Question 1
Reducing exposures to hazardous materials is a fundamental responsibility for occupational safety and health professionals. When potentially hazardous chemicals like methylene bisphenyl isocyanate (MDI) are present in the workplace, a systematic approach should be used to minimize risks to workers. The hierarchy of controls provides a framework to select the most effective strategies for controlling chemical hazards (American Industrial Hygiene Association [AIHA], 2015). For the MDI exposures in the automotive headliner production process, an in-depth analysis using the hierarchy of controls approach is warranted to identify and implement solutions that will protect employee health.
The most effective control method for reducing MDI exposures below the OSHA PEL is to substitute a less hazardous material that does not contain MDI. According to the hierarchy of controls, substitution is preferred over engineering controls, administrative controls, and personal protective equipment (AIHA, 2015; National Institute for Occupational Safety and Health [NIOSH], 2015). Although the client specifications currently require MDI, I recommend assembling a team to fully investigate alternative materials that meet performance requirements but do not contain hazardous isocyanates. Input from industrial hygienists, engineers, and clients should be obtained to determine if substitution is feasible (Occupational Safety and Health Administration [OSHA], 2012). If suitable alternatives are identified, products should be thoroughly evaluated to ensure they are less hazardous and meet all technical specifications before being implemented.
If substitution is not currently feasible, engineering controls such as improved ventilation and encapsulation of the process should be implemented to reduce MDI emissions. The press area should be equipped with local exhaust ventilation to capture MDI vapors at the source. In addition, the MDI application process could potentially be enclosed to prevent emissions from escaping into the work area (OSHA, 1999). Reducing reliance on respirators by implementing engineering and administrative controls is preferred under the hierarchy of controls framework (AIHA, 2015; NIOSH, 2015). However, administrative controls and PPE can supplement engineering controls as needed if exposures exceed the PEL despite implementation of feasible controls.
References
American Industrial Hygiene Association. (2015). The occupational environment: Its evaluation, control, and management. Author.
National Institute for Occupational Safety and Health. (2015). Hierarchy of controls. https://www.cdc.gov/niosh/topics/hierarchy/default.html
Occupational Safety and Health Administration. (1999). OSHA technical manual: Controlling occupational exposure to hazardous drugs. https://www.osha.gov/sites/default/files/otm_vi_2.pdf
Occupational Safety and Health Administration. (2012). Hazard communication guidance for combustible dusts. https://www.osha.gov/sites/default/files/publications/OSHA3371combustibledust.pdf
Question 2
Preventing hazardous chemical exposures is vital to maintaining a safe and healthful work environment. When workers are exposed to chemicals like styrene above occupational exposure limits, control measures guided by the hierarchy of controls should be implemented (American Industrial Hygiene Association [AIHA], 2015). For the styrene exposures in the paint department, using the hierarchy as a decision-making framework will facilitate selection of effective interventions to protect employee health.
For the styrene exposures in the paint department, I recommend first implementing engineering controls according to the hierarchy of controls (AIHA, 2015; National Institute for Occupational Safety and Health [NIOSH], 2015). The small room should be equipped with a local exhaust ventilation system to capture styrene vapors at their source as parts are cleaned. This system should exhaust outdoors to prevent buildup of styrene in the workplace air. To maximize capture efficiency, the exhaust hood should be positioned close to the parts cleaning operation (Occupational Safety and Health Administration [OSHA], n.d.). Regular inspections and maintenance should be conducted to ensure the system is operating as designed. Airflow measurements can confirm the system provides adequate ventilation.
If engineering controls cannot reduce styrene below the PEL, administrative controls such as limiting time in the room and job rotation should be implemented. Training workers on risks and proper use of controls is also important (OSHA, n.d.). In addition, the styrene monitoring program should track exposures before and after interventions to assess effectiveness. If controls cannot reduce exposures below the PEL, proper respiratory protection must be used to supplement the ventilation system and administrative controls. However, reducing reliance on respirators is ideal under the hierarchy of controls (AIHA, 2015).
References
American Industrial Hygiene Association. (2015). The occupational environment: Its evaluation, control, and management. Author.
National Institute for Occupational Safety and Health. (2015). Hierarchy of controls. https://www.cdc.gov/niosh/topics/hierarchy/default.html
Occupational Safety and Health Administration. (n.d.). Controlling air contaminants at the source. https://www.osha.gov/sites/default/files/publications/OSHA3079.pdf
Occupational Safety and Health Administration. (n.d.). Training workers on risks of styrene. https://www.osha.gov/styrene
Question 3
Welding fumes contain hazardous metal particulates that can endanger worker health. To protect welders from overexposure, the hierarchy of controls approach provides a framework for selecting effective interventions (American Industrial Hygiene Association [AIHA], 2015; National Institute for Occupational Safety and Health [NIOSH], 2015). For the welding stations in the rework area that exceed exposure limits, applying the hierarchy of controls methodology will guide implementation of engineering and administrative solutions to reduce fume exposures.
To control welding fume exposures in the rework area, a combination of engineering and administrative controls should be implemented (AIHA, 2015; Occupational Safety and Health Administration [OSHA], n.d.). First, local exhaust ventilation should be installed at all welding stations to capture fumes at the source. Ventilation hoods equipped with filters should be positioned close to welding activities to optimize capture efficiency (NIOSH, 2015). Regular maintenance and testing will ensure proper performance. In addition, the stations exceeding the PEL should be moved to the periphery of the rework area to improve ventilation since these areas typically have better air circulation (OSHA, n.d.).
Administrative controls include training workers on risks and proper use of controls, implementing a welding fume monitoring program, and rotating welders between stations to limit exposures (OSHA, n.d.). The exposure monitoring program should assess effectiveness of implemented controls. If controls cannot adequately reduce exposures below the PEL, proper respiratory protection must be used to supplement engineering and administrative measures. However, the hierarchy of controls identifies engineering solutions as preferable to PPE for controlling hazards (AIHA, 2015).
References
American Industrial Hygiene Association. (2015). The occupational environment: Its evaluation, control, and management. Author.
National Institute for Occupational Safety and Health. (2015). Health effects of welding fumes and gases. https://www.cdc.gov/niosh/topics/welding/healtheffects.html
Occupational Safety and Health Administration. (n.d.). Controlling fumes during welding. https://www.osha.gov/sites/default/files/publications/OSHA_FS-3644_welding.pdf
Occupational Safety and Health Administration (n.d.). Solutions for welding hazards. https://www.osha.gov/sites/default/files/publications/OSHA_FS-3644_welding.pdf
Question 4
Excessive noise is a common hazard in industrial workplaces that can cause hearing loss and other adverse health effects. The hierarchy of controls framework provides occupational health professionals with an effective methodology for mitigating noise risks (American Industrial Hygiene Association [AIHA], 2015; National Institute for Occupational Safety and Health [NIOSH], 2019). For the high noise levels in the press area, applying the hierarchy of controls will facilitate selection of engineering and administrative solutions to reduce hazardous noise exposures.
For the noise exposures in the press area, engineering controls should first be implemented according to the hierarchy of controls (AIHA, 2015; Occupational Safety and Health Administration [OSHA], n.d.). Acoustic enclosures should be installed around presses, and noise absorption materials should be added to surrounding surfaces to reduce reverberation (NIOSH, 2019). In addition, anti-vibration pads can isolate presses to reduce structure-borne noise transmission. To assess effectiveness, noise dosimetry should be conducted periodically at operator positions after installation of controls.
Administrative controls include limiting time near presses and using hearing protection devices. An enhanced hearing conservation program should also be implemented, including audiometric testing and training on noise hazards (OSHA, n.d.). Relying solely on administrative controls and PPE is less desirable than engineering solutions under the hierarchy of controls framework (AIHA, 2015). However, administrative measures and hearing protection can supplement engineering controls as needed if noise levels cannot be adequately reduced through feasible engineering solutions.
References
American Industrial Hygiene Association. (2015). The occupational environment: Its evaluation, control, and management. Author.
National Institute for Occupational Safety and Health. (2019). Noise controls. https://www.cdc.gov/niosh/topics/noisecontrol/default.html
Occupational Safety and Health Administration. (n.d.). Recommended solutions for noise exposures. https://www.osha.gov/sites/default/files/publications/OSHA3747noise-solutions.pdf
