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Frequently Asked Questions

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  • Occupational hygiene is the science of identifying, evaluating, and controlling workplace hazards that could affect the health and well-being of workers. It focuses on preventing occupational diseases and injuries by assessing exposure to chemical, physical, biological, and ergonomic risks in the workplace.

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    Key areas of occupational hygiene include:

    • Chemical hazards (e.g. dust, gases, vapours, and fumes)

    • Physical hazards (e.g. noise, vibration, radiation, and temperature extremes)

    • Biological hazards (e.g. bacteria, viruses, and mould)

    • Ergonomic hazards (e.g. repetitive strain, poor workstation design)

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    Occupational hygienists use various methods such as air monitoring, noise assessments, and ergonomic evaluations to measure risks and recommend control measures like ventilation, personal protective equipment (PPE), and process modifications. The ultimate goal is to create a safer and healthier work environment.

  • An occupational hygiene program is a structured approach to identifying, evaluating, and controlling workplace hazards that could impact employee health. It is designed to protect workers from exposure to harmful agents such as chemicals, noise, dust, and other environmental stressors.

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    Key Components of an Occupational Hygiene Program:

    1. Hazard Identification – Recognising potential chemical, physical, biological, and ergonomic risks in the workplace.

    2. Exposure Assessment – Measuring worker exposure levels through air sampling, noise monitoring, and other assessments.

    3. Risk Evaluation – Comparing exposure levels against workplace exposure standards (WES) or industry standards.

    4. Control Measures – Implementing strategies such as:

      • Engineering controls (e.g. ventilation systems, noise barriers)

      • Administrative controls (e.g. job rotation, training programs)

      • Personal protective equipment (PPE) (e.g. respirators, gloves)

    5. Health Surveillance – Monitoring workers’ health through medical examinations and biological monitoring.

    6. Training and Education – Ensuring employees and management understand workplace hazards and control measures.

    7. Program Review and Improvement – Regularly evaluating and updating the program to reflect new risks, regulations, and workplace changes.

     

    An effective occupational hygiene program helps prevent occupational diseases, reduces absenteeism, and promotes a healthier work environment.

  • A Noise Management Plan (NMP) is a structured document outlining strategies to assess, control, and reduce noise exposure in a workplace or environment. It is designed to protect workers from harmful noise levels that could lead to hearing loss, stress, or other health issues.

     

    Key Components of a Noise Management Plan:

    1. Noise Assessment – Identifying noise sources and measuring sound levels using noise surveys and personal sampling.

    2. Regulatory Compliance – Ensuring noise levels meet occupational exposure limits (Noise Regulations).

    3. Risk Evaluation – Assessing the impact of noise on workers.

    4. Control Measures:

      • Engineering Controls – Using noise barriers, silencers, dampers, and isolating noisy machinery.

      • Administrative Controls – Implementing job rotation, quiet zones, and scheduling noisy tasks for less sensitive times.

      • Personal Protective Equipment (PPE) – Providing hearing protection like earplugs and earmuffs.

    5. Hearing Conservation Program – Monitoring workers’ hearing health through regular audiometric testing.

    6. Training & Awareness – Educating employees about noise hazards and proper use of protective equipment.

    7. Monitoring & Review – Regularly reassessing noise levels, control measures, and updating the plan as needed.

     

    A well-implemented Noise Management Plan helps prevent occupational noise-induced hearing loss (NIHL), ensures legal compliance, and creates a safer, more productive work environment.

  • A Respiratory Protection Programme (RPP) is a structured plan designed to ensure workers are protected from airborne hazards such as dust, fumes, gases, and biological contaminants. It outlines procedures for selecting, using, and maintaining respiratory protective equipment (RPE) to prevent occupational illnesses related to inhalation exposure.

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    Key Components of a Respiratory Protection Program:

    1. Hazard Assessment – Identifying airborne contaminants and evaluating exposure levels through air monitoring and risk assessments.

    2. Respirator Selection – Choosing appropriate respiratory protective equipment (e.g. disposable masks, half-face or full-face respirators, powered air-purifying respirators) based on the type and concentration of hazards.

    3. Fit Testing – Ensuring a proper seal and fit of tight-fitting respirators through qualitative or quantitative fit testing.

    4. Training & Education – Teaching workers how to properly wear, use, and maintain their respirators, as well as understanding their limitations.

    5. Medical Evaluation – Assessing workers’ health to determine their ability to wear a respirator, especially for those with respiratory conditions.

    6. Proper Use & Maintenance – Establishing protocols for cleaning, storing, and inspecting respirators to ensure effectiveness and longevity.

    7. Program Monitoring & Review – Regularly evaluating the effectiveness of the program and making necessary updates based on new hazards, regulatory changes, or workplace modifications.

     

    A well-implemented Respiratory Protection Programme helps prevent occupational lung diseases, ensures compliance with health and safety regulations, and promotes a safer work environment.

  • Under the Health and Safety at Work Act 2015 (HSWA) in New Zealand, businesses (PCBUs – Persons Conducting a Business or Undertaking) have obligations to manage risks related to workplace exposures, including exposure monitoring.

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    Key Obligations for Exposure Monitoring:

    1. Duty to Monitor Worker Exposure

      • If there is a risk of worker exposure to hazardous substances, airborne contaminants, or physical agents (e.g. noise, dust, chemicals), businesses must conduct exposure monitoring to assess whether controls are effective.

      • Monitoring is required when there is uncertainty about exposure levels or the effectiveness of existing controls.

    2. Use of Competent Professionals

      • Exposure monitoring must be carried out by a competent person, such as an occupational hygienist, using recognised methods.

    3. Recording and Retaining Monitoring Results

      • Businesses must keep exposure monitoring records for 30 years if monitoring relates to hazardous substances that could cause long-term health effects.

    4. Providing Results to Workers

      • Workers must be informed about exposure monitoring results, particularly if results indicate that exposure levels exceed prescribed limits or require further risk management.

    5. Reviewing Control Measures

      • If monitoring shows that workers are exposed to hazardous levels, businesses must review and improve existing control measures (e.g. ventilation, PPE, process changes).

     

    Why Is Exposure Monitoring Important?

    • Ensures compliance with HSWA 2015 and Health and Safety at Work (General Risk and Workplace Management) Regulations 2016.

    • Helps protect workers from occupational diseases such as respiratory illnesses, hearing loss.

    • Supports risk assessment and continuous improvement in workplace health and safety.

     

    Failure to meet these obligations can result in legal penalties, increased worker health risks, and regulatory enforcement from WorkSafe NZ.

  • The health hazards that should be monitored in the workplace depend on the industry, work processes, and potential exposures. However, common workplace health hazards fall into the following categories:

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    1. Chemical Hazards

    Workers may be exposed to hazardous substances through inhalation, skin contact, or ingestion. Monitoring is essential for:

    • Dust & Particulates (e.g. silica, asbestos, wood dust)

    • Fumes (e.g. welding fumes, soldering fumes)

    • Gases & Vapors (e.g. carbon monoxide, solvents, formaldehyde, ammonia)

    • Toxic Chemicals (e.g. benzene, lead, pesticides, isocyanates)


    2. Physical Hazards

    These can cause both short- and long-term health issues, requiring regular monitoring:

    • Noise – Can lead to hearing loss if above occupational exposure limits.

    • Vibration – From tools or machinery, causing hand-arm vibration syndrome (HAVS).

    • Radiation – Ionizing (e.g. X-rays) and non-ionizing (e.g. UV, lasers, radiofrequency).

    • Temperature Extremes – Heat stress or cold exposure in extreme environments.
       

    3. Biological Hazards

    Workers in healthcare, agriculture, or waste management may be exposed to biological risks:

    • Bacteria & Viruses (e.g. tuberculosis, hepatitis, COVID-19)

    • Fungi & Moulds – Can cause respiratory issues and allergic reactions.

    • Bloodborne Pathogens – Risk from needlestick injuries or contaminated materials.
       

    4. Ergonomic Hazards

    Poor workplace design can lead to musculoskeletal disorders (MSDs):

    • Repetitive Motion & Strain – From prolonged computer use or assembly line work.

    • Manual Handling & Lifting – Risk of back injuries from heavy or awkward loads.

    • Workstation Design – Poor posture leading to neck, shoulder, and wrist strain.
       

    5. Indoor Air Quality (IAQ) Concerns

    Poor air quality can lead to respiratory irritation and long-term health effects:

    • Carbon dioxide (CO₂) & Oxygen Levels – Ensuring proper ventilation.

    • Volatile Organic Compounds (VOCs) – From paints, adhesives, and office equipment.

    • Humidity & Mould Growth – Leading to respiratory and allergy issues.

    6. Monitoring Strategies

    • Air Sampling – Measuring dust, fumes, and gas concentrations.

    • Noise & Vibration Monitoring – Using dosimeters and sound level meters.

    • Biological Testing – Surface swabbing and medical surveillance for biological risks.

    • Ergonomic Assessments – Evaluating workstation setup and manual handling tasks.

    Monitoring these hazards helps prevent occupational illnesses, ensures regulatory compliance, and improves workplace health and safety.

  • If you have already completed exposure monitoring, the next steps involve:
     

    1. Communicate Findings to Workers

    • Share monitoring results with workers, especially those directly exposed.

    • Explain what the results mean for their health and safety.

    • Provide reassurance if exposure levels are within safe limits or outline steps for improvement if they are not.
       

    2. Implement Controls

    • If exposure levels are high, determine if new or improved controls are needed. Use the hierarchy of controls:

      • Elimination/Substitution – Can the hazard be removed or replaced?

      • Engineering Controls – Improve ventilation, enclosures, or automation.

      • Administrative Controls – Change work practices, limit exposure time.

      • Personal Protective Equipment (PPE) – Ensure proper respirators, gloves, or other protection are provided.
         

    3. Update Risk Assessments and Procedures

    • Modify workplace risk assessments based on monitoring data.

    • Update Safe Work Procedures (SWPs) and training programs as needed.

    • Ensure workers understand and follow updated safety measures.
       

    5. Implement Health Surveillance (if required)

    • If exposure levels indicate a risk of occupational illness, consider health monitoring (e.g. lung function tests, audiometry for noise exposure).

    • Follow WorkSafe NZ or other regulatory requirements for worker health surveillance.
       

    6. Record and Retain Monitoring Data

    • Keep monitoring records for at least 30 years if hazardous substances with long-term health effects are involved.

    • Ensure records are easily accessible for audits, regulatory compliance, and worker inquiries.
       

    7. Plan for Ongoing Monitoring and Review

    • Schedule regular exposure monitoring to track changes over time.

    • Repeat monitoring if workplace conditions change (e.g. new chemicals, processes, or equipment).

    • Conduct periodic reviews of the entire exposure management program.
       

    By following these steps, you ensure compliance with Health and Safety at Work Act 2015 obligations and maintain a safe and healthy work environment.

  • Even if you are already using respiratory protection, measuring exposure levels is still essential for several key reasons:
     

    1. Verify the Effectiveness of Controls

    • Respiratory protective equipment (RPE) is a last resort in the hierarchy of controls. Measuring exposure helps determine whether more effective controls (e.g. ventilation, process changes) are needed.

    • Exposure monitoring confirms if current control measures (e.g. local exhaust ventilation, enclosure systems) are working properly.
       

    2. Ensure RPE is Adequate and Used Correctly

    • Different hazards require different types of respirators and filters. Measuring exposure levels ensures that the correct protection factor is being used.

    • If exposure levels are higher than expected, workers may need higher-grade RPE (e.g. switching from disposable masks to powered air-purifying respirators).

    • Monitoring helps identify improper fit, seal leaks, or incorrect usage of respirators.
       

    3. Compliance with Legal and Regulatory Requirements

    • The Health and Safety at Work Act 2015 requires exposure assessments to ensure workers are not exposed to hazardous substances that may result in ill health.

    • Even if RPE is used, you must demonstrate that exposures are being controlled as low as reasonably practicable (ALARP).
       

    4. Reduce the Risk of Occupational Diseases

    • Long-term exposure to hazardous substances (e.g. silica, asbestos, welding fumes) can lead to serious occupational diseases such as lung cancer, silicosis, or chronic respiratory conditions.

    • Monitoring helps detect hidden risks, ensuring workers are not unknowingly exposed to dangerous levels of contaminants.
       

    5. Plan for Future Workplace Changes

    • If new equipment, materials, or processes are introduced, exposure levels may increase or decrease.

    • Monitoring provides baseline data to compare against future measurements, helping businesses adapt to changes proactively.
       

    6. Provide Data for Health Surveillance Programs

    • If exposure levels are near or above workplace exposure limits (WES), workers may require health surveillance (e.g. lung function tests, biological monitoring).

    • Early detection of overexposure allows for preventive action before health effects occur.
       

    7. Legal Protection and Documentation

    • Maintaining exposure records provides evidence of compliance with health and safety laws.

    • If a worker develops an illness, exposure data helps determine whether it was work-related and protects businesses from liability.

     

    The key point is, using respiratory protection is important, but it should not replace exposure monitoring. Measuring exposure ensures that RPE is adequate, controls are effective, and workers remain safe and healthy in the long term.

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