What’s the Frequency? Industrial Hygiene Monitoring

Understanding Air and Noise Monitoring Requirements

Industrial hygiene (IH) monitoring plays a crucial role in ensuring workplace safety and compliance with OSHA standards. Assessing air quality and noise exposure helps identify potential workplace hazards and identify necessary controls for employee protection. This bulletin provides an overview of how to determine the appropriate monitoring frequency for new and existing processes.

Qualitative Assessment: The First Step

Before establishing a monitoring schedule, a qualitative assessment should be conducted to identify potential risks. This includes:

• Reviewing new processes, equipment, or materials.
• Observe employee tasks and products used.
• Identifying airborne contaminants such as dust, vapors, and fumes.
• Assessing noise sources and areas of high noise levels.
• Identifying any controls already in place to reduce exposure.
• Examine historical exposure data and employee concerns.
• Determine which contaminants to prioritize assessing based on hazard type, usage, and length of exposure.

Air Monitoring Frequency Guidelines

Monitoring frequency is determined by the level of exposure risk.

• Identify if there is an applicable OSHA standard for the contaminant.
• Baseline Monitoring: Conducted when new processes or chemicals are introduced or when there is no previous exposure data.
• Periodic Monitoring:
  • Below PEL and Action Level: Consider re-evaluating approximately every two years.
  • Greater than Action Level (if applicable to the specific standard): Evaluate within six months of initial over exposure.
  • Greater than PEL and Action Level (if applicable to the specific standard): Evaluate within three months of the initial over exposure.
  • Greater than PEL (no specific standard): Consider quarterly monitoring until exposures are less than PEL.

Noise Monitoring Frequency Guidelines

Workplace noise exposure assessments should be conducted to ensure compliance with the OSHA Occupational Noise Exposure standard (29 CFR 1910.95):

• Baseline Noise Survey: Required when introducing new equipment or processes or when there is no previous exposure data.
• Periodic Monitoring:
  • Once baseline noise exposures are identified, consider re-evaluating noise exposures every two years as best practice or when a change in process, production, equipment, or controls have the potential to increase noise exposures.
  • Note: If personal noise exposure results are greater than the Action Level (8-hour shift: 85 dBA), a hearing conservation program is required. If personal noise exposure results are greater than the PEL (8-hour shift: 90 dBA), hearing protection is required.

Program Implementation and Review

To maintain an effective monitoring program:

• Follow the OSHA recordkeeping requirements in addition to standard specific recordkeeping requirements.
• Adjust monitoring schedules-based exposure results.
• Implement and evaluate control measures for effectiveness following the hierarchy of controls.
  • Elimination
  • Substitution
  • Engineering
  • Administrative
  • PPE
• Educate employees on exposure risks and protective strategies.

Establishing a structured air and noise monitoring program ensures compliance with regulatory requirements and enhances workplace safety.