If you know your work involves exposure to health hazards such as dust, noise and fumes but aren’t sure about the level of risk your workers are exposed to and are exposed to, you might choose to engage an occupational hygienist.

What’s covered in this guide

It helps you decide:

• when to seek specialist help
• how to find and choose a competent occupational hygienist
• what to expect when you hire an occupational hygienist – their services and standards.

Before engaging an occupational hygienist, first check what you already know and can reasonably manage.

Once you've got your controls in place, you need to review them regularly, especially if you change anything like a process, a material, or your equipment.

Managing risk isn't a one-off task; it's an ongoing responsibility.

Sometimes, there could be things happening in your business that mean you choose to take another step to double-check your controls.

You can think about risk in three practical ways:

1. The risk is negligible or trivial

If exposure is non-existent or so minor that it is very unlikely to cause harm, document it and continue with normal operations.

2. The risk is clear and you know how to control it

If the risk is understood and there are standard or obvious controls, such as following WorkSafe New Zealand guidance, put those controls in place straight away. You do not usually need to measure it or bring in a specialist.

3. The situation is uncertain or complex

If you cannot easily work out the level of risk or you are unsure whether your controls are enough, you might choose to engage an occupational hygienist. This is not compulsory, but it can help if you want extra reassurance or clarity. This guide can help you work through that process if you decide to take that step.

Helpful terms

Workplace Exposure Standards

Workplace Exposure Standards (WES) are guideline values that show the exposure limits for hazardous airborne substances. They're based on the impact to people's health.

WES are not mandatory limits, or targets to reach, but they can be helpful in assessing the risk your workers might be exposed to.

Occupational hygienist

Occupational hygiene is about protecting workers' health by identifying, assessing and controlling the health hazards at work that could make people sick.

Occupational hygienists are experts who help employers and workers understand how serious the health risks in their work are.

Their work includes:

• measuring the exposure levels of health hazards
• comparing them with the relevant exposure limit, standards or guideline values – such as the WES
• assessing how well your risk controls are working
• advising on ways to eliminate the risks, or reduce exposure to a safe level.

Workplace health hazards

A workplace health hazard is anything that could cause harm to workers' health.

There are three main types of hazards that an occupational hygienists can help you manage: chemical (such as dusts and fumes), physical (such as noise or vibration), and biological hazards (such as bacteria and viruses).

Health and safety risk controls

These are the practical steps that businesses take to eliminate or minimise risks to workers' health from workplace health hazards (for example, by reducing exposure to dust, fumes, gases or vapours, noise or vibration).

Here are the steps to finding an occupational hygienist:

1. Getting started

Think about the risk and controls in your workplace, if you still want further advice you might choose to talk to an occupational hygienist.

Step 1 of this guide

2. Find an occupational hygienist

To find the right person for your job you'll need to make a shortlist of possible options.

Step 2 of this guide

3. Choose an occupational hygienist

Be prepared with information about what you need to make this easier.

Step 3 of this guide

4. The site visit

Knowing what to expect will help you be ready on the day.

Step 4 of this guide

5. Understand and act on the report

An occupational hygienist report gives you information about changes you can choose to put into place to improve health and safety outcomes.

Step 5 of this guide

Step 1: Getting started: understanding exposure levels and when to get help

As a business, you need to know the health risks from the work you do, including exposure to things like dust, fumes, gases or vapours.

It's important that there are practical steps in place to eliminate or reduce these health risks from exposure as much as possible. We call these steps 'controls'. Controls should be reviewed regularly, to make sure they are working – especially if things change, such as the material you work with, the way you do your work, or the equipment used.

If you still want further advice about the level of risk from that exposure, or what to do, then an occupational hygienist can help. Occupational hygienists can help you understand the health risks at your work, and how best to manage those risks.

Might specialist advice help me?

Ask yourself:

• Do I understand where the exposure risks in my workplace come from?
• Do I know whether I need to do a risk assessment for these hazards?
• Have I considered guidance on managing the hazards, and do I still have questions?
• Has anything changed recently in our work that could have changed our risk profile? Think about:
  • the materials and equipment you use
  • the processes you follow (how you do your work)
  • how often the work is done – has the workload increased
  • location and building layout – are you working somewhere new
  • staffing – do you have new workers on board.
• Do I want additional assurance that the health risk controls for these workplace health hazards are working?
• Have any workers raised symptoms, concerns, or discomfort about health impacts from their work?
• Have I received an enforcement or Improvement Notice from WorkSafe?

If you aren't sure about the answers to these questions, then you may choose to seek advice from an occupational hygienist.

Step 2: Find an occupational hygienist

If you need expert help, you'll need to find an occupational hygienist. You might want to have a shortlist of people to choose from.

You can find an occupational hygienist by:

• talking to people you know, who do similar work – have they worked with an occupational hygienist before?
• searching online
• using registers from industry bodies, such as the New Zealand Occupational Hygiene Society (NZOHS) and the Health and Safety Association of New Zealand (HASANZ).

Using an occupational hygienist that's a Full or Fellow member of the NZOHS or listed on the HASANZ Register can give you confidence that their credentials have been verified.

Qualifications

An occupational hygienist will have a qualification to do the job, such as:

• a master's degree with occupational hygiene specialisation (such as MOH, MWHS, MSc)
• a Bachelor of Science degree (for example, BSc)
• graduate diploma in occupational hygiene (for example, GDOH)
• an international certificate in occupational hygiene (ICertOHTA).

Certification

A certified occupational hygienist has achieved the highest available technical competency credential for occupational hygiene. You will most likely see the initials COH (from Australia), ROH (South Africa) or CIH (USA) to show they're certified.

While New Zealand doesn't have its own International Occupational Hygiene Association (IOHA) National Accredited Recognition (NAR)-accredited certification programme yet, these international credentials are the highest recognised standard.

Step 3: Choosing an occupational hygienist

It's time to choose an occupational hygienist from your shortlist.

Before you get in touch, be prepared with some information about what you need.

They'll ask you questions about your work, and the clearer you are, the easier for you to know you're getting the right person for the job.

A simple way to prepare is to use the five 'W's – what, why, where, who, and when:

What is the workplace health hazard you want help with?

• What work processes are involved?
• What are the sources of exposure (for example, materials, substances, or processes that generate dusts, fumes, gases or vapours)?
• What controls are already in place, and how well are they working?
• What documents can you share (for example, standard operating procedures, safety data sheets, previous exposure monitoring results)?

Why are you seeking help?

• What's your overall aim for this work – the problem you are trying to solve, or opportunity have you identified to assess or improve?
• Have workers raised any concerns, symptoms, or feedback?

Where does the work take place?

• Is it at one location or several sites?
• Has this changed recently?

Who is affected?

• How many workers are involved?
• What roles or duties do they have that relate to the hazard?

When does the issue happen or matter most?

• Are certain times of day, shifts, seasons, or conditions important?
• Do you have a specific deadline for the work? Do you need to have new controls in place by a certain date? If you have received an enforcement or Improvement Notice from WorkSafe, this may be the case.

The occupational hygienist will use this information to provide you with a quote.

Knowing a good quote when you see one

A quote from an OH should include:

1. An overview of your needs and their plan

• A clear summary of what you need. Can you see that they understand your issue or opportunity, your business size, and any requirements you asked for?
• An outline of their proposed plan and how it will meet your needs. It should list key tasks/stages. Any assumptions or limitations should be included.

2. Details of how they'll do the work

• Who will do the work, including contractors: their roles, qualifications, and experience.
  • Is it clear that a competent occupational hygienist has overall responsibility for the job, including the proposal and report, and will supervise any junior staff?
• Their assessment strategy. This strategy tells you what they'll test for and how. It should include any professional standards, methods, or guidelines they will follow, such as for sampling. If they plan to change how any standards, guidelines or methods are usually applied, they should explain how and why.
• What they would need from you, and when (for example, site access, or resources on the day).

3. Finer details

• Total cost of services.
• A timeline, indicating when each main task or activity will be completed.
• Information about privacy – how they will manage and protect information they collect and store about you, your workers (such as biological monitoring results) or the business.
• Insurance(s) – confirmation that they have appropriate types and levels of cover required for the nature and scope of the work.
• Contact details if you have questions.

Step 4: The site visit

Once you've hired an occupational hygienist, they'll arrange to visit your workplace. Check whether there is anything they would like you to prepare before their assessment visit.

Before the visit

Ensure that:

• workers understand the purpose of the visit. Let them know what the occupational hygienist will be doing, why, and what it means for them.
• workers know what to expect, and if biological exposure monitoring is planned, that they give their informed consent in writing.
• relevant documents are readily available (for example, your hazard register, standard operating procedures and safety data sheets).
• work processes are running as they usually do.
• relevant workers will be available on the day.
• someone is available to guide the occupational hygienist throughout the visit, including for a site induction.

During the visit

The occupational hygienist is likely to gather information by:

• walking around your workplace to observe work in progress. This is called a walkthrough survey.
• talking with your workers and supervisors/line managers about their work processes.
• reviewing relevant documents, for example your hazard register, standard operating procedures and safety data sheets. (They may ask for these before the visit).
• reviewing available information such as previous exposure monitoring results, health and safety incident records, or complaints or concerns raised by workers, where relevant.
• inspecting control measures, such as dust extraction systems and personal protective equipment (PPE).
• conducting relevant assessment methods, such as for noise exposure, or airborne or surface hazard exposure.

Step 5: Understand and act on the report

After the visit, you'll receive a report of the occupational hygienist's findings and recommendations.

The report should give you a clear explanation of what was done and why, what the results were, and what they mean for you.

It should provide practical steps to help manage the risks from your workplace health hazards.

A good report should:

• be as short and to-the-point as possible, using simple, easy-to-understand language as much as possible. Technical terms should be explained.
• assure readers the work was properly carried out and the conclusions are reasonable, based on the findings of the survey.
• clearly identify required actions.

It will usually include:

• Introduction (the purpose of the work and the scope – what, where and who it covers)
• Methods (what was done and how it was done)
• Results (the measurement data from exposure monitoring; what was found)
• Discussion and conclusions (what the results mean)
• Recommendations (what to do next).

When reviewing your report, ask yourself:

Do I understand what the results mean?

The report should use clear and easy to understand language to tell you about the level of risk, and what it means in relation to relevant guidelines, exposure limits, or what the law requires.

Are the recommendations clear and doable?

You should be able to see how every recommended action links back to the risks identified, and the findings covered in the report.

What are the top 2–3 things I need to do first?

The recommendations should be prioritised by the level of risk identified; that is, recommendations to help manage the highest, most serious risks should come first. Make sure you understand which actions are urgent, and which can wait.

Do I need more explanation before I make decisions?

If something is unclear, not what you expected, ask the occupational hygienist to talk you through the findings. This is a normal part of the process.

Act

As a business, it is up to you to decide how to act on any recommendations made by an occupational hygienist.

1. Focus on the things you can do to reduce exposure at the source. These kinds of health and safety controls usually provide the most significant long-term benefits. They are more effective than relying on Personal Protective Equipment (PPE) alone.
2. Keep a record of all actions taken. This supports good risk management under HSWA. Schedule a follow up to review progress and check whether controls remain effective.

If you've got questions, or need help with the report

Always discuss your questions or concerns first with the occupational hygienist who provided your report.

Second opinion: If that process doesn't satisfy you, you could use NZOHS(external link) or HASANZ(external link) to find another occupational hygienist for a second opinion. You will be responsible for the cost, so be clear about what you expect from a second opinion and satisfy yourself it is worth having.

NZOHS Complaints Process: If you have a grievance about the conduct of an NZOHS member, you can raise a complaint through their website(external link)

Other professional bodies: If advice or conduct you are concerned about was from a member of another health and safety profession, check their website for 'Contact' details. Alternatively, the HASANZ website lists contacts for its member professional bodies(external link)

Commerce Commission: The commission can address any concerns you have about commercial aspects of services you buy (see their website – Enforcing your rights and disputes resolution(external link)).