Pi Ds As A Hazmat Response Tool Unabridged 0207

PIDs as a HazMat Response Tool

Unabridged Version 7/02

Don’t LEL sensors measure VOCs? How can we measure in ppm? PID uses in HazMat What is a PID? The Power of Correction Factors Setting PID alarms/interpreting PID output Review of specific PID applications Tips for Using and Maintaining PIDs

Training Agenda:

Most HazMat Incidents are

VOCs

Volatile Organic Compounds (VOCs)Fuels (the majority of HazMats)

Degreasers, Heat Transfer FluidsPaints, Solvents, Plastics, Resins

The Chemical Compounds that keep Industry going!

What is a VOC?

Refrigeration & Fertilizers: Ammonia (AP-201) Plastics/Fiberglass: Styrene & Methylene

Chloride Petroleum: Hydrocarbons & Benzene Automotive: Spray Booths (Paints) & Fuels Aircraft: Wing Tank Entry, Solvents &

Degreasers (AP-200) Sausages: Carbon Disulfide

Examples of Industrial PID Usage

Wool: Perchlorethylene (PERC) Printing: MEK, Toluene, IPA Environmental: Site assessments (AP-214) Pulp & Paper: Turpentine (AP-204) Heat Transfer Fluid: Therminol/DowTherm

(AP-205) Electronics: Solvents Coke Oven gases


Marine Chemists: Ship & Barge entry Water & Wastewater: Spill investigators Drug Enforcement: Clan Labs (AP-220) College, Hospital, R&D Labs: Spills Indoor Air Quality (IAQ) Consultants (AP-

212) Air Rifle Manufacturer Waste Receiving Stations


PID Sensitivity to VOCs make them an invaluable tool for HazMat Decisions:

Initial PPE Assessment Leak Detection Perimeter Establishment & Maintenance Spill Delineation Decontamination Remediation

PID Uses in HazMat

Many VOC’s are flammable and may be detected by the LEL (Lower Explosive Limit) or combustible gas sensors found in virtually every multigas monitor.

However, LEL sensors are not particularly useful in measuring toxicity because they do not have enough sensitivity.

Doesn’t LEL measure VOCs?

Wheatstone Bridge LEL Sensor

Measures change in resistance due to change in temperature of gas burning on detector

Detector

Compensator

Output

(+)4.25 V

(-) 1 k

1 k

Wheatstone Bridge is like a Stove One element has a

catalyst and one doesn’t Both elements are turned

on low The element with the

catalyst “burns” gas at a lower level and heats up

The hotter element has more resistance and the Wheatstone Bridge measures the difference in resistance between the two elements

Is the LEL Sensor Sensitive Enough?Two mechanisms can affect the

performance of Wheatstone bridge LEL sensors:

Gases burn with different heat outputs at their LEL

“Heavier” hydrocarbon vapors have difficulty diffusing into the LEL sensor and reduce its output

Active beadCompensating bead

Flame arrestor

LEL Sensor Cut-Away

Methane (CH4)Heavier Hydrocarbons

Heavier Hydrocarbons Rejected by the Flame Arrestor

Gas/Vapor LEL (%vol) Sensitivity (%)Acetone 2.2 45Diesel 0.8 30Gasoline 1.4 45Methane 5.0 100MEK 1.8 38Propane 2.0 53Toluene 1.2 40

LEL Sensor sensitivity varies with chemical

LEL Sensor Relative Sensitivity

LEL Sensor Cal Gases Pentane and Propane are often used as LEL

sensor calibration gases because their response is closer to most common flammable vapors

LEL sensors fail to “see” Methane first, so you could calibrate properly on Pentane or Propane yet not “see” Methane at all

The safest calibration is to calibrate with Methane gas and then set the scale to Pentane or Propane

Surrogate or simulant cal.

Using PIDs for LEL Multiply %volume by 10,000 to get ppm. LEL Gasoline is 1.2% by volume or 12,000

ppm 10% of LEL Gasoline is 1200 ppm

PIDs often are a better measurement tool for 10% of LEL for fuels and

chemicals

Using PIDs for 10% of LEL

ChemicalName

LEL(%vol)

LEL inPPM

10% ofLEL inPPM

10% ofLELRU10.6

Acetone 2.5 25000 2500 2273Gasoline 1.4 14000 1400 1647MEK 1.4 14000 1400 1628Styrene 0.9 9000 900 2250THF 2 20000 2000 1111Toluene 1.1 11000 1100 2200Xylene 1.1 11000 1100 2558

Wingtank LEL Entrants can see and smell jet fuel but

their LEL meters read nothing LEL sensor just can’t see jet fuel Aircraft maintenance exposes sensor to

poisoning silicone compounds PIDs are used to make LEL decision

Wingtank LEL

Clues

Tubes

Clues: wingtank containing jet fuel residue

LEL: little or no reading PID: 800 ppm in jet fuel

units is 10% of LEL

=800 ppm is 10% of LEL

PID

Toxic Sensors

LEL

Pulp & Paper Turpentine LEL Operator using a properly calibrated monitor

did not measure flammable levels of turpentine but was severely burned in a turpentine flash during hot work

LEL sensor just can’t see turpentine Sulfur compounds in Pulp & Paper act as

chronic poisons to LEL sensor that at its best can barely see turpentine

Monitors now have LEL and PID

Pulp & Paper Turpentine LEL

Clues

Tubes

Clues: turpentine recovery unit

Toxic Sensor: low reading on H2S sensor common in a pulp plant

LEL: no reading PID: 800 ppm in

turpentine units or 10% of LEL=800 ppm is

10% of LEL

PID

Toxic Sensors

LEL

Using PIDs for 10% of LEL

1000 ppm in Isobutylene units is a conservative

measure of 10% of LEL for many common VOCs

LEL Measures EXPLOSIVITY not TOXICITY! Many VOCs are toxic well below the

sensitivity of an LEL sensor Xylene = 100 ppm

Using LEL to measure for Toxicity is like using a yardstick to measure the thickness of a sheet of paper!

A PID can measure TOXICITY!

Explosivity Vs Toxicity

LEL Compared to PIDLEL gets you home tonight

PID lets you enjoy retirement! LEL is more for Acute toxicity which will

get you immediately (IDLH) PID is more for Chronic Toxicity which will

get you over a longer period of time (TWA)

Toxicity = Concentration x Exposure Period

We now need to measure in PPM!

How can we measure in PPM? Colorimetric Tubes Metal Oxide Sensor (MOS) Portable GC/MS Flame Ionization Detectors (FID) Photo Ionization Detector (PID)

Colorimetric Tubes measure in PPM+Proven technology− “Snap Shots” like a “Polaroid” camera, non-

continuous, no alarms− “Spot Checks” result in sampling error−Respond in minutes rather than seconds−15-25% accuracy Piston/Bellows style−Readings subject to interpretation−Generate Glass splinters & chemical waste−Tubes expire & large stock is expensive

MOS Sensors Measure in PPM+Faster response than tubes & continuous+Affordable (“Poor Man’s PID”)−Detection limits in 10s of ppm at best−Non-linear output limits accuracy (its like a rubber ruler)−Still slower to respond than PID or FID−Sensitive to Temperature and Humidity leading to false

alarms −Can be poisoned & ruined by over-ranging−Non-specific

Portable GC/MS measures in PPM+Very Accurate +Very Specific− “Snap Shots” like a “Polaroid” camera, non-

continuous, no alarms− “Spot Checks” result in sampling error−Respond in minutes rather than seconds−Very complicated−Very heavy and bulky−Prohibitively expensive

FIDs Measure in PPM+Fast response+Very Accurate −Complicated−Heavy and bulky−Expensive−Non-specific

The difference between FID and PID is like the difference between a meterstick and a

yardstick!

PIDs Measure in PPM+Fastest response+Very Accurate (the “heart of a GC”). Entry

decisions can be made directly based on PPM with confidence.

+Optical Technology not affected by contaminants

+Non-specific

“Traditional” PIDs Were Just One Step Away from the Lab!

High cost of purchase & maintenance Lack of durability Bulky size & heavy weight Sensitivity to Humidity and RFI

Design breakthroughs solve these problems so that PIDs can be used for

HazMat!

Why aren’t PIDs More Common?

Initial PPE Assessment Leak Detection Perimeter Establishment & Maintenance Spill Delineation Decontamination Remediation

PID Uses in HazMat

Some “Incidents” may not be an “Incident” at all and many not require any PPE (Personal Protective Equipment)

Some non-incidents are really “INCIDENTS” and require substantial PPE

PIDs are an excellent AID in this decision making process

Initial PPE Assessment with a PID


Benzene (PEL = 1 ppm) Ambient conditions: 95oF (35oC),

95% Humidity

How do you dress out?

Pool of Liquid under Benzene Tank Car


PID is very sensitive to Benzene Level A is unnecessary if no Benzene Level A represents a Heat Stress Risk Car contents at 65oF (18oC) “Leak” really condensation

Leak Detection with a PID

PID allows you to “see” concentrations As concentration increases you are

closer to the source

“See” the Concentration Gradient

10,000 PPM Perchlorethylene (PERC)

0 PPM PERC

Perimeter Monitoring with a PIDSet based upon conditions by

experienced HazMat Techs Physical Characteristics of Chemical Toxicity of Gas or Vapor Temperature Wind Direction

Changes in Conditions are often Missed by Untrained Perimeter Workers

Perimeter Monitoring with a PIDGasoline Tank Truck Rollover

8:00 AM45oF (7oC)No wind

TWA = 100 ppm


8:00 AM45oF (7oC)No wind

10,000 PPM Gas

50 PPM (1/2 of TWA)

Perimeter = 100 feet


11:00 AM75oF (24oC)10 mph wind

10,000 PPM Gas

600 PPM

Perimeter now should be 300 feet Perimeter worker overexposed

Perimeter Monitoring with a PIDDatalogging as a Tool

Document Perimeter Worker Exposures

Provide Evidence to Justify Evacuations

PIDs for Spill DelineationMany Liquids can be present in a

HazMat Incident Water Fuels Engine Fluids Foam

PIDs for Spill DelineationIt’s Hard to tell pavement “wet” with water from

pavement “wet” with diesel just by looking

PIDs for Spill Delineation

Limited Absorbent can be Efficiently used only on the Diesel Spill

PIDs can help separate the “Water” from the “Oil”

PIDs for Decon

Is Worker Contaminated? Is Decon Complete? Can we reuse suit? Is my turn-out contaminated

with Fuel Products? This same sensitivity to

hydrocarbons makes PIDs ideally suited for arson investigation

(Ref AP-207)

PIDs can help answer these questions:

Using a PID for Remediation


Hazardous Materials can evade the best attempts at containment:

Is Soil Contaminated enough to require further clean-up?

Is Water Contaminated enough to require further clean-up?


Put contaminated soil or water in a container

Cover the container and bring it up to room temperature (~15 min)

Put PID probe into container and sample

Generally <100 ppm is good Ref AP-214

How to do a Headspace Sample:

What is a PID? PID = Photo-Ionization Detector Detects VOCs (volatile organic compounds)

and Toxic gases from <10 ppb to as high as 10,000 ppm

Over 90% of HazMat incidents are fuel product related and are easily measured with a PID

A PID is a very sensitive broad spectrum monitor, like a “low-level LEL”

100.0 ppm

Gas enters the instrument

It passes bythe UV lamp

It is now “ionized” Charged gas ions

flow to charged plates in the sensor and

current is produced

Current is measured and concentration is

displayed on the meter.

++--

++

--

++

--++

--++--

Gas “Reforms” and exits the

instrument intact

How does a PID work?An optical system using

Ultraviolet lamp to breakdown vapors and gases for

measurement

Organics: Compounds Containing Carbon (C) Aromatics - compounds containing a benzene ring

BETX: benzene, ethyl benzene, toluene, xylene Ketones & Aldehydes - compounds with a C=O bond

acetone, MEK, acetaldehyde Amines & Amides - Carbon compounds containing Nitrogen

diethyl amine Chlorinated hydrocarbons - trichloroethylene (TCE) Sulfur compounds – mercaptans, carbon disulfide Unsaturated hydrocarbons - C=C & C C compounds

butadiene, isobutylene Alcohol’s

ethanol Saturated hydrocarbons

butane, octane Inorganics: Compounds without Carbon

Ammonia Semiconductor gases: Arsine

What does a PID Measure?

What PIDs Do Not Measure Radiation Air

N2

O2

CO2

H2O Toxics

CO HCN SO2

Natural gas Methane CH4

Ethane C2H6

Acids HCl HF HNO3

Others Freons Ozone O3

Ionization Potential IP determines if the PID can “see” the gas If the IP of the gas is less than the eV output of

the lamp the PID can “see” it Ionization Potential (IP) does not correlate with

the Correction Factor Ionization Potentials are found in RAE

handouts (TN-106), NIOSH Pocket Guide and many chemical texts.


If the “wattage” of the gas or vapor is less than the

“wattage” of the PID lamp then the PID can “see” the gas or vapor!

8

9

10

11

12

13

14

15

8.4

9.24 9.549.99 10.1 10.5

10.6611.3211.47

12.1

14.01

Some Ionization Potentials (IPs) for Common ChemicalsSome Ionization Potentials (IPs) for Common Chemicals

Benzene

MEK

Vinyl Chloride

IPA

Ethylene

Acetic A

cid

Methylene

chloride

Carbon Tet.

Carbon

Monoxide

Styrene

Oxygen

Ionization Potential

(eV)

11.7 eV Lamp

10.6 eV Lamp

Not Ionizable


9.8 eV Lamp

9.8 & 10.6 provide more specificity 10.6 lasts 24-36 months 10.6 provides best resolution 10.6 costs less ($195) 11.7 is required for high energy compounds like

Methylene Chloride 11.7 crystal absorbs water and degrades 11.7 lasts about 2-3 months 11.7 costs more ($345 in ampule)

Why not always use 11.7 eV Lamps?

Selectivity Vs Sensitivity PID is very sensitive and accurate PID is not very selective


Ruler cannot differentiate between yellow and

white paper


PID can’t differentiate between ammonia &

xylene

Selectivity Vs SensitivityUse your head for Selectivity and the PID

for Sensitivity PID is sensitive to chemicals not specific Correction Factors set correct PID scale PID should stay on Isobutylene (Calibration

gas) until unknown is identified

A PID is a Gas Chromatograph where the column is between your ears!

Selectivity Vs Sensitivity

No Correction Factor is used until compound is identified

Identify then Quantify!

Correction Factors are the key to unlocking the power

of a PID for Assessing Varying Mixtures and

Unknown Environments

What is a Correction Factor?

Correction Factor (CF) is a measure of the sensitivity of the PID to a specific gas

CFs are scaling factors, they do not make a PID specific to a chemical, they only correct the scale to that chemical.

Correction Factors allow calibration on cheap, non-toxic “surrogate” gas.

Ref: RAE handout TN-106

What is a Correction Factor?

Low CF = high PID sensitivity to a gas If the chemical is bad for you then the PID

needs to be sensitive to it If Exposure limit is < 10 ppm, CF < 1

If the chemical isn’t too bad then the PID doesn’t need to be as sensitive to it

If Exposure limit is > 10 ppm, CF < 10 Use PIDs for gross leak detectors when CF

> 10

CF’s measure sensitivity

Toluene CF with 10.6eV lamp is 0.5 so PID is very sensitive to Toluene

If PID reads 100 ppm of isobutylene units in a Toluene atmosphere

Then the actual concentration is 50 ppm Toluene units

0.5CF x 100 ppmiso= 50 ppmtoluene

CF Example: Toluene

Ammonia CF with 10.6eV lamp is 9.7 so PID is less sensitive to Ammonia

If PID reads 100 ppm of isobutylene units in an Ammonia atmosphere

Then the actual concentration is 970 ppm Ammonia units

9.7CF x 100 ppmiso= 970 ppmammonia

CF Example: Ammonia

Making a Decision with a PID

Two sensitivities must be understood to make a decision with a PID

Human Sensitivity: as defined by AGCIH, NIOSH, OSHA or corporate exposure limits

PID Sensitivity: as defined through testing by the manufacturer of your PID (RAE CF)

ONLY USE A CORRECTION FACTOR FROM THE MANUFACTURER OF YOUR PID!


PID sensitivity + Human Sensitivity = Decision

orCF + Exposure Limit = Decision

Reference AP-221


Three scenarios on how to make a decision with a PID

Single Gas/Vapor Gas/Vapor mixture with constant make-up Gas/Vapor mixture with varying make-up

Single Chemicals are easy Identify the chemical Set the PID Correction Factor to that chemical Find the Exposure Limit(s) for the chemical Set the PID alarms according to the exposure

limits

The “Real World” is rarely this easy. Most applications are a “Witches Brew” of

VOCs

PID Alarms: Single Chemical

Paint: 15% Styrene and 85% XyleneELmix = 1/(0.15/50 + 0.85/100) = 87 ppm

Where: 0.15 is 15% styrene 50 is the 50 ppm exposure limit for styrene 0.85 is 85% xylene 100 is the 100 ppm exposure limit for xylene Ref: TN-106 & NIOSH Pocket guide, AP-211 & AP-

221

PID Alarms: Constant Mixtures

Paint: 15% Styrene and 85% XyleneCFmix = 1/(0.15/0.4 + 0.85/.6) = 0.56

Where: 0.15 is 15% styrene 0.4 is the CF styrene 0.85 is 85% xylene 0.6 is the CF for xylene Ref: TN-106, AP-211 & AP-221


Paint: 15% Styrene and 85% Xylene In the sealed up living room I got a reading

of 120iso on the PID in Isobutylene units Multiplying it by the correction factor of

0.56mix my real reading on the mixture was 67.2mix ppm

This is under the calculated exposure limit of 87mix ppm for the mixture


Constant Mixture Shortcut #1Paint: 15% Styrene and 85% Xylene

Lets consider it to be just Xylene In the sealed up living room I got a reading of

120 on the PID in Isobutylene units Multiplying it by Xylene CF of 0.59 my real

reading as Xylene is 70.8 ppm This is under the Xylene exposure of 100 ppm


Constant Mixture Shortcut #2 Find the average make-up of the mixture Determine the most toxic VOC Base setpoints on the most toxic VOC

WARNING: Shortcuts only provide a quick guideline!


Gasoline “Gas” contains as much as 1% Benzene Benzene is carcinogenic (PEL = 1 PPM) 100 PPM of Gasoline contains as much as 1

PPM Benzene Set High Alarm at 100 PPM Gas < 1.0 PPM

Benzene Set Low Alarm at 50 PPM Gas < 0.5 PPM

Benzene


The Controlling Compound Every mixture has a compound that is the

most toxic and “controls” the setpoint for the whole mixture

Determine that chemical and you can determine a conservative mixture setpoint

If we are safe for the “worst” chemical we will be safe for all chemicals

PID Alarms: Varying Mixtures

Ethanol “appears” to be the safest compound Toluene “appears” to be the most toxic This table only provides half of the decision

making equation Might as well compare 1000 apples to 100

oranges

PID Alarms: Varying Mixtures ChemicalName

10.6eV CF Exposure LimitChemical

Ethanol 12 1000Toluene 0.50 100Acetone 1.1 750

People are accustomed to making decisions solely on human sensitivity

Users of meters also need to take into account meter sensitivity

It is necessary to simultaneously interpret both human and meter sensitivity


Set the PID for the compound with the lowest Exposure Limit (EL) in equivalent units and you are safe for all of the chemicals in the mixture

Divide the EL in chemical units by CF to get the EL in isobutylene

ELIsobutylene = ELchemical CFchemical


ChemicalName

10.6eVCF

ELChemical

ELIsobutylene

Ethanol 12 1000 83.33Toluene 0.50 100 200.00Acetone 1.1 750 681.82

Now one can compare “Apples to Apples” Its lower sensitivity on the PID makes Ethanol

the “controlling compound” when the Exposure Limits are expressed in equivalent “Isobutylene Units”


Setting the PID to 83 ppm alarm in Isobutylene units protects from all three chemicals no matter what their ratio

IMPORTANT: in the rest of this discussion, “Exposure Limit in Isobutylene” will be called or ELiso. ELiso is a calculation that involves a vendor specific Correction Factor (CF). Similar calculations can be done for any PID brand that has a published CF list.


PID Alarms: ELiso & Unknowns ELiso thresholds are a tool to help characterize

unknown environments. The lower the reading in isobutylene units on

your PID the less risk. If the reading on your PID is below the ELiso

for a chemical there isn’t a threat.

ChemicalName

10.6eVCF

ELChemical

ELIsobutylene

PID in Iso 45Styrene 0.4 100 250Toluene 0.50 100 200.00Cumene .54 50 92

For example, if the PID reads 45iso ppm in an area with Toluene (ELiso =400), Styrene (ELiso =250) and Cumene (ELiso =92) vapors we are safe because the ELiso for all three of these chemicals is well above 45 ppm.


PID Alarms: ELiso & UnknownsA RAE PID with a 10.6eV lamp set to the following alarms and not beeping provides

protection from: 44 chemicals at a 100 ppm alarm, includes solvents like Xylene,

Toluene, MEK, Acetone 65 chemicals at a 50 ppm alarm, from Cyclohexanone to

Acetone. 81 chemicals at a 25 ppm alarm, from Diethylamine to Acetone. 105 chemicals at a 10 ppm alarm, from Toluidine to Acetone. 140 chemicals at a 1 ppm alarm, from Diethylenetriamine to

Acetone

PID Alarms: ELiso & Unknowns Setting an alarm to 1 ppm provides the highest

protection, but it also causes the most alarms. An alarm point of 1 ppm would be similar to

always wearing a Level A suit! A 50 ppm ELiso alarm is appropriate for going

to respiratory protection in a fuel tanker roll-over because an ELiso alarm of 50 is very conservative for all hydrocarbon fuels.

PID Alarms: the 50/50 Rule

Acetone Cyclohexane Diesel Fuel Ethyl alcohol Ethylbenzene Gasoline Heptane, n- Hexane, n-

Stoddard Solvent Styrene Tetrahydrofuran Toluene Trichloroethylene Xylene

When Measuring in Isobutylene Units and set to 50 ppm RAE PIDs

will protect from over 50 of the most common Chemicals:

IPA Jet Fuel MEK MIBK MPK Nonane Octane, n- Pentane

PID Alarms: ELiso & Unknowns

Of course, if there are known or suspected chemicals of higher risk a lower alarm might be called for.

In a potential terrorist chemical agent attack, a ELiso of 1.00 ppm might be more appropriate

ChemicalName

10.6eVCF

LCT50 ELIsobutylene

PID in Iso 1Mustard 0.6 231 385Tabun 0.8 20 25Sarin 3.0 12 4.0

PID Alarms: ELiso & Unknowns ELiso are only one gauge of the threat level

in any circumstance. The PID user must use all of the clues

present to reach a decision.

PIDs can be an important part of any gaseous risk assessment and

should be used with other clues present:

Response from other types of meters Response from colorimetric tubes Physical clues Worker/Victim symptoms

Integrating Gas Detection Techniques

The Gas Monitoring Pyramid is a graphic depiction of how to

integrate various gas monitoring techniques


TubesSingle Gas: CO/O2/LEL

Multigas CSEBroadband: MOS

Selective: IMSSelective: GC/MSSelective: Tubes

Broadband: PID/FID

Gas Monitoring

Pyramid

Selectivity Increases as you move up the Pyramid

The AnswerThe Answer


TubesSingle Gas: CO/O2/LEL

Multigas CSEBroadband: MOS

Selective: IMSSelective: GC/MSSelective: Tubes

Broadband: PID/FID

PID + Tubes Approximates the selectivity of GC/MS w/o the cost

Gas Monitoring

Pyramid

The AnswerThe Answer



Clues

LEL Tubes

Each circle represents the range of chemicals seen by a sensor

By overlaying multiple detection techniques we can zoom in on the solution

Use multiple techniques until you feel comfortable with the solution=The Real

Answer

PIDToxic

Sensors

In food warehouse maintenance room had 80 ppm CO indicated

Assumed that they used propane forklifts (common source of CO) but found that they used battery powered forklifts

The maintenance room was located with in the battery charging area.

Lead acid batteries generate hydrogen (H2) when charging

Food Warehouse

Food Warehouse 80 ppm indicated CO translates to 200 ppm

H2 or about 0.5% of LEL H2

No LEL reading, H2 LEL is 4% (40,000 ppm), 1% of LEL H2 is just 400 ppm

Checked with CO colorimetric tube and registered no CO reading

Concluded that CO reading on monitor was due to H2 cross-sensitivity

Food Warehouse: CO Cross-Sensitivity

Clues

Tubes

Clues: Warehouse w/ battery powered forklifts

Toxic Sensor: 80 ppm reading on CO if H2 it’s approximately 200 ppm

LEL: no reading on LEL PID: no reading on PID Tubes: no reading on CO

tube=Probably Hydrogen gas from forklift batteries

PID

Toxic Sensors

LEL

CO sensor indicated 35-45 ppm in printed circuit board plant with styrene, xylene, acetone and other aromatics and ketones

Jumped to false conclusion that CO sensor was bad or responding to hydrocarbons

Fresh aired monitor outside plant and still had high CO in plant

Printed Circuit Board Plant

Calibrated with CO gas and still had high CO in plant

Checked with CO colorimetric tube and registered 50 ppm CO reading

Investigated plant and found shrink-wrap machine pumping out 150 ppm CO in worker breathing zone



Clues

Tubes

Clues: Printed circuit board plant

Toxic Sensor: 35-45 ppm reading on CO

LEL: no reading on LEL PID: no reading on PID Tubes: 50 ppm reading on

CO tube=CO from shrink wrap machine

PID

Toxic Sensors

LEL

Portable CO monitor showed no CO CO Colorimetric tube found no CO PID read 100 ppm Investigation revealed spray painting had

taken place Home CO detectors use less filtered CO

sensors that can respond readily to hydrocarbons

Home CO Detector

Home CO Detector

Clues

Tubes

Clues: Household CO call, smells like paint solvent

Toxic Sensor: 0 ppm reading on CO

LEL: no reading on LEL PID: 100 ppm reading on

PID Tubes: no reading on CO

tube=spray paint set off home CO detector

PID

Toxic Sensors

LEL

Oil Refinery Remediation H2S Datalogging meter showed H2S of straight 199 ppm

indicating they had maxed out the H2S circuit on the meter (meter & sensor only rated to 100 ppm H2S)

This data is questionable but we certainly have more than 100 ppm and may have more than 200 ppm H2S

PID data from the same meter showed 240 ppm in Isobutylene units

No LEL reading and H2S is a LEL inhibitor

Using PID correction factor for H2S of 3.3, the concentration if it were just H2S is 792

PID measures total VOCs including H2S so part of the signal could be VOCs

We can be pretty sure that we had a lot of H2S and it could be 100-790 ppm (IDLH =100 ppm)

Further testing via sampling and lab testing was recommended

H2S colorimetric tubes could also be used

Oil Refinery Remediation H2S

Oil Refinery Remediation H2S

Clues

Tubes

Clues: Refinery clean-up with strong H2S smell

Toxic Sensor: 199 ppm reading on H2S sensor

LEL: no reading (LEL = 4% or 40,000 ppm)

PID: 240 ppm in iso units or 792 in H2S units

Tubes: not used but would have been helpful=a lot of H2S is

present

PID

Toxic Sensors

LEL

Homeowner “smells” natural gas after gas company work

Natural gas is methane and other short-chain saturated compounds

Natural gas doesn’t smell but Mercaptan odorant is added for safety purposes

Mercaptans are “sticky” and can remain on clothes and fabrics even after all work is done and the atmosphere is safe

Home Natural Gas Leak

Home Natural Gas Leak

Smell is most likely leftover from gas company work, but good idea to have gas company recheck their work

Methane %Volume ppm ppb100% LEL 5 50000 5000000010% LEL 0.5 5000 50000001% LEL 0.05 500 5000000.1% LEL 0.005 50 50000

OdorThresholdMethylMercaptan

0.0000001 0.0001 0.1

Olfactory threshold for Methyl Mercaptan is well below the detection capability of even the PID

Home Natural Gas Leak Clues: homeowner

compliants Toxic Sensor: no

readings LEL: no reading PID: no reading Tubes: no reading on

mercaptans tube=odorants are very powerful and purvasive

Clues

Tubes

PID

Toxic Sensors

LEL

Review of Specific PID Applications AP-201: Measuring Ammonia with PIDs AP-207: PIDs as an Arson Tool AP-212: PIDs for Indoor Air Quality (IAQ) AP-216: Using PIDs for Terrorist Chemical

Attacks AP-219: Using PIDs for 10% of LEL Decisions AP-220: Using PIDs in Clan Lab Investigations

PIDs to Measure Ammonia Decision to go from Respiratory protection to

Level A is typically between 250-1500 ppm Ammonia sensors “burn-out” at 200-300 ppm

so responders go to Level A early Ammonia sensors are for “nuisance” levels in

range of 0-50 ppm Use PIDs when you can “see” ammonia and

levels are over 100 ppm Ref. AP-201

PIDs for Arson Investigation Hydrocarbon liquids are common accelerants The PID provides excellent sensitivity to hydrocarbons

even after burn off PIDs aren’t specific to accelerants PIDs can help to confirm that a suspicious burn pattern is

the best place to sample for the highest levels of accelerant PIDs are less expensive than dogs PIDs don’t suffer from olfactory fatigue and are not

distractible Ref. AP-207

PIDs for IAQVOCs are one of the top IAQ Contaminants Biological Agents (mold, dustmites, etc.) Carbon Monoxide Formaldehyde Second Hand Smoke VOCs

PIDs are one of the only direct measuring meters for IAQ

PIDs for IAQ

PIDs Solve Paint Odor Problem Normal IAQ is 100-500 PPB in isobutylene

units Above 500 ppb look for problems Use PID like a “Geiger Counter” to find source Chemical formulas on most paint and glue

containers allow you to quickly identify the chemicals

PIDs for IAQ

PIDs Solve Paint Odor Problem NIOSH Pocket Guide helps you to quickly find

the safe levels for chemicals PID correction factors let you set the scale of the

PID to the chemical of interest so that the reading is accurate

Using the PID scaled with the right correction factor you can quickly and accurately measure the level of the paint fumes

PIDs for IAQ

PIDs Solve Paint Odor Problem If fumes are at safe levels, the PID can help prove

that it is safe for the occupants to stay in the building

It might be necessary to explain the difference between odor threshold and toxicity

For example, the odor threshold for toluene is 0.16-37 ppm while the 8 hour NIOSH TWA is 100 ppm.

PIDs for IAQ

PIDs Solve Paint Odor Problem In the politically charged situations posed by

many IAQ complaints, a fast measurement tool like the PID is invaluable. It can save time, money and headaches

(Ref AP-212)

Guidelines for Using PIDs for IAQ

In the politically charged situations posed by many IAQ complaints, a fast measurement

tool like the PID is invaluable. <100 ppb Isobutylene: normal outdoors 100-400 ppb Isobutylene: normal indoors 500-1000 ppb Isobutylene: threshold for

potential IAQ complaintsIt can save time, money and headaches

PIDs for Terrorist Chemical Attacks Initially WMD programs were focused on

Chemical Warfare Agents (CWAs) Terrorists don’t have to use military CWAs There is better access to Toxic Industrial

Chemicals (TICs) and there are many more TICs available

CWA Specific Detectors (IMS, SAW) can’t measure TICs and can be fooled by common chemicals

PIDs for Terrorist Chemical Attacks

Just two words separate a Terrorist chemical attack from a HazMat Incident

If the “INTENT” is to create “FEAR”, then it’s terrorism

PIDs are one of the best broadband chemical detectors and they can be very useful in a risk based WMD response

Ref. AP-216

PIDs for Terrorist Chemical Attacks

IMS

SAW Tubes

PID

Each circle represents the range of chemicals seen by a sensor

By overlaying multiple detection techniques we can provide specificity to CWA

CWA specific sensors cannot measure TICs=CWA

=TIC

Clan Labs typically are contaminated Continuous measurement reduces responder risk Wheatstone bridge sensors have difficulty in the clan

lab environmentHigh Flashpoint chemicalsCommon clan lab chemical poison LEL

Recommended Clan Lab alarms:High: 250 ppm for 10% of LELLow: 5 ppm for respiratory

Ref: AP-220

Using PIDs in Clan Lab Investigations

Tips for Using and Maintaining PIDs

Never Use Tygon tubing! Absorbs chemicals like a “sponge” Reduces ppm readout when

chemicals exist Causes “false positives” when

chemicals don’t exist

Always use Teflon or similar non-reactive tubing Will not absorb chemicals but might

get coated Clean with anhydrous methanol if it

gets dirty

PID: Tubing

How Humidity Affects PIDs

The closer to the headlights the easier it is to see something through fog.

By reducing the distance the UV light travels in a PID the affects of humidity are drastically reduced

Short Lightpath

Long Lightpath

PID: Maintenance PID Drift is Due to Poor Sampling Technique

Aspirating liquids & vapors into sample probe Aspirating dirt samples into sample probe Hot liquids and vapors condensing in probe & sensor Touching contaminated surfaces with probes

Clean PID Lamp & Sensor When display creeps upwards after good zero When PID responds to moisture When movement of PID results in response on display

PID: Maintenance How to Clean PID Sensor

Always clean sample probe and replace or clean filters FIRST! If PID holds a stable zero after this step then further cleaning may not be necessary

Use anhydrous methanol (Lamp cleaning solution) Clean lamp face with lens tissue Clean sensor by immersion in cleaning solution (an

ultrasonic cleaner will speed cleaning)

Drying the PID Let air dry overnight Warm air (not hot) will speed drying

A PID is like a Magnifying GlassA Magnifying glass lets a detective

see fingerprints; a PID lets us “see” VOCs

Identify then Quantify!

Benzene

AmmoniaCarbon Disulfide

Styrene

XyleneJet FuelPERC

Questions?

RAE PID Products

RAE PIDs: ToxiRAE The ToxiRAE is a Personal Protection PID Affordable personal monitor for

Initial PPE Assessment Perimeter Establishment and Maintenance

Use 4 to for North, South, East and West Perimeter

PID & multigas monitor For both Protection and Detection Our most versatile monitor

RAE PIDs: MultiRAE

Initial PPE AssessmentLeak DetectionPerimeter

Establishment & Maintenance

Spill DelineationDecontaminationRemediation

0-10,000 PPM w/excellent linearity

Strong pump Superior PID sensor resists

moisture & dirt Quick Lamp & Sensor Access

w/o tools Rugged rubber boot standard NiMH Drop-in battery w/backup

alkaline pack

RAE PIDs: MiniRAE 2000

Continuous detection to 1 ppb! 0-9999 PPB or 0-200 PPM Can detect VOCs at or below

the olfactory threshold for IAQ. Measures highly toxic

compounds with low vapor pressures like chemical agents and isocyanates (TDI & MDI)

RAE PIDs: ppbRAE

Rugged, one-to-five sensor monitoring system

“ProRAE Remote” software simultaneously controls and displays readings for up to 16 remote units up to 2 miles downrange

Runs up to 36 hours on Li-Ion

RAE PIDs: AreaRAE

Local Area Monitoring

( ISM )

Education

Pi Ds As A Hazmat Response Tool Unabridged 0207