MOS 6301 Advanced Industrial Hygiene Course Learning Outcome ✓ Solved

Mos 6301 Advanced Industrial Hygiene 1course Learning Outcomes For Un

Recommend controls for industrial health hazards. Calculate required flow rates based on hood design. Compare and contrast available engineering controls for noise hazards. Explain how to gauge the effectiveness of engineering controls.

Sample Paper For Above instruction

Industrial hygiene is a vital discipline within occupational health that focuses on identifying, evaluating, and controlling workplace hazards to ensure worker safety and well-being. Among the critical aspects of this field are the implementation of effective controls for health hazards, which aim to minimize or eliminate risks arising from chemical, physical, or biological hazards in the work environment. This paper discusses the essential control strategies, especially engineering controls, for occupational hazards, methods for calculating airflow requirements in ventilation systems, and approaches to evaluate their effectiveness.

Introduction

The core goal of industrial hygiene is to protect workers from harmful exposures while maintaining operational productivity. Effective hazard control strategies are central to this mission, with a hierarchical approach that favors elimination and substitution over administrative controls and personal protective equipment (PPE). This hierarchy, endorsed by organizations such as OSHA (2016), emphasizes the implementation of the most effective measures first, including engineering controls designed to modify or contain hazards at their source.

Control of Industrial Health Hazards

Controls for industrial health hazards primarily focus on chemical exposure, noise, radiation, and biological agents. The primary approach involves eliminating the hazard or substituting it with a less hazardous alternative whenever possible. For instance, replacing a carcinogenic chemical such as formaldehyde with a safer disinfectant exemplifies substitution. When elimination or substitution is unfeasible due to operational constraints, engineering controls such as ventilation systems or sound barriers are implemented to reduce worker exposure.

Engineering Controls: Ventilation Systems

Among engineering controls, ventilation systems are particularly crucial for managing airborne chemical hazards. These systems are classified into general dilution ventilation and local exhaust ventilation (LEV). General dilution ventilation involves bringing in outdoor air to dilute contaminants, while LEV captures contaminants at their source before they disperse into the work environment. Proper design and maintenance of these systems require precise calculations of airflow rates to ensure their effectiveness in contaminant removal.

Calculating Flow Rates for Ventilation

Accurate calculation of airflow rates is essential when designing ventilation systems for hazardous work environments. For example, local exhaust hoods used in fume extraction need specific airflow rates based on the size of the hood, the type of contaminant, and its generation rate. The typical procedure involves calculating the volumetric flow rate (usually in cubic feet per minute, CFM) necessary to capture the contaminant effectively. This calculation considers parameters such as hood dimensions, face velocity, and contaminant velocity in the air stream.

An example formula used in hood design is:

Q = V x A

where Q is the airflow rate (CFM), V is the face velocity (ft/min), and A is the cross-sectional area of the hood opening (sq ft).

For instance, to achieve a face velocity of 100 ft/min in a hood with an opening of 2 sq ft, the required airflow rate would be:

Q = 100 ft/min x 2 sq ft = 200 CFM

This calculation ensures the hood captures airborne contaminants efficiently, reducing worker exposure. More sophisticated methods may incorporate environmental factors and specific contaminant properties for refined airflow requirements.

Assessing Effectiveness of Engineering Controls

Evaluating the effectiveness of installed engineering controls involves conducting regular air sampling and airflow measurement. Air sampling verifies if contaminant concentrations are below occupational exposure limits like OSHA's permissible exposure limits (PELs) or more protective thresholds. Additionally, physics-based measurements including anemometers and smoke tests help determine if airflow patterns are adequate to capture hazards at the source.

For ventilation systems, periodic airflow checks ensure that ventilation rates remain within design parameters. The use of tracer gases or aerosol tests can also verify contaminant capture efficiency. The combination of these methods provides confidence in the control measures’ performance and highlights areas needing improvement.

Noise Control and Physical Hazard Management

Distinct from chemical hazards, physical hazards such as noise require different engineering controls. Sound enclosures, barriers, and absorption materials are common strategies to attenuate noise levels. For example, installing soundproof curtains or building acoustic chambers around noisy machinery can significantly reduce worker exposure, complying with OSHA's permissible noise exposure levels (~85 dB(A) over an 8-hour time-weighted average).

Similarly, for radiological hazards like X-ray exposure, shielding with lead-lined walls prevents radiation penetration, protecting workers outside the controlled area. These physical controls are designed based on hazard-specific physics and require adequate calculation, testing, and maintenance to ensure effectiveness.

Conclusion

In summary, controlling occupational health hazards involves a combination of strategies prioritized according to their effectiveness. Elimination and substitution, when feasible, are the most effective controls, followed by engineering solutions such as ventilation and physical barriers. Calculating accurate airflow rates is fundamental to designing effective ventilation systems, and continuous monitoring and testing are necessary to confirm their performance. Proper application and evaluation of these controls are vital for safeguarding worker health and complying with regulatory standards.

References

• Centers for Disease Control and Prevention. (2015). Hierarchy of controls [Graphic].
• Fuller, T. P. (2015). Essentials of industrial hygiene. National Safety Council.
• Occupational Safety and Health Administration. (2016). Recommended practices for safety and health programs: Hazard prevention and control. OSHA.
• Wheeler, M. W., Park, R. M., Bailer, A. J., & Whittaker, C. (2015). Historical context and recent advances in exposure-response estimation for deriving occupational exposure limits. Journal of Occupational and Environmental Hygiene, 12(Suppl. 1), S7–S17.
• Lee, T., Soo, J.-C., LeBouf, R. F., Burns, D., Schwegler-Berry, D., Kashon, M., & Harper, M. (2018). Surgical smoke control with local exhaust ventilation: Experimental study. Journal of Occupational and Environmental Hygiene, 15(4), 341–350.
• Bennett, J., Marlow, D., Nourian, F., Breay, J., Feng, A., & Methner, M. (2018). Effect of ventilation velocity on hexavalent chromium and isocyanate exposures in aircraft paint spraying. Journal of Occupational and Environmental Hygiene, 15(3), 167–181.
• Lo, L.-M., Hocker, B., Steltz, A. E., Kremer, J., & Feng, H. A. (2017). Performance evaluation of mobile downflow booths for reducing airborne particles in the workplace. Journal of Occupational and Environmental Hygiene, 14(11), 839–852.
• Eswein, E. J., Alexander-Scott, M., Snawder, J., & Breitenstein, M. (2018). Measurement of area and personal breathing zone concentrations of diesel particulate matter during oil and gas extraction operations. Journal of Occupational and Environmental Hygiene, 15(1), 63–70.
• Occupational Exposure to Respirable Crystalline Silica, 81 Fed. Reg. 16286 (March 25, 2016).