be longer than 15
                                       minutes in duration (OSHA, NIOSH,
                                       ACGIH)


                                    •  Should be at least 60 minutes
                                       apart (ACGIH)


                                    •  Should not be repeated more than
                                       4 times per day (ACGIH)


                                    •  Supplement TWA
Exposure Limits and Action Levels
                            10/93

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                                                           NOTES
                 CEILING
                   (C)
       c
       o

       1
       «->
       0)
       u
       o
       o
                               Calling
          6AM
10AM
Time
                                3PM
               CEILING
 The exposure that shall not be exceeded
 during any part of the work day. If
 instantaneous monitoring is not feasible,
 the ceiling shall be assessed as a 15-minute
 TWA exposure (unless otherwise specified)
 that shall not be exceeded at any time
 during a work day
Source: NIOSH Recommendations lor Occupational Safety end Health. 1992.
COMPARISON OF EXPOSURE LIMITS
Chemical OSHA NIOSH
Acetone 1000* 250
Benzene 1/5 0.1 /C 1
Lead (mg/m3) 0.05 <0.1
Benzaldehyde NA NA
Note: • units are ppm; TWA/STEL
1 ) indicates intended change
ACGIH
750/1000
10 (0.1)
0.15 (0.05)
NA

4/94
                            Exposure Limits and Action Levels

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       NOTES
                                    	IDLH	

                                     "...means an atmospheric concentration
                                     of any toxic, corrosive, or asphyxiant
                                     substance that poses an immediate threat
                                     to lite or would cause irreversible or
                                     delayed adverse health effects or would
                                     interfere with an individual's ability to
                                     escape from a dangerous atmosphere."
                                  Source- 2P CFR TB10 T20(e)
                                                    IDLH
                                   IDLH concentrations represent the maximum
                                   concentration from which, in the event of
                                   respirator failure, one could escape within
                                   30 minutes without a respirator and without
                                   experiencing any escape-impairing or
                                   irreversible health effects.

                                   Note: IDLH level defined by the Standards
                                        Completion Program - NIOSH/OSHA -
                                        only ior purposes oi respirator selection
                                                IDLH VALUES
                                                  Examples
                                      Chemical
IDLH
                                      Acetone
                                      Benzene
                                      Lead
                                      Tetraethyl lead
                                      Benzaldehyde

                                  Source: NIOSH Pockef Guide to Chemical Hazards.  1990.
20,000 ppm (LEL?)
Ca (3000 ppm)
700 mg/m3
40 mg/m3
Not available
Exposure Limits and Action Levels
                  JO/93

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                                                   NOTES
  EVALUATION OF A MIXTURE
      	 ^ /i  _i_ r* i\   _i_    c* i\
      = U /L + U /L  +... U /L
     rn   11    z  t        n  n



   Em = the equivalent exposure for the mixture

   C  = the concentration of a particular contaminant

   L = the exposure limit for that contaminant
   EVALUATION OF A MIXTURE
              Example
   Chemical A C = 500 ppm  L = 750 ppm (TWA)
   Chemical B C = 200 ppm  L = 500 ppm (TWA)
   Chemical C C = 50 ppm  L = 200 ppm (TWA)
     Em = (500/750) + (200/500) + (50/200)
     Em = 0.67 + 0.40 + 0.25
     E =1.3
  EVALUATION OF A MIXTURE
   Em should not exceed 1
   •m
  The calculation applies to chemicals
  where the effects are the same and
  are additive

  Do not mix TWAs, STELs, or ceilings
10/93
Exposure Limits and Action Levels

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      NOTES
                                       EXPOSURE LIMITS
                                    Used to determine:

                                    •  Site characterization

                                    •  Medical surveillance

                                    •  Exposure controls
                                      - Engineered controls
                                      - Work practices
                                      - Personal protective equipment
                                         (PPE)

                                Source; 29 CFR 1910.120
                                  THRESHOLD LIMIT VALUES
                                  Not intended for use:

                                  •  As a relative index of toxicity

                                  •  In the evaluation or control of
                                     community air pollution nuisances

                                  •  In estimating the toxic potential of
                                     continuous, uninterrupted exposures
                                     or other extended work periods

                               Source: ACGIH TLVs andBEIs for 1993-1994
                                  THRESHOLD LIMIT VALUES
                                 Not intended for use:

                                 •  As proof or disproof of an existing
                                    disease or condition

                                 •  For adoption by countries whose
                                    working conditions differ from those
                                    in the United States of America and
                                    where substances and processes differ
                                Source: ACGIH TLVs and BEIs for 1993-1994
Exposure Limits and Action Levels
10/93

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                                                    NOTES
        ENVIRONMENTAL
       EXPOSURE LIMITS
   •  U.S. EPA
     - National Ambient Air Quality
       Standards Program (NAAQS)

   •  State/Local
     - NAAQS
     - Modified TLVs
     - Risk assessment
         ACTION GUIDE
 • The chemical concentration or instrument
  reading at which a specific action should
  be taken

 • Sources:
  -  EPA Standard Operating Safety
     Guides (SOSGs)
  -  OSHA standards for specific chemicals
     may require an  action (e.g., medical
     monitoring) if one-half the PEL is
     reached (action level)
         EPA ACTION GUIDES
      Combustible Gas Indicator
         Level
Action
         <10%LEL
         10-25% LEL
         >25% LEL
Continue monitoring

with caution


Continue monitoring,

but with extreme

caution


Explosion hazard!

Withdraw from area

immediately.
 Confined space
4/94
                           Exposure Limits and Action Levels

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        NOTES
                                                   EPA ACTION GUIDES
                                                   Oxygen Concentration
                                                   Level
Action
                                                   <18.5%   Monitor wearing SCBA.

                                                   18.5-25%  Continue monitoring
                                                           with caution.  SCBA
                                                           not needed based only
                                                           on oxygen content

                                                   >25%    Discontinue monitoring.
                                                           Fire potential!
                                                           Consult specialist
Exposure Limits and Action Levels
                        4/94

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                  EXPOSURE LIMITS AND ACTION  LEVELS
INTRODUCTION

It is necessary, for response activities involving hazardous materials, to acknowledge and plan that
response personnel may become exposed. Most hazardous materials have levels of exposure that can
be tolerated without adverse health effects.  However, it is imperative to determine:

       •     The identity of materials involved

       •     The type and extent of exposure

       •     The possible health effects from overexposure

       •     The exposure limits and/or action levels considered safe for each hazardous material
             encountered.


SOURCES FOR EXPOSURE LIMITS FOR AIRBORNE CONTAMINANTS

Several  organizations have proposed exposure limits for chemicals  and other  hazards.   The
Occupational Safety and Health Administration (OSHA) is one such organization. It is charged with
protecting the health and safety of workers.  In 29 CFR 1910.120, the Hazardous Waste Operations
and Emergency Response standard, OSHA specifies the use of certain exposure limits.  The exposure
limits that are specified are OSHA's permissible exposure limits (PELs) and  "published exposure
levels."  The published exposure levels are used when no PEL exists.  A published exposure level
is defined as:

       the exposure limits published in "NIOSH Recommendations for Occupational Health
       Standards" dated 1986 incorporated  by reference. If none is specified,  the exposure
       limits  published  in the standards specified by  the  American  Conference  of
       Governmental Industrial Hygienists  in their publication "Threshold Limit Values and
       Biological Exposure Indices for 1987-88" dated 1987 incorporated by reference.  (29
       CFR 1910.120 (a)(3))

Organizations that have developed exposure limits are discussed below.  Not all of these groups are
specifically mentioned in 1910.120.  Many  of the following organizations have exposure guidelines
for exposures to hazards other than airborne contaminants (e.g.  heat stress, noise, radiation). This
part will deal only with  airborne chemical exposures.


Occupational Safety and Health Administration

In 1971, the OSHA promulgated PELs.   These limits  were extracted from the  1968 American
Conference of  Governmental  Industrial Hygienists' (ACGIH) threshold limit values  (TLVs), the
American National Standards Institute (ANSI) standards, and other federal standards. The PELs are
found in 29 CFR 1910.1000.  Since then, additional PELs have been adopted and a few of the

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originals have been changed.  These initial changes have been incorporated into specific standards
for chemicals (e.g., 29 CFR 1910.1028 - benzene).  There are also standards for 13 carcinogens for
which there is no allowable inhalation exposure.

OSHA is a regulatory agency.  Therefore, its PELs are legally enforceable standards and  apply to
all private industries  and federal agencies.  Depending on state or local laws,  the PELs may also
apply to state and local  employees.
National Institute for Occupational Safety and Health

NIOSH was formed  at the same time as OSHA.   NIOSH  conducts  scientific research  and
recommends occupational safety and health  standards.  The exposure levels NIOSH has researched
have been used to develop new OSHA standards.  However, many recommended exposure limits
(RELs) have not been adopted by OSHA. Unless OSHA adopts NIOSH RELs into a standard (like
1910.120), they  are only recommendations.  The RELs are found in the NIOSH Recommendations
for Occupational Health Standards.

NIOSH also publishes criteria documents that provide information on handling specific chemicals.
These  documents also provide  rationale for the chemical's exposure limit.  Additionally, NIOSH
publishes immediately dangerous to  life or  health (IDLH) values in its Pocket Guide to  Chemical
Hazards.  IDLHs will be discussed later.
 American Conference of Governmental Industrial Hygienists

 One of the first groups to develop exposure limits was ACGIH.  In  1941, ACGIH suggested the
 development of maximum allowable concentrations (MACs) for use by industry.  A list of MACs
 was compiled by  ACGIH  and published in 1946.  In the early 1960s,  ACGIH revised those
 recommendations and renamed them TLVs.

 "Threshold Limit  Values (TLVs)  refer to  airborne concentrations of substances and represent
 conditions under which it is believed that nearly all workers may be repeatedly exposed day after day
 without adverse health effects." (Threshold Limit Values for Chemical Substances and Physical
 Agents and Biological Exposure Indices, ACGIH). The publication further states that the TLVs "are
 developed as guidelines  to assist in  the control  of health hazards.  These  recommendations or
 guidelines are intended for use in the practice of industrial hygiene, to be  interpreted and applied
 only by a person trained in this discipline." (Policy Statement on the Uses of TLVs and BEIs).

 Along with the TLVs, ACGIH publishes biological exposure indices (BEIs).  BEIs are to be used
 as guides for evaluation of exposure where  inhalation is not the only possible  route of exposure.
 Because the TLVs are for inhalation only, they may not be protective  if the chemical is ingested or
 absorbed through the skin.  Biological monitoring (e.g., urine samples and breath analysis) can be
 used to assess the overall exposure. This procedure uses information about what occurs in the body
 (e.g., metabolism  of benzene to phenol) to determine if there has been an unsafe exposure. The
 BEIs serve as  a reference for biological monitoring just as TLVs  serve as a reference for  air
 monitoring.
 Exposure Limits and Action Levels            2              •                         10/93

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The TLVs are reviewed yearly and are published in ACGIH's Threshold Limit Values for Chemical
Substances and Physical Agents and Biological Exposure Indices.
American Industrial Hygiene Association (AIHA)

The AIHA has provided guidance for  industrial hygienists for  many  years.  In 1984,  AIHA
developed exposure guidelines that  it calls Workplace Environmental Exposure  Level Guides
(WEELs®). These are reviewed and updated each year.  Although the list is not as large as others,
AIHA has chosen chemicals for which other groups have not developed exposure limits.  Thus, they
are providing information to fill the gaps in information sources.
Other Organizations

In the United States, the Army and Air Force have also developed exposure limits for their purposes.
The Mine Safety and Health Administration (MSHA) has health standards for air contaminants that
may be encountered during mining activities.

Other countries have also developed exposure limits.  An example  are the Federal Republic of
Germany's maximum concentrations at the workplace (MAKs).  They can be found in ACGIH's
Guide to Occupational Exposure Values along with PELs, RELs, and TLVs.

Even though the other organizations are not part of the list of published exposure limits in 1910.120,
they are sources that may  be  useful.  1910.120 (g)  suggests  looking at published literature and
material safety data sheets (MSDS) if PELs or published exposure limits  do not exist.
TYPES OF EXPOSURE GUIDELINES

Although there are different organizations that develop exposure guidelines, the types of guidelines
they produce are similar.
Time-Weighted Average (TWA)

A TWA exposure limit is the average concentration of a chemical most workers can be exposed to
during a 40-hour work week and a normal 8-hour work day  without showing any toxic effects.
Some TWA exposure limits (e.g., NIOSH) can also be used to evaluate exposures up to 10 hours.
The  TWA permits exposure to concentrations above  the limit, provided these excursions  are
compensated by equivalent exposure below the TWA.  Figure 1 shows an example that illustrates
this point for a chemical  (e.g., acetone) with a TWA exposure limit of 750 ppm.

A TWA exposure is determined by averaging the concentrations during the different exposure periods
over an 8-hour period with each concentration weighted based on the duration of exposure.  For
example, an exposure to acetone at the following concentrations and durations would have an 8-hour
TWA exposure of:
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             1500 ppm for 1 hour
             500 ppm for 3 hours
             200 ppm for 4 hours
                (1 /ir)(1500 ppm)  +  (3 hrs)(500 ppm)  + (4
                                        8 hrs
ppm)  _
                      1500 ppm  +  1500 ppm + 800 ppm
                                     8
This exposure would be compared to an 8-hour TWA exposure limit.
               c
               o
               0)
               o
               c
               o
              O
                   750
                                                            TWA-EL
                                                           3 PM
       FIGURE 1.  EXAMPLE OF AN EXPOSURE COMPARED TO A TWA EXPOSURE LIMIT
Short-Term  Exposure Limit (STEL)

The excursions allowed by the TWA exposure could involve very high concentrations. This might
cause an adverse effect but still be within the allowable average. Therefore, some organizations felt
there was a need to limit these excursions.  OSHA, NIOSH, and ACGIH define the STEL as a 15-
minute TWA  exposure limit.  ACGIH has the additional stipulation that excursions to the STEL
should not be longer than 15 minutes in duration, should be at least 60 minutes apart, and should not
be repeated more than 4 times per day.  Figure 2 illustrates an exposure that does not exceed the
Exposure Limits and Action Levels
                  10/93

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15-minute limit for an STEL of 1000 ppm (note that in the previous example of an 8-hour TWA
calculation, the acetone STEL was exceeded but the TWA was not).

The STEL supplements the TWA and does not replace it.  Both exposure limits should be used.  The
STEL reflects  an exposure limit protecting against acute effects  from a substance which primarily
exhibits chronic toxic effects.   This concentration is  set at a level  to protect  workers against
irritation, narcosis, and irreversible tissue damage.

AIHA has some short-term TWAs that are similar to the STELs.  The times used vary from 1 to 30
minutes.  These short-term TWAs are used in conjunction with, or in place of, the 8-hour TWA.
There is no limitation on the number of these excursions or the rest period between each excursion.
             C
             o
             Q)
             O
             C
             O
            O
1000


750
                                                                 STEL
TWA-EL
                        6AM
                         10AM

                        Time
                                                                3PM
         FIGURE 2. EXAMPLE OF AN EXPOSURE COMPARED TO AN STEL AND A TWA
Ceiling (C)

Ceiling values exist for substances for which exposure could result in a rapid and specific response.
The ceiling is that concentration that should not be exceeded during any part of the work day.  If
instantaneous monitoring is not feasible, the ceiling shall be assessed as a 15-minute TWA exposure
(unless otherwise specified) that shall not be excluded at any time during a work day.  A ceiling
value  is denoted by a "C" preceding the exposure limit.

Figure 3 illustrates an exposure that exceeds a ceiling value of 5 ppm.
10193
                                      Exposure Limits and Action Levels

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            c
            o
            c
            CD
            O
            C
            o
           O
                 0
                                                                Ceiling
                  6AM
 10AM
Time
3 PM
      FIGURE 3.  EXAMPLE OF AN EXPOSURE COMPARED TO A CEILING EXPOSURE LIMIT
Peaks

"Acceptable  maximum peak" concentrations can be  found in OSHA's  1910.1000 Table  Z-2.
Table Z-2 contains exposure limits that OS HA had adopted from ANSI.  This peak exposure  is an
allowable  excursion above the ceiling values  for the chemicals.   The duration  and number of
exposures at this  peak value is  limited.   For example, for those industries not  incorporated in
1910.1028, OSHA allows the 25-ppm ceiling value for benzene to be exceeded to 50 ppm, but only
for 10 minutes during  an 8-hour period.
Skin Notation

Whereas these exposure guidelines are based on exposure to airborne concentrations of chemicals,
the organizations recognize that there are other routes of exposure in the workplace.  In particular,
there can be a contribution  to the overall exposure from skin contact with chemicals that can be
absorbed through the skin.  Unfortunately, there are few data available that quantify the amount of
allowable skin contact.

Some organizations provide qualitative information  about  skin-absorbable  chemicals.  When a
chemical has the potential to contribute to the overall  exposure by direct contact with  the skin,
mucous membranes, or eyes, it is given a "skin"  notation.

This skin notation not only points out chemicals that are readily absorbed through the skin, but also
notes  that  if there is skin  contact, the exposure limit for  inhalation  may  not provide adequate
Exposure Limits and Action Levels
                                         10/93

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protection.   The  inhalation exposure  limit is designed for exposures only from  inhalation.  If
additional routes of exposure are added, there  can  be  detrimental effects  even if the inhalation
exposure limit is not exceeded.
Immediately Dangerous to Life or Health (IDLH)

As defined in the NIOSH Pocket Guide to Chemical Hazards, "IDLH concentrations represent the
maximum concentration from which, in the event of respirator failure, one could escape within 30
minutes without  a respirator and without experiencing  any escape-impairing or irreversible health
effects."  Although 30 minutes is stated in the definition, this is not a 30 minute allowable exposure
limit. NIOSH's  purpose in developing this IDLH was  for respirator selection.

Other organizations, such as ANSI, OSHA, and MSHA, have similar definitions for IDLH, but not
always the same  application. It is accepted by all of these groups that IDLH conditions include 1)
toxic concentrations of contaminants, 2) oxygen-deficient atmospheres, and 3) explosive, or near-
explosive (above, at, or near the lower explosive limits), environments.

Guidelines for potentially explosive, oxygen-deficient, or radioactive environments can be found in
the EPA's Standard Operating Safety Guides and the NIOSH/OSHA/USCG/EPA publication entitled
Occupational Safety and Health Guidance Manual for Hazardous Waste Site Activities.

At hazardous material incidents,  IDLH concentrations should be assumed to represent concentrations
above which only workers wearing respirators that provide the maximum protection (i.e., a positive-
pressure,  full-facepiece,  self-contained breathing apparatus [SCBA] or  a combination positive-
pressure, full-facepiece, supplied-air respirator with  positive-pressure escape SCBA) are permitted.
Specific IDLH concentration values for many substances can be  found in the NIOSH Pocket Guide
to Chemical  Hazards.   For  some  chemicals, NIOSH gives  a  "Ca" designation along with a
concentration for IDLH.  Ca denotes those chemicals that NIOSH considers to be  potential human
carcinogens.  NIOSH recommends the highest level of respiratory protection for exposure to these
substances, even  below IDLH. However, carcinogenic effects were not considered when developing
the IDLH concentrations.
MIXTURES

The exposure limits that have been discussed are based on exposure to single chemicals.  Because
many exposures include more than one chemical, values are adjusted to account for the combination.
When the effects of the exposure are considered to  be additive, a formula can be used to determine
whether total exposure exceeds the limits.  The following calculation is used:

              Em = (C.-5-L.)  + (Cz-5-Lz)  +  . .  .  (Cn-Ln)

where:

        Em    =   the equivalent exposure for the mixture
         C    =   the concentration of a particular  contaminant
         L    =   the exposure limit for that substance.


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The value of Em should not exceed unity (1).

An example using this calculation would be as follows:

       Chemical A    C  = 500 ppm; L = 750 ppm (TWA)
       Chemical B    C  = 200 ppm; L = 500 ppm (TWA)
       Chemical C    C  =  50 ppm; L = 200 ppm (TWA)

        Em   =   (500+750) + (200+500) + (50+200)
        Em   =   0.67 + 0.40 + 0.25
        Em   =   1.3

Because Em exceeds unity, the exposure combination may be a problem.  The next step should be
to determine whether exposure limits are based on similar effects.   This  calculation applies to
chemicals where the effects are the same and are additive.  If the combination is not additive, the
calculation is not appropriate.  Also, mixing TWA, STEL, and ceiling limits in this equation is not
appropriate.


APPLICATION OF  EXPOSURE  GUIDELINES

OSHA's Hazardous Waste Operations and Emergency Response standard specifies uses for exposure
limits.
Site Characterization

29 CFR  1910.120 (c) (3) requires identification of IDLH conditions during site characterization.
29 CFR  1910.120 (h) (3) requires air monitoring upon initial entry to identify IDLH conditions,
other dangerous conditions, and exposures over the exposure limits.
Medical Surveillance

29 CFR 1910.120 (f) (2) (i) requires a medical surveillance program for all employees exposed to
substances or hazards above the PEL  for 30 or more days per year.  If there is no PEL, then the
published exposure levels are used for evaluation.  The exposures are considered even if a respirator
was being used at the time of exposure.
 Exposure Controls
Engineered Controls and Work Practices

29 CFR  1910.120 (g) (1) (i) states "Engineering controls and work practices shall be instituted to
reduce and maintain employee exposure to or below the permissible exposure limits for substances
regulated by 29 CFR Part 1910, to the extent required by Subpart Z, except to the extent that such


Exposure Limits and Action Levels             g                                      10/93

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controls and practices are not feasible." [emphasis added] Whenever engineering controls and work
practices are not feasible,  personal protective equipment shall be used  to  reduce  and maintain
exposures.

For those substances or hazards where there is no PEL, the published exposure levels are used. If
there are no PELs or published exposure limits,  published literature  and  MSDS may be used for
evaluation.   In these circumstances,  a combination of engineering controls, work practices,  and
personal protective equipment (PPE) shall be used to reduce and maintain  exposures.
Personal Protective Equipment

Because the selection of PPE must be based on the hazards present at the site, the exposure limits
are used to evaluate the appropriate PPE.  Comparing the actual or expected exposure to the PEL
or other exposure limits gives the wearer information on selection of the proper PPE.
LIMITATIONS AND RESTRICTIONS OF USE

The exposure guidelines discussed in this section are based on industrial experience, experimental
human studies, experimental animal studies, or a combination of the three.  The guidelines were
developed for workers in the industrial environment.  Thus, they are not meant to be used for other
purposes.  ACGIH in its Threshold Limit Values and Biological Exposure Indices states:

       These limits are intended for use in the practice of industrial hygiene as guidelines
       or recommendations in the control of potential health  hazards and for no other use,
       e.g., in the evaluation or control of community air pollution nuisances; in estimating
       the toxic potential  of continuous, uninterrupted exposures or other extended work
       periods; as proof or disproof of an existing disease or physical condition; or adoption
       by countries  whose working conditions differ from those in the United States of
       America and  where substances and processes differ. These limits are not fine lines
       between safe  and dangerous concentration  nor are they a relative index of toxicity.
       They should not be used by anyone untrained  in the discipline of industrial hygiene.

As can be seen from this  qualifier, these exposure limits  are not intended as exposure limits for
exposure to the public.

There is the limitation on the use  of the exposure guideline as a relative  index of toxicity.  This is
because the exposure limits are based on different effects for different chemicals. For example, the
TLV-TWA for acetone is chosen to prevent irritation to the  eyes and respiratory system. The TLV-
TWA for acrylonitrile is chosen to reduce the risk to cancer.  Exposures to these chemicals at other
concentration levels  could lead to  other effects.  Thus,  when  evaluating the risk  of  chemical
exposure,  consult the documentation for the exposure limit along with other toxicological data.
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NON-OCCUPATIONAL EXPOSURE LIMITS

As mentioned earlier, the occupational exposure limits are not intended for use in evaluating public
health hazards.  However, they are often used because there may not be anything else available.  In
other situations, a group may feel that the exposure may be for a short duration and the occupational
exposure limits are adequate.  For example, many  computer air dispersion models for emergency
response use the TLVs as action levels.

Some agencies have applied modifiers to the occupational exposure limits to adjust them for public
health use.  These modifiers may include adjustments for exposure time (168 hours for the public
compared to 40  hours  for occupational situations)  and safety factors  for  sensitive populations
(dividing the exposure limit by 10). While  groups like ACGIH discourage this application of their
data, the users argue that modification of human data is preferred to extrapolation of animal data.

In some cases,  ambient air quality standards or guidelines have been developed for application to
public exposure.  The federal government and  many  states have developed them.  They are based
on modification of occupational exposure limits, risk assessment data,  or both. EPA has developed
national ambient  air quality  standards in response to the Clean Air Act.  The current list is very
limited and only some chemicals (e.g., lead and particulates) are applicable to waste sites.

In the risk assessment approach for chemical exposure, it is recognized that the public exposure to
a chemical may involve more than one route of exposure. With this approach, it is not appropriate
to use just an inhalation exposure limit.  Results from air sampling are combined with other sample
results (e.g., drinking water and soil) to determine  total  exposure and risk.
ACTION LEVELS

Action levels can be developed for specific chemicals, hazards, or situations.  The concept of an
action level is that if the action level is not exceeded, then there is little probability that a hazardous
exposure will occur.

In some of its  specific standards, OSHA uses an action level that is one-half of  the  PEL.  For
example, the action  level for benzene is 0.5  ppm calculated  as an 8-hour TWA.  If this level is
exceeded, continual air monitoring and medical surveillance can be required.

EPA in its Standard Operating Safety  Guides gives actions to take if certain instrument readings
(levels) are obtained during monitoring.  These are listed in Table 1.

In some situations, site-specific action levels for direct-reading instruments may be developed. This
is done by using  knowledge about what chemicals are present on the site and the instrument's
response to the chemicals.  Whereas  this may not be as accurate as using special  monitoring
equipment and  laboratory analysis, it allows rapid response to a potentially hazardous situation.
 Exposure Limits and Action Levels             \Q                                       10/93

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CONCLUSION

There are many sources for exposure limits and action levels.  Some of these are legal requirements;
some are guidelines. The goal is to use these numbers to protect personnel working with hazardous
materials.
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                    TABLE 1. ATMOSPHERIC HAZARD ACTION GUIDES
      Monitoring
      Equipment
Atmospheric
  Hazard'
   Level
Action
   Combustible gas
   indicator
  Explosive      <10%LEL    Continue monitoring with caution.

               10-25% LEL   Continue monitoring, but with
                              extreme caution, especially as higher
                              levels are encountered.

                >25% LEL    Explosion hazard!  Withdraw from
                              area immediately.

                 <19.5%     Monitor wearing SCBA. Note:
                              Combustible gas readings not valid in
                              atmospheres with less than 19.5%
                              oxygen.

                19.5-25%    Continue monitoring with caution.
                              SCBA not needed based only on
                              oxygen content.

                  >25%      Discontinue monitoring.  Fire
                              potential! Consult specialist.
   Oxygen
   concentration
    Radiation survey
    instrument
   Gamma
  radiation
   Above
background:

  < 1mR/hr
                                           mR/hr
                              Continue monitoring. Consult a
                              Health Physicist.

                              Withdraw.  Continue monitoring only
                              upon the advice of a Health Physicist.
    Colorimetric         Organic and    Depends on   Consult reference manuals for air
    tubes                inorganic        chemical     concentration vs. PEL/TLV and
                       vapors/gases                  toxicity data.
    Photoionization
    detector
    Flame ionization
    detector
   Organic       Depends on    Consult reference manuals for air
vapors/gases     chemical     concentration vs. PEL/TLV and
                              toxicity data.

   Organic       Depends on    Consult reference manuals for air
vapors/gases     chemical     concentration vs. PEL/TLV and
                              toxicity data.
" Hazard classes are general and not all compounds in these classes can be measured by realtime
instruments.

Note:  The correct interpretation of any instrument readout is difficult.  If the instrument operator
is uncertain of the significance of a reading,  especially if conditions could be unsafe, a technical
specialist should immediately be consulted.  Consideration should be given to withdrawing personnel
from the area  until approval by the safety officer is given to continue operations.
Exposure Limits and Action Levels
                      12
                                                10/93

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            OXYGEN MONITORS,
COMBUSTIBLE GAS INDICATORS, AND
     SPECIFIC CHEMICAL MONITORS
      PERFORMANCE OBJECTIVES


      At the end of this lesson, participants will be able to:

      •   Identify the purpose for oxygen monitoring

      •   List the four factors that can affect oxygen monitor response

      •   Identify the purpose for combustible gas monitoring

      •   List the four factors that can affect combustible gas indicator
          response

      •   Identify the purpose of toxic atmosphere monitoring

      •   List three types of toxic atmosphere monitors

      •   List four types of specific chemical monitors

      •   List four factors that can affect the response of specific
          chemical monitors.

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                                            NOTES
      OXYGEN MONITORS,
COMBUSTIBLE GAS INDICATORS,
             AND
 SPECIFIC CHEMICAL MONITORS
           HAZARDS
   Oxygen-deficient atmospheres
   Combustible/explosive atmospheres
   Toxic atmospheres
   Radiation
    OXYGEN MONITORING
  Aid in determining:
  • Type of respirator needed
  • Flammability risk
  • Sufficient oxygen for combustible
    gas indicators (CGIs)
  • Presence of contaminants
JO/93
Oxygen Monitors, CGIs, and
 Specific Chemical Monitors

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     NOTES
                               OXYGEN SENSOR
I  III
                                             Membrane / Cover
                                              Electrode
                             OXYGEN MONITORS
                                Considerations
                                Life span
                                Operating temperature
                                Interfering gases
                                Atmospheric pressure
                              ALTITUDE/OXYGEN
                               METER READING
                         Instrument calibrated
                           at sea level
Oxygen Monitors, CGIs, and
Specific Chemical Monitors
                  10/93

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                                           NOTES
         FLAMMABLE
 ATMOSPHERE MONITORING
  • Used to determine risk of fire or
    explosion

  • CGI readings are indicative of
    relatively high concentrations of
    contaminants
COMBUSTIBLE GAS INDICATORS
        Catalytic Sensors
     KHHDl
    Filament
Bead
COMBUSTIBLE GAS INDICATORS
    Wheatstone Bridge Circuit
                     Sensor
                     Compensating
                      Filament
JO/93
                    Oxygen Monitors, CGIs, and
                    Specific Chemical Monitors

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      NOTES
                                 COMBUSTIBLE GAS INDICATORS
                                Instrument Reading vs Concentration
                                Concentration
                                0%
LEL   UEL
5%*  15%*
      100%
                                0%    100%
                                Meter Reading (% LEL)

                                Note: * = methane
                                    LEL = lower explosive limit
                                    UEL = upper explosive limit
                                 COMBUSTIBLE GAS INDICATORS
                                             Readouts
                                  UEL
                                  COMPARISON OF LEL READINGS
                                 WITH ACTUAL CONCENTRATIONS
                                          HexaneLEL = 1.1%

                               For an instrument calibrated to hexane measuring hexane:

                                       100% =1.1% (11,000ppm)
                                       50% =0.55%  (5,500 ppm)
                                       25% =0.275%  (2,750 ppm)
                                       10% =0.11%  (1,100 ppm)
                                        1% =0.011%   (110 ppm)
Oxygen Monitors, CGIs, and
Specific Chemical Monitors
                            10/93

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                                              NOTES
COMBUSTIBLE GAS INDICATORS
         Readout Ranges
   "Normal" units
   -  0-100%LEL
   -  0-10%LEL

   "Supersensitive" units
   -  Parts per million (ppm)
   -  Example: TLV Sniffer,
              Gastech Model 1314
 COMBUSTIBLE GAS INDICATORS
         Considerations
     Oxygen requirements

     Contaminants that foul sensor

     Temperature

     Relative response
 COMBUSTIBLE GAS INDICATORS
    Relative Response Curves
100,
               Mathin*
                      Pentane
       o>
       TJ
       s
       ? 50
       »
       "5
           £-
                    1
              St/rtiM
Source: MSA 260
         0     50    100
             Percent LEL
JO/93
                                 Oxygen Monitors, CGIs, and
                                  Specific Chemical Monitors

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      NOTES
                                TOXIC ATMOSPHERE
                                    MONITORING
                              The purpose of monitoring is to:

                              •  Identify chemicals and their
                                 concentrations

                              •  Evaluate worker/public exposures

                              •  Evaluate protective equipment
                                 selection

                              •  Help develop exposure controls
                                TOXIC ATMOSPHERE
                                      MONITORS
                                • Specific chemical monitors

                                • Total vapor survey monitors

                                • Gas chromatographs

                                • Aerosol monitors
                                 SPECIFIC CHEMICAL
                                      MONITORS	
                              Designed to respond to a specific
                              chemical

                              Common types include
                              - Electrochemical
                              - Metal-oxide semiconductor (MOS)
                              - Colorimetric indicators
                              - Mercury detectors
Oxygen Monitors, CGIs, and
Specific Chemical Monitors
4/94

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                                               NOTES
          METAL-OXIDE
   SEMICONDUCTOR (MOS)
 • Metal-oxide coating on a ceramic substrate
  wrapped around a wire

 • Contaminant alters conductivity by
  removing oxygen

 • Change in current is proportional to the
  amount of contaminant present

 • Also called "solid-state" sensor
              MOS
         Considerations
   • Interferences

   • Saturation
     Temperature

     Minimum oxygen requirements
 COLORIMETRIC INDICATORS
 Contaminant reacts with a chemical on

 a tape, badge, or tube and causes a

 color change
10/93
Oxygen Monitors, CGIs, and
 Specific Chemical Monitors

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     NOTES
                           COLORIMETRIC INDICATORS
                                  Considerations
                                    • Interferences

                                    • Humidity

                                    • Temperature
                              MERCURY DETECTORS
                           • Ultraviolet light absorption
                            - Mercury vapor absorbs a specific
                               wavelength of light

                           • Gold film
                            - Mercury reacts with film and
                               changes the electrical resistance
                               of the film
                              MERCURY DETECTORS
                                  Considerations
                             • Ultraviolet light
                              -  Interferences
                              -  Humidity

                             • Gold film
                              -  Factory calibration
                              -  AC power needed to "clean"
Oxygen Monitors, CGIs, and
Specific Chemical Monitors
10/93

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         OXYGEN MONITORS, COMBUSTIBLE GAS INDICATORS,
                    AND SPECIFIC  CHEMICAL MONITORS
INTRODUCTION

Many hazards may be present when responding to hazardous materials spills or uncontrolled waste
sites.   These  include oxygen-deficient  atmospheres, combustible/explosive atmospheres, toxic
atmospheres, and  radiation.   There  are several types of instrumentation for detecting hazardous
atmospheres.  This section will discuss oxygen monitors, combustible gas indicators (CGIs), and
monitors for specific chemicals.
OXYGEN MONITORS

Oxygen monitors are used to evaluate an atmosphere for:

       •      Oxygen content  for respiratory  purposes.  Normal air contains  20.8% oxygen
             Generally,  if the oxygen content decreases below 19.5%, it is considered oxygen-
             deficient and special respiratory protection is needed.

       •      Increased risk of combustion.  Generally, concentrations above 25% are considered
             oxygen enriched  and increase the risk of combustion.

       •      Use of other instruments. Some instruments require sufficient oxygen for operation.
             For example, CGIs do not give reliable results at oxygen concentrations below 10%.
             Also, the inherent safety approvals for instruments are for normal atmospheres and
             not for oxygen-enriched ones.

       •      The presence of contaminants.  A decrease in oxygen content can be due to the
             consumption (by  combustion  or  a reaction such as  rusting) of oxygen  or the
             displacement of air by a chemical.  If it is due to consumption, then the concern is
             the lack of oxygen. If it is due to displacement, then there is something present that
             could be flammable or toxic.  Because oxygen makes up only 20.8% of air, a 1%
             drop in oxygen  means that about 5%  air (air being  1 part oxygen and 4 parts
             nitrogen) has been displaced.  This means that 5% or 50,000 ppm (1% =  10,000
             ppm) of "something"  could be there.

Most indicators have meters that display the oxygen concentration from 0 to 25%. There are also
oxygen monitors available that measure concentrations from 0 to 5% and from 0 to 100%.  The most
useful range for hazardous material response is the 0-25 % oxygen content readout because decisions
involving air-supplying respirators and the use of CGIs fall into this range.

The oxygen sensor can be on the outside (external) or inside (internal) of the instrument.  Internal
sensors need a pump—battery operated or hand operated—to draw a sample to it. Units that combine
O2 meters and CGIs into one instrument are available from many manufacturers. Also,  flashing and
audible alarms can be found on  many instruments.  These  alarms  go off at a preset oxygen

                                                             Oxygen Monitors, CGIs, and
10/93                                      1                    Specific Chemical Monitors

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concentration to alert the users even if they are not watching the meter. A list of manufacturers of
oxygen monitors is found in this manual under Manufacturers and Suppliers of Air Monitoring
Equipment.
Principle of Operation

Oxygen monitors use an electrochemical sensor to determine the oxygen concentration in air.  A
typical sensor consists of two electrodes, a housing containing a basic electrolytic solution, and a
semipermeable Teflon* membrane (Figure 1).
            Display
Membrane / Cover

   Electrode


    Electrode


    Electrolyte
                        FIGURE 1. SCHEMATIC OF OXYGEN SENSOR

       Source: Atmospheric Monitoring for Employee Safety, BioMarine Industries Inc.

Oxygen molecules (O2) diffuse through the membrane into the solution.   Reactions between the
oxygen, the solution, and the electrodes  produce a  minute electrical current proportional to the
oxygen content.  The current  passes through an electronic circuit which amplifies the signal. The
resulting signal is shown as a needle deflection on a meter or as a digital reading.

In some units, air is drawn into the oxygen detector with an aspirator bulb or pump; in other units,
the ambient air is allowed  to diffuse to the sensor.
 Oxygen Monitors, CGIs, and
 Specific Chemical Monitors
                     10/93

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Limitations and Considerations

The operation of oxygen monitors depends on the absolute atmospheric pressure.  The concentration
of atmospheric oxygen is a function of the atmospheric pressure at a given altitude.  Whereas the
actual percentage of oxygen does not change with altitude, at sea level the weight of the atmosphere
above is greater, and more O2 molecules (and the other components of air) are compressed into a
given volume than at higher elevations. As elevation increases, this compression decreases, resulting
in fewer air molecules  being  "squeezed"  into a given volume.  Consequently, an  O2 indicator
calibrated at sea level and operated at an altitude of several thousand  feet will falsely indicate an
oxygen-deficient atmosphere because  less oxygen is being "pushed" into the sensor.  Therefore, it
is necessary to calibrate at the altitude the instrument is used.

The reaction that produces the current in  the sensor is nonreversible.  Thus, once the sensor  is
exposed to oxygen, it begins to wear  out.  The normal life span of a sensor is 6 months to 1 year.
Sensors are shipped in sealed packages that have been purged with nitrogen.  The packet should not
be opened until the sensor is to be used. Storing the sensor in an oxygen absent atmosphere after
opening the package can prolong the sensor life,  but may not be practical.

High concentrations of carbon dioxide (CO2) may shorten the useful life of the oxygen sensor. As
a general  rule, the unit can be used in atmospheres greater than 0.5% C02 only with  frequent
replacing or rejuvenating of the sensor.  Lifetime in a normal atmosphere (0.04% COa) can be from
6 months to 1 year depending on the  manufacturer's design. The service life of one sensor is 100
days in  1% CO2 and 50 days in 5% CO2.

Strong oxidizing chemicals, like ozone and  chlorine, can cause increased readings and indicate high
or normal O2 content when the actual  content is normal or even low.

Temperature can affect the response of oxygen indicators.  The normal operating range for them is
between 32°F and 120°F.  Between O°F and 32°F the response of the unit is  slower.  Below O°F
the solution may freeze and damage the sensor. High temperature can  also shorten the sensor life.
The instrument should be calibrated at the temperature at which it will  be used.
COMBUSTIBLE GAS INDICATORS

CGIs measure the concentration of a  flammable vapor or gas in air,  indicating the results as  a
percentage of the lower explosive limit (LEL) of the  calibration gas.  The LEL (or LFL - lower
flammable limit) of a combustible gas or vapor is the minimum concentration of the material in air
which will propagate flame on contact with an ignition source.  The upper explosive limit (UEL) is
the maximum concentration. Below the LEL there is insufficient fuel to support combustion.  Above
the UEL, the mixture is too "rich" to support combustion, so ignition is not possible.  Concentrations
between the LEL and UEL are considered flammable.

CGIs are available in many styles and configurations.  The combustible gas sensor can be on the
outside (external) or inside (internal) of the instrument.  Internal sensors need a pump—battery
operated or hand operated—to draw a  sample to it.  Many units are  "combination meters."  This
means they have an O2 meter  and a CGI (and sometimes one  or  two  specific gas indicators)


                                                               Oxygen Monitors, CGIs, and
JO/93                                       3                   Specific Chemical Monitors

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combined in the same instrument.   Flashing and audible alarms are options on many units.  The
alarms go off at a preset concentration to warn the instrument operator of potentially hazardous
concentrations. Other options such as longer sampling lines, moisture traps, and dust filters are also
available.  Manufacturers of CGIs are listed in Manufacturers and Suppliers of Air Monitoring
Equipment.
Principle of Operation

CGIs use a combustion chamber containing a filament that combusts the flammable gas. To facilitate
combustion, the filament is heated or is coated with a catalyst (like platinum or palladium), or both.
The filament is part of a balanced resistor circuit called a Wheatstone bridge (Figure 2),  The hot
filament combusts the gas on the immediate surface of the element, thus raising the temperature of
the filament.  As the temperature of the filament increases,  so does its resistance.   This change in
resistance causes  an imbalance in the Wheatstone bridge.  This  is measured  as the ratio of
combustible vapor present compared to the total required to reach the LEL.  For example, if the
meter reads 50% (or 0.5, depending upon the readout), this means that 50% of the concentration of
combustible gas needed to reach a flammable or combustible situation is present.  If the LEL for the
gas is 5%, then the meter would be indicating that a 2.5% concentration is present.  Thus, the
typical meter indicates concentration up to the  LEL of the gas (Figure 3a).
                                                                Sensor
                                                                 Compensating
                                                                    Filament
                         FIGURE 2.  WHEATSTONE BRIDGE CIRCUIT

       Source: Atmospheric Monitoring for Employee Safety, BioMarine Industries Inc.
 Oxygen Monitors, CGIs, and
 Specific Chemical Monitors
10/93

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If a concentration greater than the LEL and lower than the UEL is present, then the meter needle
will stay beyond the 100% (1.0) level on the meter (Figure 3b). This indicates that the ambient
atmosphere is readily combustible.  When the atmosphere has a gas  concentration above the UEL,
the meter needle may rise above the 100% (1.0) mark and then return to zero (Figure 3c).  This
occurs because the gas mixture in the combustion cell is too rich to burn.  This permits the filament
to conduct a current just as if the atmosphere contained no combustibles at all.  Some instruments
have a lock mechanism that prevents the needle from returning to zero when it has reached 100%.
This mechanism must be reset in an atmosphere below the LEL.
                 < LEL
LEL - UEL
> UEL
                                                            OVER
                   (a)
    (b)
   (C)
                     FIGURE 3.  COMPARISON OF METER READINGS TO
                          COMBUSTIBLE GAS CONCENTRATIONS
Limitations and Considerations

The  instruments  are  intended for use only  in  normal oxygen atmospheres.  Oxygen-deficient
atmospheres will  produce lowered readings.  Also, the safety guards that prevent the combustion
source from igniting a flammable atmosphere are not designed to operate in an oxygen-enriched
atmosphere.

Organic lead vapors (e.g., leaded gasoline), sulfur compounds, and silicone compounds will foul the
filament.  Acid gases (e.g., hydrogen chloride and hydrogen fluoride) can corrode the filament.
Most units have an optional filter that protects the sensor from leaded vapors.
10/93
                         Oxygen Monitors, CGIs, and
                          Specific Chemical Monitors

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The response of the instrument is temperature dependent. If the temperature at which the instrument
is  zeroed differs from the sample temperature, the accuracy  of the reading is affected.  Hotter
temperatures raise the temperature of the filament and produce a higher than actual reading.  Cooler
temperatures will reduce the reading.  The instrument should be  calibrated and zeroed at the same
temperature that a  reading will  be taken.   Some instruments have  a compensating  filament
(Figure 2).  This filament is similar to the sensor and is exposed to the same atmosphere, but it does
not combust the atmosphere.   It compensates  for any temperature  changes not caused by  the
combustible gas.

There is no differentiation between petroleum vapors and combustible gases.  If the flammability of
the combined vapors and gases  in an atmosphere is the concern, this is not a problem. However,
if  the  instrument is  being  used to detect the presence  of  a released flammable  liquid—like
gasoline—in a sewer system where methane may be present, the operator cannot tell  whether  the
reading is the contaminant or the methane.  A prefilter can be used to remove the vapors, but it will
not remove the methane.  Thus,  if readings are made with and without the filter, the user can
compare the readings and can conclude that differences in the values  indicate that a petroleum vapor
(i.e., the contaminant) is present.

Relative response is also a concern. If the CGI is used to monitor a gas/vapor that the unit is not
calibrated to, it can give inaccurate results.  Figure 4 illustrates the effect of relative response.


TOXIC ATMOSPHERE  MONITORS

Along  with oxygen concentration and flammable gases or  vapors, there is also  a concern  about
chemicals present at toxic concentrations.  This usually involves measurements at concentrations
lower than what would be indicated by oxygen indicators or CGIs.  There is a need to determine
whether toxic  chemicals are present and  identify them so the  environmental concentration can be
compared to exposure guidelines.  Toxic atmosphere monitoring is done to:

        •      Identify airborne chemicals and their concentrations

        •      Evaluate the exposure of workers and the public

        •      Evaluate the need for and type of personal protective equipment

        •      Develop controls for exposure in the form of engineered safeguards, work practices,
              safety  plans, and work zones.

Several different groups of instruments can be used for these functions. In this manual the following
types will be discussed:

        •      Specific chemical monitors are instruments designed to respond to a specific chemical.
              Common types  include instruments  that use electrochemical cells or metal-oxide
              semiconductors (MOS), colorimetric indicators, and  mercury detectors.
 Oxygen Monitors, CGIs, and
 Specific Chemical Monitors                    6                                        10/93

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             Total vapor survey meters have detectors (e.g., photoionization detector [PID] or
             flame ionization detector [FID]) that respond to a variety of chemicals.  Additional
             information can be found in Total Vapor Survey Instruments.

             Gas  chromatographs are used to  help identify what chemicals are present in the
             atmosphere.    Additional  information  is  available  in Introduction  to  Gas
             Chromatography.
                      100.
                                        Methane
                O)
                c
                T5
                (0
                o
                ?    50
                
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movement or a digital response on a meter.  The selectivity of the sensor depends on the selection
of the chemical solution and the electrodes.

In addition to the  previously mentioned oxygen monitors  (Figure  1), there are electrochemical
sensors  for ammonia, carbon monoxide,  carbon dioxide, chlorine, hydrogen chloride, hydrogen
cyanide, and  hydrogen sulfide.  Examples of these instruments are  Compur's Monitox® Personal
Monitor Alarms,  MDA's  MSTox 8600 series, and National  Draeger's  PAC series of personal
monitors.
Limitations and Considerations

Like the oxygen sensor, these electrochemical sensors  also can  wear out and  are  affected by
temperature and humidity.

Electrochemical cells are also affected by interferences.  For example, many of the carbon monoxide
sensors will also respond to hydrogen sulfide.  In fact, one manufacturer uses the  same sensor for
both carbon monoxide and hydrogen sulfide detectors.  The user must inform the instrument which
chemical is being monitored so the readout is in the proper units.
Metal-Oxide Semiconductors

MOS detectors, also  called solid-state sensors, consist of a metal-oxide film  coating on heated
ceramic substrate fused or wrapped around a platinum wire coil. When a gas conies in contact with
the metal oxide, it replaces oxygen in the oxide and alters the conductivity of the semiconductor.
The change in conductivity  can be expressed in a meter readout. The substrate  is heated to give a
constant baseline as oxygen in the air can combine with the oxide.  Selectivity can be determined by
selecting specific  metal  oxides  and/or using specific temperatures from the  heater to prevent
chemicals from reacting.

There are MOS detectors for ammonia, carbon monoxide, hydrogen chloride, hydrogen cyanide,
hydrogen sulfide, methyl chloride, nitrogen oxides, and sulfur dioxide. Examples of instruments that
use an MOS to detect specific toxic compounds are the Enmet Tritechtor® and Biosystem's Model
100 series.

Even though the  choice of metal oxide and  sensor temperature can make the detector somewhat
selective, interferences are a major problem.

Because the sensor reaction is based  on presence (or absence) of oxygen in the metal-oxide film,
factors that affect oxygen concentration affect meter response.  The sensor needs a minimum 14%
ambient oxygen for operation.  High concentrations can saturate the sensor, causing a slow recovery.

A minimum of 10% humidity is  need for some sensors (check the manufacturer's specifications).
 Oxygen Monitors, CGIs, and
 Specific Chemical Monitors                    8                                       10/93

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Colorimetric Indicators

Colorimetric indicators use a chemical to react with the contaminant to produce a color change. The
chemical can be impregnated on a tape or a badge or put inside a glass tube.  The color change can
be read by the  human eye or  by a  spectrophotometer to determine the concentration  of the
contaminant.

The chemicals are not always specific and can be affected by interfering chemicals.  Humidity can
act as an interference by producing a reaction.  Cold temperatures can slow the chemical reaction.
Hot temperatures may also cause the chemicals to indicate a reaction.

Examples of Colorimetric indicators are the Envirometrics, Inc. ACT™ cards  (badges),  MDA
Scientific's 7100 Series (tape), 2  J Draeger detector tubes.
Mercury Detectors

Mercury detectors use either ultraviolet light absorption or a gold film detector.  Mercury vapor
absorbs a certain wavelength of ultraviolet light.  The instrument draws a sample into a chamber and
exposes it to the ultraviolet light source.  The concentration of mercury vapor is measured by the
amount of light absorbed.

Some organic chemicals can absorb the ultraviolet light and act as an interference.  Water vapor also
absorbs ultraviolet light, but can be adjusted for if the instrument is zeroed in the same humidity as
the sample area.

The gold film detector has a gold film as part of a circuit. Mercury reacts with the gold and changes
the resistance of the film.  The change in resistance is used to determine concentration.

Because most operators do not have a mercury vapor standard, the gold film detector must be factory
calibrated.   After  long exposures or high concentrations,  the  film needs to be "cleaned."   This
requires heating the film and using an AC power source.

An example of an ultraviolet absorption instrument is  the Bacharach Model MV-2.  An example of
a gold film instrument is the Jerome Instruments Model 411.
CONCLUSION

Many hazards can be present at a hazardous materials operation.   Instruments are available for
determining the  presence of hazardous situations like combustible atmospheres, oxygen-deficient
atmospheres, and toxic atmospheres.  The instruments discussed in this section can only identify
certain hazardous situations and should be selected and used accordingly.  Additional information
on identifying and evaluating  toxic atmospheres will be discussed in the following sections.
                                                                Oxygen Monitors, CGIs, and
JO/93                                        9                    Specific Chemical Monitors

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TOTAL VAPOR  SURVEY  INSTRUMENTS
         PERFORMANCE OBJECTIVES
         At the end of this lesson, participants will be able to:

         •   Explain the principle  of detection for the PID, FID,
             supersensitive CGI, and metal-oxide semiconductor (MOS)

         •   Determine whether a  chemical  can be detected  by
             photoionization,  given the  ionization potential of  the
             chemical and the lamp energy of the photoionization detector

         •   Identify three considerations when using a PID

         •   Identify three considerations when using a FID

         •   Identify three consideration when using a supersensitive CGI

         •   Explain the difference between a CGI and a supersensitive
             CGI.

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      TOTAL VAPOR
 SURVEY INSTRUMENTS
   TOTAL VAPOR SURVEY
       INSTRUMENTS
 Instruments using detectors that
 respond to a wide variety of chemicals
 and give readings in the parts per
 million range
  WHAT ARE TOTAL VAPOR SURVEY
    INSTRUMENTS USED FOR?
     Site characterization
     Exposure monitoring
     Soil and water sample screening
     Soil gas monitoring
                                        NOTES
10/93
Total Vapor Survey Instruments

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      NOTES
TYPES OF TOTAL VAPOR
SURVEY INSTRUMENTS
• Photoionization detector (PID)
• Flame ionization detector (FID)
• Supersensitive CGI
• Metal-oxide semiconductor (MOS)

PHOTOIONIZATION
\ A

i
><
O
jXj
U
8

PHOTOIONIZATION
R-L hu
^ n
T ll*7 ' \\
R = chemical-abs
h(nu) = photon wi
> ionizatic
(IP) of che
++ e' -^ R
orbing UV
th energy
>n potential
mical
Total Vapor Survey Instruments
10/93

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                                              NOTES
PHOTOIONIZATION DETECTOR
              Amplifier
           Meter
       Sample Out


        Electrode
               UV
               Lamp
t
Electrode
               Sample In
10/93
                         Total Vapor Survey Instruments

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IONIZATION
POTENTIAL
Chemical
Carbon monoxide
Hydrogen cyanide
Methane
Hydrogen chloride
Water
Oxygen
Chlorine
Propane
Hydrogen sulfide
Hexane
Ammonia
Acetone
Trichloroethylene
Benzene
Triethylamine
V
IP (eV)
14.0
13.9
13.0
12.7
12.6
12.1
11.5
11.1
10.5
10.2
10.1
9.7
9.45
9.2
7.5

NOTES
   Total Vapor Survey Instruments                                        10/93

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                                             NOTES
 EXAMPLES OF LAMP ENERGIES
 AND DETECTABLE CHEMICALS
            Halourbonf
            Muthanol

            Other «ngt« C compounds
                   Vinyl chlorid*
                   MEK
                   MIBK
                   TCE
                   Other 2-4 C compounds
                        Aromatics
                        Lwgt moleculM
              Lamp
  SELECTIVE DETERMINATION
      OF VINYL CHLORIDE
        Compound
IP
        Carbon dioxide  13.8
        Propane       11.1
        Vinyl chloride    10.0
        Acetone        9.7
PHOTOIONIZATION DETECTOR
       11.7 vs. 10.2 Lamp
 • 11.7 wears out faster than 10.2

 • 11.7 is more susceptible to humidity

 • 10.2 provides better response to
  chemicals it can detect
10/93
                   Total Vapor Survey Instruments

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     NOTES
                             PHOTOIONIZATION DETECTOR
                                      Considerations
                                   Lamp energy/chemical IP
                                   Dust/humidity
                                   Interferences
                                   Electromagnetic interferences
                                   Lamp aging
                                   Relative response
                                   High concentrations
PHOTOIONIZATION DETECTOR
Relative Response
Chemical
m-Xylene
Benzene
Phenol
Acetone
Isobutylene
Hexane
Ammonia
Relative
Response*
1.12
1.00
0.78
0.63
0.55
0.22
0.03
IP
8.56
9.25
8.69
9.69
9.25
10.18
10.15
* HNU PI-101 with 10.2 eV lamp calibrated to benzene
                             PHOTOIONIZATION DETECTOR
                                High Concentration Effects
                                Ol
                                .£
                                                Benzene
                                               (gain = 9.8)
                                           ppm (by volume)
Total Vapor Survey Instruments
10/93

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                                                     NOTES
FLAME IONIZATION DETECTOR
Exhaust Vent
r-fWr^-i
c
Igniter and
Electrode 	 ,
u
1
Hydrogen Inlet
r
p 	 Collector
Electrode
\
J




FLAME IONIZATION
RH 1 0 "ame > F
Note: This ionization proces
H+ + e"-^C02 + H20
>s is destructive.

COMPOUNDS GIVING LITTLE OR
NO RESPONSE IN THE FID
He N2 HCHO (formaldehyde)
Ar NO CO
02 N02 C02
H20 N20 CS2
H2S NH3 Ethanolamine
S02 HCN
10/93
Total Vapor Survey Instruments

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      NOTES
                                    FLAME lONIZATION
                                      Considerations
                                  • Detects only organics
                                  • Detects methane
                                  • Hydrogen gas needed
                                  • Flame out
                                  • Electromagnetic interferences
                                  • Relative response
                                     FLAME lONIZATION
                                      Relative Response
                                 Chemical
% Relative Response*
                                 Benzene                185
                                 Toluene                126
                                 Methane                100
                                 Acetone                82
                                 Trichloroethylene           54
                                 Freon-12               13
                                 Carbon tetrachloride           8
                              OVA-128 calibrated to methane
                                  SUPERSENSITIVE CGI
                               Detects combustible gases and
                               vapors
                               Detector is the same as a regular CGI,
                               but an amplifier is used to obtain ppm
                               readings
Total Vapor Survey Instruments
              10/93

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                                                NOTES
      SUPERSENSITIVE CGI
          Considerations
      • Detects only combustibles
      • Detects methane
      • Temperature
      • Chemicals that foul sensor
      • Minimum oxygen
      • Electromagnetic interference
      • Relative response
          METAL-OXIDE
   SEMICONDUCTOR (MOS)
• Metal-oxide coating on a ceramic substrate
  wrapped around a wire
• Contaminant alters conductivity by
  removing oxygen
• Change in current is proportional to the
  amount of contaminant present
• Also called "solid-state" sensor
              MOS
         Considerations
   • Saturation
   • Temperature
   • Minimum oxygen requirements
   • Relative response
10/93
Total Vapor Survey Instruments

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     NOTES
                                    CONCLUSION
                                    Considerations
                              • What the instrument can detect
                              • Survey, not identification
                              • Logistical factors
                              • Environmental factors
                              • Special features
Total Vapor Survey Instruments
10/93

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                   TOTAL VAPOR SURVEY INSTRUMENTS
INTRODUCTION

Total vapor survey instruments are designed to respond  to a wide range of gases and vapors.
Although they lack selectivity, this broad response allows the operator to detect the presence of
chemicals with one instrument.  This allows the instrument to be used as a warning device during
survey operations.

If the identity of a chemical is known, the instruments can be calibrated to give a one-to-one response
for that chemical.  If there is a mixture present, the instrument gives a total vapor reading.  The
detectors themselves cannot identify the components of an  atmosphere.  The detectors can be used
in instruments, like the gas chromatograph (see Introduction to Gas Chromatography that are used
for identification.

This section will focus  on total vapor survey  instruments that are used for parts per million (ppm)
concentrations.   It will discuss four types of toxic vapor survey instruments:  photoionization
detectors (PIDs), flame ionization detectors (FIDs), supersensitive combustible gas indicators (CGIs),
and metal oxide semiconductors.
APPLICATIONS

Because of their ability to detect a wide range of chemicals, total vapor survey instruments are used
in site survey and characterization.  Although they cannot identify what chemicals are present, they
can indicate what areas may have higher concentrations (hot spots) than others and delineate work
areas based on levels of concentrations.

If the identities  of the contaminants are known, the instruments can  also be used in exposure
assessment.  The readings can give an approximate concentration and the information can be used
in selecting exposure controls.

The  instruments  are also used to screen water and soil samples to determine whether further, and
more complicated and expensive, analysis is needed.  Usually specific reading (or any response) is
used to determine which samples need further analysis.

Total vapor survey instruments are also  used in soil gas sampling as a screening tool  to indicate
"hits" and hot spots that need further sampling.
PHOTOIONIZATION DETECTORS

These instruments detect concentrations of gases and vapors in air by using an ultraviolet light source
to ionize the airborne contaminant.  Once the gas or vapor is ionized in the instrument, it can be
detected and measured.
10/93                                       1                Total Vapor Survey Instruments

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Principle of Operation

The photoionization process can be illustrated as:

                                 R + hv -» R+ + e" -* R

where R is an organic or inorganic molecule and hj/ represents a photon of ultraviolet (UV) light with
energy equal to or greater than the ionization potential (IP) of that particular chemical species.  R+
is the ionized molecule.

When a photon of ultraviolet radiation strikes a chemical compound, it  ionizes the molecule if the
energy of the radiation is equal to or greater than the IP of the compound. Because ions are charged
particles, they may be collected on a charged plate and produce a current.  The measured current
will be directly proportional to the number of ionized molecules.  The R  in the above equation
indicates that photoionization is nondestructive and the chemical exits the detector unchanged.

PIDs use a fan or a pump to draw air into the instrument's detector. There the contaminants  are
exposed to UV light and the resulting negatively charged particles (ions)  are collected and measured
(Figure 1).
                                       Amplifier
                      Sample Out
                       Electrode
                                                        Electrode
                                          Sample In
                FIGURE 1.  DIAGRAM OF PHOTOIONIZATION DETECTOR LAMP
                              AND COLLECTING ELECTRODES

The energy required to remove the outermost electron from the molecule is called the ionization
potential (IP) and is specific for any compound or atomic  species  (Table 1).  Ionization potentials
are measured in electron volts (eV).
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The ultraviolet light used to ionize the chemicals is emitted by a gaseous discharge lamp.  The lamps
contain low-pressure gas through which a high-potential current is passed.  A variety of lamps with
different ionization energies are made by varying the composition of the lamp gas.  The energy of
lamps available are 8.4, 9.5, 10.0, 10.2, 10.6, and 11.7 eV.   Not all lamps are available from a
single manufacturer.

The lamp  energy  designation is for the predominant UV wavelength emitted by the  lamp.  The
spectra from the lamp may have other wavelengths.  Wavelengths of less energy do not have a major
impact because chemicals ionized by  those wavelengths will also be ionized by the predominant
wavelength.  The higher energy (but less photons) wavelengths will ionize the higher IP chemicals
but the response will be low. Thus, a 10.2 lamp may give a response (although a small one) for a
chemical with an IP of 10.9.
Photoionization Detector Considerations

Because the ability to detect a chemical depends on the ability to ionize it, the IP of a chemical to
be detected must  be compared to the energy generated  by the UV lamp of the instrument.  As
discussed earlier, it may be possible to detect a chemical even if the chemical's IP is  slightly greater
than the lamp energy.  However, the response will be poor.

               TABLE 1. IONIZATION POTENTIALS OF SELECTED CHEMICALS
                                                    Ionization Potential
Chemical
Carbon monoxide
Hydrogen cyanide
Methane
Hydrogen chloride
Water
Oxygen
Chlorine
Propane
Hydrogen sulfide
Hexane
Ammonia
Acetone
Trichloroethylene
Benzene
Triethyl amine
(eV)
14.0
13.9
13.0
12.7
12.6
12.1
11.5
11.1
10.5
10.2
10.1
9.7
9.45
9.2
8.0
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One use for the different lamps is for selective determination of chemicals.  For example, if a spill
of propane and vinyl chloride were to be monitored with a PID, the first check would be to see
whether the chemicals can be detected.  The IP of propane is 11.1 eV and the IP of vinyl chloride
is  10.0 eV.  To detect  both, a lamp with an energy greater than 11.1 eV is needed (like a 11.7).
If vinyl chloride was the chemical of concern, then a lamp with an energy greater than 10.0 but less
than 11.1 (such as 10.2 or 10.6) could be used.  The propane would neither be ionized nor detected.
Thus, propane would not interfere with the vinyl chloride readings.

The lamp window also affects response.  The two types of windows are magnesium fluoride and
lithium fluoride.  The former is used for the lower energy lamps and the latter is for the 11.7 eV
lamp.  The lithium fluoride is used to  permit the higher energy photons to be  emitted.   Lithium
fluoride has two disadvantages.  The first is that humidity and the high-energy photons degrade the
window.  This  reduces the life span of the  lamp. The 11.7 eV lamps are expected to have a life
expectancy one-tenth of that of 10.2 or 10.6 lamps.  The second disadvantage is that lithium fluoride
also limits the amount of photons being emitted.  Thus,  if both a 10.2 and an 11.7 lamp have enough
energy to ionize a chemical (e.g., a chemical with an IP of 9.7), the 10.2 may give a higher response
because it is emitting more light.

The sample drawn into the instrument passes over the  lamp to be ionized.  Dust in the atmosphere
can collect on the lamp and block the  transmission of UV light.  This  will cause a reduction in
instrument reading. The lamp should be cleaned regularly.  Newer models of PIDs have dust filters.

Humidity can cause two problems. When a  cold instrument is taken into a warm  moist atmosphere,
the moisture can condense on the  lamp.  Like dust, this will reduce the available  light.  Moisture in
the air can also reduce the readings.  It is thought that  the water molecules collide with the ionized
chemical and deactivate them.  This reduction in response has been reported to be as much as 50%
for a relative humidity of 90%.  As mentioned earlier,  the 11.7  lamp  window is especially sensitive
to moisture.

Because an electric field is generated in the sample chamber  of the instrument,  radio-frequency
interference  from pulsed DC  or AC  power  lines,  transformers,  generators, and radio  wave
transmission  may produce an error in response.

As the lamp ages, the intensity of the light decreases.  It will still have the  same ionization energy,
but the response will decline.  This will be detected during calibration and adjustments can be made.
However, the lamp will eventually burn out.

Methane can act as an interference by absorbing the UV energy without ionization.  This reduces
the ionization  of other  chemicals  present.   The net  effect  is a  reading lower than  the true
concentration.

Although oxygen is not needed  for photoionization, a change  in oxygen will affect the response.
Thus,  there are oxygen limits for their use.  The instruments  are calibrated and used in normal
oxygen atmospheres.  The HNU  PI-101 requires a minimum of 10% oxygen for reliable results.

Photoionization detectors are calibrated to a single chemical.  The instrument's response to chemicals
other than the calibration gas/vapor can vary.   Table 2 shows the relative  responses of several
chemicals  for a specific PID.


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In some cases, at high concentrations the instrument response can decrease.  While the response may
be linear (i.e., 1 to 1 response) from 1 to 400 ppm for an instrument, a concentration of 900 ppm
may only give a meter response of 700 (Figure 2).  Some instruments use a microprocessor to
compensate for this effect by storing calibration information for the high concentrations.

Manufacturers who make photoionization detectors can be found in this manual in the Manufacturers
and Suppliers of Air Monitoring Equipment section.

                     TABLE 2.  RELATIVE RESPONSES FOR SELECTED
                       CHEMICALS USING THE HNU MODEL PI 101
                     WITH 10.2 eV PROBE CALIBRATED TO BENZENE
Chemical
m-Xylene
Benzene
Acetone
Isobutylene
Vinyl chloride
Hexane
Phosphine
Ammonia
Relative Response
1.12
1.00
0.63
0.55
0.50
0.22
0.20
0.03
                  Source:  Instruction Manual for Model PI 101, Portable
                  Photoionization Analyzer,  HNU Systems, Inc., Newton,
                  MA, 1986.
Examples of Photoionization Detector Instruments
HNU Systems, Inc.

HNU Systems,  Inc., manufactures four models of photoionization detector survey instruments:
PI-101, IS-101,  HW-101, and the DL-101.


All four consist  of two  modules connected via a single power cord (Figure 3):

       •     A readout unit having an analog meter or digital display, a rechargeable battery, and
             power supplies for operation of the amplifier and the UV lamp

       •     A sensor unit consisting of the  UV light source, pump, ionization chamber, and a
             preamplifier.
10/93                                      5               Total Vapor Survey Instruments

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The PI-101 has a fan instead of a pump and cannot draw a sample through a resistance (like a piece
of long tubing). The PI-101 is rated for Class I, Division 2, Group A, B, C, and D locations.

The IS-101 is similar to the PI-101 except it is intrinsically  safe for Division 1 locations.

The HW-101 has a pump instead of a fan, so it can be used to draw a  sample through tubing or
through a probe used for soil gas sampling.  The HW-101 also has a dust filter and is more moisture
resistant than the other models.  It also has a light-emitting diode (LED)  display on the handle that
indicates concentration changes.

The DL-101 has a pump and dust filter  like the HW-101.  However,  it has many different fixtures
than other units. It has a pistol grip for holding the probe.  There is a LED display on the handle.
The instrument has  a datalogger to store calibration information and to record time and  location of
readings.  Information from the datalogger can be transferred to a computer. It has a digital readout
instead of an analog meter.

These units have a separate sensor unit because the lamps available - 9.5, 10.2 (standard), and 11.7
eV - require separate electronic circuits. To change the energy of ionization, the whole sensor or
           O)
           C  600
           0)
           DC
           0)
               400
               200
  Benzene
(gain = 9.8)
                       100
                                 300
                                          500
                                                   700
                                                             900
                                      ppm (by volume)
         FIGURE 2.  TYPICAL CALIBRATION CURVE FOR PHOTOIONIZATION ANALYZER

 Source:  Instruction Manual for Model PI-101 Photoionization Detector, copyright  1975,  HNU
 Systems, Inc.; reprinted with permission of publisher.
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probe has to be switched, not just the lamp.  The exception is the DL-101. With the DL-101, lamps
can be interchanged and the datalogger/microprocessor makes the proper adjustments. In all models
the lamps are replaceable.
                                                                  Ion Chamber
                                              \

o 1






.



rfT

.
•


                                                                        I 4- SAMPLE
                                                         PROBE
                    FIGURE 3. PORTABLE PHOTOIONIZATION DETECTOR

Source:  Instruction Manual for Model PI-101 Photoionization Detector,  copyright 1975, HNU
Systems, Inc.; reprinted with permission of publisher.
Photovac, Inc.

Photovac has three versions of its MicroTIP®.  All three have a microprocessor that is used to
calibrate the instrument and a datalogger to store data.  Information from the datalogger can be
transferred to a computer.  The standard lamp is 10.6 eV, but it can be easily replaced with a 8.4,
9.5, 10.2 or 11.7 eV lamp.  The readout is digital with a range of 0 to 2000.  They all have a dust
filter.  The MP-1000 does not have a inherent safety approval. The HL-2000 is approved for Class
I, Division 2, Groups A, B, C, and D locations.  The IS-3000 is intrinsically safe.
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Thermo Environmental Instruments

The Organic Vapor Meter (OVM) Model 580B is 5" by 5" by 10" with a handle in the center on
top.  It can use any of four different lamps - 9.6, 10.0, 10.6 and  11.8 eV.  The instrument has a
digital readout with a range of 0 to 2000.  It has a maximum hold feature so that you can get two
readings - the current  concentration or the maximum concentration during the survey.  The meter
has a lock-out  if the readout exceeds 2000 so that high concentrations are not missed.  It must be
reset in an area of low concentrations.  The instrument has  a microprocessor for assistance in
calibration and lamp changing.

The OVM-580S is similar to the 580B, but is intrinsically safe.

Both have connections and software for interfacing the unit with a personal computer. They also
have a datalogger for recording readings at coded locations so that the readings can be looked at later
or downloaded into a computer.

Photoionization detectors are also used in gas chromatographs made by Photovac, HNU and Thermo
Environmental Instruments.  Gas chromatography will be discussed in a later section.
FLAME IONIZATION DETECTOR

These units use a flame to ionize airborne contaminants. Once they are ionized, they can be detected
and measured.
Principle of Operation

FIDs use a hydrogen flame as the means to ionize organic vapors.  FIDs respond to virtually all
organic compounds; that is, compounds that contain carbon-hydrogen or carbon-carbon bonds. FIDs
will not respond to inorganic compounds.

Inside the detector chamber, the sample is exposed to a hydrogen flame which  ionizes the organic
vapors (Figure 4):

                           RH +  O2 -» RH+ + e~ - CO2 + H2O

When most organic vapors burn, positively charged carbon-containing ions  are produced.  These can
be collected by a negatively charged collecting electrode in the  detector chamber.  An electric field
exists between the conductors surrounding the flame and a collecting electrode. As the positive ions
are collected,  a current proportional to  the hydrocarbon concentration is generated  on the input
electrode.  This current is measured with a preamplifier which  has an output signal proportional to
the ionization current.  A signal conducting amplifier is used to amplify the signal from the detector
and to condition it for subsequent meter or external recorder display.

Flame ionization detectors have  a more generalized response in detecting organic vapors.  This
generalized sensitivity is due to the breaking of chemical bonds which require a set amount of energy
and is a known reproducible event.  When this is  compared to photoionization  (PID),  a major


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difference should be noted between the detectors.  PID detection is dependent upon the ionization
potential (in eV) and the ease in which an electron can be ionized (displaced) from a molecule. This
mechanism is variable, highly dependent on the individual characteristics of a particular substance.
This results in a more variable response factor for the vast majority of organics that are ionizable.
Therefore,  in general, one does not see large sensitivity  shifts between different substances when
using an  FID  as compared to  a PID.  FIDs are the most sensitive for saturated hydrocarbons
(alkanes), unsaturated hydrocarbons (alkenes and alkynes), and aromatic hydrocarbons.  Substances
that contain substituted functional groups,  such as hydroxide (OH) and chloride (Cl), tend to reduce
the detector's sensitivity.

Companies that manufacture FIDs are listed in the Manufacturers and Suppliers of Air Monitoring
Equipment section.  The Foxboro Century Organic Vapor Analyzer (OVA) will be discussed as an
example later\
                                   Exhaust vent

                                  -^77777^
                Igniter and
                 electrode
              Hydrogen inlet
   Collector
  electrode
Sample (air) inlet
            FIGURE 4.  EXAMPLE OF A FLAME IONIZATION DETECTOR SCHEMATIC
Flame Ionization Detector Considerations

Flame ionization detectors respond only to organic compounds.  Thus, they do not detect inorganic
compounds like  chlorine, hydrogen cyanide, or ammonia.  There  are  some carbon containing
chemicals for which the FID gives little or no response also.  Table 3 illustrates this situation.
10/93
      Total Vapor Survey Instruments

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                  TABLE 3.  CHEMICALS GIVING LITTLE OR NO RESPONSE
                          WITH FLAME IONIZATION DETECTORS


                   He                 N2             HCHO (formaldehyde)
                   Ar                 NO                     CO
                   02                N02                     C02
                   H20               N20                     CS2
                   H2S               NH3                     TDI
                   S02               HCN                ethanol amine

             Source:  Relative Response Data Sheet for Organic Vapor Analyzer,
             January  16, 1989. The Foxboro Company.

Flame  ionization, unlike  photoionization, is  a destructive form  of  monitoring.  Typically,  the
combustion products are carbon monoxide  and water.  However, substituted hydrocarbons (e.g.
chlorinated compounds) may produce toxic or  corrosive byproducts.

The FID responds  very well to  methane.  Methane is used as a  calibration gas for many FIDs.
However, if monitoring is being done near a landfill or in a sewer system, the methane can mask
the response to low concentrations of other organics.

Hydrogen gas is used as  fuel for the flame.   This  requires the  extra logistics of maintaining a
hydrogen gas supply and  recharging the instrument.  It also involves working  with a flammable
compressed gas.

Inadequate oxygen  can cause the flame to go out.  High concentrations of organics can also cause
a flame out.  Without the  flame, there is no detection.

Cold weather can also  cause the  flame to extinguish or inhibit startup (ignition) of the instrument.

Because an amplifier is used to enhance the signal from the detector, radio-frequency interference
from pulsed DC or AC power lines, transformers, generators, and radio wave transmission may
produce an error in response.

As with  all instruments,  flame  ionization detectors respond differently to different  compounds.
Table 4 is a list of the relative responses of the Foxboro CENTURY OVA to some common organic
compounds.  Since that instrument  is factory calibrated to methane, all responses are relative to
methane and are given by percentage, with methane at 100%.
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                    TABLE 4. RELATIVE RESPONSES FOR SELECTED
                 CHEMICALS USING THE OVA CALIBRATED TO METHANE
Compound
Methane
Ethane
Propane
Acetylene
Benzene
Toluene
Acetone
Methanol
Isopropyl alcohol
Carbon tetrachloride
Freon-12
Trichloroethylene
Relative Response
(%)
100
77
70
225
185
126
. 82
12
65
8
13
54
                 Source:  Product Literature, The Foxboro Company; used
                 with permission of The Foxboro Company.
Examples of Flame lonization Detector Instruments
Foxboro CENTURY Organic Vapor Analyzer (OVA)

One of the more common FID instruments is the Foxboro CENTURY OVA. There are two models:
the OVA-128 and the OVA-108. Both consist of two major parts (Figure 5):

      •      A 12-pound package containing the sampling pump, battery pack, support electronics,
             flame ionization detector, hydrogen gas cylinder, and an optional gas chromatography
             (GC) column.

      •      A hand-held meter/sampling probe assembly.
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        INTERNAL HYDROGEN
           CYLINDEP
    SIGNAL PROCESSOR
              v_y
                           ELECTRODE	*H
                                      I   u  I
                                                                       SAMPLE
                   FIGURE 5.  ORGANIC VAPOR ANALYZER SCHEMATIC

Source:   Product Literature,  The Foxboro  Company,  used with permission  of The Foxboro
Company.

The OVA-128 has a range of 0-1000 ppm.  The OVA-108 reads  from 0-10,000.   Both are
intrinsically safe for Class 1, Division 1, Groups A, B, C and D. Both models are factory calibrated
to methane, but can be calibrated to other chemicals.

Other FID units are the Sensidyne Portable  FID, Heath Consultants  Porta-FID II, and Summit
Industries SIP-1000. The Portable FID and the SIP-1000 have gas chromatograph options.
Combination PID and FID

Foxboro also manufactures the TVA-1000. The instrument can use a PID, an FID, or both.  The
instrument has datalogging capabilities and digital readouts on a probe and side pack.
Total Vapor Survey Instruments
12
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SUPERSENSITIVE COMBUSTIBLE  GAS INDICATORS

The CGI is a type of total vapor survey monitor.  However, the normal range for a CGI is in the
percent  LEL  concentration.  This range is too high for toxic concentration monitoring.  Super-
sensitive combustible gas indicators  use the combustible gas sensor with  circuitry to amplify the
signal.  Instead of measuring per cent of the LEL, the readout is in part per million.  Because the
detection is based on combustion, the instruments can detect both organic and inorganic combustible
gases/vapors.

Some units—like the Bacharach TLV Sniffer—only measure in the ppm range.  Other units (e.g.,
the GasTech Model 1314) can be switched from percent LEL to ppm readout.

These units have the same limitations and considerations as the regular combustible gas indicators.
In some cases, like sensitivity to temperature changes, the effects are a bigger problem because of
the amplifier circuit.  Because of the  amplifier, they are more sensitive to electromagnetic radiation
than  standard combustible gas indicators.
METAL-OXIDE SEMICONDUCTORS (MOS)

MOS, also called solid-state sensors, consist of a metal  oxide film coating on a heated ceramic
substrate fused or wrapped around a platinum wire coil. When a gas comes in contact with the metal
oxide, it replaces oxygen in the oxide and alters the conductivity of the semiconductor.  The change
in conductivity can be expressed in a meter readout. The bead is heated to give a constant baseline
as oxygen in the air can combine with the oxide.  Oxygen can combine with the sensor to cause an
instrument response.

Selectivity can be determined by selecting specific metal oxides and/or using specific temperatures
from the heater to prevent chemicals reacting. To use as a toxic  atmosphere  survey monitor, the
sensor should respond to  a wide variety of chemicals.  Thus, the sensor  should be designed to be
nonselective.

Examples  of instruments  using a MOS  for a total vapor sensor are the  AIM 2000/3000 and the
Dynamation Model CGM™.
CONCLUSION

This section has described several types of detectors used for monitoring the presence of a wide
range of gases and vapors.  While these are not the only types of detectors or monitors available,
they are the more commonly used devices for field surveys.
10/93                                       13               Total Vapor Survey Instruments

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  AIR SAMPLE  COLLECTION
PERFORMANCE  OBJECTIVES






At the end of this lesson, participants will be able to:



•   List four advantages to using air sample collection



•   List three sources of sampling and analysis methods



•   List three considerations when using liquid sorbent samplers



•   List three considerations when using solid sorbent samplers



•   List three considerations when using whole air samplers




•   Describe two methods of collecting whole air samplers.

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                                                 NOTES
         AIR SAMPLE
        COLLECTION
DIRECT-READING INSTRUMENTS (DRI)
    vs. AIR SAMPLE COLLECTION
Features
Response time
Quantitative
Identification
Detection range

Cost
DB1
Seconds to minutes
Yes
No
Parts per million (ppm)
to percent
Inexpensive
Air Sample Collection
Hours to days
Yes
Yes
Parts per trillion (ppt)
to parts per million (ppm)
Expensive
  AIR SAMPLE COLLECTION
               Uses
 • Identify and quantify airborne
  chemicals onsite
 • Evaluate personal exposures
 • Evaluate releases from site
 • Data for public health/ecological risk
  assessment
10/93
                                        Air Sample Collection

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     NOTES
                           AIR SAMPLE COLLECTION
                           	  Components	
                                                  Laboratory
                                                   analysis
                             Contaminant
                                          Pump
                                COLLECTION AND
                             ANALYTICAL METHODS
                             EPA
                             -  Compendium of Methods for
                                Determination of Toxic Organic
                                Compounds in Ambient Air
                             -  Compendium of Methods for
                                Determination of Air Pollutants in
                                Indoor Air
                             -  Compendium of Methods for
                                Determination of Toxic Inorganic
                                Compounds in Ambient Air
                                COLLECTION AND
                             ANALYTICAL METHODS
                          • NIOSH Manual of Analytical Methods

                          • OSHA Analytical Methods Manual

                          • American Society for Testing and
                            Materials

                          • Specialty methods
Air Sample Collection
10/93

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                                                 NOTES
       COLLECTION AND
    ANALYTICAL METHODS
 • Air Methods Database
  - Combines previous methods into
     a database
  - Free from EPA
  - See fact sheet
      COLLECTION MEDIA
     Types of Contaminants
   Aerosols/particulates (nonvolatile)

   Gases and vapors (volatile)

   Combination (semivolatile)
          FILTER MEDIA
             Examples
  Filler Media

  0.8-micron (fj)

  mixed cellulose ester (MCE)


  Glass fiber


  Polyvinyl chloride (PVC)
  Polytetrafluoroethylene
Application

Metals; asbestos



Pesticides


Total particulates;

hexavalent chromium


Alkaline dusts
10/93
                             Air Sample Collection

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     NOTES
Air Sample Collection
                         AEROSOLS/PARTICULATES
                          Size Selection Terminology
                         • Total suspended particulate (TSP)

                         • Particulate matter - 10/Y (PM-10)

                         • Total

                         • Respirable
                         AEROSOL SIZE SELECTION
                         	Inertial Impactor
                                               Air flow
                         Filter
                                    Pump
                         AEROSOL SIZE SELECTION
                         	 Cascade Impactor
                        Collector
                              Air flow
                                   A
                               Pump
/
                                     Plates
                                        N,
          10/93

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                                                  /VOTES
      GASES AND VAPORS
             Examples
         Organic vapors
         -  Benzene
         -  Trichloroethylene
         -  Ethyl alcohol

         Inorganic gases
         -  Ammonia
         -  Hydrogen cyanide
         -  Hydrogen chloride
     SOLID SORBENT MEDIA
             Examples
Solid Sorbent

Activated carbon


T  ®
Tenax


Carbon molecular sieve


Silica gel
Compound

Nonpolar organics (NIOSH)


Volatile, nonpolar organics (EPA)


Highly volatile, nonpolar organics (EPA)


Polar organics (NIOSH)
     SOLID SORBENT TUBE
        	Example
              t       t     t
                    Dividers


      A = Solid sorbent
      B = Solid sorbent (backup or different sorbent)
10/93
                                     Air Sample Collection

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     /VOTES
                                   SOLID SORBENT
                                  CONSIDERATIONS
                                    •  Breakthrough
                                    •  Sorption efficiency
                                    •  No universal media
                                    •  Stability/handling
                                    •  Desorption
                                      - Thermal
                                      - Solvent
                                LIQUID SORBENT MEDIA
                                       Examples
                            Media
                            O.INNaOH
                            Aniline

                            DNPH reagent + isooctane

                            0.1MHCI
Compound
Cresol/phenol (EPA)
Phenol (NIOSH)

Phosgene (EPA)

Aldehydes/ketones (EPA)

Hydrazine (NIOSH)
                                   LIQUID SORBENT
                                  CONSIDERATIONS
                                     Spillage
                                     Fragile holders
                                     Hazardous liquids?
                                     Stability
                                     Evaporation
Air Sample Collection
             10/93

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                                                        NOTES
   WHOLE AIR COLLECTION
          "Sampling Lung"
                           Sample flow
                         Air flow
 Source: "Sampling and Analysis ol Emissions from Stationary Sources,' Schuatzto st
 •I., Joumtl ollhtAir Pollution Control Aaodttion. Voluma 25, No. 8, Sapt 1975.
  BAG SAMPLING vs. CANISTER
             SAMPLING
  Baa
  Grab
  Need field pump
  Less stable sample
  Cannot clean
  Disposable
  Cannot pressurize
Canister
Integrated
Need lab pump
More stable sample
Clean to reuse
Reusable
Can pressurize
        COMBINATION MEDIA
               Examples
    Media             Compound
    Quartz fitter          PCBs/pesticides (EPA)
    + polyurethane foam (PUF) PAHs (EPA)

    Quartz filter + XAD-2    PAHs (EPA)

    Glass filter + Florisil®   PCBs (NIOSH)

    MCE filter + 0.1 N KOH   Cyanides (NIOSH)
4/94
                                    Air Sample Collection

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      NOTES
                                  SAMPLING PUMPS
                               Most collection methods require a
                               pump to pull air through medium

                               Exceptions
                               - Evacuated canister
                               - Passive dosimeter
                                PASSIVE DOSIMETER
                                       Example
                               Contaminant
                                                 Sorbent
                               Chemical permeates membrane and/or ditluses into
                               sampler
                                PASSIVE DOSIMETERS
                                    Considerations
                                No pump
                                Sorbent limits
                                -  Breakthrough
                                -  Humidity
                                -  Temperature
                                Early and late exposure problems
                                Gases and vapors only
Air Sample Collection
JO/93

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                                          NOTES
       SAMPLE PUMPS
       High Flow Rates
  Greater than 10 cubic feet per minute
  Ambient air sampling
       SAMPLE PUMPS
   Medium/High Flow Rates
       1 to 6 liters per minute
       Personal sampling
       Aerosol sampling
       SAMPLE PUMPS
        Low Flow Rates
    • 10 to 750 cubic centimeters
     (milliliters) per minute
    • Personal sampling
    • Gas and vapor sampling
10/93
Air Sample Collection

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     /VOTES
                                       SUMMARY
                              Collect sample for laboratory analysis

                              Determine whether air sampling is
                              appropriate

                              Identify appropriate air sampling
                              method
Air Sample Collection
10/93

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                            AIR SAMPLE COLLECTION


INTRODUCTION

The types of equipment discussed in this section are media (filters and sorbents), containers (gas bags
and canisters) and pumps for collecting air samples.  Unlike direct-reading instruments that give
immediate results, these samples must be analyzed by instruments that are not usually taken onsite.
The analysis may be done in the support area of a site or at a laboratory many miles away.  This
causes a delay in receiving information.   However, there are advantages to their use.

       •     The chemicals in the atmosphere can be concentrated so that the detection limit can
             be lower than for a direct-reading instrument, even when the same type of detector
             is used.

       •     Specialized detectors can be used.  Some detectors (e.g., PID and FID) are used in
             both direct-reading instruments and analytical instruments.  However, some detectors
             are only found in analytical instruments (e.g., electron capture detector). For specific
             analysis of aerosols (e.g., lead), there are no direct-reading instruments. A sample
             must be collected and then analyzed by a nonportable instrument.

       •     The analytical instruments used generally allow identification and quantification of
             the chemicals.  Instead  of a  total  vapor reading, it  may  be possible to get an
             identification and concentration of the components.

       •     The collection devices allow long duration (hours to days) and unattended sampling.


SAMPLE COLLECTION COMPONENTS


General

The basic components of a sample collection system are:

       •     A collection  media for  separating the contaminants  from  the atmosphere  or a
             collection container for holding part of the atmosphere.

       •     A pump to pull air through the media to push the sample into a container.  When a
             pump is used, the method is called "active" sampling.  Some methods do not require
             a pump and are called "passive" samplers.

       •     A method to analyze the  collected sample.  This part will not cover the analysis of
             a sample.  A limited discussion of analyses and detector types is found in Total Vapor
             Survey  Instruments and Introduction to Gas Chromatography.
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Selection of Components

Several factors affect the selection of the components for a sample collection system.  These include
1) the chemical and physical properties of the chemical to be collected, 2) the purpose of the sample,
3) the analytical method used by  the laboratory, 4) the laboratory's  capability to do a specific
procedure and their experience with the method, and 5) equipment characteristics.  The following
elaborate on these factors:

       •      Chemical and physical properties of the chemical—The chemical/physical properties
              of the chemical to be collected affect the type of media used. Volatile chemicals pass
              readily through a filter. Therefore, some kind of sorbent is needed.  In some cases,
              a reaction, like an acid gas with an alkaline solution, may be used instead of sorption.

       •      Purpose of  the sample—Two types of  samples are the  "personal" sample and the
              "area"  sample:

                     Personal sample—A personal sample requires a pump that can be worn by the
                     person being sampled. This means the pump must be compact and battery
                     operated.  A personal sample is used to evaluate the exposure level of the
                     person being  sampled.   The sample results  are  usually compared to an
                     exposure limit (see Exposure Limits and Action Levels'). A personal sample
                     collects  the contaminants  in  the  "breathing  zone,"  a   12-inch-radius
                     hemisphere  in front of the wearer's nose.

                     Area sample—An area sample, to determine chemicals and concentrations in
                     a specific area,  can use the same type of pump.   However, area samples
                     generally are for checking lower concentrations than personal samples. This
                     is because they are  used for identification or evaluation of public exposure.
                     The lower concentrations  require a larger volume of air to concentrate the
                     sample.  This can be done by using a higher flow  rate, by sampling longer,
                     or both. Longer sampling times are used because public exposure can be 24
                     hours each day compared to a site worker's exposure of 8 to 10 hours each
                     day. A long sampling time and a high flow rate require a pump that is AC
                     powered. Battery pumps are only rated for 8 to 10 hours of use.

       •      Analytical  method  used by the  laboratory—The analytical method used by the
              laboratory  also affects  the collection  devices used.   There are  commonly used
              methods developed by the U.S. Environmental Protection Agency  (EPA), National
              Institute of Occupational Safety and Health (NIOSH), and Occupational Safety and
              Health Administration (OSHA) that specify sampling and analysis procedures. These
              methods are found in EPA's Compendium of Methods for the Determination of Toxic
              Organic Compounds in Ambient Air, NIOSH's Manual of Analytical Methods, and
              OSHA's Analytical Methods Manual.
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              Although these methods were developed for similar chemicals, there are differences
              in the procedures. The laboratory being used may also have different requirements.
              The laboratory should be consulted  prior to sampling.

              EPA's Environmental Response Team (EPA-ERT)  has  developed an Air Methods
              Database so that the user can determine what methods are available for sampling a
              chemical.  The database  includes EPA, NIOSH, OSHA, and  American Society for
              Testing and Materials (ASTM) methods.  Further information  is found in a technical
              bulletin (Appendix A).

              Capability of the laboratory—When you choose a laboratory for analysis, make sure
              you consider its  capability to do a specific procedure and its experience with the
              desired method.   For NIOSH and OSHA methods, use an American  Industrial
              Hygiene Association (AIHA) accredited laboratory.

              Equipment characteristics—This is an important consideration. For example,  some
              pumps have  timers that may be useful or even necessary.  Some collection  devices
              are fragile and may not be desirable under  certain operating conditions.
AEROSOL (NONVOLATILE CHEMICALS) SAMPLERS
Media

Airborne aerosols  include both dispersed liquids (mists  and fogs) and  solids (dusts, fumes, and
smoke). The most common method of sampling aerosols, especially the solids or particulates, is to
trap them  on filters using active systems.  Impingers (see Liquid Sorbents in the Gas and Vapor
(Volatiles) Samplers section) have been used, but filters are more convenient.  Two types of filters
are used.

       •      Fiber filters are composed of irregular meshes of fibers forming openings or pores
              of 20 /xm in diameter or less.  As particulate-laden air  is drawn through such filters,
              it is forced to change direction.  Particulates then impinge against the filter fibers and
              are  retained.  A number of fiber filters are available (Table 1).  The two with  the
              greatest application to hazardous materials  operations are cellulose and glass.  Filters
              of these materials typically consist of thick masses of fine  fibers and have low mass-
              to-surface area ratios.  Of the two, cellulose is the least expensive, is relatively low
              in ash, has high tensile strength, and  is available in a variety of sizes. Its greatest
              disadvantage is  its tendency to absorb water,  thus creating problems in weighing.

       •      Membrane filters are microporous plastic films formed  by precipitating a resin. Pore
              sizes of 0.01-10 j*m can be formed during manufacture.  Membrane filters act as a
              sieve with collection of most particulates on the surface.  This can be useful  for
              visual examination of the sample. This group of filters includes such materials as
              cellulose  ester,  polyvinyl chloride, and polytetrafluoroethylene  (Table 1).   These
              filters have an extremely low mass and ash content.  Some are completely soluble in
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              organic solvents.  This allows particulates to be concentrated into a smaller volume
              for analysis.

                   TABLE 1.  FILTER MEDIA FOR AIRBORNE PARTICULATES


                   Filter Medium            Representative Application/Analysis
            Mixed cellulose ester (MCE),   Metals/atomic adsorption; asbestos/phase
            0.8-fjm pore                 contrast microscopy
            Glass fiber                   Pesticides/various
            Polyvinyl chloride (PVC)       Total particulates/gravimetric; hexavalent
                                        chromium/visible spectrophotometry
            Polycarbonate                Fibers
            Polytetrafluoroethylene        Alkaline dusts/acid-base titration

            Source: N1OSH Manual of Analytical Methods, Third Edition, Volume 1,
            February 1984 and supplements.

Piker sizes range from  13 mm in diameter to 40 by 40 inches.  Small sizes (25 mm and  37 mm
diameter) are generally used for personal samples and the larger sizes are normally used for Hi-Vol
sampling.   Selection  of the size and type of filter depends on the user application  and analysis.
Table 1 gives examples of different  filters and their applications.

The common filter  holder used for personal samples is the polystyrene plastic cassette (Figure 1).
It  consists  of two or three stacked  sections, the number depending  on the contaminant and  the
collection method.  The sections of a cassette are molded to fit tightly when stacked  and to tightly
grip the outer edge of the filter.  Each cassette has end plugs to seal the inlet and tubing connector
part once the sample collection is completed.

Other materials than polystyrene can be used.  Metal is used in large samplers with high flow rates.
Carbon-filled polypropylene is used for asbestos sampling because it prevents an accumulation of a
static charge, which would result in  the attraction of the asbestos fibers to the cassette walls.
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                                                      Ring piece
                                                       Filter paper

                                                       Backup pad
                 FIGURE 1.  ASSEMBLY OF A THREE-PIECE FILTER CASSETTE

          Source:  OSHA Technical Manual,  U.S. Department of Labor, OSHA, 1990.
Size Selection

Unlike gases and vapors, not all aerosols reach the deeper portions of the respiratory system. The
nose and bronchioles remove the larger sizes.  Environmental or public health samples are usually
classified as total suspended particulates (TSP) or paniculate matter - 10 fi (PM1Q).  PMi0 samples
collect particulates  that are 10 n and smaller.  This represents the fraction of airborne particles that
would be inhaled.  PMi0 samples are used to assess the inhalation route of exposure.  TSP is used
to assess exposure to contaminants that may be deposited downwind and available through ingestion.

Occupational samples are classified as total or respirable.  Total samples are  equivalent to TSP.
Respirable  samplers are designed  to collect particles that would reach farther into the respiratory
system. Most occupational  exposure limits for particles are based on total samples.  A few, silicon
dust, coal dust, and nuisance dust, are based on respirable samples.

The most common devices used for aerosol size separation are the inertial impactor, the centrifugal
separator, and the cascade impactor.
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             The inertial impactors rely on a sudden change in velocity and direction to separate
             the sizes of particles. Figure 2 illustrates the principle.  The example shows that the
             larger particles (having  more inertia) cannot follow the change in air direction and
             impact in the separator.  The smaller particles can make the turns and are collected
             at the filter.

             The centrifugal separator or cyclone is similar to the inertial  impactors.  Cyclones
             commonly are conical  or cylindrical  in shape,  with  an opening  through  which
             particulate-laden air is drawn along a concentrically curved channel. Larger particles
             impact against the interior walls of the unit due to their inertia and drop into the base
             of the separator.  The lighter particles continue on  through and are drawn up through
             the separator and collected on a filter.  Cyclones can be very  compact and thus are
             often used for personal  sampling.
                                                                Air flow
              Filter
                                        Pump
                    FIGURE 2. ILLUSTRATION OF AN INERTIAL IMPACTOR

              Cascade  impactors  (Figure  3)  are composed  of a number of stacked  perforated
              collection beds or plates, each with openings narrower than the one before it. The
              cascade impactor separates particulates in an airstream  by directing them toward a
              dry or coated flat surface.   As  the particulate-laden air moves through  the plates,
              larger particles  are deposited near the top and smaller near the  bottom.
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              One major difference between the cascade impactor and other separators is that it can
              be used to collect each separate fraction for analysis. The other separators are used
              to separate the "respirable" fraction for analysis from the "total" mass of particulates.

With all preselectors, the separation efficiency is dependent on flow rate control.  A  specific flow
rate is needed for the device to do proper separation.
                            Air flow
            Collector
                                              Plates
                             Pump
                             FIGURE 3.  CASCADE IMPACTOR
GAS AND VAPOR (VOLATILES) SAMPLERS

Gases and vapors have different physical properties than aerosols and thus would pass through
untreated filters without being collected.  For gas and vapor collection, a sorbent is needed to
separate the contaminant from the atmosphere or a container is needed to collect a whole air sample.
The sorbents may be solid or liquid and the containers can be glass, plastic, or metal.
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Solid Sorbents

Solid sorbents are a class of media widely used in hazardous materials sampling operations.  Table 2
gives some examples and their applications.  These materials collect by sorption and are often the
media of  choice  for insoluble or nonreactive  gases or vapors.  Their advantages include high
collection  efficiencies,  indefinite shelf lives  while unopened, ease of use and  specific analytical
procedures.

                       TABLE 2. COMMONLY USED SOLID SORBENTS


                  Solid Sorbent         Representative Gas or Vapor Adsorbed
              Activated charcoal      Nonpolar organics (NIOSH)
              Tenax®                 Volatile, nonpolar organics (EPA)
              Carbon molecular sieve  Highly  volatile, nonpolar organics (EPA)
              Silica gel               Polar organics  (NIOSH)

              Sources:  NIOSH Manual of Analytical Methods,  Third  Edition,
              Volume 1,  February  1984 and Supplements; EPA's Compendium of
              Methods for  the  Determination of Toxic  Organic  Compounds in
              Ambient Air, EPA/600/4-89/017, June 1988.

There are  several considerations when using solid sorbents.  One of the major concerns with the use
of solid sorbents is the potential for "breakthrough."  Breakthrough occurs when the sorptive capacity
of the media is exceeded.  There is  a limit to the amount of chemical that  the sorbent can hold.
Most methods limit the volume of air pulled through the sorbent to prevent this problem; hence, the
use of low flow pumps for sorbent tube sampling.   A way  to check for breakthrough  is to use a
double section tube (Figure 4) and analyze each section separately.  If a excessive amount of the
total sample—one agency uses 25%—is found  in the "back-up" section, then the sample is considered
incomplete.   Breakthrough is affected by humidity, temperature, total amount of chemicals in air,
and the type and amount of sorbent.   The problem of breakthrough can be reduced by reducing the
air sample volume, increasing the amount of  sorbent (e.g., use  a 750 mg tube instead of a 150 mg
tube) or using tubes in  series.  For example,  the NIOSH methods  for vinyl chloride and methylene
chloride use two tubes  in series.

A sorbent may not be able to collect all  of a chemical. The efficiency will vary with sorbent and
chemical.  That is why there is no universal collection media. The sampling method usually selects
the sorbent that will get the highest sorption efficiency (the closer to 100% the better).

Storage and  handling  of  the sorbent samples can also  be a  problem.   They cannot be stored
indefinitely.  Analysis usually must be done within 2 weeks.  Some sorbents require special handling.
The EPA  method that uses Tenax® tubes for sampling requires the operator to wear cotton gloves
so as not to contaminate the media with skin oils.  The method requires storage away from sunlight.
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                                                         B
                                                   t          t
                                                Dividers

                   A = Solid sorbent
                   B = Solid sorbent (backup or different sorbent)
                     FIGURE 4. TYPICAL 150 MG SOLID SORBENT TUBE

When the samples are analyzed, the chemicals must be desorbed from the media. This can be done
with solvents (e.g., carbon disulfide) or with heat (thermal desorption).   Solvent desorption can
involve hazardous liquids and needs a controlled laboratory environment.  Thermal desorption can
be done with automated equipment and does not need hazardous chemicals. However, the elevated
temperatures may cause a change in some unstable chemicals.

Once the sample is desorbed, it can be analyzed by a variety of detectors.
Liquid Sorbents

Liquid sorbents are used to collect soluble or reactive gases and vapors (Table 3).  Only a relatively
few analytical methods use liquid sorbents.  Further, most of the common liquid absorbers tend to
be contaminant-specific and have limited shelf lives.

The liquid sorbents need a sampler to hold the liquid during sampling.  These samplers ensure that
contaminants in the sampled air are completely absorbed by the liquid sampling medium. There are
several varieties of samplers. Differences in design are due to the efficiency needed for absorption.

       •      Impingers, or simple gas washers (Figure 5a), are a basic liquid holding sampler.
              This device consists of an inlet tube connected to a stopper fitted into a graduated vial
              such that the inlet tube rests slightly above the vial bottom.  A measured volume of
              liquid  is placed  into the  vial, the stopper inlet is put in place, and the unit is then
              connected  to  the  pump  by flexible tubing.   When the pump is turned  on, the
              contaminated air is channeled down through the liquid at a right angle to the bottom
              of the  vial. The air stream then impinges against the vial bottom,  mixing the air with
              the liquid and the necessary air-to-liquid contact achieved by agitation.   The
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                    TABLE 3.  COMMONLY USED LIQUID ABSORBERS
                   Absorbing Liquid
     Gas/Vapor Absorbed
             0.1 N NaOH                 Cresol/phenol (EPA); phenol (NIOSH)
             0.1 M HCI                   Hydrazine (NIOSH)
             Aniline                      Phosgene (EPA)
             DNPH reagent and isooctane    Aldehydes/ketones (EPA)

             Sources:   NIOSH Manual of Analytical Methods,  Third Edition,
             Volume 1, February  1984 and supplements;  EPA Compendium of
             Methods for the Determination  of Toxic Organic  Compounds in
             Ambient Air, EPA/600/4-89/017, June 1988.

      popularity of impingers rests on such qualities as simple construction, ease of cleaning, the
      small quantity of liquid used (typically less than 25 to 30 milliliters), and a size suitable for
      use as a personal monitor.
                                                        B
                      FIGURE 5. A - IMPINGER; B • FRITTED BUBBLER

Source:  The Industrial Environment - Its Evaluation and Control, NIOSH, 1973.
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       •      Fritted bubblers (Figure 5b) are generally used when a high degree of air-liquid
              mixing is desired.  They are similar in construction to the impinger, but have a mass
              of porous glass, called frits, at the end of the submerged air tube.  The frits break
              the air stream into numerous small bubbles.  The frits are categorized as fine, coarse,
              or extra coarse, depending  on the number of openings per unit area.  By producing
              smaller sized bubbles, a greater surface area of the air sample is in contact with the
              liquid medium.

One of the major disadvantages with liquid sorbent sampling is that the samplers are generally made
of glass and, thus, are fragile.  Other disadvantages are the need for low, controlled flow rates to
prevent overflow of liquid; spillage of liquid if the sampler is worn as  a personal sampler;  extra
handling and storage of liquids; possible evaporation of liquid sorbent during sampling and thus loss
of sample; and a need for a safety device (extra impinger, for example) between sampler and pump
to prevent liquid contamination of the pump.
Passive Dosimeters

Passive dosimeters now available apply to gas and vapor contaminants only. These devices primarily
function as personal exposure monitors, although they have some usefulness in area monitoring.
Passive dosimeters are commonly divided into two groups, primarily on how they are designed and
operated.

       •      Diffusion  samplers (Figure 6)  function by the passive movement of contaminant
              molecules through a concentration gradient created within a  stagnant layer of air
              between the contaminated atmosphere and the collection material.

       •      Permeation  dosimeters  rely on natural permeation of a contaminant  through  a
              membrane.  The efficiency of these devices depends on finding a membrane that  is
              easily permeated by the contaminant of interest and  not by other contaminants.
              Permeation dosimeters are therefore useful in picking out a single contaminant from
              a mixture  of possibly interfering contaminants.

There are liquid and solid sorbents available for passive dosimeters.  However,  solid sorbents are
the most common.
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                  Contaminant
                                                      Sorbent
                  Chemical permeates membrane and/or diffuses into
                  sampler
                     FIGURE 6.  DIFFUSION TYPE PASSIVE DOSIMETER

Quantitative  passive  dosimeters have become available only  since the early  1970s, though a
semiquantitative passive monitor for carbon monoxide was patented as early as 1927.  The key
advantage of dosimeters  is their simplicity  (Figure 6).   These small, lightweight devices do not
require a mechanical pump to move a contaminant through the collection media.  Thus, calibration
and maintenance of sampling pumps are not needed.  However, the sampling period must still be
accurately measured.  Like active systems, these devices can be affected by temperature and
humidity.  Sources of error unique to passive  dosimeters arise from the need for minimum face
velocities and the determination of contaminant diffusion  or permeation coefficients.
Container Sampling

Because of the problems associated with sorbent sampling (breakthrough, sorbent efficiency, etc.),
methods have been used to collect a whole air sample in a container.  Several types of containers
have been used.

Glass bottles have been used because of the relative inertness of glass.  The procedure can be done
several ways.  The glass container can be evacuated to produce a vacuum and then opened in the
sampling area.  While this technique does not use a sampling pump, some way of evacuating the
container is needed. Another method uses a pump to pull air through the container.  When the air
sample has replaced the air in the container, the container is closed. Another device uses a container
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filled with water.  When the water is drained, the air sample fills the space left by the departing
water. This method is undesirable if water vapor is a problem in the analysis.

The  devices have two problems.  The containers are fragile and only give a sample  at ambient
pressure. To get a sample out, a vacuum needs to be pulled on the container or air added to equalize
pressure as a sample is taken out.  As more and more samples are removed, it becomes harder and
harder to  get the  sample out.  This  also requires a pressure correction when  calculating the
contaminant concentration.  If air is added to equalize pressure, the sample becomes diluted.

Sample collection bags can be constructed of a number of synthetic materials, including polyethylene,
Saran™, Mylar™, Teflon™.   They are square or rectangular with heat-sealed seams,  hose valve
fittings, inlet valves,  and septums for syringe extraction of samples.  They come  in a variety of
volumes. The selection of a bag should be based on a number of characteristics, including resistance
to adsorption and permeation, tensile strength, performance under temperature extremes, construction
features (seams, eyelets, and fittings), and intended service life.

Bag sampling can be done by connecting the bag inlet valve with  flexible tubing to the exhaust outlet
of a  sampling pump.  The bag inlet valve is opened, the pump turned on, and the.sample collected.
Once sampling is completed, the pump is turned off, the bag valve closed and the bag disconnected.
The bag contents may be analyzed by connecting the bag to a direct-reading instrument; or a portion
of the contents can be taken  from the bag by a syringe and injected into a gas chromatograph.

In situations where there is concern about sample contamination  due to passing through a pump, an
alternate sampling apparatus  can be constructed.  This apparatus involves using the pump  to evacuate
a chamber (a desiccator or a scalable box) in which the sample bag is installed (Figure  7).  As the
pump creates a partial vacuum, the sample bag expands and draws the sample in through a sample
tube.

The  major disadvantage of gas sample bags is sample stability.   Chemicals in the sample may sorb
to the bag material or permeate through the bag walls.  This would cause a decrease in sample
concentration.  The sample  can also be affected  by contaminants  outside the bag  by  permeation
through the bag walls. If a  bag is reused, sorbed chemicals may desorb into the new sample and
cause contamination.  Because of these problems, bags are seldom reused, and samples are analyzed
as quickly as possible (usually within 24 hours).

Chemicals in  the bag can degrade with  exposure to sunlight.   The bags  should  be  stored in a
container (e.g., a cooler or garbage bag) to prevent exposure to sunlight.

Recently, metal canisters have gained popularity.  Until  recently, there have been problems with
reactions occurring with the  metal  on the insides of the container.  New  polishing techniques have
greatly reduced the problem.  Metal  canisters  are used  similarly  to glass  containers.   They are
evacuated to produce a vacuum.  Unlike glass containers, metal canisters can be filled several ways.
The valve can be opened to get a  instantaneous, or grab, sample.  The canister can also be connected
to a controlled flow orifice so that the sample fills the canister at a fixed rate.  This gives a long term
sample.

A pump can also be used to pressurize the canister so that a sample volume greater than the canister
size  is obtained. This latter  capability is not available for glass  containers or gas bags.


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                                                         Sample flow
                                                      Air flow
           Source: 'Sampling and Analysis of Emissions from Stationary Sources,* Schuetzle et
           al., Journal of the Air Pollution Control Association, Volume 25, No. 9, Sept. 1975.
                FIGURE 7. NEGATIVE PRESSURE BAG SAMPLING APPARATUS

Metal canisters are more durable than glass containers.  They have better sample stability than gas
bags. There are special cleaning procedures that allow the canister to be reused.

Metal canisters have a problem with recovery of polar compounds (e.g., alcohols).

Syringes can also be used to take a sample. Although 1-liter syringes are available, most are rather
small and there may be a problem with having an adequate amount of sample.

Container sampling allows whole atmosphere  sampling.   This type of sampler eliminates the
problems associated with sorbent media. It also allows the use of more than one analytical method
per sample.  Glass containers are fairly inert but are fragile. They also are limited in size.  Gas bags
are more durable and have a variety of sizes, but have sample stability problems. Metal canisters
are durable, have good sample stability and can  get a larger sample than their actual size (but only
if special equipment is used).  There are systems for taking personal  samples with a gas bag.  Gas
bags and metal canisters can also obtain long term samples with  controlled flow pumps.

SEMIVOLATILE  SAMPLERS

Some chemicals, because of their physical properties, may be present in both solid and vapor form.
There are also chemicals that are not very  volatile, but will vaporize  gradually if air is passed over
them. This could happen is the chemical was captured on a filter. Because of these situations, some
methods use more  than one type of media. Usually a filter (for the  aerosol phase) is followed by
a sorbent (for the vapor phase).  Table 4 gives examples of chemicals that are in this category and
the methods used to collect them.
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Because two separate media are used, both will probably be analyzed by different methods. It will
also take more time and be more expensive for the analysis.

                       TABLE 4.  COMMON MULTIMEDIA SAMPLERS


                         Media Used                  Chemical Being Sampled

            0.8-/t/m MCE filter + 0.1 N KOH           Cyanides (NIOSH)

            13-mm glass fiber filter and Florisil         Polychlorinated biphenyls
                                                   (PCBs) (NIOSH)

            Quartz filter and polyurethane foam (PUF)   PCBs/pesticides (EPA)
                                                   Polycyclic aromatic
                                                   hydrocarbons - PAHs (EPA)

            Quartz filter + XAD-2	PAHs (EPA)	

            Sources:  NIOSH Manual of Analytical Methods, Third Edition, Volume
            1, February 1984 and supplements; EPA Compendium of Methods for the
            Determination of Toxic Organic Compounds in Ambient Air, EPA/600/4-
            89/017, June 1988.
SAMPLING PUMPS


Pump Characteristics

Air sample collection systems, with the exception of evacuated canisters and passive dosimeters, rely
on electrically powered pumps to mechanically induce air movement.  The power source may be
batteries or an AC source.  Battery-powered pumps can operate for 6-10 hours. AC-powered pumps
can operate longer, but are not usable as personal samplers.

Generally, sampling pumps incorporate several of the following features:

       •     A diaphragm or a piston-type pumping mechanism

       •     A flow regulator to control the sampling flow rate

       •     A rotameter or stroke counter to indicate flow rate or sample volume

       •     A pulsation dampener to maintain a set flow rate

       •     A programmable timer to start the pump at a set time and/or to stop the pump after
             a set sampling period

       •     An inherent safety  approval for gas/vapor and dust atmospheres
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       Other than differences in features mentioned above, the main difference in pumps is their
       flow rate.  Low flow pumps have a flow rate range from 10 cubic centimeters per minute
       (cc/min) to about 750 cc/min.  Medium flow pumps have a flow rate of about 1-6 liters per
       minute (1pm). High volume (Hi-Vol) pumps are AC powered and can achieve up to 40 cubic
       feet per  minute (cfm). That is equivalent to 1130 1pm.

       The choice of flow rate depends on the type of sampling done.  Sorbent media, like carbon
       tubes, cannot be used with a high flow rate. The capacity of the sorbent would be exceeded
       and there would be a loss of sample (breakthrough).  Also, the Hi-Vol pumps are not used
       as  personal  samplers.  Some pumps  have the  ability  to do both  low and medium flow
       sampling, but not Hi-Vol.

Calibration

All pumps must be calibrated.  The flow rate must be known so that a sample concentration can be
calculated.  Calibration is also necessary to ensure the constant flow rate needed for some methods.
The flow rate stability of a pump should be accurate to within +5% of its set flow rate.

An active  sampling  system must be calibrated  prior to and after sampling. The overall frequency
of calibration depends upon the general handling and  use a system received and the  quality control
considerations of the user.  Pump  mechanisms must be recalibrated after they have  been repaired,
when newly purchased, and following any suspected abuse. The sampling system as a whole must
be calibrated to the  desired  flow rate rather than the pump alone.  The sampling system should be
calibrated  prior to  and after each  use.  The system  can be adequately examined under field-like
conditions only  with all components connected.

There are  several devices for calibrating sampling pumps:

       •      The  soap bubble meter represents a basic method of calibration and  is a primary
              standard.  This device typically consists of an inverted  graduated burette connected
              by flexible tubing to the sampling train.  Figure 8 shows one  example.

              Do the calibration as follows:

                     Start the system's pump to create airflow into the burette

                     Dip the open end of the burette  into a  soap solution  to create a soap  film
                     bubble across the opening

                     Remeve the solution and allow the bubble to rise up through the burette

                     Measure the travel time of the bubble between  two graduated points on the
                     burette;  vary the flow rate by  adjusting the pump flow regulator.

The  general formula used for the calculation of the flow rate is:

                   PI         _  volumetric distance traveled by bubble (ml)
                                       travel time of bubble (sec)
Air Sample Collection                      16                                       10/93

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   Inverted
    buret
                    250
                                                         Filter
                                                        cassette
                              Soap bubble trap
                                                                      Pump
     Beaker
                              Soap solution
                  FIGURE 8. CALIBRATION SETUP FOR FILTER SAMPLER
                             USING A SOAP BUBBLE METER

Source:  OSHA Technical Manual, U.S. Department of Labor, OSHA, 1990.

If the desired flow rate is 1pm, then the units need to be converted by multiplying the previous
equation by the following:

                                  60 seconds/minute
                                      1000 mill

      •      There are electronic bubble meters that use sensors to detect the soap bubble and start
             and stop an electronic timer.   The calibrator then  automatically calculates and
             displays the pump flow rate.
10/93
17
Air Sample Collection

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             The precision rotameter consists of a vertically mounted tapered tube with a float
             inside the tube. When attached to an operating pump, the float rises until the rate of
             flow is sufficient to hold the float stationary.  The flow rate is read from markings
             on the tube at the point the float is  stationary.  Figure 9 illustrates  a precision
             rotameter.




















•



1

	 3500
=_ 3000
~ 2500
I— 2000
Z_ 1500
£_ 1000
5_ 500
cc/min
	 | ' p rump






I 4 - Air Flow

                     FIGURE 9.  EXAMPLE OF A PRECISION ROTAMETER
Whereas the precision rotameter usually is more compact and portable than the soap bubbler meter,
it is considered a secondary standard. This means that the rotameter must be checked occasionally
with a primary standard such as a bubble meter.

       •      A manometer is sometimes used to calibrate Hi-Vol samplers because of the high
              flow rates.  A  manometer is a tube filled with a liquid.  The level of the liquid
              changes due  to pressure changes at the end attached to the sampling pump.   A
              calibration chart is used to convert the change in liquid level to flow rate.
CONCLUSION

When taking air samples for laboratory analysis, several factors need to be considered.  Sampling
and analytical methods have been developed for many chemicals by several agencies that have looked
at these considerations.  The References section provides a list of references on air monitoring and
sampling.
Air Sample Collection
18
10/93

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                                United States
                                Environmental Protection
                                Agency
Office of
Solid Vteste and
Emergency Response
January 1993
                                Air Sampling Methods
                                Database
      Office of Emergency and Remedial Response
      Emergency Response Division
                       Technical Bulletin
                       Volume 1, Number 1
What is the Air Sampling Methods

Database?
The Air Sampling  Methods Database is a PC-based
software package which allows its users to access sum-
marized standard methods for chemical analysis. The
program, which was designed to be used in conjunction
with the Representative Air Sampling Guidance for the
Removal Program document, formulate sampling plans
to give the best possible site characterization. This al-
lows users to make quick determinations about which
methods are most appropriate to use and which best
suit their  informational needs in order to plan a sam-
pling event that most aptly depicts the objectives of a
particular site investigation.

The user can search the software by method name and
number, chemical name, or Chemical Abstracts Num-
ber (CAS #). The method summary can be viewed and
the method marked for printing. Furthermore, the soft-
ware can be tailored to its users since they have the ca-
pacity to input their own user-developed methods into
the database without affecting the  established  stand-
ardized methods. Users can submit supporting docu-
mentation for  their  methods  to  the United  States
Environmental Protection Agency's Environmental Re-
sponse Team (U.S. EPA/ERT) for possible permanent
inclusion to the database.

Who Are the Anticipated Users?
On-Scene Coordinators  (OSC), Technical  Assistance
Team  (TAT) members, Emergency Response Contrac-
tors (ERCs), site Health and Safety air personnel, and
U.S. EPA air plan  reviewers are the primary users of
the Air Sampling Methods Database. By using the pro-
gram,  these individuals gain access to the sampling ob-
jectives which best characterize a site. Then, users can
assimilate this information  into an acceptable  repre-
sentative sampling program. The Air Sampling Methods
Database also can aid any  U.S.  EPA personnel  or
agency that performs air monitoring at hazardous waste
sites.

Why Was the Air Sampling

Methods Database Designed?
The Air Sampling Methods Database was created to ex-
pand the knowledge base during remedial emergency
response actions. It gives insight to two major criteria
for preparation of a representative air sampling plan:
selecting the appropriate air sampling approach and
choosing the proper equipment to collect and analyze a
sample. Timely decisions regarding health and  safety
and acute health risks can be made by utilizing these
summarized methodologies:
•   National Institute  of Occupational  Safety and
    Health (NIOSH) 2nd and 3rd Edition Methods.
•   Occupational Safety and Health  Administration
    (OSHA) Methods.
•   Selected American Society of Testing  and Materi-
    als (ASTM)  Methods. Volume 11.03 Atmospheric
    Analysis;  Occupational  Health and Safety.
•   EPA Toxic Organic Compounds Methods.
•   Contract Laboratory Program - Statement of Work
    Methods.
•   Indoor Air Compendium Methods.
•   Code of Federal Regulations (CFR) Methods.
This facilitates a greater variety of options for the users,
who then can select the appropriate air sampling objec-
tives and plans that best suit the needs of a  particular
assignment.

-------
Features of the Air Sampling
Methods Database
•   Is user friendly.
•   Requires no other software for support (self-con-
    tained).
•   Adds, deletes, and edits methods added by a user.
•   Traces information by on-line references.
•   Provides single point of update.
•   Givessemi-annualJy updates.
•   AlJows access to update information available via
    Environmental Response Center (ERC), Office of
    Solid Waste and Emergency Response (OSWER),
    U.S. EPA/ERT, and Dataport  bulletin boards by
    modem.
•   Generates hard copy.
Future Features:
•   Hot-Key on-line help.
•   Hot-Key on-line glossary of terms.
    50-100 word text summaries discussing sampling
    trains, flow rates, interferences, detection limits,
    analysis information, etc.
    Synonym searching of chemical names.
Requirements
To run the Air Sampling Database, you must have the
following:
•   An IBM PC or IBM-compatible computer
•   A hard drive
•   640KRAM
•   A printer (for hard copy output)


 For more information about the Air Sampling Database,
                    contact:
     Mr. Thomas Pritchett. Phone: (908) 321-6738
         U.S. Environmental Response Team
               2890WoodbridgeAve
               Building 18, MS-101
           Edison, N'ew Jersey 08837-3679

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       APPENDIX A
Air Sampling Methods Database

-------
   INTRODUCTION  TO GAS
     CHROMATOGRAPHY
PERFORMANCE OBJECTIVES


At the end of this lesson, participants will be able to:

•   List the components of a gas chromatograph

•   Define retention time

•   List the factors that affect retention time

•   Name the two types of columns and describe their
    differences.

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                                         NOTES
  INTRODUCTION TO GAS
    CHROMATOGRAPHY
   GAS CHROMATOGRAPHY
 	Definition	


    A technique for separating
    volatile substances in a mixture
    by percolating a gas stream
    over a stationary phase


  Source: Basic Gas Chromatography
   SEPARATION OF A MIXTURE
   BY GAS CHROMATOGRAPHY
                B
                     ConpmnlA
                      mi
      IZ2
ConpmntA
          Conpannt 6
4/94
                       Introduction to Gas Chromatography

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      NOTES
                                    RETENTION TIME
                                         Definition
                                   Retention time is the time
                                   from sample injection to peak
                                   maxima (signal maxima)
                                   InjMtlon
                                                      Tim*
                                    RETENTION TIME
                                        Application
                              Used for qualitative identification of
                              chemicals by comparing the retention
                              time of an unknown chemical with
                              retention times of known (standard)
                              chemicals
                                    RETENTION TIME
                                    Peak Comparisons
                               Injection
                                                        Standard
                                                        Unknown
                                      1   2    3
                                             Tim*
Introduction to Gas Chromatography
4/94

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     FACTORS AFFECTING
        RETENTION TIME

        • Column
          - Type
          - Temperature
          - Length

        • Carrier gas flow rate
   EFFECT OF COLUMN TYPE
      AND TEMPERATURE
  Chemical
 Benzene
Temperature
  CO)
  0

  40
 Retention Time
   (min.)
                    G-8 Column  T-6 Column
1:16

0:25
 Carbon tetrachloride
1:43

0:32


0:37
              40
          0:25
       0:17
  Source Th* Foxboro Company Chromatographic Column Guide lor the
  Century OVA, 1986
       PEAK RESOLUTION
            Problems
              Overlapping peaks
                                                NOTES
4/94
                           Introduction to Gas Chromatography

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      NOTES
                                         PEAK AREA
                                         Application
                                   Peak area is used to quantify chemical
                                   /S*mpl«v

                                  Concentration Sample

                                  Concentration Standard     Area Standard
                                   GAS CHROMATOGRAPH
                                         Components
Flow
control
    Infection port
  V     I    Column
                                                           Output
                                     Carrier go
                                        CARRIER GAS
                                        Characteristics
                                  • Suitable for detector

                                  • High purity

                                  • Does not interfere with sample
Introduction to Gas Chromatography
                           4194

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                                                  NOTES
    GAS CHROMATOGRAPH
             Columns
Packed
           Liquid ttalionary phate
           coated on solid stationary
           support
                        Capillary
            Liquid stationary phase
            coated on wall
    COLUMN TEMPERATURE


  • Ambient
    - Variable

  • Isothermal
    - Constant temperature

  • Temperature programming
    - Temperature increases over time
       DETECTORS USED IN
          PORTABLE GCs
    Common detectors
    - Flame ionization detector (FID)
    - Photoionization detector (PID)

    Specialized detectors
    - Thermal conductivity detector (TCD)
    - Argon ionization detector (AID)
    - Electron capture detector (BCD)
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                                   Introduction to Gas Chromatography

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      NOTES
                                SPECIALIZED DETECTORS
                                    Why Are They Used?
                                One detector may be more sensitive
                                than another for certain compounds.

                                e.g. The BCD is best detector for
                                halogenated compounds.
                                  MASS SPECTROMETER

                               Chemical exposed to electrons
                               Molecule or fragments are ionized
                               Ions separated by magnetic field
                               Separation based on speed and
                               mass-to-charge ratio
                               Only detector capable of providing
                               additional compound identification beyond
                               retention time
                                     MASS SPECTRUM
                                          Benzene
                                   1001
                                    50-
                               Relative
                              abundance
«*  74
                                        40  SO 10  70 60  90  100 110  120

                                            Mass-to-charge ratio
Introduction to Gas Chromatography
                4/94

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                                                NOTES
        MASS SPECTRUM
             Toluene
      1001
       50-
  Relative
 abundance
IB  51
 45 .   .1
  I I,   I 70 n Ml
 L..||| ll   UI 11.1 ..l
           40  80  «0 70 80  »0 100 110  120
              Mass-to-charge ratio
    GAS CHROMATOGRAPHY
        Field Applications

          • Air analysis
          • Field screening
          • Soil gas
           SUMMARY
     Gas chromatography is used to
     identify and quantify chemicals
     Qualified operators are needed
     Right tool for the job?
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                            Introduction to Gas Chromatography

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              INTRODUCTION  TO GAS CHROMATOGRAPHY
INTRODUCTION

Gas chromatography is a separation technique wherein components of a sample are separated by
differential distribution  between a gaseous  mobile phase (carrier  gas) and a solid  (gas solid
chromatography) or liquid (gas liquid chromatography) stationary phase held in a column.  The
sample is injected into the carrier gas as a sharp plug and individual components are detected as they
come  out ("elute") of the column at  characteristic  "retention  times" after  injection.   Figure 1
illustrates this concept with a two component mixture.
                    A + B
           Gas
           Flow
Column
                                                             Component A
                                                               in Detector
                            Component A
         Component B
                FIGURE 1.  SEPARATION OF A TWO COMPONENT MIXTURE
                             BY GAS CHROMATOGRAPHY

As different components elute from the column, they pass through a detector which generates a
response (or "peak") based upon the amount of each compound present and upon the sensitivity of
the detector.  The signal vs. time plot is called the  "chromatogram."
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     Introduction to Go? Chromatography

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QUALITATIVE ANALYSIS

If the temperature of the column and the flow rate of the carrier gas are constant, compounds will
elute from the column at a characteristic time (retention time). The retention is characteristic of the
compound and the type of column used. Retention time is the time from injection of the sample to
peak response of the detector to the eluted compound (Figure 2).
                            Retention time
            Injection
                                                          8    9
                                                                   Time
               FIGURE 2. CHROMATOGRAM ILLUSTRATING RETENTION TIME

Qualitative analysis can be done by comparing the retention times of the compounds in an unknown
sample with the retention  times  of known compounds in a standard  analyzed under identical
conditions.  Figure 3 shows a comparison of a sample with a standard.
Retention Time

Retention times are governed by several factors:

       1.      The type of column used.  Different packings and liquid coatings change retention
              time.

       2.      The column temperature.  As the column temperature increases, the retention time
              decreases.  This is why temperature controls are used to keep the column temperature
              constant.
Introduction to Gas Chromatography
10/93

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      3.     The column length. Double the column length and double the retention time.

      4.     The carrier gas flowrate. Double the flowrate and halve the retention time.
 Injection
              Standard
                                                              Unknown
                                  Time
            FIGURE 3.  EXAMPLE OF A GC CHROMATOGRAM AND THE USE OF
                    RETENTION TIMES TO IDENTIFY COMPOUNDS
Resolution

Resolution, or relative peak width, governs the number of discrete, detectable components of a
sample that can be identified and quantified during the GC run.  Resolution is governed by:
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Introduction to Gas Chromatography

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      3.
The type of column. Capillary columns have much greater resolution (narrower peak
widths) than a packed column.

Column length. The longer the column, the narrower the peak weak width at a given
retention time.  However, with  ambient temperature GCs,  increasing the column
length will increase the retention times.

The carrier gas flowrate.  There exists  an  optimum value for peak resolution.
Increasing  or decreasing the flowrate from this optimum will widen the peaks.
A problem with poor resolution is co-eluting and overlapping. If two chemicals elute at the same
time—co-elute—identification is  hindered.   If peaks overlap, quantitation of the compounds  is
difficult.  Figure 4 illustrates overlapping peaks.
                                    Overlapping  peaks
                     FIGURE 4. EXAMPLES OF OVERLAPPING PEAKS
QUANTITATIVE ANALYSIS
Signal Output

The  size of the chromatogram peak for a specific compound is proportional to the amount of
chemical in the detector.  Quantitative analysis is done by comparing the peak size of the sample
compound with the peak size of a known amount of the compound (the standard). The peak size can
be quantified in several ways.
Introduction to Gas Chromatography
                                                                   10/93

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Planimetering

Planimetering uses a planimeter  to trace the peak.   A planimeter  is a mechanical  device that
measures area by tracing the perimeter of the peak. The area is presented digitally on a dial.  This
method is considered tedious, time-consuming, and less precise than other methods.
Peak Height

Peak height compares the height of the sample compound with the height of the standard.  This is
a quick and simple method for quantitation.  However, peak heights and widths are dependent on
sample size and sample feed rate.
Height x Width at Half-Height

The height x width at half-height uses the height of the peak times the width of the peak at the half-
height of the peak.  The normal peak base is not used because large deviations may be caused by
peak tailing.
Triangulation

Triangulation (Figure 5) transforms the peak into a triangle using the sides of the peak to form the
triangle and the baseline to form the base of the triangle.  The area of the peak is calculated using
Area = 1/2 Base X Height.
Integrators

Peak height,  height  x  width at half-height,  and  triangulation are  done manually  using the
chromatogram and a pencil and straight edge.  Integrators calculate the peak size electronically and
record the output.  Because of ease of operation, integrators are most frequently used in portable
GCs.

When a microprocessor is used, the retention times of the compounds in the sample are compared
to the compounds  in the standard  and the readout  identifies the compounds  in  the sample.
Quantitative analysis is done by an integrator.  If a compound has been identified, the peak size in
the sample is compared to the peak size of the compound in the standard and a sample concentration
is given.  Thus, the sample is evaluated both qualitatively and quantitatively.
 10/93                                       5           Introduction to Gas Chromatography

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                             Area = 1/2 x base x height
                             Area = 1/2 b h
                 FIGURE 5. MEASUREMENT OF AREA BY TRIANGULATION

Source:   An Introduction to Gas Chromatography,  National Training Center, Water Program
Operations, U.S. Environmental Protection Agency, Cincinnati, OH.
COMPONENTS OF A GAS CHROMATOGRAPH

A gas chromatograph (GC) consists of (Figure 6):

             A carrier gas
             A flow control for the carrier gas
             A sample inlet or injector
             A column
             A temperature control for the column
             A detector
             A recorder.


Carrier Gas

A high pressure gas cylinder serves as the source of the carrier gas.  The carrier gas should be:

       1.     Inert to avoid interaction with the sample or solvent
       2.     Able to provide a minimum of gaseous diffusion
       3.     Readily available and of high purity
       4.     Inexpensive
       5.     Suitable for the detector used.

Commonly used gases are helium, nitrogen, and hydrogen.



Introduction to Gas Chromatography         5                                      10/93

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               Flow
             control
                   \
Injection port
      I
                                               Output
                                                  Detector
               Carrier gas
                  FIGURE 6. COMPONENTS OF A GAS CHROMATOGRAPH

Source:  The Industrial Environment - Its Evaluation &  Control, 1973, National Institute for
Occupational Safety and Health.

Portable gas chromatographs (GCs) have internal cylinders  that usually have an 8- to 10-hour gas
supply. Many of these  also have connections for external cylinders  to provide longer duration
analysis.
Flow Control

Because compounds elute at a characteristic time (retention time) based on a given temperature and
a constant flow rate, carrier gas flow control and column temperature  are important.  A flow
controller is necessary to maintain a constant flow rate.
Sample Injection System

Samples are introduced into the column as a single sharp plug.  The sample injection system allows
introduction of the sample rapidly and in a reproducible manner. Samples can be manually injected
by a syringe.  Syringe injection allows the operator to control the sample volume.  Some GCs have
a built-in sample loop that injects a known and consistent volume by manual operation or automatic
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                              Introduction to Gas Chromatography

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programming.  Sample volume is important in that the quantitative evaluation of a chromatogram is
affected by the sample volume.  Also, some columns are limited by the size of sample that can be
injected onto them.
Column

The column is a tube made of stainless steel, glass, aluminum, or Teflon®.  Packed columns contain
a solid adsorbent (gas-solid chromatography) or an inert solid support coated with liquid stationary
phase (gas-liquid chromatography).  Capillary columns consist of a liquid stationary phase coated to
the inside wall of a thin tube.  Gas-liquid chromatography columns and capillary columns are the
more common types for the portable GCs.

Tube sizes range from 0.5- to 6-mm outside diameter and from 20 cm to 50 m in length. Capillary
columns are usually longer than packed columns. Portable GC columns are typically 4 m in length.
Columns can  be coiled to fit inside  portable units.

Capillary columns give  better  resolution  than packed columns.   However, they require smaller
injection volumes than packed columns and thus need sample inlets and detectors that  can handle
small volumes.
Temperature Control

Column temperature affects the retention time of a chemical.  A constant temperature is desired to
ensure comparison of sample and standards. Temperature control can be:

       •      Ambient temperature control—The column temperature  is the same as ambient air.
              As ambient temperature changes, the retention times change.  Consequently, frequent
              calibration  checks are  needed.    Ambient  temperature limits  use   to  volatile
              compounds.   The time to run  a sample is  longer and thus limits the  number  of
              samples that can be run per day.

       •      Isothermal temperature control—The column temperature is maintained  at constant
              temperature by an oven. Retention times are much more stable.  Temperatures can
              be adjusted to reduce analysis time or expand  the range of compounds  that can  be
              analyzed.   Retention times are halved  for  every 30'C  increase in temperature.
              Isothermal temperature  control consumes more electricity  than ambient.

       •      Temperature programming—Column temperature is  slowly  increased  under very
              controlled conditions.  This allows simultaneous analysis of compounds with a wide
              range of boiling points.  A lower  temperature  is used for the volatile components.
              The temperature is raised to elute the less volatile compounds.  More electrical power
              is needed for this operation.

Temperature control can also be used on the injector and the  detector. Heating the injector prevents
condensation of the sample (if a vapor) or can ensure vaporization of a liquid sample. The detector
may need to be heated to prevent chemical condensation.


Introduction to Gas Chromatography           g              .                         10/93

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Detector

There are a  variety of  detectors available  for GCs.   Flame  ionization detectors  (FID) and
photoionization detectors  (PJD) are frequently used.  Characteristics of these two detectors are
discussed in the Total Vapor Survey Instruments section.   Other detectors include:

       •       Thermal conductivity detector (TCD)—This detector is based on the principle that a
              hot  object will lose heat  at a rate that  is  dependent on the composition of the
               surrounding gas.  When a compound enters the detector, there is a change in the
              thermal conductivity of the carrier gas.  Its advantage is that it is a universal detector
               for noninert gases and all organics.  Its drawback is limited sensitivity—ppm levels.
               Preconcentration of samples has been used to offset this limitation.

       •      Electron capture detector (ECD)-A radioactive  source is used to  ionize the carrier
               gas.  Secondary electrons are produced and an electrical current flows between the
               electrodes  in the detector.  When a separated  compound which has an affinity for the
               slow electrons enters the detector,  electrons are captured with a resultant decrease in
              electrical current in the detector.   This  decrease  of current is a function of the
               concentration of the electron capturing compound.

               The detector is especially  selective  for polyhalogenated (e.g., pesticides) and nitro
               compounds.   It has a high sensitivity—mid ppb to  high ppt.   Sensitivity is a direct
               function of halogen atoms  per molecule.

               Its main limitation is that a radioactive source (tritium or nickel-63) is needed, which
               requires a  Nuclear Regulatory Commission (NRC)  license.

       •       Argon  ionization detector (AID)-Argon ionization  detector depends upon two
               reactions:  the excitation of argon to its metastable state by electron bombardment and
               the  ionization of vapor  molecules by the transfer of energy from the metastable
               atoms.  When an ionization chamber contains argon and a source of free electrons,
               the addition of vapor causes an increase in current flow.   The current flow change
               is detected and used as the signal  for the presence of the compound in the  sample.

               Ionization  is caused by a radioactive source.  As with the  ECD, an NRC license is
               required for use of the radioactive source.

               The reaction of the metastable argon atoms with the vapor molecules applies to all
               molecules  with an ionization potential equal to, or less than, the stored energy of the
               metastable atoms, which is 11.7 eV.

       •       Mass Spectrometer (MS)—]n an MS, the chemical is first exposed to a source of
               electrons.  The molecules  or fragments are ionized.  The ions are passed through a
               magnetic field. The magnetic field separates  the ions based on their speed and mass-
               to-charge ratio. The ions are collected and a  mass spectrum is produced showing the
               relative  abundance of each  type  of ion.   Each chemical  has a  distinctive mass
               spectrum.  Thus, this detector is the only  one listed here that  is capable of providing
               additional  compound identification beyond retention time.


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Recording Devices

A device is needed to record when a signal is produced in the detector and to record the strength of
that signal.  A plot  of signal vs. time is called a chromatogram.  The chromatogram is used for
qualitative and quantitative analysis of the sample.  Integrators and microprocessors can be used to
electronically evaluate the chromatogram.
Power Supply

A power supply is needed to operate the detector, recorder, oven, and additional electronics of the
gas chromatograph.  To make them portable, field portable GCs usually have a built-in rechargeable
battery supply.  If only using the battery, time of operation is limited to 8-10 hours.  These units
are also designed  to operate off AC power sources.  A few field GCs only operate on AC power.
APPLICATIONS

Portable gas chromatographs allow analysis in the field.  Although the results may not be as accurate
and precise as a laboratory GC analysis, they can be used for screening purposes.  This can reduce
the number of samples  that need to be handled  by a more sophisticated (and more expensive)
analysis.

Ambient Air Analysis

Portable GCs can analyze ambient air samples through several methods.  Some units can be taken
to the area where the sampling is required and an analysis can be performed on the spot.  Some units
can be programmed to do periodic sampling and store the chromatograms for later retrieval. Newer
units can do continual total vapor monitoring and run a sample if the total vapor reading exceeds a
designated level.  The GC can also be set up in a more stable environment, and grab samples (e.g.,
a Tedlar bag of ambient air) can be brought to the GC for analysis.
Sample Screening

Soil and  water  samples can  be screened  for  further analysis  by doing headspace  sampling.
Headspace sampling involves drawing a sample from above the  surface of a liquid or soil in  a
container.  The sample is usually drawn with a small syringe which is also used to inject the sample
into the GC.
Soil Gas

Gas chromatography can be used to screen soil gas samples. Dissolved volatile organic compounds
have  a  tendency to partition into the atmosphere between the soil particles.   By sampling this
atmosphere, underground contamination can be tracked.
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EXAMPLES OF PORTABLE GAS CHROMATOGRAPHS
The Foxboro Company

The Foxboro Century organic vapor analyzer (OVA) is the instrument described in the Total Vapor
Survey Instruments section. The OVA-128GC is equipped with a column.  The detector used is an
FID.  The column is at ambient temperature unless an optional temperature  pack is used.  The
portable isothermal pack allows column temperatures of O'C, 40'C and 100'C.  The unit can be
purchased with an external recorder/plotter. The company does not supply an integrator, but there
are models from other suppliers that can be used.
Photovac International, Inc.

The Photovac  series of GCs use photoionization  detection.  The  temperature of the column is
controlled by an oven.  The currently available models (10S50, 10S70, 10S Plus, Snapshot) have a
built-in microprocessor that aids in calibration and handles compound identification and quantitation.
These units can be programmed for automatic sampling.  The 10S Plus can be programmed to do
total vapor monitoring and to  do  an  analysis if an action level is reached.   Options include  a
telephone connection for transferring data from the instrument to a computer and for notifying the
user of unusual results during remote monitoring.
Sentex Sensing Technology, Inc.

The Sentex Scentograph is capable of using an AID or an ECD.  One of the most notable features
of the Scentograph is that a lap-top computer is used for handling the data.  This gives a more
graphic visual display of the chromatogram and makes operator use easier because of the normal size
keyboard.  The GC can do automatic functions.  It has a temperature controlled column. There is
the capability of concentrating the sample before injection.  The air sample is pulled through and
collected on a sorbent. The sample is then desorbed and injected using a smaller volume than was
pulled through the sorbent. A primary consideration with the Scentograph is that, if an AID or an
ECD is used, a radioactive source is needed and thus an NRC license is required.  A PID and TCD
are also available.

The Sentex Scentoscreen is similar to the Scentograph except it uses a PID and can also do total
hydrocarbon analysis.  It can be switched to an AID/BCD, but can not do total hydrocarbon readout
with those detectors.
HNU Systems, Inc.

The HNU Systems' Model 311  is available with a PID or an ECD for its dete.ctor.  The unit has a
microprocessor for data handling.  The instrument does not have a battery supply and thus, needs
a line power or a portable generator.
10/93                                      11          Introduction to Gas Chromatography

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Microsensor Technology, Inc.

Microsensor Technology's M200 Microsensor Gas Analyzer uses a TCD. Although this is a more
universal detector, it suffers from poor sensitivity. A preconcentrator has been developed and used
to reduce this  limitation.  The  more notable characteristic of the M200 is  that it sends  a sample
through two columns at the same  time.  This gives a better chance of correctly  identifying the
compounds present.
Thermo Environmental Instruments

Thermo Environmental Instruments manufactures the Model 511 Portable Gas Chromatograph. The
main features of this GC is the variety of available detectors (FID, PID, ECD, TCD) and their easy
changeability.   The  unit does not  have  a built-in  data handler,  so an  external integrator  or
microprocessor is needed.
SUMMARY

Gas chromatography is a separation technique that can be used for identification of the components
of a mixture. Portable GCs can be used in the field for a variety of applications.  This process of
identification can be affected by many factors that must be considered to ensure quality of data.
Because the  equipment  is more complicated to operate  than  most direct-reading  instruments,
operators require more training and experience.
Introduction to Gas Chromatography           \2                                       10/93

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DISPERSION MODELING
      DURING
EMERGENCY RESPONSE

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        Dispersion Modeling During Emergency Response
     Objectives:   •  \_\s\ fjve major atmospheric dispersion considerations
                   •  Describe the concept of stability as it applies to air
                     modeling
                     Given a set of environmental conditions, choose the
                     relevant stability class
        Dispersion  Modeling During Emergency Response
     Objectives:  •  Describe the concept of Gaussian plume distribution

                   •  Define near-field meandering and its effects to onsite
                     receptors

                   •  Given an air dispersion model, list the data inputs needed
                     to run the model for an emergency response

                   •  Given an emergency response scenario, list the elements
                     of the modeling plan
Notes:
                                                                        AMFHM
                                                                         10/93
                                                                         P«g« 2

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Collect site data
i
r
Collect source data


Collect contamination data


Collect meteorological data
i
r
Choose appropriate accidental release model
^
r
Input collected data to model and run model
T
r
Compare output to air action limits
'
//\ Do the
<^ require «
^^ proce
^
r


dures ^^
Yes
r
Evacuate affected onsite/offsite populations as necessary
Figure 1.  Dispersion modeling during emergency removal.
                                                                         AMFHM
                                                                          10/93
                                                                          page 3

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Dispersion Model Classes
Physical Models
Small-scale, laboratory
representations of the overall
process (e.g., wind tunnel, water
tank)

Mathematical Models
A set of analytical or mathematical
algorithms that describe the
physical and chemical aspects of
the problem (e.g., ALOHA, ISC,
and PAL)
Dispersion Model Classes
Mathematical models are primarily used because physical models (especially in an emergency response)
are much less  practical for most Superfund applications.

Mathematical models can be:

•      Deterministic models, based on fundamental mathematical descriptions of atmosphere processes,
       in which effects (i.e., air pollution) are generated by causes (i.e., emissions).

•      Statistical models, based on semi-empirical statistical relationships among available data and
       measurements.
                                                                                           AMFHM
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                                                                                            P«0« 4

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Notes:
                                                                             AMFHM
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                                                                              page 5

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                         Diffusion  Model  Footprint
              750
              250

               750
                 500           0          500        1000
                                        Yards
    Reproduced with permission from The National Safety Council
1500
Diffusion Model
An example of a deterministic model is a diffusion model from which the output (the concentration field
or footprint) is  computed from mathematical manipulations of specified inputs (emission rates and
atmospheric parameters).

A statistical model is given by the forecast, in a certain region, of the concentration levels in the next
few hours as a statistical function of:

1.     The current available measurements
2.     The past  correlation between these measurements and the concentration trends.
                                                                                     AMFHM
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                       Source-Receptor  Relationship
                               Wind Direction
 Receptor Location
Transport Medium
     (Air)
                                                                            Release
                                                                            Mechanism
                                                                            (Volatilization)
                                                                             Waste Pile
                                                                             (Source)
Source-Receptor Relationship
The source-receptor relationship is the goal of studies aimed either at improving ambient air quality
(usually the Superfund site goal) or preserving the existing concentration levels from future urban and
industrial development. Only a deterministic model can provide an unambiguous assessment of the
fraction of the responsibility of each pollutant source to each receptor area. This information then allows
the definition and implementation of appropriate emission control strategies.
                                                                                     AMFHM
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                                                                                     page 8

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Notes:
                                                                             AMFHM
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                                                                              page 9

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                     Dispersion  Modeling  Applications
           The two major dispersion modeling applications for Superfund are:



           •  To design an air monitoring program


           •  To estimate concentrations at receptors of interest
Dispersion Modeling Applications
Dispersion models can be used when designing an air monitoring program to see how offsite areas of
high concentration relate to actual receptor locations. Places where high concentration areas correspond
to actual receptors are priority locations for air monitoring stations.

Dispersion models can also be used to provide  seasonal dispersion concentration patterns based on
available representative historical meteorological data (either onsite or offsite). These dispersion patterns
can be used to evaluate the representativeness  of any  air monitoring data collection period.  Data
representativeness is determined by  comparing  the dispersion concentration patterns for  the  air
monitoring period with historical  seasonal dispersion concentration patterns.

It is often  not practical to place air monitoring stations at actual offsite receptor locations of interest.
It will be necessary, however, to characterize concentrations at these locations to conduct a health and
environmental assessment.  In these cases, dispersion patterns based on modeling results can be used to
extrapolate concentrations monitored at the site to offsite receptor locations.
                                                                                        AMFHM
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Notes:
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                  Atmospheric Dispersion  Considerations
                                 Stability
                                 Inversions
                                 Wind speed and direction
                                 Air temperature
                                 Terrain effects
Atmospheric Dispersion Considerations
There are many different types of dispersion models, ranging from simple models that only require a
few basic calculations to three-dimensional models that require massive amounts of input data and
intense computational platforms to handle the complexity. Choosing the model to use depends on the
scale of the problem, the level of detail available for input, the required output, the background of the
user, and the turnaround time needed for an answer.

The five atmospheric dispersion considerations (i.e., stability, inversions, wind speed and direction, air
temperature, and terrain effects) must all be considered throughout the modeling process.
                                                                                 AMFHM
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                                                                                 page 12

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Notes:
                                                                                 AMFHM
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                                                                                 page 13

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                                Stability Class
                   B
               \  \
    Weak Winds
Sunshine         %l
Strong Heating <§H
                                 Strong Winds
\  \
                                                                     \  \
   Weak Winds

   Night Cooling
   (Ground
   Trapping)
         The Relationship Between Stability Class, Heating, and Wind Speed
Stability Class
Atmospheric stability is the extent of physical stirring and mixing on the vertical plane. When an
atmosphere is stable, there will be little mixing, which results in a persistent concentration.  Stable
conditions will also generally result in longer, narrower plume shapes.
                                                                              AMFHM
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                                                                              p«ge 14

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Notes:
                                                                              AMFHM
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                                      Inversions
Inversions
Inversions limit upward movement of air masses due to temperature differentials.  The inversion height
a modeler is concerned with is generally less than 100 feet.  Inversions are generally an evening/night-
time phenomenon and their presence results in increased stability.
                                                                                       AMFHM
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                                                                                       p«g« 16

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Notes:
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             Effects of Wind Speed and Direction
          CD
     CD \o
 C7>
   CD CD
   CD
        'CD
            CD
           x:
 ;^°TC;
    /
  Weak Winds
                                        CD
                    CD
                             High Winds
                                     ^D~
                                   CD
        CD

Moderate Winds




    CD

       CD
                                            CD
               CD
           CD
                     CD
           Effect of Wind Speed and Direction on a Plume
Effects of Wind Speed and Direction
Weak winds result in a decrease in stability. As wind speed increases, a corresponding increase in
atmospheric stability  is produced.
                                                                  AMFHM
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                                                                  p«e* '8

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              Ground Roughness - Terrain  Steering Effects
Ground Roughness - Terrain Steering Effects
Areas with hills or valleys may experience wind shifts where the wind actually flows between hills or
down into the valleys, turning where these features turn.
                                                                           AMFHM
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                             Gaussian  Dispersion
           Source of Spill
                                                          Crosswind
Gaussian Dispersion
In a Gaussian dispersion model, a curve is used to describe how a contaminant will be dispersed in the
air after it leaves the source.  At the source, the concentration of the contaminant is very high and the
Gaussian  distribution looks like a spike or a tall column.  As the contaminant drifts farther downwind,
it spreads out and the "bell shape" gets continually wider and flatter.
                                                                                    AMFHM
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                                                                               page 23

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                           Near-Field  Meandering
Near-Field Meandering
Near-field meandering is caused by individual drifting eddies in the wind that push the plume from side
to side. These eddies, or small gusts, are also responsible for much of the mixing that makes the plume
spread out.  As the plume drifts downward from the spill source, these eddies shift and spread the
plume until it takes on the form of a Gaussian distribution.
                                                                                   AMFHM
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                                                                                   PWJ.24

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Notes:
                                                                                AMFHM
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    Emission Rates
    APA Guidelines
    Volumes II & III
     EPA Modeling
       Guidelines
                     Yes
 COLLECT AND REVIEW INFORMATION

 •  Source data
 •  Urban/rural classification data and
    receptor data
 •  Environmental characteristics
  Available
Monitoring Data
                               SELECT MODEL CLASS AND
                                 SOPHISTICATION LEVEL

                               •  Screened
                               •  Refined
     DEVELOP MODELING PLAN

Select model
Select constituents to be modeled
Define model input requirements (emissions,
meteorology, receptors)
Select receptors
Select modeling period
Evaluate modeling uncertainty
    EPA
Review/Approval
                                  CONDUCT MODELING

                          Develop emission inventory
                          Process meteorological data
                          Develop receptor grid
                          Run model test cases
                          Verify input files
                          Perform calculation for averaging times under
                          consideration
                            SUMMARIZE/EVALUATE RESULTS

                            •  Determine concentrations
                            •  Prepare meteorological summaries
                            •  Consider modeling uncertainty
                                                                  No
                             ADDITIONAL ANALYSES NEEDED?
Reproduced from NTGS Volume IV
                                                Input to EPA
                                              Remedial/Removal
                                               Decision-Making
     Figure 2.  Superfund air impact assessment dispersion  modeling protocol.
                                                                                          AMFHM
                                                                                           10/93
                                                                                          page 16

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Superfund Air Impact Assessment Dispersion Modeling Protocol


Associated guidance documents:

•    National Technical Guidance Study (NTGS) Volumes II and III
•    Air quality modeling at Superfund sites factsheet
•    Guidelines on air quality models (revised).
 Notes:
                                                                         AMFHM
                                                                          10/93
                                                                         pace 27

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                        Dispersion Modeling  Protocol
    Emission Rates
    APA Guidelines
    Volumes II & III
    COLLECT AND REVIEW
        INFORMATION

• Source data
• Urban/rural  classification
  data and receptor data
• Environmental characteristics
   Available
Monitoring Data
 Reproduced from NTGS Volume IV
Step 1:
Step 1 involves collecting and compiling existing information pertinent to air dispersion modeling. This
information is obtained during a literature survey. Information that should be collected and compiled
includes source data, receptor data, and environmental data (e.g., land use classification, demography,
topography, and  meteorology).  Once the existing data have been collected and compiled, a thorough
evaluation will define the data gaps. A coherent dispersion modeling plan can then be developed using
site-specific parameters and requirements.
                                                                                    AMFHM
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                                                                                    page 28

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                                                                               AMFHM
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                         Dispersion Modeling Protocol
                             SELECT MODEL CLASS AND
                              SOPHISTICATION LEVEL


                             •  Screened
                             •  Refined
  Reproduced from NTGS Volume IV
Step 2:
Step 2 involves the selection of the dispersion modeling sophistication level and screening and refined
modeling techniques.  The selection process depends on program objectives as well as available resource
and technical constraints.  Screening models generally use limited and simplified input information to
produce a conservative estimate of exposure. Screening models assist in the initial determination of
whether the Superfund site, or site activity, will present an air impact problem. The emission source(s)
should then be evaluated with either a more sophisticated screening technique or a refined model. When
selecting a more  sophisticated  modeling  technique or approach, the following  aspects  should be
considered: availability of appropriate modeling techniques for the Superfund list of toxic constituents;
site-specific factors,  including  source configuration and  characteristics; applicability; limitations;
performance for similar applications; and  comparison of advantages and disadvantages  of  alternative
modeling techniques and approaches.
                                                                                       AMFHM
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                                                                                       page 30

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                                                                               AMFHM
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                        Dispersion Modeling Protocol
   EPA Modeling
    Guidelines
    DEVELOP MODELING PLAN

•  Select model
•  Select constituents to be modeled
•  Define model input requirements
   (emissions, meteorology,  receptors)
•  Select receptors
•  Select modeling period
•  Evaluate modeling uncertainty
EPA Review/
 Approval
 Reproduced from NTGS Volume IV
Step 3:
Step 3 involves preparing a dispersion modeling plan. Elements that should be addressed in the plan
include overview  of  the Superfund  site  area,  selection of constituents to be  modeled, modeling
methodology (emission inventory, meteorology, receptor grid, rural/urban classification, models to be
used, concentration averaging time, and special situations such as wake effects), and documentation of
the air modeling plan.
                                                                                 AMFHM
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                                                                                 P.O. 32

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/Votes:
                                                                              AMFHM
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                                                                              page 33

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                        Dispersion  Modeling Protocol
                               CONDUCT MODELING

                         •  Develop emission inventory
                         •  Process meteorological data
                         •  Develop receptor grid
                         •  Run model test cases
                         •  Verify input files
                         •  Perform calculation for averaging
                           times under consideration
  Reproduced from NTGS Volume IV
Step 4:
Step 4 specifies the actual activities involved in conducting air dispersion modeling for a Superfund site.
Activities that are performed include developing an emission inventory, preprocessing and verifying
modeling, setting model switches, running model test cases, performing dispersion calculations, and
obtaining a printout of modeling input and output.
                                                                                  AMFHM
                                                                                   10/83
                                                                                  P«3« 34

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Notes:
                                                                                 AMFHM
                                                                                  10/93
                                                                                 r>6'g? 36

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                      Dispersion Modeling Protocol
             SUMMARIZE/EVALUATE RESULTS

            • Determine concentrations
            • Prepare meteorological summaries
            • Consider modeling uncertainty
     Yes
                                                No
            ADDITIONAL ANALYSES NEEDED?
Input to EPA
Remedial/Removal
Decision Making
     •	> Return to Select Model Class and Sophistication Level

  Reproduced from NTGS Volume /V
Step 5:
Step 5 involves the review and assessment of the dispersion modeling results.

Additional components of this step include preparation of data summaries, concentration mapping (i.e.,
isopleths), estimation of uncertainties, and assessment.
                                                                             AMFHM
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                      Accidental Release Modeling
        •  Provides worst-case results

        •  Results used to determine evacuation of shelter-in-place options

        •  Cannot account for near-field patchiness

        •  Examples:   ALOHA ™ ARCHIE, CHARM ™, TRACE, and TSCREEN
Accidental Release Modeling
Accidental release modeling is performed when results are needed immediately.  Accidental release
models that assist in making source-term calculations, or provide probability warnings, are best when
real-time solutions are essential.

ALOHA™, ARCHIE, CHARM™, TRACE, and TSCREEN are examples of accidental release models.

Each model is a relatively simple estimation technique that provides conservative estimates of air quality
impact(s).
                                                                               AMFHM
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                                                                               page 38

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Notes:
                                                                               AMFHM
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                          Accidental Release  Models
                          ALOHA™   (NOAA/EPA)
                                    Areal

                                    Locations

                                    Of

                                    Hazardous

                                    Atmospheres
ALOHA
          TM
The Areal Locations of Hazardous Atmospheres (ALOHA) model was developed through a joint venture
between the National Oceanic and Atmospheric Administration (NOAA) and EPA. It is an emission
estimation and air quality dispersion model for estimating the emission rate, movement, and dispersion
of gases released into the atmosphere.  The model estimates pollutant concentrations downwind from
the source of a release, taking into account the toxicological and physical characteristics of the material.
ALOHA considers the physical characteristics of the release site, the atmospheric conditions, and the
initial source conditions.

The model has a built-in database of chemical names and properties that the model uses to calculate
emission rates.  The  program performs buoyant gas dispersion based on Gaussian dispersion equations
and heavier-than-air dispersion based on algorithms in the DEnse GAs DISpersion (DEGADIS) model.

Emission estimations can be made for puddles, tanks, and pipe releases or for direct input of material
into the atmosphere.  The model uses  hourly meteorological data that can be entered by the user or
obtained from real-time measurements.   The results of the model can be displayed as concentration
plots or in text  summary screens. The concentration outputs are limited to a 1-hour (or less) exposure.
                                                                                     AMFHM
                                                                                      10/93
                                                                                     PSO« 40

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Notes:
                                                                               AMFHM
                                                                                10/93
                                                                               pago 41

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                        Accidental  Release Models
                         ARCHIE   (FEMA/DOT/EPA)


                                   Automated

                                   Resource for

                                   Chemical

                                   Hazard

                                   Incident

                                   Evaluation
ARCHIE
The Automated Resource for Chemical Hazard Incident Evaluation (ARCHIE) model was developed
through a joint effort by the Federal Emergency Management Agency (FEMA), the U.S. Department
of Transportation (DOT), and EPA.  It is an emission estimation and atmospheric dispersion model that
can be used to  assess the vapor dispersion,  fire, and explosion  impacts associated with  episodic
discharges of hazardous materials into the environment.  The model can estimate the emissions and
duration of liquid/gas releases from tanks, pipelines, and liquid pools, as well as the associated ambient
concentrations downwind of these releases. ARCHIE can also evaluate the thermal hazards resulting
from the ignition of a flammable release and the consequences of an explosion caused by a flammable
gas, tank overpressurization, or ignition of an explosive material. In addition, it can estimate the size
of the downwind hazard zone that may require evacuation or other public protection because of the
release of a toxic gas or vapor into the atmosphere.

To estimate downwind concentrations,  simulated meteorological conditions are input to the model. The
user must input chemical properties of the material released from information contained in the material
safety data sheets.
                                                                                    AMFHM
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                                                                                    p«8« 42

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/Votes:
                                                                                    AMFHM
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                       Accidental  Release Models
                     CHARM™   (Radian  Corporation))
                                   Complex

                                   HAzardous

                                   Release

                                   Mode!
CHARM
          TM
The Complex Hazardous Release  Model (CHARM™) is a proprietary Gaussian  puff model  for
continuous and instantaneous releases of gases or liquids. The model is configured to handle chemicals
that are buoyant, neutrally buoyant, or heavier-than-air. CHARM™ can estimate the emission rates of
chemicals using a modification of the SHELL spill model and  a multiphase pressurized gas release
model. CHARM™ contains a database of chemical information that is used in calculating emission
estimates.  The program is menu driven and  can accept simulated meteorological data for up to 24
hours.  The CHARM™ model can simulate  the transport of chemicals in  spatially and temporally
varying wind fields. The results from the program may be displayed graphically on a screen or output
to a printer.
                                                                                  AMFHM
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                                                                                  page 44

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Notes:
                                                                               AMFHM
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                       Accidental  Release Models
                   TRACE   (E.I.  Dupont de  Nemours)


                                   Toxic

                                   Release

                                   Analysis  of

                                   Chemical

                                   Emissions
TRACE
The SAFER System TRACE model is an engineering analysis tool for dispersion modeling.  It models
accidental toxic releases, including those caused by pipe/flange leaks, aqueous spills, hydrogen fluoride
spills, fuming acid spills, stack emissions, or elevated dense gas emissions.  The program is menu
driven and contains several modules to estimate the evaporation and dispersion of chemicals and analyze
the effect of certain parameters on downwind concentrations.  The program has a built-in database of
chemicals and their properties and various source-term modules. The model uses real-time or simulated
meteorological data for atmospheric dispersion calculations. These data can vary with time during the
release.  The results of the modeling analysis can be displayed visually on graphs or stored in tables.
                                                                                    AMFHM
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                                                                               AMFHM
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                        Accidental Release  Models
                             TSCREEN   (EPA)
               •  Model for screening toxic air pollutant concentrations
TSCREEN
TSCREEN, a model for screening toxic air pollutant concentrations, is an air quality dispersion model
that implements the procedures in A Workbook of Screening Techniques for Assessing Impacts of Toxic
Air Pollutants (EPA-450-88-009). The TSCREEN model is an atmospheric dispersion model that uses
the dispersion  algorithms of SCREEN,  Release Valve  Discharge  (RVD), and PUFF models.  It
automatically selects the worst-case simulated meteorological conditions based on the criteria presented
in the workbook.  The model contains a data table of chemicals and their associated parameters (limited
to two  chemicals at this time) that  TSCREEN can access. It can calculate the source term for dust
particles within a pile of a specified dimension. The model can also simulate the dispersion of gaseous,
liquid, and particulate matter releases. TSCREEN outputs graphical and tabular summaries of predicted
pollutant concentrations.
                                                                                    AMFHM
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                                                                                    page 48

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                                                                               AMFHM
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-------An error occurred while trying to OCR this image.

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Notes:
                                                                                 AMFHM
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                                    REFERENCES
The following list represents a partial list of background references on the subject of air monitoring
and sampling.  Although other sources may be available, it is believed that these will provide the
reader with a good understanding of the subject.

The  references are listed alphabetically by  title and include author, publisher, and  place  of
publication.  The year of publication is given for governmental sources only.  For the remainder,
the reader should attempt to obtain the most recent edition.  An * after the title indicates that a copy
of the document is part of the course library and is available for review.
1.     Advances in Air Sampling'
       Lewis Publishers, Inc.
       121 South Main Street
       P.O. Drawer 519
       Chelsea, MI 48118
       (Also available through ACGIH. See #4.)

2.     Air Methods Database
       Available on the Cleanup Information electronic bulletin board (CLU-IN), formerly OSWER
       BBS.  For further information, call 301 589-8366.

3.     Air Monitoring For Toxic Exposures: An Integrated Approach", 1991
       Shirley A. Ness
       Van Nostrand Reinhold
       115 Fifth Avenue
       New York, NY 10003

4.     Air Monitoring Instrumentation:  A Manual for Emergency, Investigatory, and Remedial
       Responders', 1993
       C. Maslonsky and S.  Maslonsky
       Van Nostrand Reinhold
       115 Fifth Avenue
       New York, NY 10003

5.     Air Sampling Instruments*
       American Conference of Governmental Industrial Hygienists
       6500 Glenway Avenue, Building D-E
       Cincinnati, OH 45211
       513 661-7881

6.     Air/Superfund National Technical Guidance Series:

       •      Volume IV—Guidance for Ambient Air Monitoring at Superfund Sites (revised). EPA-
              451/R-93-007,May 1993
10/93                                       1                                   References

-------
       •      Compilation of Information on Real-Time Air Monitoring for Use at Superfund Sites.
             EPA-451/R-93-008, May 1993

7.      Atmospheric Analysis: Occupational Health and Safety, ASTM Standards, Volume 11.03
       American Society for Testing and Materials
       1916 Race Street
       Philadelphia, PA 19103-1187
       215 299-5400

8.      Basic Gas Chromatography
       H.M. McNair and E.J. Bonelli
       Varian Instrument Division
       Purchase  from Supelco, Inc.
       Supelco Park
       Bellefonte, PA 16823-0048

9.      Compendium of Methods for the Determination of Toxic Organic Compounds in Ambient Air,
       EPA/600/4-89/017, June 1988
       Atmospheric Research and Exposure Assessment Laboratory
       U.S. Environmental Protection Agency
       Office of Research and Development
       Research  Triangle  Park, NC 27711

10.    A Compendium of Superfund Field Operations Methods', EPA/540/P-87/001, December 1987
       U.S.Environmental Protection Agency
       Office of Emergency and Remedial Response
       Office of Waste Programs Enforcement
       Washington, DC 20460

11.    Data  Quality Objectives for Remedial  Response  Activities:    Development Process,
       EPA/540/G-87/003, March 1987
       U.S. Environmental Protection Agency
       Office of Emergency and Remedial Response
       Office of Waste Programs Enforcement
       Washington, DC 20460

12.    Fundamentals of Industrial Hygiene
       National Safety Council
       444 North Michigan Avenue
       Chicago,  IL60611

13.    Guidance on Applying the Data Quality  Objectives Process for Ambient Air Monitoring
       Around Superfund Sites (Stages I & II), EPA-450/4-89-015; (Stage III), EPA-450/4/90-005
       U.S. Environmental Protection Agency
       Office of Air Quality  Planning and Standards
       Research Triangle Park, NC 27711
References                                 2              •                        10/93

-------
14.    Guide to Occupational Exposure Values*
       American Conference of Governmental Hygienists
       6500 Glenway Avenue, Building D-E
       Cincinnati, OH 45211
       513 661-7881

15.    Guide to Portable Instruments for Assessing Airborne Pollutants Arising from Hazardous
       Wastes
       International Organization of Legal Metrology
       Paris, France
       (Available through ACGIH)

16.    The Industrial Environmental - Its Evaluation and Control, 1973
       National Institute for Occupational Safety and Health
       Rockville, MD
       (Available  from  the  Superintendent  of Documents,  U.S. Government Printing  Office,
       Washington, DC  20402  [202 783-3238])

17.    Industrial Hygiene and Toxicology, Volumes I and III
       Frank A. Patty
       John Wiley  and Sons, Inc.
       New York,  NY

18.    Manual of Recommendation Practice for Combustible Gas Indicators and Portable Direct
       Reading Hydrocarbon Detectors, 1980,  1st edition
       John Klinsky (ed)
       American Industrial Hygiene Association
       Akron, OH

19.    Methods of Air Sampling and Analysis"
       Lewis Publishers, Inc.
       121 South Main Street
       P.O. Drawer 519
       Chelsea, MI 48118
       (Also available through ACGIH)

20.    NIOSH Manual of Analytical Methods, Editions 1, 2, and 3"
       National Institute for Occupational Safety and Health
       Rockville, MD
       (Available  from  the  Superintendent  of Documents,  U.S. Government Printing  Office,
       Washington, DC  20402  [202 783-3238])

21.    OSHA Analytical Methods Manuaf
       Superintendent of Documents
       U.S. Government Printing Office
       Washington, DC  20402
       202 783-3238
10/93                                      3                                  References

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22.     OSHA Technical Manual", 1990
       (See ACGIH)

23.     Removal Program Representative Sampling Guidance:  Air
       U.S.  Environmental Protection Agency
       Office of Emergency and Remedial Response
       Emergency Response Division
       Environmental Response Branch
       Washington, DC

24.     Standard Operating Safety Guides, June 1992
       U.S.  Environmental Protection Agency
       Environmental Response Team
       2890 Woodbridge Avenue
       Building 18 (MS-101)
       Edison, NJ 08837-3697
       908 321-6740

25.     Standard Operating Guide for the Use of Air Monitoring Equipment for Emergency Response
       (See #21)

26.     Standard Operating Guide for Air Sampling and Monitoring at Emergency Responses
       (See #21)

27.     Technical Assistance Document for Sampling and Analysis of Toxic Organic Compounds in
       Ambient Air,  EPA-600/4-83-027
       U.S.  Environmental Protection Agency
       Environmental Monitoring Systems Laboratory
       Research Triangle  Park, NC 27711
References                                 4                                      10/93

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                 MANUFACTURERS AND  SUPPLIERS OF
                      AIR MONITORING EQUIPMENT
AIR MONITORING EQUIPMENT
Aerosol/Particulate Direct-Reading Monitors:

            Air Techniques Incorporated
            HUND Corporation
            Met One, Inc.
            MIE, Inc.
            MST Measurement Systems, Inc.
            Pacific Scientific (HIAC/ROYCO Instrument Division)
            Particle Measuring Systems, Inc.
            PPM Enterprises
            TSI Incorporated
Calibration Gases: (most manufacturers of instruments provide calibration gases for
use with their instruments; these companies provide a variety of calibration gases)

            Airco Industrial Gases
            Alphagaz
            Bryne Specialty Gases
            Digicolor
            Environics, Inc.
            GC Industries
            Kin-Tek laboratories, Inc.
            Liquid Air Corporation
            National Specialty Gases
            Norco, Inc.
            Scott Specialty Gases
            VICI Metronics
Calibrators, Pump:

            Accura Flow Products Co., Inc.
            Air Systems International
            AMETEK
            BGI Incorporated
            BIOS International Corp
            DuPont
            Gillian Instrument Co.
            Sensidyne


10/93                                  1                Manufacturers and Suppliers

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             SKC, Inc.
             Spectrex Corporation
Canister Samplers:
             Andersen Samplers Incorporated
             Nutech Corporation
             Scientific Instrumentation Specialists
             Wedding & Associates, Inc.
             Xontech, Inc.
Collection Media:
              Ace Glass Incorporated
              BGI Incorporated
              DACO Products
              Gelman Sciences
              Gilian Instrument Corporation
              Hi-Q Environmental Products Company
              LaMotte Chemical Products Company
              Micro Filtration Systems
              Millipore Corporation
              Mine Safety Appliances  Company
              Nuclepore Corporation
              Omega Specialty  Instruments Company
              Paliflex, Inc.
              Poretics Corporation
              Schleicher & Schuell
              Sipin, Anatole, J., Co.,  Inc.
              SKC, Inc.
              Supelco, Inc.
Colorimetric Detectors: (B = badges or dosimeters; DT = regular detector tubes; LT = long term
detector tubes)

              American Gas & Chemical Co., Ltd. (B)
              Analytical Accessories International  (B)
              Bacharach, Inc. (B)
              Chemsense (B)
              Crystal Diagnostics (B)
              Enmet Corporation (DT, LT)
              GMD Systems, Inc. (B)
              Matheson Safety Products (DT, LT)
              MDA Scientific (B)
              Mine Safety Appliances Co. (B, DT, LT)


Manufacturers and Suppliers                  2                                      10/93

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             National Draeger, Inc. (B, DT, LT)
             PPM Enterprises (B)
             Sensidyne (DT), Inc.
             SKC, Inc. (B, LT)
             VICI Metronics (B)
             Willson Safety Products  (B)
Combustible Gas Meters:
Gas Bags:
             A.I.M.  Safety Company, Inc.
             Astro International Corp.
             Bacharach Instruments
             Biosystems, Inc.
             Chestec, Inc.
             Control Instruments Corp.
             Dynamation Incorporated
             Energy  Efficiency Systems,Inc.
             Enmet Corporation
             Gas Tech, Inc.
             GfG America Gas Detection  Ltd.
             Grace Industries, Inc.
             Heath Consultants Incorporated
             Industrial Scientific Corporation
             J and N Enterprises, Inc.
             Lumidor Safety Products e.s.p., Inc.
             Mine Safety Appliances  Co.
             National Draeger, Inc.
             Neotronics N.A., Inc.
             Quatrosense Environmental Ltd.
             Scott Aviation
             Sieger Gas Detection
             Sierra Monitor Corporation
             Texas Analytical Controls, Inc.
             TIP Instruments, Inc.
             AeroVironment, Inc.
             The Anspec Company, Inc.
             BGI Incorporated
             Calibrated Instruments, Inc.
             Digicolor
             Jensen Inert
             KVA Analytical Systems
             Norton Performance Plastics
             Nutech Corporation


10/93                                      3                  Manufacturers and Suppliers

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             Plastic Film Enterprises
             Pollution Measurement Corporation
             Science Pump Corporation
             SKC, Inc.
Gas Chromatographs:  (types of detectors available: AID = argon ionization; ECD
electron capture;  FID  =  flame  ionization;  MS  =  mass  spectroscopy;  PID
photoionization; SS = chemical specific sensor; TCD = thermal conductivity)

             Bruker Instruments (MS)
             Canaan Scientific Products
             CMS Research Corporation (SS)
             The Foxboro Company (FID)
             GOW-MAC (FID, TCD)
             HNU Systems, Inc. (PID, FID)
             Microsensor Systems Inc.
             Microsensor Technology, Inc. (TCD)
             Photovac Incorporated (PID, FID)
             S-Cubed (ECD)
             Sensidyne (FID)
             Sentex Sensing Technology, Inc. (ECD, PID, PID, TCD)
             Summit Interests (FID, PID, TCD)
             Thermo Environmental Instruments, Inc. (ECD, FID, PID, TCD)
             Viking Instruments (MS)
             XonTech, Inc. (AID, ECD)
Oxygen Meters:

             A.I.M. Safety Company, Inc.
             Bacharach, Inc.
             Biosystems, Inc.
             Dynamation Incorporated
             Energy Efficiency Systems, Inc.
             Enmet Corporation
             GasTech, Inc.
             GC Industries
             GfG America Gas Detection Ltd.
             Industrial Scientific Corporation
             Lumidor Safety Products e.s.p., Inc.
             MDA Scientific, Inc.
             Metrosonics, Inc.
             Mine Safety Appliances Co.
             National Draeger, Inc.
             Neotronics N.A., Inc.
             Rexnord Safety Products
             Scott Aviation


Manufacturers and Suppliers                4                                     10/93

-------
             Sensidyne
             Sieger Gas Detection
             Sierra Monitor Corporation
             Teledyne Analytical Instruments
Passive  Dosimeters:   (these devices require laboratory analysis; for direct-reading
dosimeters see G. Colorimetric Detections)

             Advanced Chemical Sensors
             Air Technology Labs, Inc.
             Assay Technology
             EnSys, Inc.
             Gilian Instrument Corporation
             Landauer, R.S. Jr. & Company
             Mine Safety Appliances Co.
             National Draeger, Inc.
             Pro-Tek Systems, Inc.
             Sensidyne
             SKC, Inc.
             3M
Sampling Pumps and Accessories:  (letters denote primary function  of pumps and
apparatus:  P  = Personal; A = Area; B =  Bag filling)

             AeroVironment, Inc. (B)
             Air Systems International, Inc. (A)
             AMETFK (P)
             Analytical Accessories International (A,P)
             Andersen Samplers Incorporated (A)
             Arjay Equipment Corporation (A)
             Barnant Company (A)
             BGI Incorporated (P, A)
             BIOS International Corp
             Calibrated Instruments, Inc. (B)
             California Measurements, Inc. (A)
             DuPont (P)
             Environmetrics, Inc.  (A)
             General Metal Works, Inc. (A)
             Gillian  Instrument Corp. (P)
             LaMotte Chemical Products Company (A)
             Midwest Environics, Inc.  (A)
             Mine Safety Appliances Co. (P)
             Omega Specialty  Instrument Co. (A)
             Wedding & Associates, Inc. (A)
             Sensidyne (P)
             Sipin, Anatole J., Co.,  Inc.  (P)

JO/93                                     5                 Manufacturers and Suppliers

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             SKC, Inc. (P)
             Spectrex Corporation (P)
             Staplex Air Sampler Division (A)
             Supelco, Inc. (P)
             Thermedics, Inc. (P)
             Wedding & Associates (A)
Toxic Monitors:  (direct-reading instruments for low concentrations of contaminants;
letters denote types of detectors  available; PID  =  photoionization; FID =  flame
ionization; IR =  infrared spectroscopy; TCD  = thermal conductivity; GS = general
sensor, e.g., MOS or super-sensitive CGI;  SS = sensor for specific chemical, e.g.,
CO, H2S)

             A.I.M. Safety Company, Inc.(GS,  SS)
             Anacon Detection Technology (SS)
             Analect Instruments (IR)
             Arizona Instrument, Jerome Division (SS)
             Astro International Corp.  (SS)
             Bacharach, Inc. (GS, SS)
             Biosystems, Inc. (SS)
             Bruel & Kjaer (IR)
             CEA Instruments,  Inc. (GS, SS)
             Dynamation Incorporated (GS, SS)
             Enmet Corporation (SS)
             Environmental Technologies Group (GS)
             The Foxboro Company (FID, IR)
             GasTech, Inc. (GS, SS)
             GfG America Gas  Detection Ltd. (SS)
             GMD Systems, Inc. (colorimetric)
             GOW-MAC (TCD)
             Grace Industries, Inc.  (GS)
             Graesby Ionics Ltd. (Ion Mobility Spectrometry)
             Heath Consultants  Incorporated (FID)
             HNU Systems, Inc. (PID)
             Industrial Scientific Corporation (SS)
             International Gas Detectors, Inc.
             InterScan Corporation (SS)
             J and N Enterprises, Inc. (GS)
             MDA Scientific, Inc. (SS)
             Macurco, Inc. (GS, SS)
             Mast Development Corporation (SS)
             Matheson Safety Products (TCD)
             Metrosonics, Inc.  (SS)
             Microsensor Systems, Inc. (SS)
             Mine Safety Appliances Co. (PID, FID, SS)
             National Draeger (SS)
             Neotronics N.A.,  Inc. (SS)

Manufacturers and Suppliers                 6             '                        10/93

-------
             Nicolet Instrument Corp. (IR)
             Photovac Incorporated (PID)
             Quatrosense Environmental Ltd. (SS)
             Scott Aviation (SS)
             Sensidyne (SS, FID)
             Sentex Sensing Technology, Inc. (FID)
             Servomax Company (IR)
             Sieger Gas Detection (SS, IR)
             Sierra Monitor Corporation (SS)
             Spectrex Corporation (SS)
             Summit Interests (FID, PID, TCD)
             Tekmar Company (TCD)
             Texas Analytical Controls, Inc. (SS)
             Thermo Environmental Instruments, Inc. (FID, PID, TCD)
             TIF Instruments, Inc. (GS)
             Transducer Research, Inc. (SS)
MANUFACTURERS' AND SUPPLIERS' ADDRESSES

      AccuRa Flow Products Co., Inc.              A.I.M. Safety Company, Inc.
      P.O. Drawer  100                           P.O. Box 720540
      Warminster, PA 18974                      Houston, TX 77272-0540
      214 674-4782                              713 240-5020
                                                1-800-ASK-4AIM
      Ace Glass Company
      P.O. Box 688                              Air Systems International
      Vineland, NJ                               814-P Greenbrier Circle
      609 692-3333                              Chesapeake, VA 23320
                                                1-800-866-8100
      Advanced Chemical Sensors
      350 Oak Lane                             Air Techniques Incorporated
      Pompano Beach, FL 33069                  1801 Whitehead Road
      305 979-0958                              Air Techniques Incorporated
                                                1801 Whitehead Road
      Advanced Calibration Designs, Inc.            Baltimore, MD 21207
      7960 S. Kolb Rd.                           301 944-6037
      Tucson, AZ 85705
      602 574-9509                              Airco Industrial Gases
                                                Division of Airco, Inc.
      AeroVironment, Inc.                        575 Mountain Avenue
      145 Vista Avenue                           Murry Hill, NJ 07974
      Pasadena, CA 91107                        201 464-8100
      818 357-9983
10/93                                    7                 Manufacturers and Suppliers

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      Alphagaz
      Specialty Gases Division
      Liquid Air Corporation
      2121 N. California Blvd.
      Walnut Creek, CA 94596
      415 977-6506

      AMETEK
      Mansfield & Green Division
      8600 Somerset Drive
      Largo,  FL 34643
      813 536-7831

      American Gas & Chemical Co., Ltd.
      220 Pegasus Avenue
      North vale, NJ 07647
      201 767-7300
      1-800-288-3647

      Anacon Detection Technology
      117 South Street
      Hopkinton, MA 01748
      508 435-6973

      Analect Instruments
      Division of Laser Precision Corp.
      1231 Hart Street
      Utica, NY 13502
      315 797-4449

      Analytical Accessories International
      P.O. Box 922085
      Atlanta, GA 30092
      1-800-282-0073

      Anderson Instruments, Inc.
      4801 Fulton Industrial Blvd.
      Atlanta, GA 30336
      404 691-1910

      The Anspec Company, Inc.
      122 Enterprise Drive
      Ann Arbor, MI 48107
      313 665-9666
      1-800-521-1720
Arizonia Instrument Corp.
P.O. Box 1930
Tempe, AZ 85280
602 731-3400
1-800-528-7411

Arjay Equipment Corp.
P.O. Box 2959
Winston-Salem,  NC 27102
919 741-3582

Assay Technology
1070 E. Meadow Cir.
Palo Alto, CA 94303
1-800-833-1258

Astro International Corp.
100 Park Avenue
League City, TX 77573
713 332-2484

BGI, Inc.
58 Guinan Street
Waltham, MA 02154
617 891-9380

BIOS International Corporation
756 Hamburg Turnpike
Pompton Lakes, NJ 07442
201 839-6908

Bacharach, Inc.
625 Alpha Drive
Pittsburgh, PA 15238
412 963-2000

Barnant Company
28W092 Commercial  Avenue
Barrington, IL 60010
312 381-7050

Biosystems, Inc.
P.O. Box 158
Rockfall, CT 06481
203 344-1079
Manufacturers and Suppliers
                                10/93

-------
      Bruel & Kjaer Instruments, Inc.
      185 Forest Street
      Marlborough, MA 01752
      508 481-7000

      Bruker Instruments, Inc.
      Manning Park
      Billerica, MA 01821
      617 667-9580

      Byrne Specialty  Gases, Inc.
      118 S. Mead Street
      Seattle, WA 98108
      206 764-4633

      Calibrated Instruments, Inc.
      200 Saw Mill River Road
      Hawthorne, NY 10502
      914 741-5700

      CEA  Instruments, Inc.
      16 Chestnut Street
      Emerson, NJ 07630
      201 967-5660

      CMS  Research Corporation
      100 Chase Park, Suite 100
      Birmingham, AL 35244
      205 733-6900

      California Measurements, Inc.
      150 E. Montecito Avenue
      Sierra Madre, CA 91024
      818 355-3361

      Canaan Scientific Products
      P.O.  Box 50527
      Indianapolis, IN 46250
      317 842/1088
      1-800-842-8578

      ChemSense
      3909  Beryl Rd.
      Raleigh,  NC 27607
      919 821-2929
Chestec, Inc.
P.O. Box 10362
Santa Ana, CA 92705
714 730-9405

Compur Monitors
7015 West Tidwell
Suite Glll-A
Houston, TX 77092
713939-1103

Control Instruments Corp.
25 Law Drive
Fairfield, NJ 07006
201575-9114

Costar/Nucleopore
One Alewife Center
Cambridge, MA 02140
617 868-6200

Crystal Diagnostics, Inc.
600 West Cummings Park
Woburn, MA 01801
617933-4114

DACO Products, Inc.
12 S. Mountain Avenue
Montclair, NJ 07042
201 744-2453

Digicolor
2770 East Main Street
P.O. Box 09763
Columbus, OH 43209
614236-1213

Dynamation Incorporated
3784 Plaza Drive
Ann Arbor, MI 48104
313 769-0573

Enmet Corporation
P.O. Box 979
2308 S.  Industrial Highway
Ann Arbor, MI 48106-0979
313761-1270
10/93
           Manufacturers and Suppliers

-------
      Energy Efficiency System, Inc.
      1300 Shames Drive
      Westbury, NY 11590
      516 997-2100
      1-800-645-7490

      EnSys, Inc.
      P.O. Box 14063
      Research Triangle Park, NC
      919 941-5509

      Envirometrics, Inc.
      1019 Bankton Dr.
      Charleston, SC 29406
      1-800-255-8740

      Environics, Inc.
      33 Boston Post Road West
      Marlborough, MA 01752
      617 481-3600

      Environmental Technologies Group
      1400 Taylor Avenue
      Baltimore, MD 21284-9840
      301 635-4598

      The Foxboro Company (EMO)
      P.O. Box 500
      600 N. Bedford St.
      East Bridgewater, MA 02333
      508 378-5556

      GasTech, Inc.
      8445 Central Avenue
      Newark, CA 94560
      415 745-8700

      GC Industries, Inc.
      8976 Oso Ave., Unit  C
      Chatsworth, CA 91311
      818 882-7852

      GfG Gas Electronics, Inc.
      6617 Clayton Rd., Suite 209
      St. Louis, MO 63144
      314 725-9050
       GMD Systems, Inc.
       Old Route 519
       Hendersonville, PA 15339
       412 746-3600

       Gelman Sciences, Inc.
       600 South Wagner Road
       Ann Arbor, MI 48106
       313 665-0651

       General Metal Works, Inc.
       145 South Miami
       Village of Cleves, OH 45002
       513 941-2229

       Gilian Instrument Corporation
       35 Fairfield Place
       West Caldwell, NJ 07006
       201 808-3355

       GOW-MAC
       P.O. Box 32
       Bound Brook, NJ 08805
       201 560-0600

       Grace Industries, Inc.
       P.O. Box 167
       Transfer, PA 16154
       412 962-9231

       Graseby Ionics Ltd.
       Analytical Division
       Park Avenue, Bushey
       Watford Herts Wb2 2BW
       England
       0923 816166

       Heath Consultants, Inc.
       100 Tosca Drive
       P.O. Box CS-200
       Stoughton,  MA 02072-1591
       617 344-1400

       Hi-Q Filter Environmental Products
       7386 Trade Street
       San Diego, CA 92121
       619 549-2820
Manufacturers and Suppliers
10
10/93

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      HNU Systems, Inc.
      160 Charlemont Street
      Newton Highlands, MA 02161
      617 964-6690
      1-800-527-4566

      HUND Corporation
      777 Passaic Ave.
      Clifton, NY 07012-1804
      202 473-5009

      Industrial Scientific Corporation
      355 Steubenville Pike
      Oakdale, PA 15071-1093
      412 788-4353
      1-800-338-3287

      International Gas Detectors, Inc.
      11221 Richmond Ave., Suite C-109
      Houston, TX 77082
      713 558-4099

      InterScan Corporation
      P.O.  Box 2496
      21700 Nordoff Street
      Chatsworth, CA 91313-2496
      1-800-458-6153

      J and N Enterprises, Inc.
      P.O.  Box 108
      Wheeler, IN 46393
      219759-1142

      Jensen Inert
      P.O.  Box 660824
      Miami, FL 33266-0824
      305 871-8839
      1-800-446-3781

      Kin-Tek Laboratories
      2395  Palmer Highway
      Texas City, TX 77590
      409 945-3627
       KVA Analytical Systems
       281 Main St.
       P.O. Box 574
       Galmouth, MA 02541-99811
       508 540-0561

       LaMotte Chemical Products Co.
       P.O. Box 329
       Chestertown, MD 21620
       301 778-3100
       1-800-344-3100

       Lumidor Safety Products/E.S.P., Inc.
       5364 NW 167th Street
       Miami,  FL 33014
       305 625-6511

       Macurco, Inc.
       3946 S. Mariposa Street
       Englewood, CO 80110
       303 781-4062

       Mast Development Company
       Air Monitoring Division
       2212 East 12th Street
       Davenport,  IA 52803
       319 326-1041

       Mateson Chemical Corporation
       1025 E. Montgomery Avenue
       Philadelphia, PA 19125
       215 423-3200

       Matheson Gas  Products, Inc.
       30 Seaview Drive
       Secaucus, NJ 07096-1587
       215 641-2700

       MDA Scientific,  Inc.
       405 Barclay Blvd.
       Lincolnshire, IL 60069
       312 634-2800
       1-800-323-2000
                                                 MG Industries
                                                 175 Meister Avenue
                                                 North Branch, NJ 08876
                                                 201/231-9595
10/93
11
Manufacturers and Suppliers

-------
      MIE, Inc.
      213 Burlington Road
      Bedford, MA 01730
      617 275-5444

      MST Measurement Systems, Inc.
      327 Messner Drive
      Wheeling, IL 60090
      708 808-2500

      Met One, Inc.
      481 California Avenue
      Grants Pass, OR 97526
      503 479-1248

      Metrosonics, Inc.
      P.O. Box 23075
      Rochester, NY 14692-3075
      716 334-7300

      Micro Filtration Systems
      6800 Sierra Court
      Dublin, CA 94568
      415 828-6010

      Microsensor Systems, Inc.
      6800 Versar Center
      Springfield, VA 22151
      703 642-6919

      Microsensor Technology, Inc.
      47747 Warm Springs Blvd.
      Fremont, CA  94539
      415 490-0900

      Midwest Environics, Inc.
      10 Oak Glen Court
      Madison, WI  53717
      608 833-0158

      Millipore Corporation
      Lab Products  Division
      80 Ashby Road
      Bedford, MA  01730
      617 275-9200
       Mine Safety Appliances
       P.O.  Box 427
       Pittsburgh, PA 15230
       412 967-3000
       1-800-MSA-INST

       National Draeger, Inc.
       P.O.  Box 120
       101 Technology Drive
       Pittsburgh, PA 15230-0120
       412 787-8383

       National Specialty Gases
       630 United Drive
       Durham, NC 27713-9985

       Neotronics N.A., Inc.
       P.O.  Box 370
       411 North Bradford Street
       Gainesville, GA 30503
       404 535-0600
       1-800-535-0606

       Nicolet Instrument Corp.
       5225 Verona Rd.
       Madison, Wl 53711
       608 271-3333

       Norco, Inc.
       1121 W. Amity
       Boise, ID 83705
       208 336-1643

       North Performance Plastics
       150 Dey Road
       Wayne, NJ 07470-4699
       1-800-526-7844

       Nutech Corporation
       2806 Cheek Road
       Durham, NC 27704
       919 682-0402

       Omega Specialty Instruments Company
       4 Kidder Road, Unit 5
       Chelmsford, MA 01842
       508 256-5450
Manufacturers and Suppliers
12
10/93

-------
       Pacific Scientific
       HAIC-ROYCO Instruments Division
       141 Jefferson Drive
       Menlo Park, CA 94025

       Paliflex, Inc.
       125 Kennedy Drive
       Putnam, CT 06260
       203 929-7761

       Particle Measuring Systems
       1855 South 57th Court
       Boulder, CO 80301-2886
       303 443-7100

       Photovac International, Inc.
       25-B Jefryn Blvd. W.
       Deer Park, NY 11729
       516 254-4199

       Plastic Film Enterprises
       2011 Bellaire Avenue
       Royal Oak, MI 48067
       313 399-0450

       Pollution Measurement Corporation
       P.O. Box 6182
       Chicago, IL 60680
       708 383-7794

       Poretics  Corporation
       151 I Lindbergh Avenue
       Livermore, CA 94550-9412
       415 373-0500
       1-800-922-6090

       PPM Enterprises
       11428 Kingston Pike
       Knoxville, TN 37922
       615 966-8796

       Pro-Tek Systems, Inc.
       64 Genung Street
       Middletown, NY 10940
       914 344-4711
        Quatrosense Environmental Ltd.
        5935 Ottawa Street
        P.O. Box 749
        Richmond, Ontario, Canada KOA 2ZO
        613/838-4005

        S-Cubed
        P.O. Box 1620
        La Jolla, CA 92038-1620
        619/453-0060

        Schleicher & Schuell, Inc.
        10 Optical Street
        Kenne, NH  03431
        603/352-3810
        800/245-4024

        Scientific Instrumentation Specialists
        P.O. Box 8941
        Moscow, ID 83843
        208/882-3860

        Science Pump Corporation
        1431 Ferry Avenue
        Camden, NJ 08104
        609/963-7700
        Scott Aviation
        225 Erie Street
        Lancaster, NY  14086
        716/683-5100

        Scott Specialty Gases
        Route 161 North
        Plumsteadville, PA  18949
        215/766-8861

        Sensidyne, Inc.
        16333 Bay Vista Dr.
        Clearwater,  FL  34620
        813/530-3602
        800/451-9444

        Sentex Sensing Technology, Inc.
        553 Broad Avenue
        Ridgefield, NJ  07657
        201/945-3694
10/93
13
Manufacturers and Suppliers

-------
      Servomax Company
      90 Kerry Place
      Norwood, MA 02062
      617 769-7710

      Sieger Gas Detection
      405 Barclay Blvd.
      P.O. Box 1405
      Lincolnshire, IL 60069-1405
      1-800-221-1039

      Sierra Monitor Corporation
      1991 Tarob Court
      Milipitas, CA 95035
      408262-6611

      Anatole J.  Sipin Co., Inc.
      505 Eighth Avenue
      New York, NY  10018
      212 695-5706

      SKC, Inc.
      334 Valley View Road
      Eighty Four, PA 15330-9614
      412 941-9701
      1-800-752-8472

      Spectrex Corporation
      3580 Haven Avenue
      Redwood City, CA 94063
      415 365-6567

      Staplex Company
      Air Sampler Division
      777 Fifth Avenue
      Brooklyn,  NY 11232-1695
      212 768-3333
      1-800-221-0822

      Summit Interests
      P.O. Box  1128
      Lyons, CO 80540
      303 444-8009

      Supelco, Inc.
      Supelco Park
      Bellefonte, PA 16823-0048
      814 359-3441
       3M OH & ESD
       3M Center
       Building 220-3E-04
       St. Paul, MN 55144-1000
       612 733-5608

       TIF Instruments Inc.
       9101  NW 7th Avenue
       Miami, FL 33150
       305757-8811

       TSI Incorporated
       500 Cardigan Road
       P.O.  Box 43394
       St. Paul, MN 55164
       612 483-0900

       Tekmar Company
       P.O.  Box 371856
       Cincinnati, OH 45222
       1-800-543-4461

       Teledyne  Analytical Instruments
       16830 Chestnut Street
       City  of Industry, CA 91749
       213 283-7181

       Texas Analytical Controls, Inc.
       P.O. Box 42520
       Houston,  TX 77242
       713 240-4160

       Thermedics, Inc.
       470 Wildwood Street
       Woburn,  MA  01888
       617 938-3786

       Thermo Environmental Instruments, Inc.
       8 West Forge Parkway
       Franklin, MA 02038
       508 520-0430

       Transducer Research, Inc.
       999 Chicago Ave.
       Naperville, IL 60540
       708 357-0004
Manufacturers and Suppliers
14
10/93

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        VICI Metronics
        2991 Corvin Drive
        Santa Clara, CA 95051
        408 737-0550

        Viking Instruments Corp.
        12007 Sunrise Valley Drive
        Reston, VA 22091-3406
        703 758-9339

        Wedding & Associates, Inc.
        P.O. Box 1756
        Fort Collins, CO 80522
        303 221-0678

        Whatman Paper Division
        9 Bridewell Place
        Clifton, NJ 07014
        201  773-5800
Wheaton Scientific
1000 North 10th Street
Millville, NJ 08332
609 825-1400

Willson Safety Products
P.O. Box 622
Reading, PA 19603-0622
215 376-6161

Xetex, Inc.
600 National Avenue
Mountain View, CA 94043
415 964-3261

XonTech Inc.
6862 Hayvenhurst Avenue
Van Nuys, CA 91406  -
818 787-7380
10/93
                                          15
          Manufacturers and Suppliers

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           AIR MONITORING FOR HAZARDOUS MATERIALS
                                WORKBOOK

                                CONTENTS
Exercise                                                                  Page

1           Oxygen Monitor, Combustible Gas Indicators,
            and Specific Chemical Monitors	1

2           Photoionization Detectors - Survey	  13

3           Flame lonization Detectors - Survey	21

4           Gas Chromatography - Organic Vapor Analyzer	29

5           Detector Tubes 	'.	39

6           Direct-Reading Aerosol Monitors	53

7           Gas Chromatography - Photoionization Detector	63

8           Sampling Pumps and Collection Media	71

9           Field Exercise	87
10/93                                 \                                Contents

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                                   EXERCISE 1

               Oxygen Monitors, Combustible  Gas Indicators,
                        and Specific Chemical Monitors
OBJECTIVE
In this exercise, students will calibrate or check the calibration of a variety of combustible gas
indicators (CGIs),  combination CGI/O2 monitors, and combination CGI/O2/toxic monitors.  The
instruments will then be used to sample a variety of test atmospheres and the results will be
interpreted.
PROCEDURE

The exercise is divided into three different stations.  Each station is equipped with an air monitoring
instrument or group of instruments.

      Station 1:    MSA Model 260/261 combination CGI/O2 monitor

      Station 2:    MSA Model 360 combination CGI/O2/carbon monoxide monitor

      Station 3:    GasTech Model 1314 combination CGI/O2/toxic monitor

There may be more than one of each numbered station to reduce crowding. Follow the instructions
given for each instrument.  Sample the indicated gas bags and record your results.  At the end of
the exercise, answer the questions. The instructor will then hold a brief discussion.

The instructions given  for each instrument are based on the manufacturers' operating  manuals.
However,  some steps may  have  been added for illustration purposes  and some may have been
shortened for purposes  of time or space.   As with any instrument, consult the operator's manual
before using in the field.
10/93                                     \                                 Exercise 1

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                                    STATION 1

             MSA Model  260/261  Combination  CGI/0, Monitor
The MSA Model 260/261 is a combination combustible gas and oxygen monitor.  There are meter
displays for both indicators.  Visual and audible alarms for a % LEL reading and a low oxygen
reading are included. The Model 261 also has a high oxygen reading alarm.  The audible alarm can
be deactivated. Air is drawn into the instrument by a battery-operated pump.
SETUP

1.     Record the instrument serial number or ID number on the data sheet.

2.     Attach the sampling hose to the instrument.  Make sure that the connection is hand tight.


STARTUP

3.     Turn the center "ON-OFF" control clockwise to the "HORN-OFF" position.  Both meter
       pointers will move, both alarm lights will light, and the center green lamp will blink on and
       off. (Note:  On the Model 261, the light will not turn on until after the reset button  is
       pushed.) The green light indicates alarms status.  When it glows continuously, the audible
       alarm is operable.  When it blinks on and off, it  indicates that the audible alarm has been
       deactivated.

4.     Adjust the meter  pointer  on the % oxygen monitor  by pulling and turning the  "O2
       CALIBRATE KNOB."  The knob is supplied with a clutch  to prevent  accidental field
       decalibration.  Adjust the pointer to read  20.8%,  which is the  hatch mark below the 21%
       mark.

5.     Adjust the meter pointer on the %LEL  meter by pulling and turning the  "LEL ZERO
       KNOB."  Adjust the pointer to read 0%.

6.     Press the red alarm "RESET" button to reset the alarms.  Both  red lights should  stop
       flashing. (Note: The "RESET" button will not reset the alarms if the meter pointers exceed
       the alarm levels.)

7.     Press the black "CHECK" button and observe the pointer on the %LEL meter. The pointer
       should move  above 80% LEL into the BATTERY  zone of the meter. This indicates that the
       battery is okay.  If it does  not reach the BATTERY zone, inform an instructor/technician.


LEAK TEST

8.     Momentarily hold a finger over the sample inlet or end of sample probe.  Observe that the
       flow indicator float (lower right hand corner of instrument face) drops out of sight, indicating

Exercise 1                                2                                     10/93

-------
       no flow.   If the float does not drop out of sight, check the system for leaks.  If the
       instrument does not pass the leak test, inform an instructor/technician.


ALARM CHECK

The purpose of these steps is to check the meter readings at which the alarms will sound.

9.      Turn the O2 CALIBRATE knob counterclockwise (decreasing the % oxygen reading) while
       watching the % oxygen meter and the oxygen alarm light.  Note the reading at which the
       alarm sounds and the light starts flashing.  Adjust the reading back to 20.8% and press the
       reset button.  Record the reading on the data sheet.  The lower alarm reading should be
       19.5%.

10.    (MSA 261  only)  Turn the O2 CALIBRATE knob clockwise (increasing the  % oxygen
       reading) while watching the % oxygen meter and the oxygen alarm light.  Note the reading
       at which the alarm sounds and the light starts  flashing.  Adjust the reading back to 20.8%
       and press the reset button.  Record the alarm  reading on the data sheet.  . The upper alarm
       reading should be 25 %.

11.    Turn the zero LEL knob clockwise until the alarm is activated.  Record this reading.  Return
       the meter pointer to zero and press the reset button. The alarm should have activated at 25%
       LEL.

12.    If any of the alarm points are not what they should be, inform an instructor/technician.

13.    The instrument is ready for calibration.


CALIBRATION

14.    Open the clamp to the gas bag labeled "PENTANE 0.75%" and attach the sample line to the
       bag.  Draw a sample into the instrument until  a constant reading is obtained.

15.    Record your reading on the data sheet.  The instrument should  give a reading of 50% LEL.
       Inform the instructor if it does not.

16.    Disconnect  the  sample line and clamp the bag.   Allow  fresh air to  flow  through the
       instrument until the reading returns to zero. Rezero the instrument, if needed.


SAMPLING

17.    Please note that the  Model 261 has a latching mechanism that engages the %LEL meter
       pointer if it reaches or exceeds 100.  To disengage the lock, the instrument must be turned
10/93                                       -\                                  Exercise 1

-------
       off and then turned back on in an area where the LEL readings are less than 100%.  Room
       air will do.

18.     For field monitoring, the alarm should be in the operable mode. For this exercise, you may
       keep the audible alarm deactivated to reduce noise levels.

19.     Sample each of the gas bags listed on the data sheet.  Record the readings.
SHUTDOWN

20.    When sampling is complete,  flush fresh air through the instrument.  Turn the instrument
       OFF.
Exercise 1                                  4                                       10/93

-------
                                    STATION 2

             MSA Model 360 Combination CGI/OJCO Monitor
The MSA Model 360 is a combination combustible, oxygen, and carbon monoxide (CO) monitor.
It has a digital display that shows only one reading.  It has alarms for a specific % LEL reading, low
and high oxygen, and a specific carbon monoxide reading.  If the alarm levels are reached for any
of these responses, there will be a visual and audible indication.  This will occur no matter what
function is being displayed at the time. The audible alarm can be deactivated.  Air is drawn into the
instrument by a battery-powered pump.
SETUP

1.      Record the instrument serial number or ID number on the data sheet.

2.      Attach the sampling hose to the instrument. Make sure the connection is- hand tight.


STARTUP

3.      Turn the FUNCTION control to the "HORN-OFF" position.  Alarm signals will flash for
       all three chemicals, the "HORN OFF" green/yellow lamp will be off and % LEL will show
       in the readout.

4.      A low battery condition is indicated by a BATT sign in the readout or by a steady horn.
       Inform an instructor/technician if this occurs.

5.      Set the readout to zero (00) by  lifting and turning the LEL ZERO knob.  This must be done
       within 30 seconds of turning ON to prevent the possibility of activating the off-scale, LEL
       latching alarm.

6.      Press the SELECT button firmly to obtain % OXY on the readout.   Then set the readout to
       20.8% by adjusting the OXY CALIBRATE knob.

7.      Press the SELECT button firmly to obtain PPM TOX on the readout. Then set the readout
       to zero (00) by adjusting the TOX ZERO knob.

8.      Press the RESET button. (Note:  The "RESET" button  will not  reset the alarms  if the
       exceed the  alarm levels.)  The "HORN OFF"  green/yellow lamp will start flashing.  The
       light indicates alarm status.  When it glows continuously, the audible alarm is operable.
       When  it blinks on and  off,  as it  does now, it indicates that the audible  alarm has been
       deactivated.
10/93                                     5                                 Exercise 1

-------
LEAK TEST

9.     Momentarily hold a finger over the sample inlet or end of sample probe.  Observe that the
      flow indicator float (lower right hand corner of instrument face) drops out of sight, indicating
      no flow.   If the float does  not drop out of sight,  check  the  system for leaks.  If the
      instrument does not pass the leak test, inform an instructor/technician.
ALARM CHECK

The purpose of these steps is to check the meter readings at which the alarms will sound.

10.    Press the SELECT button until  % LEL is displayed.  Adjust the LEL ZERO knob until the
       alarm sounds.  Record the %  LEL reading.  Set the reading back to zero and press the
       RESET button.  The alarm should activate at 25%.

11.    Press  the SELECT button until OXY is displayed.   Turn the  OXY CALIBRATE knob
       counterclockwise (decreasing the  %  oxygen reading) until the alarm sounds.  Record the %
       OXY  reading.  Adjust the reading back to 20.8% and press the RESET button. The lower
       alarm reading should be 19.5%.

12.    Turn the OXY CALIBRATE knob  clockwise (increasing the  % oxygen reading) until the
       alarm sounds. Record the % OXY.  Adjust the reading back to 20.8% and press the RESET
       button. The upper alarm reading should be 25%.

13.    Press  the SELECT button until TOX  is displayed.  Turn the TOX ZERO knob clockwise
       until the alarm is activated.  Record  this reading.  Adjust the reading back to zero and press
       the RESET button.  The alarm  should have activated at 35 ppm.

14.    If any of the alarm points are not what they should be, inform an instructor/technician.

15.    Turn the FUNCTION control  to MANUAL for continuous readout of any one gas or to
       SCAN for automatic scanning of the three gas readings.  Note:  All alarm functions operate
       in either position.

16.    The instrument is ready for sampling.
 CALIBRATION

 17.    Open the clamp to the gas bag labeled "PENTANE 0.75%" and attach the sample line to the
       bag. Draw a sample  into the instrument until a constant reading is obtained.

 18.    Record your readings  on the data sheet. The instrument should give a reading of 50% LEL.
       Consult the instructor for proper oxygen and carbon monoxide readings.

 19.    Disconnect the  sample line and clamp the bag.  Allow  fresh air to  flow  through the
       instrument until the reading returns to zero.  Rezero the instrument,  if needed.


 Exercise 1                                  6                                      10/93

-------
SAMPLING

20.    For field  monitoring, the  alarm  should be in the operable mode  (SCAN or MANUAL
       setting).   For this exercise, you  may keep the audible alarm deactivated to reduce noise
       levels.

21.    Note:  The Model 360 has a latching mechanism that engages if the % LEL exceeds 100.
       To disengage the lock, the instrument must be turned off and then turned back on in an area
       where the LEL readings are less than 100%. Room air will do.

22.    Sample each of the gas bags listed on the data sheet.  Record the readings.
SHUTDOWN

23.    When done sampling, flush fresh air through the instrument. Turn the instrument OFF.
10/93                                      7                                 Exercise 1

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                                     STATION 3

                        Gastech Model  1314 Gastechtor
The GasTech Model 1314 is a combination combustible, oxygen, and toxic monitor.  There is no
separate toxic sensor.  The "toxic" response is provided by an amplification of the combustible
sensor (supersensitive CGI). Thus the toxic response is actually ppm combustible.  The readout is
an analog meter that only displays one reading.  The readout being displayed depends on the position
of the buttons on the side of the instrument.  It has a specific % LEL, low and high oxygen, and
toxic level alarms. The oxygen alarm will sound even if % LEL is being displayed and vice versa.
The toxic alarm, however, will only sound if in the "PPM" mode.  The unit has a battery-powered
pump for drawing air.
STARTUP

1.     Attach the hose to instrument by means of the quick release fitting.

2.     Put the PPM/LEL switch in the LEL (out)  position, with the black indicator showing, and
       OXY/LEL switch also in the LEL (out) position.

3.     Press the POWER switch to turn the instrument on, with orange indicator dot showing. The
       meter will normally rise upscale and a pulsing or steady alarm signal may sound.  Audible
       hum of pump will be noticed.  The cause of the alarm condition (combustibles, oxygen, or
       both) can be identified by the blinking lights.

4.     Press the BATT CK button and note the meter reading. If reading is close to or below the
       BATT CHECK mark on the meter, consult an instructor/technician.

5.     Allow the instrument to warm up until the meter stabilizes (about a minute).  If a pulsed
       oxygen alarm continues to  sound, turn the OXY CAL potentiometer clockwise to stop it.
       If the sound is steady, turn the potentiometer counterclockwise.

6.     With the hose inlet in a clean air location,  turn the ZERO LEL potentiometer to bring the
       meter to "0" indication.   If this is not possible, consult an instructor/technician.

7.     Put the OXY/LEL switch in the OXY (in) position, so that the orange indicator shows. Turn
       the OXY CAL potentiometer to bring the meter to the 02 CAL mark (21 %).

8.     As a quick check, gently breathe into hose inlet and allow instrument to sample exhaled air.
       Reading should come down to  about 16%,  and alarm should  sound at 19.5%.  Allow it to
       return to 21%, then put switch back in LEL position.

9.     These particular units have  a high oxygen alarm that will sound in a steady tone and the
       amber alarm lights will blink when reading reaches or exceeds 25%.
Exercise 1                                  »                                       10/93

-------
10.    The instrument will automatically test for oxygen whenever it is used, and will give a pulsed
       audible and an amber light alarm if oxygen content drops to 19.5%.  It is not necessary to
       use the instrument with the switch in the OXY position unless oxygen measurements are of
       primary interest.  If both abnormal gas conditions exist simultaneously, both lights will blink
       in their normal pattern, but alarm will sound continuously.

11.    For readings in the 0-100%  LEL range, hold inlet at point to be tested.  Watch meter and
       observe maximum reading as taken from the upper set of graduations. 0-100% scale.  If
       reading rises above the alarm setting (20% LEL), a pulsed red light and an audible alarm will
       commence, and will continue as long as reading remains above alarm point.

12.    If the reading  on the 0-100% range is imperceptible or very small, use the sensitive range,
       0-500 ppm.  First allow to warm up in the LEL range, and then push range switch to put
       circuit in  PPM range (colored  indicator showing). Rezero carefully with the ZERO LEL
       potentiometer.

       Because of the very high sensitivity of this range, the meter will tend to drift until instrument
       is thoroughly  warmed up.  Always let  it run  for 5 minutes or more, whenever possible,
       before  operating  on the PPM  range.   Take the  reading immediately  after zeroing, and
       observe maximum deflection  as taken from the middle set of graduations, 0-500 PPM scale.
       The alarm will sound  whenever the reading rises above the preset alarm level - 100 ppm.
CALIBRATION

13.    Put the PPM/LEL switch in the LEL (out) position.

14.    Unclamp the bag labeled  "HEXANE 0.55%" and attach it to the sample inlet.  Record the
       reading when it has stabilized.  The reading should be 50%.  If not,  please inform the
       instructor.


SAMPLING

15.    Sample each of the gas bags listed on the data sheet.  Record the readings.  DO NOT USE
       THE PPM SETTING UNLESS THE LEL RESPONSE IS VERY LOW.


SHUTDOWN

16.    When sampling is complete, flush fresh air through the instrument.  Turn the instrument
       OFF.
                                                                              Exercise 1

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Exercise  1
10

-------
                                    QUESTIONS





1.     Did the alarms activate at the appropriate readings? Which instruments did not?
2.      Why do the different instruments give different responses to similar combustible gases?
3.     What are the hazards (if any) associated with each unknown bag?
10/93                                     11                                 Exercise 1

-------
4.      List the limitations  and advantages  of each instrument  for  monitoring  an unknown
       atmosphere.
      MSA 260/261:
       MSA 360:
       GasTech 1314:
Exercise 1                                 12             .                        10/93

-------
                                  EXERCISE #2

                      Photoionization  Detectors - Survey


OBJECTIVE

Participants will learn how to calibrate and operate the HNU Model PI-101 Photoionization Detector.


PROCEDURE

Students will divide into groups as directed by the laboratory instructor. Each group will have an
HNU PI-101 Photoionization Detector with either a 10.2 eV or 11.7 eV lamp, and eight gas bags.
Also, five containers with unknown chemicals will be placed around the room.
       STATION 1:        Bag A        100 parts per million (ppm) toluene
                          Bag B        100 ppm acetone
                          Bag C        100 ppm toluene/100 ppm acetone
                          Bag D        800 ppm acetone
                          Bag E        250 ppm acetone
                          Bag F        50 ppm acetone
                          Bag G        50 ppm hexane
                          Bag CH4      100 ppm methane

      STATION 2:         Five containers with unknowns
By following the instructions, sample each station and record your results.  A discussion of your
findings will be held at the end of the exercise.
10/93                                    13                                Exercise 2

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SETUP

1.      Record the instrument serial number or ID number on the data sheet.

2.      Record the lamp energy.


STARTUP

Refer to Figure  1 for location of instrument controls.

3.      Connect  the probe.

4.      Turn the FUNCTION SWITCH to the BATTERY CHECK position.  The needle should
       deflect within or above the green arc.  If not, inform the instructor. If the red indicator light
       (low battery) comes on, do not use the instrument.

5.      To ensure that the lamp will light, turn the FUNCTION switch to any RANGE setting and
       place a solvent based  marker near the sample intake on the probe.  A needle deflection
       should occur, thus indicating that the lamp is on.

6.      There are two methods of zeroing an instrument. For this lab, use METHOD 1.

       •     METHOD  1 - Turn the FUNCTION SWITCH to the STANDBY
             position and  zero  the  instrument  using the ZERO knob.  This
             procedure is used to zero the instrument electronically.  If the SPAN
             setting is altered, the zero should be rechecked and adjusted.  Wait
             fifteen to twenty seconds to ensure that the zero reading is stable.  If
             necessary, readjust the zero.

       •     METHOD 2 - Turn the FUNCTION SWITCH to  the range being
             used and rotate the ZERO knob until the meter reads zero. Now you
             have zeroed out background. If the SPAN setting is changed after the
             zero is set, the zero should be rechecked and adjusted.
       You are now ready to calibrate your instrument.
CALIBRATION

7.     The instructor will assist the students in the calibration procedure.  A compressed gas
       cylinder containing isobutylene will be used to calibrate the instrument. Set the FUNCTION
       SWITCH to the 0-200 RANGE setting.

8.     Connect the probe to the tubing from the ISOBUTYLENE cyclinder.  Unlock the SPAN
       knob by moving the black lock handle counter clockwise.  By adjusting the SPAN setting
       between 0-100, obtain the appropriate instrument reading.  The instructor will tell you the
Exercise 2                                 14                                     10/93

-------
      appropriate reading. Do not lock the SPAN knob at all during this lab exercise.  Record the
      SPAN setting at calibration on the data sheet.
SAMPLING

9.     When taking readings, adjust the FUNCTION SWITCH to get the maximum on scale needle
      deflection.  If the reading exceeds the meter range, adjust the FUNCTION SWITCH.

10.    Measure for contaminants in BAGS A, B, C, G, and CH, and record the results.

11.    Take readings over the openings of each of the unknown containers.  Record the readings.


CALIBRATION CHANGE

12.    By  adjusting the SPAN, calibrate the  instrument to  BAG B (acetone).   Measure the
      concentration of BAGS C, D, E, and F and record your results.  Then plot the instrument
      readings vs. actual concentration from BAGS B, D, E, and F on Graph 1.


SHUTDOWN

13.    Turn the FUNCTION SWITCH to the OFF position.
10/93                                   15                                Exercise 2

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    Low Battery Indicator
    Light (LED)
             Power Off
            Sensitivity
            Adjustment
            Hi-Voltage
              Interlock
                                      Battery Check
                                      Position
                                                                         Ranges (ppm)
                                                                              Function
                                                                              Switch
                                                   12 Pin Interface Connector
                                                   between readout unit and
                                                   season
                                                                              Zero Adjustment
                                Recorder Output
                                 1-5V DC)
                              FIGURE 1.  HNU PI 101  CONTROLS

Source:  Instruction Manual for Model PI 101 Photoionization Analyzer, 1975, HNU Systems, Inc.
Used with permission of HNU Systems,  Inc.
Exercise 2
16
10/93

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                                DATA SHEET
                                  TABLE 1
       INSTRUMENT MODEL
       I.D. NUMBER
       LAMP ENERGY
       GAS
       CONCENTRATION
       INSTRUMENT READING
       SPAN SETTING
                                  TABLE 2
        BAG
CONCENTRATION
INSTRUMENT
  READING
 RELATIVE
RESPONSE*
  A - TOLUENE
    100 ppm
  B - ACETONE
  C - TOLUENE/
    ACETONE
  G-HEXANE
    100 ppm
    100/100
    50 ppm
  CH4 - METHANE
    100 ppm
* Relative Response = Instrument Reading
% Relative Response.
              + Actual Concentration.  Multiply by 100% to get
10/93
                17
                         Exercise 2

-------
                                DATA SHEET
TABLE 3
SAMPLE LOCATION*
1
2
3
4
5
READING





*Add information about location of probe when taking the reading.
                                   TABLE 4
                             ACETONE CALIBRATION
        BAG
    ACTUAL
CONCENTRATION
INSTRUMENT
  READING
        B
    100 ppm
                          100/100
                          800 ppm
                          250 ppm
                          50 ppm
Exercise 2
                18
                              10/93

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     GRAPH 1. INSTRUMENT READING VS. TRUE CONCENTRATION


    900
    800
    700
 D)
    600
 CO
 0
rr 500
 CD
    400
    300
    200
    100
10/93
      0   100  200   300  400   500   600  700   800  900


         True Concentration (ppm)
19
Exercise 2

-------
                                    QUESTIONS


1.      Calculate and record the relative response for each of the chemicals in Table 2.



2.      Why is the reading for Bag C in Table 2 different from the reading in Table 4?
3.     From Graph 1, does the instrument accurately measure all four concentrations?  If you were
       going to measure acetone vapors at concentrations of 0-10 ppm, would this calibration curve
       be of value to you?
4.     Unknown 2 is found to be acetone.  Develop a method(s) using the HNU to determine the
       concentration of acetone at the location.
5.     You are using an HNU to survey a site and obtain a reading of 200.  How do you report
       your findings and what additional  information would you like recorded?
Exercise 2                                  20                                      10/93

-------
                                  EXERCISE #3

                     Flame lonization Detectors - Survey
OBJECTIVE
Participants will learn how to calibrate and operate the Foxboro Organic Vapor Analyzer OVA-128
in the survey mode.
PROCEDURE

Students will divide into groups as directed by the laboratory instructor. Each group will have an
Foxboro OVA-128 plus eight gas bags. Also, five containers with unknown chemicals will be placed
around the room.

      Station 1:     Bag A        100 parts per million (ppm) toluene
                    Bag B         100 ppm acetone
                    Bag C        100 ppm acetone/100 ppm toluene
                    Bag D        800 ppm acetone
                    Bag E         250 ppm acetone
                    Bag F         50 ppm acetone
                    Bag G        50 ppm hexane
                    Bag CH4      100 ppm methane

      Station 2:     Five sampling containers

By following the instructions, sample each station and record your results.  A discussion of your
findings  will be held at the end of the exercise.
10/93                                    21                                Exercise 3

-------
Please read each paragraph completely before following the directions and proceeding to the next
paragraph.
SETUP

1.      Record the instrument serial number or ID number on the data sheet.


STARTUP

2.      Turn off the charger and disconnect the charger cable from the instrument.

3.      Unlock the GAS SELECT dial and adjust it to 300 (i.e., a  3 in the window and 00 on the
       dial).

4.      Turn the VOLUME knob fully counter clockwise.

5.      Ensure that the SAMPLE INJECT VALVE and BACK FLUSH VALVE are in the full pjai
       position.

6.      The toggle switches on this instrument have a lock to prevent accidental changes.  To move
       the toggle switch, lift and then move the  lever.

7.      Move the INSTRUMENT switch to ON and allow 5 minutes for warm-up.

8.      Move the PUMP switch  to ON.  You should hear the pump running.  Place the instrument
       in a vertical position and look at the SAMPLE FLOW RATE (rotameter at  lower left of
       panel).  The flow  rate (read at center of ball) should be 2.0 (liters/minute). A reading
       between  1.5 and 2.5 is considered adequate.

9.      Set the CALIBRATE switch to X10. Adjust the CALIBRATE knob until the meter reads
       0.

 10.    Open the H2 TANK VALVE and H2 SUPPLY VALVE one and one-half turns counter
       clockwise. The TANK gauge should be 500 psi or higher. The SUPPLY gauge should read
       between 10 and 12 psi.  If they do not, inform the instructor.

 11.    Wait about 1 minute.  Depress the red IGNITER BUTTON (on the side of the pack) until
       the flame ignites or until 6 seconds have passed.  Flame ignition is  indicated by a sharp
       meter needle deflection towards 10 along with a small "pop" sound. Also, the meter needle
       should return to a  reading above 0 instead of 0.  Do not depress  the button longer than 6
       seconds.  If the flame does not ignite on the first try, wait a minute, and try again.  If it does
       not ignite on a second try, check that steps 1 through 10 have been  completed.  Then consult
       an instructor or technician for assistance.

 12.    Use the  CALIBRATE knob to adjust the meter reading  to zero.  Move the CALIBRATE
       switch to XI and rezero.


Exercise 3                                 22                                     10/93

-------
CALIBRATION

13.     Set the CALIBRATE switch to X10.

14.     Locate the METHANE calibration gas bag.  Methane is the normal calibration gas for the
       OVA.

15.     Open the bag clamp and attach the methane bag to the probe inlet.  It is important that the
       bag be open before attaching it so that a "flame out" does not occur from oxygen starvation.

16.     Unlock and adjust the GAS SELECT knob  so that the meter  reading is equal to the bag
       concentration divided by the CALIBRATE switch  setting.   For example, if the bag
       concentration is 90 ppm, then the reading should be 9 (90 divided by 10).

17.     Disconnect the gas bag and close the clamp.

18.     The GAS SELECT setting  should be about 300.   300 is the  "ideal" setting,  but your
       instrument may have a different reading. If the setting must be adjusted above 400 or below
       200, internal calibration may be advisable.

19.     The instrument is now calibrated to methane and ready for survey purposes.
SAMPLING

20.    During the next two steps, change the CALIBRATE switch setting as necessary to get the
       maximum on-scale reading. If the meter reads above 10 on the X100 setting, report the
       reading as greater than 1000.

21.    Take readings of bags A, B, C and G. Record the data.

22.    Take readings at the five containers.  Record the readings and locations.


CALIBRATION

23.    Change the CALIBRATE switch to X10.

24.    Open and connect Bag B  to the probe inlet.   Adjust the GAS SELECT knob until the
       instrument reads 10 on the X10 range.

25.    Disconnect and close the bag.  Use the CALIBRATE ADJUST knob to rezero, if needed.

26.    Take readings of bags C, D, E, and F.  Record the readings. Plot the readings from bags
       B, D, E, and F on GRAPH 1.
10/93                                     23                                 Exercise 3

-------
SHUTDOWN




27.    Close the H2 SUPPLY valve, then the H2 TANK valve.




28.    Move the INSTRUMENT switch to OFF.




29.    When the SUPPLY pressure gauge falls to zero, move the PUMP switch to OFF.
Exercise 3                              24                                 10/93

-------
                                DATA SHEET
                                   TABLE 1
       INSTRUMENT MODEL
       I.D. NUMBER
       CALIBRATION
       GAS
       CONCENTRATION
       INSTRUMENT READING
       GAS SELECT SETTING
                                   TABLE 2
        BAG
CONCENTRATION
INSTRUMENT
  READING
 RELATIVE
RESPONSE*
  A - TOLUENE
    100 ppm
  B - ACETONE
  C - TOLUENE/
     ACETONE
  G-HEXANE
    100 ppm
    100/100
    50 ppm
*Relative Response = Instrument Reading  + Actual Concentration.  Multiply by 100% to get
% Relative Response.
10/93
                                     25
                                              Exercise 3

-------
                                DATA SHEET
TABLE 3
SAMPLE LOCATION*
1
2
3
4
5
READING





* Add information about location of probe when taking the reading.
        BAG
                                   TABLE 4
                            ACETONE CALIBRATION
    ACTUAL
CONCENTRATION
                         100 ppm
                          100/100
                         800 ppm

                         250 ppm

                          50 ppm
INSTRUMENT
  READING
GAS SELECT
  SETTING
Exercise 3
                26
                              10/93

-------
GRAPH 1.  INSTRUMENT READING VS. ACTUAL CONCENTRATION {from Table 4)


    900
    800
    700
 G)
    600
 CtJ
 CD
 rr 500
    400
    300
    200
    100
      0   100   200   300  400   500   600  700   800   900


          True Concentration  (ppm)
10/93
27
Exercise 3

-------
                                      QUESTIONS
1.      Calculate the relative response for each of the chemicals in Table 2.
2.      Why is the reading for Bag C in Table 2 different from the reading in Table 4?
3.     From Graph 1, does the instrument accurately measure all four concentrations? If you were
       going to measure acetone vapors at concentrations of 0-10 ppm, would this calibration curve
       be of value to you?
4.     Unknown 2 is found to be acetone.  Develop a method(s) using the OVA to determine the
       concentration of acetone at the location.
5.     You are using an OVA to survey a site and obtain a reading of 200.  How do you report
       your findings and what additional information would you like recorded?
Exercise 3                                  28                                       10/93

-------
                                  EXERCISE #4

              Gas Chromatography - Organic Vapor Analyzer
OBJECTIVE
Participants will learn how to operate the Foxboro OVA-128 with gas chromatograph option as a
portable gas chromatograph.
PROCEDURE

The students will divide into groups as directed by the laboratory instructor.  Each group will have
a Foxboro OVA-128 with gas chromatograph option and three gas bags.

             Bag CH4:     Calibration gas
             Bag C:        Standard of 100 ppm toluene and 100 ppm acetone
             Unknown #1

By following the instructions of the  lab manual and instructor, each group will produce a gas
chromatograph for each bag. By comparing the results from the standard to the unknown,  the group
will try to determine what  chemicals  are present and at what concentrations. The results will be
recorded and discussed at the end of the exercise.
10/93                                    29                                Exercise 4

-------
Please read each paragraph completely before following the directions and proceeding to the next
paragraph.
SETUP

1.      Record the instrument serial number or ID number on the data sheet.


STARTUP

2.      For gas chromatograph use, the charger can remain on and connected to the OVA.

3.      Unlock the GAS SELECT dial and adjust it to 300 (i.e., a 3 in the window and 00 on the
       dial).

4.      Turn the VOLUME knob fully counter clockwise.

5.      Ensure that the SAMPLE INJECT VALVE and BACK FLUSH VALVE are in the full out
       position.

6.      The toggle switches on this instrument have a lock to prevent accidental changes.  To move
       the toggle switch, lift and then move the lever.

7.      Move the INSTRUMENT switch to ON and allow 5 minutes for warm-up.

8.      Move the PUMP switch  to ON.  You should hear the pump running.  Place the instrument
       in a vertical position and look at the SAMPLE FLOW RATE (rotameter at  lower left of
       panel).  The flow  rate (read at center of ball) should be 2.0 (liters/minute). A reading
       between  1.5 and 2.5 is considered adequate.

9.      Set the CALIBRATE switch to X10. Adjust the CALIBRATE knob  until the meter reads
       0.

10.    Open  the H2 TANK VALVE and H2 SUPPLY VALVE one and one-half turns counter
       clockwise. The TANK gauge should be 500 psi or higher. The SUPPLY gauge should read
       between  10 and 12 psi.   If they do  not, inform the instructor.

11.    Wait about 1 minute. Depress the red IGNITER  BUTTON (on the side of the pack) until
       the flame ignites or until 6 seconds have passed.  Flame ignition  is  indicated by a sharp
       meter needle deflection toward 10 along with a small "pop" sound.  Also, the meter needle
       should return to a reading above 0 instead  of 0.  Do not depress the button longer than 6
       seconds.  If the flame does not ignite on the first try, wait a minute, and try again.  If it does
       not ignite on a second try, check that steps 1 through 10 have been completed.  Then consult
       an instructor or technician for assistance.

12.    Use the  CALIBRATE knob to adjust the meter reading to zero.  Move the CALIBRATE
       switch to XI and rezero.


Exercise 4                                 30                                     10/93

-------
CALIBRATION

13.    Set the CALIBRATE switch to X10.

14.    Locate the METHANE calibration gas bag.  Methane is the normal calibration gas for the
       OVA.

15.    Open the bag clamp and attach the methane bag to the probe inlet.  It is important that the
       bag be open before attaching it so that a "flame out" does not occur from oxygen starvation.

16.    Unlock and adjust  the GAS SELECT knob  so that the meter reading is equal  to the bag
       concentration divided by the CALIBRATE switch  setting.   For example, if the bag
       concentration is 90 ppm, then the reading should be 9 (90 divided by 10).

17.    Disconnect the gas  bag and close the clamp.

18.    The GAS SELECT setting  should be  about 300.  300  is the  "ideal" setting, but your
       instrument may have a different reading.  If the setting must be adjusted above 400 or below
       200, internal calibration may be advisable.
GAS CHROMATOGRAPH SETUP

19.    Connect the strip chart recorder to the OVA.  Move the HI/LO switch (on the side of the
       recorder) to the LO position.  The chart paper should start moving and you should hear a
       clicking sound.  If the chart does not operate, check the cable connections.   Inform the
       instructor if the chart doesn't work.

20.    Turn the ZERO knob on the recorder (next to  HI/LO switch) completely clockwise.

21.    Turn the OVA CALIBRATE knob to adjust the baseline (black line produced by the pin) on
       the chan.  Do not use the ZERO knob on the  recorder.  The baseline  should be about 1/4
       inch (two thin brown lines) above the thick brown line next to the  sprocket holes.

22.    Locate the  stopwatch.  Practice with the stopwatch until you can do lap counting.  The
       instructor will demonstrate. Lap counting involves stopping the readout without stopping the
       stopwatch timing.  This is useful for timing more than one peak.
STANDARD CHROMATOGRAM

23.    Open and connect the STANDARD  (Bag  C:  Acetone/Toluene) bag to the probe inlet.
       Watch the meter needle.  When the needle has deflected to its highest point, depress the
       SAMPLE INJECT VALVE and start the stopwatch. Disconnect and close the gas bag.  If
       the needle passes 10, wait 3 seconds, then depress the INJECT VALVE.

       Keep the SAMPLE INJECT VALVE depressed until the end of the chromatogram.  The
       instructor will discuss how to determine when the chromatogram is done.


10/93                                     31                                  Exercise 4

-------
24.    Strike a line across the chart with a pen or pencil to indicate the start of a chromatogram.
      Write the OVA CALIBRATE SWITCH setting (XI, X10, X100) and the recorder HI/LO
      setting on the chart paper.

25.    Watch the chart paper or meter face for an upward needle deflection.   When the needle
      reaches a maximum reading and starts to drop, note the time. This is the top of the peak and
      the time is the retention time for the peak.  Do this for each peak.  Record the retention
      times for each peak.

26.    If a peak is too small or goes off scale, you will need to rerun the standard at a different
      CALIBRATE  SWITCH setting and/or different HI/LO setting.   Table  1  shows the
      relationship between peak size and instrument settings.  For example, if a peak is off scale
      on a HIX10 setting, changing the settings to LOX10 or HIX100 would make the peaks 1/2
      or  1/10 the size of the original peaks.
TABLE 1
RECORDER RANGE
FACTOR
HI
LO
HI
LO
HI
LO
OVA SCALE
X1
X1
X10
X10
X100
X100
RELATIVE
PEAK SIZE
1
1/2
1/10
1/20
1/100
1/200
27.    When a chromatogram is done (i.e, the last peak is out and the baseline is back to normal),
       lift the SAMPLE INJECT VALVE.  The instrument is ready for another run.
SAMPLE CHROMATOGRAM

28.    Repeat steps 22 through 26 using the UNKNOWN sample bag.


SHUTDOWN

29.    Close the H2 SUPPLY valve, then the H2 TANK valve.

30.    Move the INSTRUMENT switch to OFF.
Exercise 4
32
10/93

-------
31.    Move the RECORDER RANGE SETTING switch to OFF.

32.    When the SUPPLY pressure gauge falls to zero, move the PUMP switch to OFF.
CALCULATIONS FOR QUALITATIVE EVALUATION

27.    (Optional) Tear off the strip chart and measure the distance from the injection point to the
      middle of the peak in mm (see Figure 1 below).
                           Retention time
        Injection
                                                                    Time
                 FIGURE 1.  RETENTION TIME (DISTANCE) ILLUSTRATION

28.   Compare the retention times of the known standard and the unknown. If the retention times
      are relatively close, then the unknown can possibly be identified through comparison to the
      known.  For example, if a standard of acetone released at 144 seconds and a peak on our
      unknown was at 136 seconds, then we can assume that the peak was acetone.
QUANTITATIVE ANALYSIS

29.    To find the concentration of a chemical that has been identified with a standard, you will
      need a ruler,  a calculator, and a pencil.

30.    Draw a triangle that approximates the area of the curve similar to the example (Figure 2)
      below.
10/93
33
Exercise 4

-------
                              Area = 1/2 x base x height
                              Area = 1/2 b h
                          FIGURE 2.  PEAK AREA ILLUSTRATION

31.     Calculate the area of the triangle for the  standards and unknowns by using the following
       formula:
32.
33.
                              Area = V4(b)(h)

To compensate for the different instrument settings a corrected area formula must be used:

Corrected Area = OVA Setting x Recorder Range Factor  x Area of Triangle
                             X100
                              X10
                               XI
                                            HI  = .5
                                            LO =  1.0
To obtain the actual concentration of the unknown, divide the corrected area of the unknown
by the corrected area of the standard and multiply by the standard concentration.
                                    Corrected Areaun]mnm
         Concentration of unknown - —	——unamwn  x Standard concentration
                                    Corrected Area
                                                  standard
Exercise 4
                                    34
10/93

-------
TABLE 2


CONCENTRATION
RETENTION TIME
RETENTION
DISTANCE (mm)
PEAK BASE (mm)
PEAK HEIGHT (mm)
PEAK AREA (mm2)
OVA SCALE
SETTING
RECORDER
SETTING
CORRECTED AREA
(mm2)
STANDARD BAG C
ACETONE









TOLUENE









UNKNOWN #1
PEAK 1









PEAK 2









PEAK 3









10/93
35
Exercise 4

-------
                        CALCULATIONS
Exercise 4                       36                           10/93

-------
                                    QUESTIONS
1.     Identify the peaks in Unknown #1. For the peaks that can not be positively identified, list
       the possible candidates.
2.     What are the concentrations of the identified peaks?  Compare your numbers with the actual
       concentrations (from the instructor). Give reasons why your results may vary from the actual
       concentrations.
10/93                                      37                                  Exercise 4

-------
                          CHROMATOGRAPHY AND SURVEY GUIDE
                       FOXBORO CENTURY ORGANIC  VAPOR ANALYZERS
       COMPOUND
ACETONE
ACETONTTRILE
ACRYLONITRILE
ALLYL ALCOHOL
ALLYL CHLORIDE
BENZENE
BROMOETHANE
BROMOMETHANE
BROMOPROPANE
BUTADIENE.1.3-
BUTANE
BUTANOL
BUTANOL.2-
BUTANONE.2-
BUTENE
BUTYL ACETATE
BUTYL ACRYLATE
BUTYL ACRYLATE.tert-
BUTYL FORMATE
BUTYL FORMATE.tert-
BUTYL METHACRYLATE
BUTYL METHYL ETHER.tert-
CARBON TETRACHLORIDE
CKLOROBENZENE
CHLOROFORM
CHLOROMETHANE
CHLOROPROPANE
CHLOROPROPANE.2-
CUMENE
CYCLOHEXANE
CYCLOHEXANONE
 DECANE
 DIACETONE ALCOHOL
 D1BROMOETHANE.1.2-
 DICHLOROBENZENE.1.2-
 DICHLOROETHANE.1.1-
 DICHLOROETHANE.1.2-
 D1CHLOROETHYLENE, 1.1-
 DICHLOROETHYLENE.trans-l
 DICHLOROMETHANE
 DICHLOROPROPANE.1.2-
 DICHLOROPROPANE.1.3-
 DIOXANE.p-
. . • ':•< :'"
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98
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185
72
23
73
36
58
46
55
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43
67
60
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48
64
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57
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56
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..-'.' . 	 SYNONYM ; ;.;;:":.::.::U:
;,-.."x.:: .-.".--
-PROPANONE

VUs'YL CYANIDE



ETHYL BROMIDE
METHYL BROMIDE
PROPYL BROMIDE
BUTADIENE

BUTYL ALCOHOL
sec-BUTYL ALCOHOL
METHYL ETHYL KETONE



2-BUTYL ACRYLATE / PROPYLENE

2-BUTYL FORMATE



MONOCHLOROBENZENE
TRICHLOROMETHANE
METHYL CHLORIDE
PROPYL CHLORIDE
ISOPROPYL CHLORIDE
ISOPROPYL BENZENE
HEXAMETHYLENE


4-HYDROXY-4-METHYL-2-PENTANON'
ETHYLENE DIBROMIDE
o-DICHLOROBENZENE

ETHYLENE DICHLORIDE
VINYLIDENE CHLORIDE

METHYLENE CHLORIDE
PROPYLENE DICHLORIDE

DIETHYLENE DIOXIDE

-------
      COMPOUND
ENFLURANE
ETHANE
ETHANETHIOL
ETHANOL
ETHENE
ETHER
ETHYL ACETATE
ETHYL ACRYLATE
ETHYL BENZENE
ETHYL BUTYRATE
ETHYL FORMATE
ETHYL METHACRYLATE
ETHYL PROPIONATE
ETHYLENE OXIDE
FREON-11
FREON-113
FREON-114
FREON-123
FREON-12
FREON-21
FREON-22
HALOTHANE
HEPTANE
HEXADECANE
HEXAFLUOROPROPENE
HEXANE
ISOBUTANE
ISOBUTENE
 ISOPRENE
 ISOPROPYL ACETATE
 METHANE
 M ETHANOL
 METHYL ACETATE
 METHYL ACRYLATE
 METHYL CYCLOHEXANE
 METHYL CYCLOPENTANE
 METHYL ISOBUTYL KETONE
 METHYL METHACRYLATE
 METHYL SULFIDE
 NITROMETHANE
 NITROPROPANE
 NITROPROPANE,2-
 NONANE
 OCTANE
 PENT AN E
 PENTANOL
 PENTANONE.2-

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*
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*
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200
10
400
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50
100
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200
300
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T-12. COLUMN
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146
77
23
20
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67
71
111
91
44
73
83
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91
110
86
13
71
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80
52
81
70
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G-24 COLUMN
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sec
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I
31
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1
38
108
254
1054
538
43
514
274
35
24
43
3
22
5
17
3
51
232
	
2
88
14
10
32
130
1
64
49
107
230
114
353
266
35
73
285
191
1939
748
29
728
227
a.

'0.24
0.0 1
0.25
0.37
0.01
0.31
0.38
2.07
8.57
4.73
0.35
4.18
2.23
0.23
0.20
0.35
0.07
0.18
0.04
0.14
0.02
0.41
1.89
0.00
0.02
0.72
0.11
0.08
0.26
1.46
0.0 1
0.52
0.40
0.37
2.23
0.93
2.37
2.16
0.28
0.59
2.32
1.53
15.76
6.0
0.24
5.92
1.8


-C

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Ti
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IE







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FL
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_2
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,-*.


PE

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P
M
             SYNONYM
  -CHLORO-1,1.2TTRIFLUOROETHYL-DI-
   FLUOROMETHYL ETHER / ETHRANE
 ETHYL MERC APT AN
 ETHYL ALCOHOL
 ETHYLENE
  IETHYL ETHER
  :?OXYETHANE
 FLUOROTRICHLOROMETHANE
  RICHLOROTRIFLUOROETHANE
  .2-DICHLORO-l 122-TETRAFLUOROETH,
  .2-DICHLORO-l. 1,1-TRIFLUOROETHANE
 DICHLORODIFLUOROMETHANE
 DICHLOROFLUOROMETHANE
 CHLORODfFLUOROMETHANE
 2-BROMO-2CHLORO-11ITRIFLUOROETH,
   ERFLUOROPROPENE

  2-BUTANE / 2-METHYL PROPANE
  SOBUTYLENE / 2-METHYL PROPENE
  2-METHYL-1,3-BUT AD IENE
  METHYL ALCOHOL
.7 4-METHYL-2-PENTANONE / HEXONE
  DIMETHYL SULFIDE
  PENTYL ALCOHOL
  METHYL PROPYL KETONE

-------
       COMPOUND
PENTANONE.3-
PROPANE
PROPANOL
PROPANOL.2-
PROPYL ACETATE
PROPYL ETHER
PROPYL FORMATE
PROPYLENE
FROPYLENE OXIDE
PYRIDINE
3TYRENE
TETRACHLOROETHANE, 1.1.1.
TETRACHLOROETHYLENE
TETRAHYDROFURAN
TOLUENE
TRICHLOROETH ANE, 1.1.1-
TRICHLOROETHANE, 1.1.2-
TRICHLOROETHYLENE
TRIETHYLAMINE
TRIMETHYLPENTANE.2.2.4-
VINYL ACETATE
VINYL CHLORIDE
XYLENE.m-
XYLENE.o-
XYLENE.p-

 KEY:
 •   No TWA levels available.

 TWA  8 Hour Time Weighted Average for
     Maximum allowable exposure.

 RR   Relative Response to METHANE in Percent =
     (Measured Response / Prepared Concentration) x 100.

 	 tR data not available

TWA.
ppm
200...
1000
200
400
200
•
•
*
20
5
50
•
25
200
too
350
to
50
10
•
to
1
too
too
too
T-12 COLUMN
RR
%
.61
70
35
60
60
56
53
36
66
109
92
81
67
47
126
101
95
54
59
91
40
38
107
106
106
tR'
. sec
355
1
351
153
283
36
157
2
46
	
1384
956
141
106
262
53
1158
104
	
14
116
5
563
804
545
a.

6.70
0.02
6.62
2.S9
5.34
0.68
2.96
0.04
0.87
0.00
26.11
18.04
2.66
2.00
4.94
1. 00
21.85
1.96
0.00
0.26
2.19
0.09
10.62
15.17
10.28
G-24 COLUMN
tR'
sec
257
5
102
57
286
217
111
4
40
	
1355
810
603
125
391
123
378
222
34
221
77
9
1135
1366
1140
a.

2.09
0.04
0.83
0.46
2.33
1.76
0.90
0.03
0.33
0.00
11.02
6.59
4.90
1.02
3.18
1.00
3.07
1.80
0.28
1.30
0.63
0.07
9.23
11.11
9.27
                           SYNONYM
              DIETHYL KETONE

              PROPYL ALCOHOL
              ISOPROPANOL
              1.2-EPOXYPROPANE
              PERCHLOROETHYLENE

              METHYL BENZENE
              METHYL CHLOROFORM
              ISOOCTANE
              1.3-DIMETHYL BENZENE
              1.2-DIMETHYL BENZENE
              1.4-DIMETHYL BENZENE
tR * Solute Retention Time from point of injection
tR'= Adjusted Retention Time in seconds
tM = Gas Hold-Up, or Dead Time
      tR1  = tR - tM

a = Relative Retention as compared to a Reference
Reference Compound is 1.1,1-Trichloroethane

Data collected at a chart speed = 1 cm/min. at
concentrations of 50 or 100 ppm. and at ambient
temperature

-------
HOW TO USE THIS CHART FOR IDENTIFICATION OF UNKNOWNS BY GC
1. Calculate the Adjusted Retention time of the Unknown solutes and of the Reference compound for the selected
column. This can be accomplished by either running the reference compound separately, under similar conditions
as che unknown will be run, or along with the questioned sample by introducing it into the sample stream via
direct injection, dilutor accessory, or other like means.  The tR' for any solute is equal to the time elapsed
from the point of injection to the projection of the peak maximum, minus the gas hold-up time of the column.
The gas hold-up time is the time elapsed from the point of injection to the minimum deflection of che air peak.
(NOTE: approximate hold-up times are 5 sees for a T-12 column and 10 sees for a C—24 column.)

2. In order to minimise the effects of minor variation in operating conditions and in the stationary phase
loading of the columns, the parameter of Relative Retention (a) is used.  To calculate a. for a particular
solute on a given column, divide the tR' of the solute by the tR' of the reference compound.  If the value of a
falls within W- 10% of the chart value, then the chances are good that the questioned solute is one of the
compounds in this range.

 3. To increase the probability of identifying an unknown solute, this chart provides the user with the option
 of Two-Column dimensional chromaiography. By utilizing a second type column, one can calculate a second a value
 for the questioned solute.  If this value of a falls within */- 10% of the chart value, and the  value of a for
 the previous columnn falls within +/- 10% of that chart value, then there is a high probability that the unknown
 has been identified.       *

 i.  Laboratory GC analysis and standard  preparation may be required for confirmation, depending upon the
 application.

-------
                                    EXERCISE #5

                                   Detector Tubes
OBJECTIVE

During this exercise, participants will learn how to do a leak check and a volume check of both a
Draeger and a Sensidyne detector tube pump and how to  use  detector tubes quantitatively and
qualitatively.
INTRODUCTION

There are chemical indicators that use the reaction of a chemical reagent with the airborne chemical
of interest to produce a color change.  The intensity of the color change or the length of color change
is used to determine the amount of airborne  chemical present.   The chemical reagent may be
impregnated on a piece of paper or tape and the  color change read by eye or by an electronic device.
The chemical could also be placed in a glass tube called a colorimetric  indicator tube or detector
tube.
PRINCIPLE OF OPERATION

Colorimetric indicator tubes or detector tubes (Figure 1) consist of glass tube impregnated with an
indicating chemical.  A known volume of contaminated air passes through or into the tube.  The
contaminant reacts with the indicator chemical in the tube, producing a change in color whose length
or intensity is proportional to the contaminant concentration.

The tubes may have a preconditioning filter preceding the indicating chemical to:

       •      Remove  contaminants (other than the one  in question) that may interfere with the
              measurement.  Many have a prefilter for removing humidity.

       •      React with a contaminant to change it into a compound that reacts with the indicating
              chemical.
TYPES OF TUBES

Detector tubes can be classified by the way air is drawn into the tube:

       •      Short-term tubes use a hand pump to draw air through the tube for a sample duration
              of a few seconds to  a few minutes.  This is used to give an instantaneous sample.
              The hand pump may be a piston or bellows type pump.  This exercise will use both
              types.  A piston pump has  a handle that is pulled to evacuate a cylinder of known
              volume.  Air is pulled through the tube  to equalize the pressure in the cylinder.


10/93                                      39                                  Exercise 5

-------
             MSA, Sensidyne,  Enmet, and Matheson manufacture piston pumps.  In a bellows
             pump, the bellows is squeezed and released. Air is pulled through the tube as the
             bellows expands.  Draeger and MSA manufacture bellows-type pumps.
                               Plug
                              Glass
                               vial
10


20


30

40
                                        50
                                        n » 5
                                                 Prefilter
                                               or reagent
 Indicating
  chemical
on silica gel
                               Plug
                          FIGURE 1. DETECTOR TUBE EXAMPLE
             Long-term tubes (pump) use a battery-operated pump to draw air through the tube
             over a longer period of time, usually 8 hours. These are used to determine 8-hour,
             time-weighted average exposures.

             Long-term tubes (dosimeter) do not use a pump. Contaminants diffuse into the tube
             over a long period of time, usually 8 hours.  These also are used for 8-hour, time-
             weighted average exposure  determination.  However, a pump is not required for
             operation.
The three types of tubes are not interchangeable.  They are calibrated for their specific applications.
There are many more short-term tubes than there are long-term tubes.
Exercise 5
  40
                                   10/93

-------
Detector tubes can also be classified by the information generated the results:

       •      Chemical groups—Some tubes will react to a class of chemicals (e.g.,  alcohols or
              hydrocarbons).  They will  only indicate that a chemical of a certain class is present.

       •      Specific chemicals—There are a few tubes that only react to that specific chemical.
              Most tubes have a specific chemical listed for the  tube, but  can react to other
              chemicals (interferences).

       •      Concentration ranges—There may also be different concentration ranges for the same
              chemical.   For example, there are tubes for carbon  monoxide  with  concentration
              ranges of 5-150 ppm, 10-300 ppm, 0.1-1.2% and 0.3-7%.
DETECTOR TUBE CONSIDERATIONS

There are several factors that determine the effective use of detector tubes.  These factors can be
found in the instructions issued with each box of tubes.

Chemical  Group: Some tubes are for a specific chemical and some are for a group of chemicals.

Lot #:   The instructions for the tubes may change with different model numbers or different lots.
Thus, the  instructions should be matched with the proper tubes.

Expiration Date:  The chemicals used in the tubes deteriorate over time. Because of this, the tubes
are assigned a shelf life and the expiration date is printed on the box.  This varies from 1 to 3 years.

Pump Strokes/Volume/Time:   The total volume of air to be drawn through the tube varies with the
type of tube.  The volume needed is given as the number of pump strokes needed, i.e., the number
of times the piston or bellows is manipulated.  Also, the air does not instantaneously go through the
tube. It may take 1 to 2 minutes for each volume  (stroke) to be completely drawn.  Therefore,
sampling times  can vary from 1 to 30 minutes per tube.  This can make the use of detector tubes
time consuming.

Color Change:  The  instructions will give the appropriate color change for indicating the chemical
of concern.  Other color changes may be noted for interferences.  This information can be used to
check for  the presence of other chemicals.

Interferences:  As mentioned previously, not every tube is specific.   For example,  an acetone tube
will also respond to other ketones.  Thus, methyl ethyl ketone would be considered an interference
if one were checking for acetone.  The instructions will give known interferences or color changes
that are not for the chemical  of interest.

Temperature/Humidity/Pressure:  The length of color change (stain) can be affected by temperature,
humidity and barometric pressure.  If this is a problem, the instructions will note it and  may give
correction factors. Cold  weather  slows the chemical reaction in the  tube and reduces the reading.
Hot temperatures increase the reaction and can cause a problem by discoloring the indicator even
JO/93                                       41                                   Exercise 5

-------
when a contaminant is not present. This can happen even in unopened tubes.  Therefore, the tubes
should be stored at a moderate temperature or even be refrigerated during storage.

Reusable?:  Most tubes can only be used once, even if there is a negative result.  There are some
tubes, however, that can be reused the same day until a positive result is obtained.

Accuracy:  The accuracy of detector tubes vary. Some studies have reported error factors of 50%
and higher for some uncertified tubes. Some tubes are certified to be +25% accurate at readings
from 1 to 5 times the OSHA  Permissible Exposure Limit (PEL) and ±35% at concentrations one-
half the PEL. Only a few tubes are presently certified.  Certification of detector tubes is being done
by a private organization -  Safety Equipment Institute (SEI).

One factor that affects accuracy is the interpretation of the end of the color change.  Some color
changes  are diffused and  the endpoint is  not definite;  others  may have an  uneven  endpoint
(Figure 2). When in doubt, use the highest value that would be obtained from reading the different
aspects of the tube.
APPLICATIONS

Although there are many limitations and considerations for using detector tubes, detector tubes allow
the versatility of being able to measure a wide range of chemicals with a single pump. Also, there
are some chemicals for which detector tubes are the only direct-reading indicators.

They can be used to  get a reading for a specific chemical in an atmosphere where  a total vapor
survey  instrument would  response to all  the chemicals in  the  atmosphere.   They  also give  an
immediate response.  Laboratory analysis  (see the Air Sample Collection section) that can identify
and quantify a chemical in a mixture takes time.

Manufacturers use general tubes for identification in their  HazMat kits.  These kits identify  or
classify  the  contaminants  as a  member  of  a chemical group such as  acid  gas,  halogenated
hydrocarbon, etc.  This is done by sampling with certain combinations of tubes at the  same time  by
using a special  multiple tube holder or by  using  tubes in a specific sampling sequence.  All
manufacturers of detector tubes have some kind of system for hazard categorization.  Detector tube
manufacturers are listed in the Manufacturers  and Suppliers of Air Monitoring Equipment section of
this manual.
 SAFETY

 Do not directly inhale the contents of the bags and keep the bags  closed when not in use.  The
 contents of the gas bags, if released into the room, will not pose a hazard to the occupants.

 Breaking the tips off the detector tubes can create a hazard.  Please ensure that the glass tips are
 discarded into the containers provided and not onto the table or floor.  The tube breakers  built into
 the pumps  can propel bits of glass. Direct the glass into the container provided. The instructor will
 demonstrate proper procedures.  The  ends of the detector tubes are also  sharp, so handle them
 carefully.


 Exercise 5                                   42                                        10/93

-------
Eating or drinking is not allowed during this exercise because it is nearly impossible to prevent small
shards of glass from being deposited on the desk, table, or floor. Also, check the work area so that
you do not pick up glass on your hands or arms.
PUMP CHECK - DRAEGER
Leak Test

The purpose of this test is to ensure that air is going through the tube and not around it or through
a leaky valve.

1.     Insert an  unopened tube into the socket of the pump. Do not  use your finger to seal the
       orifice. The instructor will demonstrate why not.

2.     Squeeze the pump completely and release.  If the indicator mark has not appeared in 15
       minutes, the pump passes the test.  You may want to go to the Sensidyne pump check while
       this is taking place.

3.     If the pump fails the test, inform the instructor.

4.     Remove tube from the socket.

5.     (New model pump) Press counter reset button with a ball point pen or end of unopened tube
       to set at zero.
Volume Check

The purpose of this step is make sure that the pump is drawing the specified volume (100 cubic
centimeters or milliliters).   The tubes are calibrated for this volume.  If the volume is not within
limits, the tubes can not be used quantitatively.

6.     Break off the tips of a tube or use a previously opened tube.

7.     Connect the detector tube and pump to the apparatus as shown in Figure 2.
                                           43                                   Exercise 5

-------
                                                 Flexible tubing
         Buret
         Soap
        solution^
                                                           Detector tube
                                                               Detector tube
                                                               ^  pump
              FIGURE 2. DETECTOR TUBE PUMP VOLUME CHECK APPARATUS

8.     Start a bubble at the mouth of the inverted buret by just touching the soap solution to the
      mouth of the buret.

9.     Squeeze the bellows pump in order to pull the bubble up the buret.  Continue to squeeze and
      release the pump until the bubble stops above  the "0" mark on the buret.  This maneuver
      may require disconnecting the flexible tubing after the bubble passes the "0" mark.

10.   Start with the bellows  fully expanded.  Reconnect the detector tube to the tubing.  Record
      the start point (ml) in Table 1.

11.   Squeeze and release the pump.

12.   When the bubble stops, record the stopping point (ml).

13.   The difference in the two points (the travel volume) is the volume pulled  by one stroke of
      that pump.  This volume should be between 95 and 105 ml (100 ml ±. 5%).

14.   You may repeat the test to see whether  the results are consistent.

Exercise 5                                 44

-------
PUMP CHECK - SENSIDYNE


Leak Test

1.      Insert an unbroken tube into the orifice of the pump.

2.      Align the index marks on the pump handle and the pump cap.  Pull the handle straight out
       as far as it will go.  It should lock in place.

3.      Wait 1 minute.  Turn the handle 1/4 turn and release the handle.  Hold the pump barrel
       firmly as the handle will pop back rapidly if the pump does not leak.  The handle should
       return to within 1/4 inch of the cap.  If the pump is equipped with a "Flow Finish Indicator,"
       the red button will remain down if there is no leak.

4.      If the pump fails the test,  inform the instructor.


Volume Check

5.      Break off the tips of a tube or use a previously opened tube.

6.      Connect the detector tube and pump to the apparatus as shown in Figure 2.  An adapter may
       be needed because of the small diameter of the tube.

7.      Start a bubble at the mouth  of the inverted buret by just touching the soap solution to the
       mouth of the buret.

8.      Pull the handle back in order to pull the bubble up the buret.  Continue to pull the handle
       until the bubble stops above  the  "0"  mark  on the  buret.  This maneuver may require
       disconnecting the flexible  tubing after the bubble passes the "0" mark.

9.      Start with the piston empty  (handle fully in).  Reconnect  the detector tube to the tubing.
       Record the start point (ml) in Table 1.

10.    Pull back the pump handle all  the way.

11.    When the bubble stops, stop the stopwatch.   Record the time and the stopping point (ml).

12.    The difference in the two points (the travel  volume) is the volume pulled by one stroke  of
       that pump.  This volume should be between 95 and 105 ml (100 ml +  5%).

13.    You may repeat the test to see if the results are consistent.
JO/93                                      45                                   Exercise 5

-------
QUANTITATIVE RESULTS - DRAEGER AND SENSIDYNE

The pumps and detector tubes will be used to determine the concentration of two chemicals.  The
Draeger pump and tube will be used to determine the concentration of carbon dioxide in the gas bag.
The Sensidyne pump and tube will be used to determine the concentration of isopropyl alcohol in the
air above a beaker of liquid.

1.     Read the instructions for the detector tube.

2.     Determine the  number of pump  strokes needed; the color change  expected;  and  any
       adjustments to  the reading.

3.     Use a fresh tube.  Break off both ends of the tube.  Insert the opened tube into the pump
       orifice with the arrow on the tube pointing  towards the pump.  Sample the bag (carbon
       dioxide) and the air above the liquid (isopropyl alcohol).  Do not pull liquid into the tube.
       (This is  air, not water, monitoring.)  Liquid drawn into the tube can produce a change even
       if the  chemical is not present.

4.     Record your results on Table 1.
CHEMICAL CLASSIFICATION - DRAEGER

In this step,  a  series of Draeger tubes will be used to  determine the types of chemicals in an
unknown mixture.  The flow chart on the  next page will be used to determine the mixture's
components.  The chart was provided by National Draeger, Inc.  Other manufacturers have similar
systems for chemical classification.

This sample taking schedule refers to a selection of substances which occur frequently in practice.
Other situations may necessitate another sequence of measurements and, the case being, the use of
additional detector tubes, or measurements according to other procedures must be carried out. (from
National Draeger, Inc.)

The information on the next two pages  has been reprinted  with the permission of National Draeger,
Inc., Pittsburgh, PA.  This  information can also be found in their  Haz Mat Kit.  Similar flow
charts/decision logics have also been developed by MSA and Sensidyne for use with their detector
tubes.

1.     Read the instructions for the tubes.

2.     Use the tubes to  sample the unknown atmosphere.

3.     Record the result in the appropriate space in Table 2.

4.     Repeat process with all the tubes provided.

5.     Extra space is provided should  any special tubes be used.
Exercise 5                                  46                                      10/93

-------
Safety Tips

The POLYTEST and HYDROCARBON tubes use sulfuric acid as a reagent. When the bellows is
squeezed, an aerosol (smoke-like) containing the acid will be emitted. Avoid breathing the "smoke."
If you think you may have some problems with the aerosol, please inform your instructor.  You
should not have any problems unless you are more sensitive than the average person.
10/93                                     47                                 Exercise 5

-------
         Detection of unknown substances by means of DRAEGER detector tubes*
                            Detection of various organic and some inorganic substances:
                                                     Polytest
  i.g.. Acetone        Gasoline (engine fuels)
     Acetylene       Benzene
     Arsenic hydride   Ethylene
Liquid gases
(propane, butane)
Carbon monoxide. Monostyrene
Perchloroethylene     Municipal gas (with more than 2 vol. % of CO)
Carbon disuHkte      Nitrogen monoxide (NO)
Hydrogen sulfide      Toluene, xylene. trichloroethytene
                     positive
                        positive
     Detection of various organic substances:
               Ethyl acetate 200/a
                  Detection of some
              halogenated hydrocarbons:
                  Methyl bromide 5/b
 e.g., esters of acetic acid, alcohols, ketones, benzene,
     toluene, benzine hydrocarbons
            e.g., methyl bromide UN N°
                1062 (chloroform, dichlo-
                roethylene, dichloroethane,
                dichloropropane), trichlo-



>.


>.



V
r




Detection of important
aromatic hydrocarbons:
Benzene 0.05
e.g.. benzene UN N" 1114
(ethyl benzene, toluene
and xylene in small
quantities discolor the
prelayer)


Acetone 100/b
e.g.. acetone UN N° 1090
methylisobutyl ketone,
methylethyl ketone
.

Alcohol 100/a



Detection of
propane butane:
Hydrocarbon 0.1 %/b
e.g.. propane UN N° 1 978
. r*r\

Carbon monoxide 10/b
e.g.. CO UN N° 1016


of other substances may be


>



j
^





                                                                                       Detection of amines:
                          Hydrazine 0.25/a
                   e.g., triethylamine UN N° 1296
                       (ethylene diamine,
                       hydrazine, ammonia)
                                                                                        Detection of acid-
                                                                                       reacting substances:
                                                                                          Formic acid 1 /a
                                                                                  e.g.. hydrochloric acid UN N°
                                                                                      1789, HNOj. Clj, NOj, SO2
                                                                                         Further detection
                                                                                  e.g., methane, ethane. H2.
                                                                                      CO2 and other substances
                                                                                      may be necessary
                                               negative
  e.g., alcohol UN N° 1096
      butanol, methanol,
      propanol


  'Important: This sample taking schedule refers to a selection of substances which occur frequently in practice. Other situations may
            necessitate another sequence of measurements and, the case being, the use of additional detector tubes, or measurements
            according to other procedures must be carried out.
                        ©\ National  Draeger,  Inc.
                                  101 Technology Drive (Shipping) • P.O. Box 120 (Mailing) • Pittsburgh, PA 15230 • 412/787-8383 • Telex: 86-6704
Exercise 5
                 48
                                          10/93

-------
       Examples for the (qualitative) indication response of the DRAEGER Polytest tubes

The results were obtained under the following test conditions:
                  Temperature 20°C; Humidity 50% relative; All tests carried out with pure substances
Substance
Acetone
Acetone
Acetylene
Acetylene

Ursine
Arsine

Benzine (Gasoline)
Benzine (Gasoline)
Benzene
Benzene
Butane
Butane

Carbon disulfide
Carbon disulfide
Carbon monoxide
Carbon monoxide

Ethylene (ethene)
Ethylene (ethene)

Nitrogen monoxide (NO)
Nitrogen monoxide (NO)

Perchloroethylene
Perchloroethylene
Propane
Propane

Styrene (monostyrene)
Styrene (monostyrene)
Toluene
Toluene
Trichloroethylene
Trichloroethylene
Xylene
Xylene
Concentration
5000 ppm
above liquid
2OO ppm
high cone.
(over 1 %)
10 ppm
high cone.
(over 1 %)
50 ppm
above liquid
100 ppm
above liquid
100 ppm
high cone.
(over 1%)
10 ppm
above liquid
100 ppm
high cone.
(over 1 %)
500 ppm
high cone.
(over 1 %)
50 ppm
high cone.
(over 1 %)
50 ppm
above liquid
500 ppm
high cone.
(over 1%)
500 ppm
above liquid
200 ppm
above liquid
50 ppm
above liquid
500 ppm
above liquid
Number
of strokes
of the bel-
lows pump
5
5
5
5

5
5

5
5
5
5
5
5

5
5
5
5

5
5

5
5

5
5
5
5

5
5
5
5
5
5
5
5
Length of Discoloration
approx. 10 mm
completely colored
approx. 10 mm
completely colored

approx. 10 mm
completely colored

approx. 10 mm
completely colored
approx. 10 mm
approx. 10 mm
approx. 10 mm
completely colored

approx. 10 mm
completely colored
approx. 10 mm
completely colored

approx. 10 mm
completely colored

approx. 10 mm
completely colored

approx. 10 mm
completely colored
approx. 10 mm
completely colored

approx. 10 mm
approx. 10 mm
approx. 10 mm
approx. 10 mm
approx. 10 mm
completely colored
approx. 10 mm
approx. 1 0 mm
Notes on the indication
brownish green
brownish
brownish green
brownish

brownish green
brownish

brownish green
brownish
brownish
brownish
faded green (spotty)
brownish green

greenish
brownish green
brownish green
brownish

brownish green
brownish

brownish green
brownish with
bleaching effect
greenish
brownish green
faded green (spotty)
brownish green

brownish
• brownish
brownish
brownish
brownish green
faded yellow
brownish
brownish
Examples for the (qualitative) indication response of the DRAEGER tubes for ethyl acetate 200/a

The results were obtained under the following test conditions:
                  Temperature 20°C; Humidity 50% relative; All tests carried out with pure substances
Substance
Acetone
Acetone
Benzene
Benzene
Ethyl alcohol
Ethyl alcohol
Octane
Octane
Toluene
Toluene
Xylene
Xylene
Concentration
3000 ppm
above liquid
500 ppm
above liquid
20OO ppm
above liquid
10O ppm
above liquid
500 ppm
above liquid
500 ppm
above liquid
Number
of strokes
of the bel-
lows pump
5
5
5
5
5
5
5
5
5
5
5
5
Length of Discoloration
approx. 1 0 mm
completely colored
completely colored
completely colored
approx. 5 mm
approx. 20 mm
approx. 10 mm
completely colored
approx. 10 mm
completely colored
approx. 10 mm
completely colored
Notes on the indication
greenish
greenish
very pale grey
greenish grey
greenish
greenish
grey-brown-greenish
greenish
greenish grey
greenish grey
greenish brown
greenish brown
   10/93
National  Draeger, Inc.
101 Technology Drive (Shipping) • P.O. Box 120 (Mailing) • Pittsburgh. PA 15230 • 412/787-8383 • Telex: 86-6704

               49                                  Exercise 5

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                                   TABLE 1

                                     SENSIDYNE
                            DRAEGER
 ID NUMBER
 LEAK CHECK
 VOLUME CHECK
 BURET STOP POINT (ml)
    PASS  FAIL
PASS  FAIL
 BURET START POINT (ml)
 TOTAL VOLUME
 SAMPLE TIME
 ACCEPTABLE VOLUME?'
    PASS  FAIL
           SAMPLES
ISOPROPYL ALCOHOL
 UNADJUSTED READING
 READING ADJUSTED FOR
 TEMPERATURE
 READING ADJUSTED FOR
 BAROMETRIC PRESSURE"
• The acceptable volume for a full pump stroke is 100 ml ± 5% (i.e., between 95 and 105 ml).
b Assume the sampling conditions were 30*C and 720 mm barometric pressure.
Exercise 5
     50
             10/93

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TABLE 2
NAME OF TUBE
POLYTEST
METHYL BROMIDE
ETHYL ACETATE
BENZENE
ACETONE
ALCOHOL
HYDROCARBON
CARBON MONOXIDE
HYDRAZINE
FORMIC ACID





READING/INDICATION















What types of chemicals are present in the mixture?
10/93
51
Exercise 5

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                                  QUESTIONS





1.  Based on your test results, how long should you wait between pump strokes for the MSA?
2.  What factors could affect the detector tube results?
3.  Does the CO2 concentration exceed the PEL?  REL?  TLV?  IDLH?
4. Does the isopropyl alcohol concentration exceed the PEL? REL?  TLV?  IDLH?
Exercise 5                               52                                   10/93

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                                   EXERCISE #6

                        Direct-Reading Aerosol Monitors
OBJECTIVE
Participants will learn how to operate the MIE Real-Time Aerosol Monitor Model RAM-1 and the
MIE MINIRAM Personal Monitor Model PDM-3.
DESCRIPTION OF EQUIPMENT

The RAM-1 and the MINIRAM are portable, self-contained aerosol monitors.  Their detection
system is based on the detection of near-forward, scattered, near-infrared radiation.

The RAM-1 uses a pump to draw air into the unit to the sensors.  It uses an air screen to prevent
contamination of the sensors.   The MINIRAM does not require a pump. Air passes through the
sensing volume by convection, circulation, ventilation and personnel motion.  The sensors are also
in direct contact with the environment.  Thus, there is a chance the sensors may get covered with
dust.  The MINIRAM sensors require cleaning on a regular basis.

Both units indicate the aerosol concentration in milligrams per cubic meter (mg/m3).  Both use a
digital display. The MINIRAM's displayed reading is updated every 10 seconds.  The RAM-1 has
a variable time display.

The RAM-1 has a range of 0.000-200.0 mg/m3. The readout range is selected by the operator. The
MINIRAM normally operates in the 0.00 to 9.99 mg/m3 range. Whenever a 10-second concentration
exceeds 9.99 mg/m3, the MINIRAM automatically switches to the 0.0 to 99.9 mg/m3 range and
remains in that range as long as the measured  10-second concentration exceeds 9.99 mg/m3.
Otherwise the MINIRAM reverts to its lower  range display.

The RAM-1 only displays real-time concentrations.  A output device can be connected to record
data.  The MINIRAM can store data for later output and for TWA calculations. Thus, it can be used
as a direct-reading monitor  and a dosimeter.

Both instruments can be powered by internal batteries or an external AC source.

It is important to remember that these instrument only give total or respirable quantities of aerosols.
They  do not give the composition of the aerosol.  To determine the composition of the aerosol, a
sample must be taken  and  analyzed.  Refer  to the Air Sample  Collection section of the course
manual.
10/93                                     53                                 Exercise 6

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MIE MINIRAM PERSONAL MONITOR MODEL PDM-3
Before using the instrument without the charger, charge the MINIRAM for a minimum of 8 hours.
Initial Condition

       •     Blank display—Indicates that the MINIRAM has not been in the measurement mode
             for 48 hours or more, and is in the minimum power off mode.

       •     "OFF" display—MINIRAM has been in the off mode for less than 48 hours.

       •     Concentration display  that changes or  "blinks"  once every  10 seconds:  the
             MINIRAM is in the measurement mode.
Controls (refer to Figure 1)
"MEAS'
 "ZERO"

 "TIME"
When this button is pressed, the measurement mode will start.   Once the MEAS
mode has been entered, this sequence can only be interrupted by pressing OFF.
Pressing ZERO, TWA, SA, TIME, or ID# only affects the display during the time
the keys are pressed.

The readout will first display "GO" (or "CGO" if TIME is also pressed) followed by
the last concentration reading or ".00."

Approximately  36  seconds later, the first new  10-second-averaged concentration
reading is displayed. The reading will be updated and displayed every 10 seconds.

The MINIRAM will now run in the measurement mode for 500 minutes (8 hours and
20 minutes), after which time it will stop, displaying the OFF reading.  It will retain
in storage the concentration average and elapsed time information.

If both MEAS and  TIME are pressed at the same time (press TIME first and while
depressing it actuate MEAS) the MINIRAM will display "CGO," and  will then
operate as above (i.e., pressing MEAS only), except that after the first 8.3-hour run,
it will restart automatically  and continue to  measure for an indefinite number of
8.3-hour runs, (with the battery charger) until the OFF key is pressed, or until the
batteries are exhausted. Concentration averages and timing information for the last
seven 8.3-hour runs will remain in storage at any give time.

When instrument displays "OFF," pressing this button initiates the ZERO procedure.

During the measurement mode, if TIME is pressed, the display will show the elapsed
time, in minutes, from the start to the last measurement run.  The MINIRAM will
automatically return to concentration display after the TIME key is released.
Exercise 6
                             54
10/93

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                     1.85  -
                    -4 OVR
                    ~4 ID
                    •4 BAT
  — MIE
                        ^ MINIRAM

                          AEROSOL

                          MONITOR

                  MODEL PDM-3
                                          (CLIP)
"TWA"
"SA"
"PBK"
"OFF"
             FIGURE 1. FRONT PANEL OF MINIRAM

During the measurement mode, if the time-weighted average (TWA) is pressed, the
display will indicate the average concentration in milligrams per cubic meter (mg/m3)
up to that instant, from the start of the last run.  The value of TWA is updated every
10 seconds.  After releasing the TWA key, the MINIRAM display returns to the 10-
second concentration display.

During the measurement mode, pressing SA (Shift-Average) will provide a display
of the aerosol concentration,  up to  that moment, averaged over  an 8-hour shift
period.

With the MINIRAM in the off mode, the stored information can be played back by
pressing PBK (Play Back). Pressing the PBK key for more than 1 second will cause
stored data to be automatically played back through the MINIRAM display:  First,
the identification number is displayed with the ID indicator bar on; next the shift or
run number  (i.e., 7  through 1, starting with the last run) is shown (with the OVR
indicator bar on as identification); followed by the sampling time in minutes, for that
run; followed by the off-time between the last and next run (in tens of minutes:;
finally, the average in mg/m3.  This sequence is repeated seven times.  An average
reading of 9.99 indicates that  a significant overload condition occurred during that
run. The total time required for the complete automatic playback on the MINIRAM
display is  approximately 70 seconds.

When this key  is  pressed,  the  MINIRAM will  discontinue  whatever mode is
underway  displaying "GCA" followed by the display segments check ("8.8.8=") and
finally "OFF."  The MINIRAM will then remain in this reduced power condition
(displaying "OFF").
10/93
                              55
                                                                  Exercise 6

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Display

During the measurement mode, the display indicates the present concentration in mg/m3.  If one of
the function buttons is pushed, the information indicated in CONTROLS is displayed.  If a bar
appears in the display, the bar's location indicates one or more of the following:

"OVR"        The concentration exceeds the range of the instrument or there is an overload due to
              reflected line (e.g., sunlight).
"ID"          This indicates that the ID number is being displayed and not a concentration.

"BAT"        This indicates a low battery.


Zero Procedure

1.     Zeroing must be performed in a clean-air environment.  This can be done by using a clean
       room or clean-bench,  flowing clean air through the sensing  chamber, or using an air-
       conditioned office (without smokers).

2.     Press OFF and wait until the display indicates "OFF."

3.     Depress the ZERO button. Wait until the  display again indicates "OFF."  The average of
       four consecutive 10-second zero  level measurements will then be stored by the MINIRAM
       as the  new ZERO reference value.  The  ZERO reference value will be subtracted from
       subsequent readings.   When operating  the MINIRAM is  high particle concentration
       environments (>5 mg/m3) the zero value should be updated approximately every 8 hours.
       At aerosol concentrations below  approximately 1 mg/m3 this update may  only be required
       once a week.


Start Measurement  Cycle

4.     Place the MINIRAM in the area to be monitored. The instrument should be placed vertically
       (i.e., display/control panel facing upwards) by clipping it to a belt, shoulder strap, etc.

5.     If the MINIRAM shows a blanked display, press OFF and wait until the display reads "OFF"
       (approximately 5 seconds after pressing OFF) before pressing MEAS to initiate measurement
       cycle.

6.     If the MINIRAM  shows "OFF," press MEAS directly to initiate measurement cycle (there
       is no need to  press OFF first, in this case).

7.     Press MEAS.

8.     Observe the readings for 1 minute to verify that the levels change every 10 seconds and that
       the OVR bar  is not displayed.
Exercise 6                                 56                                      10/93

-------
9.     Avoid objects being placed in the sensing chamber.  Also avoid direct sunlight scattering in
       the sensing chamber.

10.    At the end of the sampling period, press "TIME."  Record the sample duration in Table 1.

11.    Press the TWA button.  Record the reading in Table 1.

12.    Press OFF.
TABLE 1
INFORMATION
INSTRUMENT SERIAL #
START TIME
TWA
SHIFT AVERAGE (SA)
OFF TIME
RESULTS





MIE REAL-TIME AEROSOL MONITOR MODEL RAM-1

In the following procedure, the numbered buttons, displays, and switches refer to the illustration of
the RAM-1 in Figures 2 and 3.
Startup

1.     Lift up protective cover of control panel.

2.     Place selector switch (1) in battery (BATT) position.

3.     Place inlet valve (2) in CLEAR position (horizontal).

4.     Replace sealed cap  on inlet valve with the restrictor orifice.

5.     Switch instrument on (3) and check battery voltage. The digital readout (4) should indicate
       between 6.0 and 6.6 volts.  If not, inform the instructor.  The reading should be identified
       by a display of VDC (volts DC).  Low battery voltage is indicated by a flashing  "VDC" on
       the right-hand side of the display, whenever the selector switch is not in the BAT position.
10/93                                      57                                  Exercise 6

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Zeroing

6.     Check that the inlet valve is in the CLEAR position (horizontal).  Place the selector switch
       in the 0-200 position.  The letter "m" should appear to the right of the display reading,
       indicating that the instrument is set to read concentration measurements.

7.     Place the time constant switch (5) in the 2-second position.

8.     Allow 1 minute for instrument to stabilize (warm-up).  IMPORTANT!

9.     If necessary, lift the cover over the ZERO control (6) and adjust the control until a reading
       of 00.0 is obtained.

10.    Switch the selector to the 0-20 position and repeat step #9.

11.    Switch the selector to the 0-2 position and repeat step #9.  Readings may fluctuate. Try to
       obtain an average reading of 0±0.005.
Secondary Calibration

12.    Keep inlet valve in its CLEAR position.

13.    Set the range selector to the 0-20 position.

14.    Unlock the hinged flow chamber cover and place in the horizontal position.
                                                2,
                                         SAMPLE
                                                     «VDC CHARGE
                            CAL
                                  Sf~»,

                                     '
                                               ZERO \
                                                       RANGEV.  POWER
                                               8     6
                                                            s^r
                                                               '
                                FIGURE 2.  RAM-1 TOP VIEW
Exercise 6
58
10/93

-------
                        Filters
Desiccant
12    11
                              FIGURE 3. RAM-1 SIDE VIEW

15.    Push the reference scatterer knob (REF SCAT) (9) inward until a positive stop is detected.
       The pump will automatically shut off. The letter "K" should be flashing in the upper right
       side of the display.  Allow the reading to stabilize for 30 seconds.

16.    See if the instrument reading corresponds with the factory calibration label (10) by the (REF
       SCAT).

17.    If the indicated readings differ by more than 5%, adjust the CAL control (7) as required.
       The CAL control has a lock that must be disengaged before attempting to turn the knob.
       Allow to stabilize and repeat if required. Relock the CAL control.

18.    Pull the REF SCAT back out.

19.    Close the flow chamber cover and tighten thumb-screws.
Measurement Procedures

20.    Switch RAM on.

21.    Select measurement range (usually the 0-20 position).

22.    Select desired time constant (usually 2 seconds).

23.    Place inlet valve in SAMPLE position (vertical downwards).

24.    Check the flow meters. The TOTAL (11) should read about 2 and the PURGE (12) should
       read about 0.2  (or 10% of TOTAL).  Adjust the total flow rate with the flow adjust screw
10/93
    59
                       Exercise 6

-------
      (8). Adjust the purge flow with the black valve on the rotameter. If the rotameter is pegged,
      check that the inlet valve is in the SAMPLE position.

25.    Measure the aerosol concentrations in the areas designated by the instructor.

26.    If the aerosol concentration exceeds the maximum selected range, the RAM-1 will indicate
      1 with all zeros blanked out.  If this occurs, change the range selection to higher ranges as
      needed.

27.    Check and update zero periodically.

28.    BEFORE SHUTTING OFF THE RAM-1, CLOSE THE INLET VALVE (CLEAR
      POSITION) AND OPERATE FOR 3 MINUTES TO ALLOW PURGING OF THE
      DUSTS INSIDE THE OPTICAL CAVITY.

29.    When sampling and purging is complete, turn the instrument OFF.
Exercise 6                              60                                  10/93

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                                    QUESTIONS
1.     Discuss the advantages and disadvantages of these instruments.
2.     Analysis of the site soil or analysis of a filter sample shows the soil composition to be 5%
       lead. You obtain a reading of 1.35 mg/m3 with the RAM-1.  Determine (approximately) the
       airborne lead concentration based on your reading.
3.     The action level for lead at your site has been determined to be 1.5 /*g/m3. The soil on the
       site is 5% lead,  a)  What instrument reading would be equivalent to your lead action level?
       b)  What reading would you be concerned about if your action level was 50 jig/m3?

       a)
       b)
10/93
61
Exercise 6

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                                   EXERCISE #1

                            Gas Chromatography  -  PID
OBJECTIVE
The student will learn the basic operation of the Photovac 10S50 portable gas chromatograph and
analyze several air samples.
PROCEDURE

The  instructor will describe  and  illustrate the different parts of the Photovac 10S50  and  their
functions.  Since the 10S50 needs a certain amount of warm-up time, the student will not be able to
go through start-up of the instrument.  After the introduction, students will run a calibration standard
and an unknown sample. Students will also collect an air bag sample and analyze it.
OPERATING INSTRUCTIONS FOR THE  PHOTOVAC 10S50 (CAPILLARY COLUMN
OPERATION)
Preparation for Use

Refer to the Photovac 10S50 instrument panel and Figure 1."


Recharge the Carrier Gas

1.     Connect the fill line for the Photovac 10S50 to a cylinder of "Ultra-Zero Air" (contents <0.1
       ppm hydrocarbon).

2.     Attach the "Quick-Connect" from the fill line to the REFILL receptacle on the upper right-
       hand  corner of the Photovac 10S50.

3.     Turn on the cylinder  and rotate the valve for the fill  line  so that the pointed end points
       toward the cylinder.  Be sure not to stand directly in front of the regulator.

4.     The reservoir in the instrument will be filled to the maximum pressure of the supply cylinder.
       The pressure is indicated on the CONTENTS gauge on the upper left of the instrument panel.
       (The  maximum pressure at which the instrument  can be filled is 1750 psi.)  The delivery
       pressure is indicated on the DELIVERY gauge. This pressure should be 40 psi.  When the
       reservoir is filled, the excess air will be expelled at the fritted outlet on the supply cylinder
       regulator. This will be indicated by a "hissing" sound. Turn off the supply cylinder valve
       and then turn off the valve on  the fill line.

5.     Disconnect the fill  line.

10/93                                     63                                 Exercise 7

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Set the Carrier Gas Flow Rate

6.    The pieces of tubing to the flow meter are attached to the ports on the instrument panel.

7.    Attach the line on the left side of the meter to the DETECTOR OUT port.

8.    Attach the line on the right side of the meter to the needle valve marked AUX OUT.

9.    Connections should be secured with a 7/16 inch open-ended wrench (1/4 turn past tight).

10.   Adjust the flow rates on the meter.

      a.     If the instrument is being set up to stabilize overnight,  set the DETECTOR OUT
             FLOW using the red FLOW adjustment knob on the left side of the panel to 5
             ml/min. Note:  Turn knob clockwise to decrease the flow or counterclockwise to
             increase the flow. Set AUX OUT flow using the needle valve to 0 ml/min. Allow
             to stabilize overnight.

      b.     If the instrument is being set up for analysis, set the DETECTOR OUT flow using
             the red FLOW adjustment knob to 10 ml/min.  Set AUX OUT flow using the needle
             valve to 10 ml/min.


Activate the Power Source

11.   When the instrument is ready for use, attach the power cord for the instrument to the 3-prong
      socket in the upper left-hand corner of the instrument. The cord is then plugged into an AC
      outlet.

12.   Press the ON key.   The instrument will respond with "LAMP NOT READY, PLEASE
      WAIT."

13.    Wait until the display reads "READY ENTER COMMAND."


Set Instrument Parameters

14.   Locate the LIBRARY block and press the USE key.  The instrument will respond with
      "LIBRARY IN USE?"  There are four libraries numbered 1 to 4. Library #1 is the default.
      We will use  #1 for this exercise.  Press the 1 key and then the ENTER key.

15.   The instrument will prompt for "DAY" (1-31). Press the appropriate value for the day of
      the month and then press the ENTER key.
10/93                                    65                                Exercise 7

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16.    The following information is entered in the same manner:

      a.     MONTH (1-12), then press ENTER

      b.     YEAR (e.g., 1993), then press ENTER

      c.     HOUR (0-23), then press ENTER

      d.     MINUTE (0-59), then press ENTER.

17.    The instrument will read:  "READY ENTER COMMAND."


Obtain a Status Report

18.    Locate the STATUS block and press the TEST key.  The instrument will respond with
      "FUNCTION, USE < >, STATUS REPORT."  Respond by pressing the ENTER key.

19.    The instrument will print a status report containing the following information:

      a.     Current field date and time.

      b.     Field: The # represents the detector field in volts/10.

      c.     Power:  The # indicates the current lamp consumption at mA/10.

      d.     EVENT  settings show the ON  and OFF times of the 10S50 sample pump  and
             solenoid valves. The instructors will have set the following EVENT values:
SAMPLE
CAL
EVENT #3
EVENT #4
EVENT #5
EVENT #6
EVENT #7
EVENT #8
(EVENT #1)
(EVENT #2)






0
0
10
0
13
0
0
0
10
0
60*
10
60*
0
0
0
             * Some units may have a longer time (e.g., 80) instead.

20.    Allow the instrument to stabilize for approximately 45 minutes. The instrument has been
       stabilizing prior to the exercise so we may continue.
Select the Analytical Parameters

21.   Locate the SETUP block on the instrument panel.



Exercise 7                                66                                    10/93

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22.    Press the GAIN key.  The gain controls the amplification from the detector. The default
       value is "2"  For higher values, press the UP ARROW key until the desire value appears.
       For this exercise, choose a gain setting of "5" and then press ENTER.

23.    Press the CHART key.  The instrument will respond with  "CHART ON" or some other
       readout.  "CHART ON"  means the chromatogram will be displayed along with identification
       information and some instrument settings (e.g., GAIN).  "CHART OFF" means that the
       chromatogram will not be displayed, but identification  information and some instrument
       settings will be displayed. "CHART ON WITH BASELINE" prints out the same information
       as "CHART  ON," but also shows the baseline the instrument uses to calculate peak area.
       "CHART ON WITH  SETUP"  prints out the same information as "CHART ON WITH
       BASELINE" but also  includes the setup information (e.g., SENS, WINDO). Use the UP
       ARROW or DOWN ARROW key until "CHART ON WITH SETUP"  is displayed.  Press
       ENTER. The next display is the chart speed. The default is 0.1 cm/min.  Press the UP
       ARROW key until 0.5 appears. Press ENTER.

24.    Press the SENS key.  The key controls the instrument integrator.  The following  settings
       specify the minimum response that will be recognized as  a peak on the chromatogram.

             SLOPE UP; Use the arrow keys to display 18 mv.  Then ENTER.
             SLOPE DOWN;  Use the arrow keys to display 16 mv. Then ENTER.
             PW (Peak Width) at 4  minutes; Use the arrow keys to display 6 (sec).   Then
             ENTER.

25.    Press the WINDO key.  This key adjusts the lOSSO's tolerance to retention  time drift. A
       peak, must be within a specified percentage  of a stored retention to be  identified as that
       chemical by the  instrument. Choose a value of "10" (i.e., 10%) and press ENTER.

26.    Press the AREA key.  This key sets a peak size threshold.  All peaks smaller than the AREA
       setting are deleted from  the "PEAK INFORMATION"  listing at the end of the analysis.
       (However, these peaks will still be numbered on the chromatogram.) Set the minimum area
       at "50" and ENTER.

27.    Locate the PROGRAM block and press the CYCLE key. The instrument will prompt for
       the following information:

       a.     "TIMER DELAY."  This  setting determines the delay in time from  when the
             START/STOP key is pressed and when the instrument will start looking for peaks.
             Choose  "10" seconds and ENTER.

       b.     "ANALYSIS TIME." The duration of the analysis is dependent upon the types of
             compounds that are being considered for  analysis. Select an analysis time of 600
             seconds for this exercise. Press ENTER.

       c.     "CYCLE TIME." These times refer to the mode for continuous monitoring.   This
             mode will  not be  used in  this exercise.  Choose  "0"  min and ENTER.   The
             instrument will respond with  "CYCLING  DISABLED, COUNTERS  RESET."
10/93                                   67                                Exercise 7

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Establish a Baseline for the Chromatogram

28.    The baseline will be established by analyzing a bag of ultrazero air (a BLANK sample).
       Connect the "zero" bag to the PROBE IN CONNECTION. Open the bag. To initiate the
       analysis, locate the ANALYSIS block and press the START/STOP key. The instrument will
       respond:  "PROBE IN?"  Press ENTER.

29.    As soon as the ENTER key is pressed,  the pump should start and run 10 seconds.  If the
       pump does not start, inform the instructor.

30.    Allow the chromatogram to be generated.   Examine the baseline for significant drift or
       extraneous peaks.  The baseline should  be flat and smgoth. Repeat this procedure until a
       stable (zero slope) baseline is obtained or until the instructor informs you to stop.
Analyze the Standard Gas Bag

31.    For this exercise, we will use the chemicals in Library 1 as the standard. The "standard gas
       bag" will be used to check retention times and allow you to see a chromatogram.

32.    Connect the "sample bag" bag to the PROBE IN CONNECTION. Open the bag. To initiate
       the analysis, locate the ANALYSIS block and press the START/STOP key. The instrument
       will respond:  "PROBE IN?"  Press ENTER.

33.    Allow the chromatogram to be generated.  This will take 600 seconds (the analysis time we
       selected).

34.    At the end of the chromatogram, the printout will print the peak numbers that exceed the area
       setting, the identity of the peaks (if they match the  retention times in the library) and the
       concentration of identified peaks.   Consult the instructor for the expected results.  If the
       peaks are not properly identified, a update adjustment or calibration run will be necessary.
       See Updating the Library and Creating a Library before analyzing any samples.
 Updating the Library

 35.    If library does not recognize all of chemicals in the standard, the library should be updated.

 36.    Select a peak (one that you can identify) as a reference point. Press the CAL key.  The
       instrument will request a plotter peak number.  Enter the peak number you have selected.
       Press ENTER.

 37.    The  instrument will  request an ID number.  Look at the previous printout of the library.
       Enter the number for the chemical that matches the peak. Press ENTER.

 38.    The  instrument will request a concentration.  Enter the concentration of the  compound
       corresponding to the plotter peak used.  Press ENTER.
Exercise 7                                 68                                      10/93

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39.    The plotter will print out a listing of the peaks from the recent analysis and hopefully identify
      the peaks using retention times and peak areas adjusted by the reference peak.
Creating a Library

40.    Connect the "sample bag" bag to the PROBE IN CONNECTION. Open the bag. To initiate
      the analysis, locate the ANALYSIS block and press the START/STOP key. The instrument
      will respond: "PROBE IN?"  Press ENTER.

41.    Allow the chromatogram to be generated.

42.    The information from the chromatogram must be stored in the library IMMEDIATELY
      FOLLOWING completion of the analysis. IF ANY OTHER KEY IS PRESSED BEFORE
      STEP #43, THE STANDARD CHROMATOGRAM WILL NEED TO BE GENERATED
      AGAIN TO UTILIZE ITS INFORMATION.

43.    Locate the LIBRARY block and press the STORE key. The instrument will prompt for:

      a.     PLOTTER  PEAK #:   Select the number of the first peak  of interest on the
             chromatogram and press ENTER.

      b.     CHEMICAL NAME:  Select the name of the compound using the alpha-numeric
             keys on the key pad.  After the name is  complete press ENTER.  (To change to
             numbers, press the CAL (NUM) key. This key must also be pressed again to return
             to letters.)

      c.     CONCENTRATION (in ppm): Select the actual concentration of the compound in
             ppm.  Press ENTER.

      d.     LIMIT VALUE: The limit value is the concentration, which if exceeded, causes the
             plotter to print the concentration value in red instead of green.  This "flags" the
             compound. Press ENTER. This will instruct the instrument to use 0 as the limit, so
             all concentrations will be in red.

      e.     This procedure is repeated for subsequent compounds in the chromatogram by
             pressing the STORE key and following steps a through d.

      f.     To check the contents of the library, press CAL.  The instrument prompts with
             "PLOTTER PEAK #?"  ENTER TO RELIST. Press ENTER. The plotter will print
             out the added compounds and their concentrations.

             Note: DO NOT enter a value here or the  instrument will prompt for recalibration.
10/93                                   69                               Exercise 7

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Editing the Library

44.     A compound can be added to the library after any analysis. A compound can be added to
       the library even if it is already in the library.  However, the new entry will not replace the
       old entry.  There will be two listings for the compound.

45.     To remove a compound from the library, first press EDIT.

46.     The instrument will prompt with "ID NUMBER." Enter the ID number for the compound
       in the library. The instrument will list the name of the compound.

47.     Press CLEAR, then press ENTER.  The instrument will respond with  "COMPOUND
       REMOVED FROM LIBRARY."

48.     Repeat for any additional compounds.


Analyse the Samples

49.     Using steps 31 through 34, analyze the unknown samples provided.

50.     IMPORTANT!  DO  NOT USE ANY GAS  BAGS, other than those provided by the
       instructors, WITHOUT THE PERMISSION OF THE INSTRUCTORS. High concentrations
       can contaminate the column.


Exercise Shutdown

51.     When sample analysis  is complete, do not turn the instrument off.


Shutdown (Overnight)

52.     Generate a chromatogram of the baseline to ensure that there are no residual materials in the
       column.

53.     Locate the POWER block and press the  OFF key.  The instrument will respond with
       "ENTER=OFF."  Press ENTER.

54.    Adjust the flow rate for the DETECTOR OUT to 5 ml/min.  Make sure the air supply is
       adequate for overnight operation.


Shutdown (Long Term)

55.    Follow the same steps as in Shutdown (Overnight).

56.    Disconnect the power  cord from the AC source.

57.    Before shipping, drain the carrier gas supply reservoir.

Exercise 7                                70                                    10/93

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                                   EXERCISE #8

                    Sampling Pumps and Collection Media
OBJECTIVE
Participants will  assemble a variety of sampling trains and calibrate them using an electronic
bubble meter.  They will also  check the pump's flow compensator.  The students will review
sample results and evaluate exposure levels.
PROCEDURE

The  class  will be divided into teams.  Each team will  be given a Gilian® HFS  113UT air
sampling pump.

The instructor will explain the operation of the Gilian* HFS 113UT sampling pump.

The  students will calibrate the Gilian* sampling pump using different media and an electronic
bubble meter.

      Demonstration:      Calibration of Gilian* pump with filter media using a bubble-meter
                          (page 82).

      Station 1:           Calibration of Gilian* pump with filter media and with sorbent tube
                          media using an electronic bubble-meter (page 85).

      Station 2:           Check flow compensator of Gilian* pump using Gilian* Calibrator
                          Pack (page 92).

      Note:  The procedures  shown here apply only to this  specific sampling pump.  The actual
             procedures for other pumps may vary. Consult the manufacturer's instructions for
             the pump you use in the field.

After calibrating their sampling pump, the students will look at sampling results and calculate
concentration levels (page 94).
10/93                                     71                                 Exercise 8

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   OPERATION AND  CONTROLS OF GILIAN® HFS  113UT SAMPLER
The Gilian® HFS 113UT sampler is a lightweight, battery-powered air sampling pump.  It has a
high flow range—0.5-3.5 liters per minute (1pm) and a low flow range—1-500 cubic centimeters
per minute (cc/min).  It has a built-in timer to shut off the pump after a preset time.  The pump
is equipped with a flow compensation control that provides for constant air flow from the pump
at any preset flow within its performance limits.

The following  is a brief description of the controls for operating the pump.

1.     ON - OFF Switch.  This turns pump on and off.

2.     PRESS TO TEST Button.  When the pump is on, pressing this button gives battery power
      indication and also gives an elapsed time indication in TIME MIN window. If the pump
      has stopped because of end of time or fault, pressing this button before turning the pump
      off gives the pump run time.

3.     PROGRAMMABLE TIMER.  Allows operator to set sample time from 10 minutes to 990
      minutes in  ten minute increments.  Note: The pump will not start if the timer  is set at
      00.  When setting  the timer, the dials should be turned clockwise past the  zero point
      several times.

4.     BAT CK - Battery Check.  Turn on pump and press the  test button.  If the BAT CK
      illuminates, then the battery is fully charged.

5.    FAULT.   This light illuminates  and the pump shuts down,  if the  pump is unable to
      maintain the preset flow rate.

6.    TIME  OUT.  This illuminates when the pump stops at the programmed time.

7.    FLOW ADJUST.   Turning  clockwise increases  flowing;  turning  counterclockwise
      decreases flow.

8.    PUMP INLET. Inlet to pump. Point where tubing and sampling media are connected.

9.    DISCHARGE  AIR CAP SCREW.   Removing mis screw provides access to discharge
      port.  Inserting adapter allows pump to be used to  fill gas bag.

10.   REGULATOR  SHUTOFF CAP SCREW.   Removing screw provides access  to  (he
      regulator shutoff valve.  The valve is used to switch the pump from high to low flow.

11.   FLOW METER.   Rotameter used  to show flow.   Read center of  flow meter ball.
      Reading is ±20% of true flow.
 Exercise 8                                72                                   10/93

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            DEMONSTRATION:  CALIBRATING  GILIAN® PUMP
                           USING A BUBBLE METER

During this demonstration, the Gilian® pump will be calibrated for lead paniculate sampling.
The NIOSH analytical method for lead sampling (Method 7802) uses a 0.8-p cellulose ester
membrane  filter.   The  appropriate  filter is provided with  the calibration  setup.   The
recommended flow rate is between 1 and 4 liters per minute.  For this exercise, calibrate the
pump  to about 2 liters per minute (between 1.8 and 2.2 is okay).  The important thing is to
know  the actual flow rate  of your pump.  Step 4 explains how to convert the pump to the high
flow range.
BUBBLE METER PREPARATION

During this step, the Gilian® pump will be calibrated using an inverted buret and soap bubbles
(bubble meter).   This method is considered a primary calibration method because the buret
volume and the stopwatch time can be traced to an original standard.

1.    Check the calibration set-up (Figure 1).   It should contain all the parts shown in the
      figure. If not, inform the  instructor.

2.    Wet the buret by pouring a small amount  of soap solution into it, and tilting it up and
      down while rotating. Seal the outlet end to  prevent soap from getting into the tubing.

3.    Reassemble the calibration setup.
PUMP PREPARATION

4.    Remove the Pump Regulator Shutoff Protective Cap.  Turn the exposed screw clockwise
      until closed - DO NOT OVERTIGHTEN.  Replace the protective cap.

5.    Using the small screwdriver provided, set the programmable timer to 240 minutes.  Turn
      each dial clockwise past zero several times before setting the time.

6.    Turn the pump on.

7.    Press the test button.  The BAT CK light should illuminate or flicker.
10/93                                    73                                Exercise 8

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         Inverted
          burst
                        250
                                                        Filter
                                                       cassette
                                 Soap bubble trap
                                                                    Pump
           Beaker
                                 Soap solution
                     FIGURE 1. BUBBLE METER CALIBRATION SETUP

8.      Connect the tubing and filter to the pump.  The filter pad should be nearest to the pump.
       Connect the filter to the tubing attached to the bubble meter.

9.      Start a bubble in the buret by briefly touching the surface of the soap solution to the open
       end of the buret.   When the bubble passes the "0" mark, start the stopwatch.  Stop the
       stopwatch when the bubble passes the "250" mark.

10.    Flow rate is calculated using the following formula:
          FLOW RATE (L/min)
                                   VOLUME TRAVELED (ml)
                         60 sec/min
                                TIME (sec) BUBBLE TRAVELED     1000 mllL
11.    Use Data Sheet 1 to record your calibration data.
Exercise 8
74
10/93

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                             DATA SHEET 1

1.    PUMP MFG. AND MODEL:      	

2.    PUMP IDENTIFICATION #:
3.    BATTERY CHECK       	YES        	NO

4.    LOCATION/TEMP & BAROMETRIC PRESSURE:
5.    CALIBRATION METHOD:
6.    FLOW RATE CALCULATIONS
        FLOW RATE 0/min)-  VOLUME ^4KgI£D (TO/) x 60 secondslminute
                              TIME (seconds)          1000 mt/L
     VOLUME TRAVELED    TIME       FLOW RATE      AVERAGE
     (Continue calibration until three consecutive flow rates are within ± 5% of the average.)

7.    FLOW RATE:           	

8.    ROTAMETER SETTING:   	

9.    SIGNATURE:           	

10.   DATE/TIME:
10/93                              75                           Exercise 8

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         STATION 1:  CALIBRATING THE  GILIAN® PUMP USING
                      AN ELECTRONIC BUBBLE METER

The Gilibrator™ is an example of an electronic bubble meter.  It is a primary calibration method.
A fixed volume is located in the center tube of the flow  cell. A quartz-controlled timer is used to
measure the travel time for a bubble between  two sensors.  A microprocessor calculates  the
volume per unit time.  The flow rate is displayed in cc/min for this model.

The control unit  will display the actual  flow for each  sample and will accumulate and average
each successive reading.

      AVERAGE  -  To  display average and number of samples,  depress  and  hold  the
      AVERAGE BUTTON.  Releasing the button will display the last flow reading.  Pressing
      the button again and the number of reading made will be displayed.  Release and  the
      display returns to the last flow reading.

      DELETE  - To delete  obvious false readings, push the DELETE BUTTON.   This will
      delete the false information from the average and reset the average and sample number
      back to the previous reading.

      RESET -  To reinitiate  the sequence, hit the RESET BUTTON.  This  will zero  out all
       sample and average registers within the Control Unit. The Reset Button is also used if a
       malformed bubble is generated and has not been  subtracted from the average by use of
      the DELETE Function.
GILIBRATOR™ PREPARATION

1.     Remove the storage tubing between the air inlet and air outlet of the Gilibrator™.  Pour a
       small amount of soap through the BOTTOM AIR INLET of the Gilibrator™ to thoroughly
       cover the bottom of the flow cell.  Skip this step if already done.

2.     Connect a pump to the UPPER AIR OUTLET using the piece of tubing provided.

3.     Turn the regulator shutoff valve on the Gilian® pump (the screw under the brass cap on
     •i top  of the pump)  fully clockwise.  DO NOT OVERTIGHTEN.  Turn  on  the pump.
       Initiate  soap film  up  the flow tube  by rapidly pressing the  CALIBRATOR BUTTON
       down and releasing.  Repeat this  procedure until a bubble travels the length of the tube
       without breaking.

4.     After the Flow Tube walls have been "primed" (Step 3), turn on the Power switch of the
       Control Unit.   Wait approximately 10 seconds while the system runs through its check
       sequence.  The RUN LED will light at this time as well and a LO Battery  indication and
       a series of five dashes  will be displayed on the LCD  Readout.  Do not  operate the
       Gilibrator until the RUN LED signal extinguishes.  Ready operation  is indicated by a
       series of 4 dashes.

5.     Calibrate the pump using the following steps.

Exercise 8                                76                                    10/93

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                         77
         Exercise 8

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HIGH-FLOW CALIBRATION (1 to 4 liters/min)

6.      Insert a filter  cassette  and tubing between  the pump  and the tubing attached  to  the
       calibrator.

7.      Turn on the pump.

8.      Depress the  BUBBLE INITIATE  BUTTON  and hold to initiate  1  bubble  up the Flow
       Tube.  Release the button  to initiate a second bubble up the flow tube.  At low flow rates,
       the button can be depressed and released quickly for a single bubble.

9.      After a bubble completes passage up the FLOW TUBE, a flow reading will appear on the
       LCD display.

10.    Adjust the flow rate (pump adjustment) and repeat Steps 8 and 9 until you have  a flow
       rate of about 2 liter/min.

11.    RESET the calibrator.

12.    Repeat Steps 8 and 9 until you have three consecutive readings that are within 5% of their
       average.

13.    If the first set of 3 readings are not within the 5% allowable range,  press the RESET
       Button.  Then  repeat step 15 for 3 more readings.  The  Reset  Button is used because the
       Gilibrator™ averages all readings and not just the last 3.  If the first reading was outside
       the 5% limits,  you wouldn't know till readings 2 and 3 were made.  Readings 2, 3, and 4
       may  be within the limits, but you would not be able to check because reading 1 would
       still be in the average.

14.    If  a  bubble  breaks before  completing  the  timing sequence,  timing will continue until
       another bubble is generated to trip the second sensor.   This will  cause  an erroneous
       reading and should be subtracted from the average by hitting the Delete Button.

15.    Record each run, the average, and  other pertinent information on Data Sheet 2
LOW-FLOW CALIBRATION (20-500 cc/min)

16.    Connect the pump to the Gilibrator™ with a piece of tubing.

17.    Turn on the pump.

18.    Using the steps above, adjust the pump to about 1 liter/min.

19.    Open the regulator shutoff valve (located  under the brass  cap on top of the pump) by
       turning it counterclockwise at least 5 turns.
 Exercise 8                                 78                                       10/93

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20.    Put a carbon tube in the sorbent tube holder.  Connect the inlet side of the holder to the
       upper outlet of the calibrator (Figure 2).  Connect the outlet side of the holder  to the
       pump inlet.

21.    Depress the Bubble  Initiate Button to  initiate a bubble up  the Flow  Tube.   After the
       bubble completes passage up the Flow Tube, a flow  reading will appear on the LCD
       display.

22.    Remove the knurled  cap from the end of the tube holder.  Repeat Step 21 and adjust the
       variable flow controller screw  to get the desired  flow rate.  For this exercise,  try to
       obtain about 50 cc/min.

23.    RESET the calibrator after each run if not at the desired flowrate.  Reset after each flow
       adjustment.  Do three runs at the desired flow rate.  Record your results on Data Sheet 3.
SHUTDOWN

24.    Turn off the pump.

25.    Turn off the calibrator.

26.    Remove the air sampler from the Gilibrator™.  Replace the Storage Tubing between the
       upper and lower cell chambers.

27.    Disconnect the pump from the tube holder.

28.    Replace the cap on the tube holder.
10/93                                       79                                  Exercise 8

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                            DATA SHEET 2

1.    PUMP MFG. AND MODEL: 	

     PUMP IDENTIFICATION #:
     BATTERY CHECK       	PASS        	FAIL


2.    CALIBRATOR MFG. AND MODEL:

     CALIBRATOR IDENTIFICATION #:
3.    COLLECTION MEDIA:
4.    LOCATION/TEMP & BAROMETRIC PRESSURE:
5.    FLOW RATES: (Continue calibration until three consecutive flow rates are within ±5%
     of average.)
     FLOW RATE      AVERAGE             FLOW RATE      AVERAGE
6.    ROTAMETER SETTING:

7.    FLOW RATE: 	

8.    SIGNATURE: 	

9.    DATE/TIME:
ExerciseS                          80                              10/93

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                            DATA SHEET 3
1.    PUMP MFG. AND MODEL:

     PUMP IDENTIFICATION #:

     BATTERY CHECK
         PASS
2.    CALIBRATOR MFG. AND MODEL:

     CALIBRATOR IDENTIFICATION #:


3.    COLLECTION MEDIA:   	
     FAIL
4.    LOCATION/TEMP & BAROMETRIC PRESSURE:
5.    FLOW RATES: (Continue calibration until three consecutive flow rates are within ±5%
     of average.)
     FLOW RATE
AVERAGE
FLOW RATE
AVERAGE
6.    FLOW RATE:

7.    SIGNATURE:

8.    DATE/TIME:
10/93
            81
                   Exercise 8

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  STATION 2:  CHECKING GILIAN® PUMP WITH CALIBRATOR  PACK

The Gilian® Calibrator Pack has precision rotameters that can be used to calibrate a pump.  A
rotameter is considered a secondary calibration standard since it needs to be calibrated  or checked
with a primary calibration method periodically.  The pack also  has a magnehelic to produce a
pressure drop along the flow of a pump.  This, in combination with the rotameters, can be used
to check the constant flow compensator on the Gilian* pump.

In this step, the precision rotameter will be used to check the constant flow compensator.
COMPENSATOR CHECK

1.    Remove the Regulator Shutoff Protective Cap on the pump.  Turn the exposed screw
      clockwise until closed - DO NOT OVERTIGHTEN.  Replace the protective cap.

2.    On the Calibrator pack, move the BYPASS/CAL switch to the BYPASS position.

3.    Move the CAL SELECT (V2) switch to the upward position (3 liters/minute).

4.    Connect the pump to the PUMP SUCTION (Bl) outlet on the calibrator pack.

5.    Turn on the pump.

6.    Adjust (on the pump) the flow rate so that precision rotameter on the  calibrator (not the
      pump rotameter) reads "3.0" (3 liters/min or 3000 cc/min).  The flow  rate is read at the
      center of the rotameter ball.

7.    Move the CAL/BYPASS switch to the CAL position.

8.    Turn the V3 knob until the magnehelic dial reads 10 inches of back pressure.

9.    Read the flow rate on the rotameter.  If the difference in flow rates with and without back
      pressure is more  than ±5% (i.e., if the flow rate is not between 2850 and 3150), the
      pump needs adjustment. Consult the instructor.

10.   Move the BYPASS/CAL switch to the BYPASS position.

11.   Move the CAL SELECT (V2) switch to the downward position (1 liter/minute).

12.   Adjust the flow  rate to  "1.0"  (1  liter/min or 1000 cc/min) - reading  the precision
      rotameter on the calibrator.

13.   Move the BYPASS/CAL switch to the CAL position.

14.   Turn the V4 knob until the magnehelic dial reads 20 inches of back pressure.
 Exercise 8                                82                                    10/93

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IS.   Read the flow rate on the rotameter.  If the difference in flow rates with and without the
      back pressure is more than ±5% (i.e., if the flow rate is not between 950 and 1050), the
      pump needs adjustment.  Consult the instructor.
SHUTDOWN

16.    When completed with the compensator check, turn off the pump and disconnect the pump
       from the pack.
10/93                                     83                                  Exercise 8

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                     QUESTIONS AND CALCULATIONS

1.     Calculate  the  concentrations  in the  sampled  atmospheres  based  on  the  following
      information.

             Units:        1000 liter = 1 m3
                          1000 ml =  1000 cc = 1 liter
                          1 mg  = 1000 micrograms
(A)   Lead samples.  Pump flow rate = 2.0 liters per minute.
SAMPLE DURATION
4HR
2HR
2HR
LAB ANALYSIS
0.041 mg
0.029 mg
0.008 mg
AVERAGE
CONCENTRATION

      To calculate the Average Concentration (for each sample):
                               r _    mg chemical
                               \* ~
                                   sample volume (m3)
      where:
  sample volume (m3) = pump flow rate (liters/minute) x sample time (minutes) x	—	
                                                                        1000 liters
       To calculate an 8-hour TWA:


                                      C.T, + CJ". + .  . C T.
                        8 hour TWA
                                             8 hours
       where T is sample time in hours.  Minutes can be used for T if 480 minutes is used
       instead of 8 hours in equation.
Exercise 8                                84                                   10/93

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(B)    Solvent vapor sampling.  Flow rate = 50.0 cc/min.
SAMPLE
TIME
1 HR
2HR
1 HR
15 MIN
15 MIN
15 MIN
30 MIN
15 MIN
30 MIN
2HR
CONCENTRATION (ppm)
TOLUENE
10
32
21
175
140
100
93
85
54
10
XYLENE
5
11
8
70
50
67
40
30
10
ND
ACETONE
ND
ND
100
300
1000
820
1000
50
45
30
              Calculate an 8-hour TWA exposure for the three chemicals.
              Calculate an 8-hour TWA exposure for the mixture.  Is this calculation valid?
10/93
85
Exercise 8

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(C)    Do any of the concentrations in (A) and (B) exceed an exposure limit?
2.     Calibration of a pump prior to sampling gave a flow rate of 2.0 liters/minute.  Calibration
       after sampling gives a flow rate of 1.8 liters/minute. What do you do?
Exercises                                  86                                        10/93

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                                     EXERCISE #9

                                     Field Exercise


OBJECTIVE

Using the instruments and information provided, participants will:

1.     Perform a survey of the zones on the "hazardous waste site."

2.     Characterize the "hazards" present at each "zone" on the site.

3.     Identify as completely as possible the materials present on the site.

4.     Quantify  the airborne concentrations in each "zone" and evaluate the risk associated with
       these concentrations.


PROCEDURE

The class will be divided into teams. Each team will select a leader/spokesperson. Each team will
receive the same equipment.  The equipment available is the same equipment used earlier in the
week.  Before each entry, the team must submit plan of action for that entry to an instructor.

The "site" simulates a much larger site. It is divided into six zones. A description of each zone is
on the next page. A "map" of the site also follows.  Treat the readings obtained with the instruments
taken inside the containers as representing the average airborne concentrations in the "zone."
10/93                                       87                                  Exercise 9

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                     DESCRIPTION OF EXERCISE AREA


ZONE 1:

100 to 200 drums. Some with "FLAMMABLE" labels.


ZONE 2:

About 100 drums.  Some with "CORROSIVE" labels.


ZONE 3:

Box trailer containing drums.  Records indicate that the following chemicals were in the load. (Note:
This zone can be treated as a transportation incident separate from the site.)

       Acetone
       Methyl ethyl ketone
       Methyl isobutyl ketone
       Ethyl alcohol
       Butyl alcohol
       Toluene
       Benzene
       Xylenes
       1,1,1 -Trichloroethane
       Trichloroethylene
       Tetrachloroethylene

Readings taken in the drum represent readings at the trailer.


ZONE 4:

About 50 drums with "Waste Cleaner" labels.


ZONE 5:

Opening to underground vault. The vault could contain many drums.  Readings inside container are
equivalent to readings taken inside vault (using extended probes).


ZONE 6:

50 to  100 drums. Some with hand-painted labels reading "Paint Waste."


Exercise 9                                 88                                     10/93

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10/93
         89
                               Exercise 9

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