1

Setting Action Levels and

Controlling exposure with Air Monitoring

A review...

2

Objectives

Understand the factors that go into establishing an action level

Understand the variables affecting action levels when working with multiple chemical contaminants

Understand how to monitor VOCs in the air and metals in airborne dust particles

3

Why set Action Levels?

Protect against the inhalation of toxic materials

Protect against the absorption of toxic materials

Protect against other affects of toxic materials

Protect against explosion and oxygen deficiency/enrichment

4

What are the challenges that are important to consider in setting action levels?

Challenges

5

Chemicals of concern PEL/REL/TLV, IDLH

Exposure pathways Inhalation Absorption Ingestion Injection

Concentrations of chemical Physical state of chemical

gas, solid mist, vapor, fume, particles density, vapor pressure, etc…

Environment of the work zone Temperature Access

Challenges

6

Other considerations

Nature of the work PPE levels of protection available

(A/B/C/D) Training Physical demands Work activity

Respirator compatibility PPE compatibility Physical condition of the workers Air monitoring instrumentation

limitations and capabilities

7

Resources available to help you...

NIOSH pocket guide PEL/REL Ionization potential (Ip) Physical characteristics Recommended respirators

ACGIH TLV/BEI book SMS 17 Hazardous Waste Operations SMS 43 Personal Monitoring SMS 050 Specific Chemical Hazards Your Regional H&S Manager One of the 50+ CSP/CIH/CHPs in URS

8

The focus today….

Action levels for inhalation risks particularly between Level D and C PPE

Particular emphasis on VOCs Particulates

9

Volatile Organic Compound

A VOC is... an organic compound (carbon) typically an inhalation and absorption hazard typically present in low levels on a site

Chemical TLV______ REL* PEL

IDLH IonizationPotential

Xylene 100PPM 100 PPM 100 PPM

900 PPM 8.56 eV

Toluene 50 PPM 100 PPM 200 PPM

500 PPM 8.82 eV

Benzene 0.5 PPM 0.1PPM

1.0 PPM

500 PPM (Ca)

9.24 Ev

* REL from NIOSH

10

Typical VOC site...

Action levels… depend first on an instrument: PID with a 10.6 eV bulb

Calibrated to hexane? Isobutylene?

What is the relative response (response factor)?

Air monitoring is completed in the Operator’s Breathing Zone Greater than 3 minutes

(sometimes 5 minutes) 15 meter units (or 25, or 50) above

background with a PID

11

But what about Benzene?

How can an action level of 15 meter units be acceptable if Benzene is a possible chemical of concern?

Chemical TLV______RELPEL

IDLH IonizationPotential

Xylene 100PPM100 PPM100 PPM

900 PPM 8.56 eV

Toluene 50 PPM100 PPM200 PPM

500 PPM 8.82 eV

Benzene 0.5 PPM0.1PPM

1.0 PPM

500 PPM(Ca)

9.24 Ev

12

Solution

Add another “level” to the action levels.

Have the ability to discriminate Benzene from other VOCs. This can be done easily with a colorimetric tube, a Benzene chip detector, or a Benzene PID pre-filter.

If > 2 PPM (meter units) in the OBZ for more than 5 minutes, test for Benzene. If no Benzene, increase action level to 15/25/50 meter units using the PID.

Or upgrade to Level C… (Why is the IDLH level important when using Level C PPE?)

13

What if?

You have a PCE site with Vinyl Chloride contamination...

Chemical TLV______RELPEL

IDLH IonizationPotential

Perclorethylene (aka tetrachlorethylene)

25 PPMCa100 PPM

300 PPM 9.32eV

Vinyl Chloride 1 PPMCa1 PPM

None 9.99 eV

14

Solution?

Eliminate the potential of VC in the breathing area - use a colorimetric tube or CHIP for VC in combination with a PID.

If > 3 meter units in the OBZ for more than 3 minutes, test for Vinyl Chloride. If no VC is present, increase action level to 10 meter units.

Question… Can you upgrade to Level C if VC is present above 1 PPM? What was that IDLH?

15

Action Level Matrix for BTEX scenario

PID Reading In Operator Breathing Zone for more than 3 minutes

Action (PID with 10.6 eV bulb) (Draeger Benzene Chip Detector)

Note

0-2 PPM Conduct Air monitoring every 15 Minutes

Level D PPE

(modified) required.

>2 PPM Test for Benzene using Benzene Monitor

If Benzene is present > 1 PPM, Notify RHSM. Upgrade to Level C PPE with OV cartridge. Stop work if Benzene exceeds 2.5 PPM.

>2 & <50 PPM (with NO Benzene)

Conduct Monitoring every 15 minutes with the PID and every 30-60 minutes with a Benzene Monitor

If greater than 2 PPM Benzene, or greater than 50 PPM on the PID indicated, upgrade to Level C PPW with OV cartridge. Notify the RHSM.

16

Contaminated Soils The challenge is often Lead (Pb) or Arsenic (As)

Other metals May also include PCBs and PAHs Typically present an inhalation hazard - expressed an mg/m3

ChemicalTLV______RELPEL

IDLH IonizationPotential

Lead(Pb)

0.1 mg/m3

0.05 mg/m3

0.05 mg/m3

100 mg/m3NA

Arsenic(As)

0.01 mg/m3

None0.5 mg/m3

5 mg/m3 NA

Airborneparticulates

3 mg/m3 (respirable)

10 mg/m3 (inhalable)

3 mg/m3 (respirable)

10 mg/m3 (inhalable)

5 mg/m3 (respirable)

15 mg/m3 (inhalable)

None NA

17

Scenario

Contaminated soils site. Pb in the soil is present at 1000 mg/kg

What amount of airborne Pb soil particles should we set as permissible to breath?

How are we measuring the particles in air?

(mg/m3)

18

The Pb example in formula...

The formula for equivalent dust concentration: Exposure Limit = (106 mg/kg) (TLV or PEL in mg/m3)

(conc in soil in mg/kg) (safety factor)

(106 mg/kg) (TLV or PEL in mg/m3)

(conc in soil in mg/kg) (safety factor)

106 * 0.05mg/m3 = 25 mg/m3 1000 * 2

Safety factors are: 2 when site data is good; highly confident 4 when site data is okay; some confidence 10 when no data exists; no confidence

19

And finally... Remember what the exposure to Dust was limited to?

10 mg/m3 inhalable 3 mg/m3 respirable

So the maximum exposure level on the site for soils with 100 mg/kg of Pb is 10 mg/m3 even though we could go to 25 mg/m3 for Pb.

Above 10 mg/m3 in the air (TLV-TWA) workers should be in level C PPE with a particulate filter (P-100). Note: typically dust is visible in the air at 5 mg/m3

20

Action Levels for Intrusive Activities

MonitoringEquipment Sampling Result/Observation Action

PID (10.6 eV lamp) >1 ppm Continue to monitor with PID; monitorwith benzene chips.

Benzene detector chip(with CMS device)

<0.5 ppm Continue to monitor with PID.

0.5 ppm, <25 ppm Upgrade to Level C. Continue tomonitor with PID.

25 ppm Stop work; evacuate area and contactHSM.

PID (10.6 eV lamp) >1 ppm, 25 ppm; IF nobenzene detected

Continue to monitor with PID.

>25 ppm, 250 ppm; IF nobenzene detected

Upgrade to Level C. Continue tomonitor with PID.

>250 ppm Stop work; evacuate area; contact HSM.

Hydrogen sulfidemonitor

2.5 ppm Stop work; evacuate area; contact HSM.

MiniRam DustMonitor

>15 mg/m3 Use dust control measures until dust iscontrolled. If dust cannot be controlledupgrade to Level C.

Observation Workers enter sheds or utilitybuildings where rodents mayhave nested; and workers maydisturb nesting materials orrodent droppings.

Upgrade to Level C.

Observation Workers exhibit symptoms ofchemical exposure

Stop work. Evacuate area and contactthe HSM.