1 / 20

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

Understand the factors and challenges in setting action levels for air monitoring of VOCs and metals in airborne dust particles. Learn how to protect against toxic materials and ensure worker safety.

afarley
Download Presentation

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

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

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

  5. Challenges • 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

  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 * 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?

  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...

  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

  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

  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

More Related