1 Setting Action Levels and Controlling exposure with Air Monitoring A review...

2 Objectives n Understand the factors that go into establishing an action level n Understand the variables affecting action levels when working with multiple chemical contaminants n Understand how to monitor VOCs in the air and metals in airborne dust particles

3 Why set Action Levels? n Protect against the inhalation of toxic materials n Protect against the absorption of toxic materials n Protect against other affects of toxic materials n Protect against explosion and oxygen deficiency/enrichment

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

5 n Chemicals of concern l PEL/REL/TLV, IDLH n Exposure pathways l Inhalation l Absorption l Ingestion l Injection n Concentrations of chemical n Physical state of chemical l gas, solid mist, vapor, fume, particles l density, vapor pressure, etc… n Environment of the work zone l Temperature l Access Challenges

6 Other considerations n Nature of the work n PPE levels of protection available (A/B/C/D) l Training l Physical demands l Work activity n Respirator compatibility n PPE compatibility n Physical condition of the workers n Air monitoring instrumentation limitations and capabilities

7 Resources available to help you... n NIOSH pocket guide l PEL/REL l Ionization potential (Ip) l Physical characteristics l Recommended respirators n ACGIH TLV/BEI book n SMS 17 Hazardous Waste Operations n SMS 43 Personal Monitoring n SMS 050 Specific Chemical Hazards n Your Regional H&S Manager n One of the 50+ CSP/CIH/CHPs in URS

8 The focus today…. n Action levels for inhalation risks particularly between Level D and C PPE n Particular emphasis on l VOCs l Particulates

9 Volatile Organic Compound A VOC is... l an organic compound (carbon) l typically an inhalation and absorption hazard l typically present in low levels on a site * REL from NIOSH

10 Typical VOC site... n Action levels… depend first on an instrument: l PID with a 10.6 eV bulb  Calibrated to hexane? Isobutylene?  What is the relative response (response factor)? n Air monitoring is completed in the Operator’s Breathing Zone l Greater than 3 minutes (sometimes 5 minutes) l 15 meter units (or 25, or 50) above background with a PID

11 But what about Benzene? n How can an action level of 15 meter units be acceptable if Benzene is a possible chemical of concern?

12 Solution n Add another “level” to the action levels. n 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. n 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. n Or upgrade to Level C… l (Why is the IDLH level important when using Level C PPE?)

13 What if? n You have a PCE site with Vinyl Chloride contamination...

14 Solution? n Eliminate the potential of VC in the breathing area - use a colorimetric tube or CHIP for VC in combination with a PID. n 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. n Question… Can you upgrade to Level C if VC is present above 1 PPM? l What was that IDLH?

15 Action Level Matrix for BTEX scenario

16 Contaminated Soils n The challenge is often Lead (Pb) or Arsenic (As) l Other metals l May also include PCBs and PAHs l Typically present an inhalation hazard - expressed an mg/m 3

17 Scenario n Contaminated soils site. Pb in the soil is present at 1000 mg/kg l What amount of airborne Pb soil particles should we set as permissible to breath? l How are we measuring the particles in air?  (mg/m 3 )

18 The Pb example in formula... n The formula for equivalent dust concentration: Exposure Limit = (10 6 mg/kg) (TLV or PEL in mg/m 3 ) (conc in soil in mg/kg) (safety factor) (10 6 mg/kg) (TLV or PEL in mg/m 3 ) (conc in soil in mg/kg) (safety factor) 10 6 * 0.05mg/m 3 = 25 mg/m * 2 n Safety factors are: l 2 when site data is good; highly confident l 4 when site data is okay; some confidence l 10 when no data exists; no confidence

19 And finally... n Remember what the exposure to Dust was limited to? l 10 mg/m 3 inhalable l 3 mg/m 3 respirable n So the maximum exposure level on the site for soils with 100 mg/kg of Pb is 10 mg/m 3 even though we could go to 25 mg/m 3 for Pb. n Above 10 mg/m 3 in the air (TLV-TWA) workers should be in level C PPE with a particulate filter (P- 100). l Note: typically dust is visible in the air at 5 mg/m 3

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