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Appendix D - Training Program

Air Monitoring Principles

Objectives/Samples of Behavior:

  1. Explain the difference between direct and indirect reading instruments.

  2. Explain the use of direct and indirect reading instruments at hazardous waste sites.

  3. Differentiate between personal and area monitoring.

  4. Determine when periodic monitoring is needed.

A.  Purposes of Air Monitoring

  1. Hazards & risks to public & personnel

  2. Personal protective equipment selection

  3. Site work zones

  4. Effects on environment

  5. Mitigation actions

B.  General Types of Air Monitoring

  1. DIRECT

  2. INDIRECT

C.  Desired Characteristics of Field Instruments

  1. Portable and rugged

  2. Easy to operate

  3. Inherently safe

  4. Reliable and useful results

  1. Response time

  2. Sensitivity

  3. Selectivity

  4. Accuracy

  5. Precision

D.  Direct Reading Instruments - General

  1. Disadvantages/considerations

  1. Variable results

  2. Low end sensitivity problem

  3. Only measure/detect specific classes of chemicals

  4. Multiple contaminants

  5. Interferences, relative response

  6. Worker training

  7. Recording of results

  8. Not for compliance (Air Force)

  1. Inherent safety approval area

  1. Electrical devices such as portable air monitoring instruments are to be constructed in such a fashion as to eliminate the possibility of igniting a combustible atmosphere.

  2. Hazardous atmospheres - National Electric Code

Definition of a hazardous atmosphere:

Concentration between the lower explosive limit and upper explosive limit (LEL - UEL)

Presence of ignition source

Exothermic reaction

  1. Definitions

Intrinsically safe: Designed so that parts are not exposed to explosive atmosphere, or if there is insufficient energy for ignition.

Explosion proof: Designed to contain an explosion and cool gases to prevent spread.

Purged system: Inert gas-filled system; positive pressure to prevent explosive gases or vapors from entering.

  1. Hazardous atmospheres & locations - inherent safety

Class

I

Combustible gases and vapors

II

Combustible dusts

III

Combustible fibers and flyings

Group

A, B, C, D

Gases and vapors found in Class I atmosphere

E, F, G

Dusts found in Class II atmosphere

Division

1

Location in which hazardous concentrations exist continuously,  intermittently, or periodically under NORMAL operating conditions

2

Location in which hazardous concentrations do NOT normally exist under normal operating conditions

  1. Instrument protection criteria

Class I, Groups A, B, C, & D, Division 1

"Intrinsically safe"

"Explosion-proof"

"Purged system"

Class I, Groups A, B, C, & D, Division 2

"Non-incendive"

Class II, Groups E, F, & G, Division 1 & 2

"Dust-ignition proof"

E.  Oxygen Indicators

To determine:

  1. Types of respiratory protection

  2. Combustion risk

  3. Use of other instruments

  4. Presence of contaminants

F.  Combustible Gas Indicators (CGIs)

  1. To determine:

  1. Risk of fire/explosion

  2. Indication of contaminants

  1. Reads % LEL

  2. Combination units

  3. Calibration gas & conversion charts, e.g., methane vs combustible gas to be measured

  4. Interpretation of results - reading of 100% for example

G.  Toxic Atmosphere Monitors

  1. Detector tube system

  1. Length of stain/color change = concentration

  2. Different # pump strokes for different chemicals / concentrations - specified in manufacturer's instruction

  1. Monitors for specific agents (e.g. CO, hydrogen sulfide)

  2. Total vapor analyzers

  3. Gas chromatograph

H.  Site Monitoring

  1. Monitoring variables

  1. Inside or outside?

  2. Temperature

  3. Wind

  4. Rain - humidity

  1. Unknown conditions

  1. Sequence

Oxygen deficiency - 1st - 19.5%

Explosive atmosphere - 2nd - 25% LEL for levels A & B - (10% LEL foe level C - when site has been characterized sufficiently to downgrade level)

Radiation - 3rd = 1 mR/hr

  1. Level B:  minimum for initial entry into unknown area

  1. Perimeter Monitoring

  1. Check for off-site impacts: public health

  2. Evaluate site clean areas

  3. Site safety plan dictates need

  1. Periodic monitoring

  1. Locate sources of contamination

  2. Working in obvious contamination

  3. When new contaminants are handled

  4. Different operations, drum opening vs well drilling

  5. When work begins on a different portion of the site

  1. Personal Monitoring

  1. Monitor "high risk" employees

  2. OEL monitoring - compliance

  3. Respirator protection factors

  4. After the fact - legal reasons