Haz Mat Monitoring And You!!!
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Haz Mat Monitoring And You!!!

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A pretty good presentation of air monitoring...

A pretty good presentation of air monitoring...

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Haz Mat Monitoring And You!!! Haz Mat Monitoring And You!!! Presentation Transcript

  • HazMat Monitoring and You!!! …or what they taught you in HM School but you already forgot!!!
  • Your Instructor… Professor Russell Peterson MS, HM Specialist Honorary Associate Professor of Hazmatology and Applied Chemically Contaminated Atmospheric Sampling Sciences
  • What we will learn today: • Understand the operations of the various types of monitors the BFD uses; • Understand and demonstrate the usage of these monitors; • Understand the limitations of these monitors; and • Understand and demonstrate the calibration of these monitors.
  • Types of monitors • Lower Explosive Limits (flammable gases) • Oxidizers • Toxic gases (CO, H2S, Cl2, NH3, etc.) • Radiation • Hazardous Chemicals
  • Two sources of monitoring • Point source – This is taken at the source of the contaminant or material – used for determining presence of HM. – Contaminant is drawn into the monitor via an air pump – representative of the atmosphere at the end of the probe. • Ambient – This is taken at the monitor face and is more representative of the total atmosphere – used for responder safety (“breathing zone”). – Is gas dependent. Some gases sink or rise so ambient monitoring is not as effective as point source monitoring.
  • Lower Explosive Limit monitors • Measures the concentration of a flammable vapor or gas in air indicating the results as a percentage of the LEL of the calibration gas • Instruments use a combustion chamber containing a filament that combusts the flammable gas
  • LEL, continued… • Filament is coated with a catalyst to facilitate combustion • The filament is part of a balanced resistor circuit called a “Wheatstone Bridge” • The filament burns the gas which increase the temperature of the filament • As filament temperature rises, so does resistance
  • LEL, continued… • This increased resistance results in an imbalance in the Wheatstone circuit and is reflected by a digital or analog readout on the meter. • Organic lead vapors (leaded gasoline) foul the filament and acid gases will cause the filament to corrode. • Instrument is temperature dependent, as are most flammable gases.
  • Relative Response • The different types of instruments that we use are calibrated to specific flammable gases • When you are “measuring” gases other than the calibration gas, the instrument will read either higher or lower depending on the material • Spilled gasoline in a sewer system that contains methane can be a problem • BE CAREFUL!!!
  • Cross Sensitivity Multipliers for the CMX and TMX monitors • Hydrogen 0.5 • Methanol 0.6 • Methane 0.7 • Ethanol 0.8 • Acetylene 0.7 • Acetone 0.9 • Ethylene 0.6 • Isopropanol 1.1 • Ethane 0.7 • Benzene 0.9 • Propane 0.8 • Toluene 1.0 • Butane 0.8 • Styrene 1.5 • Pentane 1.0 • Xylene 1.3 • Hexane 1.3 Subject to an accuracy of +/- 25% per manufacturer
  • Rule of thumb The lighter the material (or the fewer carbons it has), the less the multiplier. The number on your LEL meter will be greater than the percentage of actual LEL you have present…
  • Oxidizer monitors • These monitors are used to monitor the atmosphere for four reasons: – Oxygen content for respiratory purposes – below 19.5%, atmosphere is oxygen deficient – Increased risk of combustion – above 25%, atmosphere is oxygen enriched – Use of other instruments. Below 10% affects LEL monitors – Presence of contaminants. Many other chemicals will displace oxygen. Each % decrease on the monitor means a 5% drop in oxygen and a 5% increase in “something else”
  • Oxidizer monitors, continued • Caveat – an “oxygen” monitor measures all oxidizers, from O2 to O3 (ozone) to off gassing nitrates, chlorates (Cl2 and O2 radicals), and perchlorates. Don’t get in the habit of thinking that the number you are reading is the oxygen percentage; it is the percentage of an oxidizer which is in the atmosphere.
  • Oxidizer monitors, continued • Monitor uses a electrochemical sensor that measures oxidizer concentration in the air. • Sensor is made on two electrodes, a housing containing a basic electrolyte solution, and a semi-permeable Teflon membrane. • Atmosphere enters the membrane, reacts with the solution which results in produces an electrical current. • This current is passed through an amplifier which is reflected on a digital or analog meter.
  • Oxidizer monitors, continued • Process is non-reversible and is a chemical reaction (rxn). Whenever it is removed from a nitrogen purged atmosphere, it is active. Sensor life span is about 1 year. • Exposure to CO2 and strong oxidizing chemicals (such as chlorine and ozone) will cause the sensor to wear out quicker.
  • Effects of Oxygen levels • +23% Extreme fire hazard • 21% Normal air concentration • 19.5% Minimum OSHA safe level • 16% Disorientation, impaired judgement and breathing • 14% Faulty judgement, fatigue • 8% Mental failure, fainting • 6% Difficult breathing, death in mins
  • Toxic gases monitors • Used to: – identify airborne chemicals, – evaluate exposures to occupants and responders, – evaluate the need for PPE, and – develop control methods to reduce exposure.
  • Toxic gases monitors • Four kinds of Toxic Gas monitors – Colorimetric inidicators • Can be tubes, tape, or badges – Specific chemical sensors • Electrochemical sensors – Total vapor survey meters • PID’s and FID’s – Gas Chromatographs
  • Toxic gases monitors, continued • Colorimetric tubes – Works through a chemical rxn which results in a color change when the reagent is exposed to a specific chemical. – Amount of color change correlates to a concentration that is drawn through the tube. This concentration is correlated to a percentage or ppm via the number of pump strokes.
  • Toxic gases monitors, continued • Specific chemical sensors – Monitor uses a electrochemical sensor that measures oxidizer concentration in the air. – Sensor is made on two electrodes, a housing containing a basic electrolyte solution, and a semi- permeable Teflon membrane. – Atmosphere enters the membrane, reacts with the solution which results in produces an electrical current. – This current is passed through an amplifier which is reflected on a digital or analog meter. – Sensor is non-reversible – is used up as long as it is exposed to the gas
  • Toxic gases monitors, continued • Specific chemical sensors – Metal Oxide sensor • Consists of a metal oxide film coating on heated ceramic substrate fused or wrapped around a platinum wire coil • Gas comes in contact with metal oxide, replaces the oxygen in the oxide which results in a change in conductivity • Change in conductivity is reflected in a change in the analog or digital meter • Sensors are not always chemical specific. CO sensors, for example, can rx with H2S gas
  • Effects of Carbon Monoxide • 35 ppm PEL, 8 hrs (OSHA) • 200 ppm frontal headache in 2-3 hrs • 400 ppm frontal headache and nausea in 1-2 hrs; Occipital in 2.5-3.5 hrs • 800 ppm Headache, nausea in 45 mins • 1600 ppm Headache, nausea in 20 mins • 3200 ppm Headache, nausea in 5 mins • 6400 ppm Headache, nausea in 1 min • 12,800 ppm Unconscious immediately; death in 1-3 mins
  • Toxic gases monitors, continued • Total vapor survey meters – PID’s (Photo Ionization Detector) • Uses an ionizer (UV in the case of the PID) to ionize the chemical • The ionized chemical flows to the + and – charged plates • The mass of each ionized element is measured • The chemical reforms and exits through the pump • Not chemical specific
  • Toxic gases monitors, continued • Total vapor survey meters – FID’s (Flame Ionization Detector) • Uses an ionizer (CH3 in the case of the FID) to ionize the chemical • The ionized chemical flows to the + and – charged plates • The mass of each ionized element is measured • The chemical is destroyed during the process • Not chemical specific – specific for HC’s (must be able to burn)
  • Toxic gases monitors, continued • Gas Chromatography
  • Radiation
  • Radiation • Radiation detectors measure alpha, beta, gamma, and neutron radiation. • Detection of radiation can provide you with info on exposure rates and dose
  • Alpha Radiation • Alpha is positively charged particles consisting of two protons and two neutrons. They are very heavy and have low penetrating power.
  • Beta Radiation • Beta is produced when an electron is emitted from the nucleus of a radioactive atom, along with an unusual particle called an antineutrino. The neutrino is an almost massless particle that carries away some of the energy from the decay process. Because this electron is from the nucleus of the atom, it is called a beta particle to distinguish it from the electrons which orbit the atom.
  • Gamma Radiation • Gamma is a ray made up of high energy photons of electromagnetic radiation. It has no mass and is highly penetrating.
  • Radiation, continued • Gamma is a ray made up of high energy photons of electromagnetic radiation. It has no mass and is high penetrating.
  • Gas Filled Radiation Detectors • The most common type of instrument is a gas filled radiation detector. • Works on the principle that as radiation passes through air or a specific gas, ionization of the molecules in the air occur. • A high voltage is placed between two areas of the gas filled space, the positive ions will be attracted to the negative side of the detector (the cathode) and the free electrons will travel to the positive side (the anode).
  • Gas Filled Radiation Detectors • Charges are collected by the anode and cathode which then form a very small current. This small current is measured and displayed as a signal on the meter. • The two most common are the ion chamber used for measuring large amounts of radiation and the Geiger-Muller or GM detector used to measure very small amounts of radiation.
  • Scintillation Radiation Detector • The second most common type of radiation • Uses a special material which glows or “scintillates” when radiation interacts with it. • The most common type of material is a type of salt called sodium-iodide. • As electron enter the front, they strike a photocathode which produces more electrons. These electrons are multiplied until they strike an anode at the rear of the detector which causes an energy pulse. This pulse is reflected on the meter.
  • Hazardous Chemicals • To identify unknown chemicals, the HazCat System is an effective method. It provides for immediate on-site ID & characterization of virtually any spilled material.
  • Hazardous Chemicals What is it??? Flammable? Toxic? Corrosive? Reactive?
  • The different brands of monitors and detectors that BFD uses are: • Industrial Scientific CMX 271 • Industrial Scientific TMX 412 • BW Defender • Ludlum Radiological Response Kit • HazTech HazCat Kit
  • Operation and Maintenance of the Industrial Scientific CMX 271 • Technical Specifications – Sensor types • CO – electrochemical • LEL – catalytic, diffusion type • O2 – electrochemical – Battery life is 10 hours on full charge – Temperature range is -15oC to +40oC – Humidity range is 0-95% RH
  • CMX 271 TechSpecs • Technical Specifications – Measuring range • CO – 0 to 1999 PPM • LEL – 0 to 99% LEL • O2 – 0 to 30% vol – Accuracy • CO - +/- 5% of reading for 0 to 300 ppm; +/- 7.5% of reading for 300 to 1999 ppm • LEL – +/- 3% LEL for 0 to 30%; +/- 7.5% for 30 to 99% • O2 - +/- 0.5% O2 for 10 to 30%; +/- 0.75% for 0 – 10%
  • Operation and Maintenance of the Industrial Scientific TMX 412 Technical Specifications – Sensor types • CO – electrochemical • LEL – catalytic, diffusion type • O2 – electrochemical • H2S – electrochemical – Battery life is 10 hours on full charge – Temperature range is -4oF to +122oF – Humidity range is 0-99% RH
  • TMX 471 TechSpecs • Technical Specifications – Measuring range • CO – 0 to 999 PPM • LEL – 0 to 100% LEL • O2 – 0 to 30% vol • H2S – 0-999 PPM
  • Operation and Maintenance of the Industrial Scientific CMX 271 and the TMX 412 • Turning the unit on • Testing the sampling pump • Calibrating the unit • Turning the unit off
  • Operation and Maintenance of the BW Defender Technical Specifications – Sensor types • CO – electrochemical • LEL – catalytic, diffusion type • O2 – electrochemical – Battery life is 12 hours on full charge – Temperature range is -20oC to +50oC – Humidity range is 5-95% RH
  • BW Defender TechSpecs • Technical Specifications – Measuring range • CO – 0 to 500 PPM • LEL – 0 to 100% LEL • O2 – 0 to 30% vol • H2S – 0-100 PPM
  • Operation and Maintenance of the BW Defender • Turning the unit on • Testing the sampling pump • Calibrating the unit • Turning the unit off
  • Operation and Maintenance of the Ludlum Radiological Response Kit
  • Operation and Maintenance of the Ludlum Radiological Response Kit • DISPLAY RANGE: Auto ranging from 0.0 microR/hr - 9999 R/hr; 0.000 microSv/hr - 9999 Sv/hr; 0 cpm - 999k cpm; or 0 cps - 100k cps • BATTERY LIFE: Typically 200 hours with alkaline batteries (low battery indicated on display) • CONSTRUCTION: Cast and drawn aluminum with beige polyurethane enamel paint • TEMPERATURE RANGE: -4° F(-20° C) to 122° F(50° C) May be certified for operation from -40° F(-40° C) to 150° F(65° C) • WEIGHT: 3.5 lbs (1.6kg) including batteries
  • Model 44-9 Pancake G-M Detector • Used to frisk for alpha-beta-gamma
  • Model 44-2 Gamma Scintillator • High energy gamma detection
  • Model 133-7 Energy Compensated G-M High range gamma measurements Range is 25 mR/hr - 100 R/hr
  • Operation and Maintenance of the Ludlum Radiological Response Kit • Turning the unit on • Calibrating the unit • Turning the unit off
  • Orientation to the HazTech Systems HazCat Kit • Reagents • Associated Labware • Safety concerns – Chemicals – Flammable gas • Classification Process
  • Limitations of Detection Equipment • Detection equipment is limited in the specificity of materials that it detect. • There are numerous environmental parameters such as temperature, humidity, et cetera that must exist for the detector to work properly. • The detectors have an inherent error margin. • The detector will not work properly if it is not calibrated for the existing conditions.
  • Any Questions???
  • Air Monitoring Worksheet Station 2 Instructions: Take a reading of the atmosphere at the opening of each can. Record your answers. CMX 271 TMX 412 BW Defender Source Can A Can B Can C Questions: •Are the readings from all three instruments the same for each can and what do you think is in each can? •List the possible reasons why the reading might differ. •Why is 10% of the LEL used as an action level for atmospheric monitoring?
  • Practical Exercise • Station 1 – Calibration station • Station 2 – Liquid monitoring • Station 3 – Atmospheric monitoring • Station 4 – Gas monitoring • Station 5 – Radiological monitoring
  • Station 1 • The purpose of this station is to practice calibrating the different monitoring instruments before usage. • This will be a group activity!!! • Pay attention…you might have to do this sometime!!!
  • Station 2 • The purpose of this station is to determine which liquid container is producing an explosive or flammable vapor. • DO NOT STICK THE PROBE INTO THE LIQUID!!! And, yes, IT HAS BEEN DONE BEFORE $!$!$! • Record your answers on your work sheet.
  • Station 3 • The purpose of this station is to determine the effect distance has on an explosive atmosphere. • DO NOT STICK THE PROBE IN THE LIQUID!!! • Record your observations on the work sheet.
  • Station 4 • The purpose of this station is to determine the concentration of explosive and/or toxic gases within a closed environment. • DO NOT INHALE THE GASES IN THE BAGS!!! • Record your answers on the work sheet.
  • Station 5 • The purpose of this station is to determine which material is radioactive. • DO NOT GET THE MATERIAL ON YOUR HANDS!!! WEAR GLOVES!!! • Record your answers on the work sheet.