Question 1: Are You An Industrial Hygienist Conducting Perso

Question 1you Are An Industrial Hygienist Conducting Personal Sampling

You are an industrial hygienist conducting personal sampling on a worker who is overseeing a production process involving use of acetone. The Occupational Safety and Health Administration (OSHA) has established a Permissible Exposure Limit (PEL) of 1000 ppm for acetone. You have measured the worker's exposure during different periods: 700 ppm for 3 hours, 1300 ppm for 2 hours, and 900 ppm for 3 hours. Your task is to calculate the Time-Weighted Average (TWA) exposure for the worker, evaluate whether this exposure complies with OSHA's PEL, and advise plant management accordingly.

Paper For Above instruction

Introduction

Worker exposure to volatile organic compounds such as acetone presents significant occupational health concerns. Precise assessment of exposure levels, notably through calculations like the Time-Weighted Average (TWA), is essential to ensure compliance with safety standards and protect worker health. This paper details the calculation of the TWA for a worker exposed to acetone during various intervals and interprets the findings in the context of OSHA’s permissible exposure limits (PELs).

Calculation of TWA Exposure

The TWA is a measure used in occupational hygiene to evaluate an average exposure over a specified period, typically an 8-hour workday. It accounts for varying concentrations and durations of exposure. The formula for TWA is:

TWA = (Ca × Ta + Cb × Tb + ... + Cn × Tn) / (Ta + Tb + ... + Tn)

where Ca, Cb, ... Cn are concentrations during respective periods, and Ta, Tb, ... Tn are the durations of these periods.

Applying this formula to the acetone exposure data:

  • 700 ppm for 3 hours
  • 1300 ppm for 2 hours
  • 900 ppm for 3 hours

The total exposure in weighted terms is:

TWA = (700 ppm × 3 hours + 1300 ppm × 2 hours + 900 ppm × 3 hours) / (3 + 2 + 3) hours

Calculating numerator:

700 × 3 = 2100 ppm-hours

1300 × 2 = 2600 ppm-hours

900 × 3 = 2700 ppm-hours

Sum: 2100 + 2600 + 2700 = 7400 ppm-hours

Calculating denominator:

3 + 2 + 3 = 8 hours

Final TWA calculation:

TWA = 7400 ppm-hours / 8 hours = 925 ppm

Interpretation and Compliance

The calculated TWA of approximately 925 ppm is below OSHA’s PEL of 1000 ppm for acetone. This indicates that the worker’s exposure, based on these measurements, complies with occupational safety standards. However, the proximity to the PEL suggests that continued monitoring is essential to prevent possible exceedances and associated health risks.

Recommendations

  • Maintain regular exposure monitoring to ensure ongoing compliance.
  • Implement engineering controls like improved ventilation or process modifications to reduce peak exposure levels.
  • Ensure that workers wear appropriate personal protective equipment (PPE) where necessary.
  • Provide ongoing training to workers regarding chemical hazards and safe work practices.

Conclusion

The calculated TWA for acetone exposure in this scenario is 925 ppm, which falls within the OSHA PEL of 1000 ppm. Proper compliance and safety measures should be continued to maintain a safe working environment. Regular monitoring and proactive controls are vital to ensure exposure levels remain within permissible limits and to safeguard workers’ health.

References

  • Occupational Safety and Health Administration (OSHA). (2020). Permissible Exposure Limits — Annotated Tables. OSHA. https://www.osha.gov
  • US Environmental Protection Agency (EPA). (2012). Exposure Factors Handbook. EPA/600/R-09/052F.
  • NIOSH. (2016). Worker Exposure to Volatile Organic Compounds. NIOSH Pocket Guide to Chemical Hazards. https://www.cdc.gov/niosh/npg/npghtml
  • Chacon, R., & Ross, M. (2020). Industrial Hygiene Monitoring Techniques. Journal of Safety Research, 72, 45-55.
  • American Conference of Governmental Industrial Hygienists (ACGIH). (2021). TLVs and BEIs. ACGIH Publications.
  • LeBouf, R. F., et al. (2017). Assessment of Personal Exposures to Organic Solvents. Journal of Occupational & Environmental Hygiene, 14(4), 301-308.
  • Hathaway, H. J., et al. (2019). Occupational Chemical Exposure Risk Assessment. Annals of Occupational and Environmental Medicine, 31, 15.
  • Environmental Protection Agency (EPA). (2011). Toxicological Review of Acetone. EPA/635/R-11/007F.
  • Chung, Y. H., et al. (2018). Personal Exposure Monitoring in Industrial Settings. Safety Science, 106, 1-10.
  • Pearson, F. R., & Stokes, L. (2022). Strategies for Monitoring Industrial Chemical Exposures. International Journal of Occupational Safety and Ergonomics, 28(2), 315-325.

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