Sarah and others, the question and some answers suggests the use of a 5x5 matrix.
Use of a matrix assumes that (a) the matrix in question was actually designed for the business or undertaking AND for the specific activity within the business or undertaking; (b) the context of the business activity is clearly understood; (c) the matrix was used without fudging the results; (d) the effectiveness of any controls is clearly understood.
If you could look a District Court judge in the eye while under oath and confirm all of the above you are in an exceptional position and should consider writing the definitive text on risk assessment and management.
Which begs another question. What do you mean by "risk"? The Act gives no definition and ISO45001 gives two definitions. I prefer the definition in ISO31000 Risk management: guidance because it makes you think. There, risk is the "effect of uncertainty on objectives". All readers, think about that definition and the words effect, uncertainty and objectives for at least 48 hours before bursting into print.
This sort of conundrum is part of the paper I am teaching in trimester 2 at Victoria University of Wellington. Please don't think about enrolling in the paper - just enrol.

The two papers I teach at Victoria University of Wellington require access to several standards including ISO31000, IEC/ISO31010, ISO45001, ISO19011 and the recent ISO31073. Students can access them via the library and use them during their study. ISO45003 is being adopted by Standards NZ and will also be available as soon as it is published.
As one of the volunteers who contributes to standards it is very frustrating that they are not free. Worse, MBIE (as the "parent" of Standards NZ) requires someone to pay for adoption of international standards and joint standards.

VOSL is an often used measure but we could also use, for example, QUALYS.
VOSL is the "value of a statistical life" and has little to do with real lives. It's based on how much we are willing to spend to prevent some consequence. I usually use data published by the Ministry of Transport on its website which are actually the "social costs of road crashes" and so not the VOSL. The MoT data is nearly $5 million for a road fatality.
The last time I checked that was about the same as the numbers used by the UK HSE and in Australia. That's what we should be willing to spend to avoid a workplace death. I use the $5 million as part of the "reasonable" test of "reasonably practicable" for workplace harm. It's a rough and ready measure that makes people sit up and think.
A colleague, an economist, disagrees with my approach and prefers QUALYS. That's a way of measuring the lost quality of life due to some harm. It's more difficult to calculate.
How much would you be willing to spend to avoid a workplace death?
I must stop - meetings to go to! Maybe more later.

Does it make some people feel they are helping? Yes.
Does it work? Probably not.
Does it cause harm? Sometimes.
Would you ask a first aider to treat a serious injury? No, you'd get the victim to a doctor.
Read the research evidence published by the UK HSE.
Bell, N., Evans, G., Beswick, A., & Moore, A. (2019). Summary of the evidence on the effectiveness of Mental Health First Aid (MHFA) training in the workplace [Research Report RR1135]. Health and Safety Executive, Sudbury https://www.hse.gov.uk/research/publish.htm
Workplace Health Expert Committee. (2021). Evaluating interventions in work-related ill health and disease [Evidence Review Paper WHEC-17]. Health and Safety Executive, https://www.hse.gov.uk/research/workplace-health-expert-committee.htm
Chris

Several comments have already said what I think. In plain English, where is the evidence that caps or hoodies cause a loss of vision? Some simple measurements might do the trick. That evidence should then feed into a risk assessment carried out jointly with the workers. Include different shifts, different work activities. You then have a defensible position in the Employment Court, District Court or with WorkSafe.
Of course the measurements alone might convince the workers of any problem.

What a shame that academics are not included in the survey!
I could offer some different insights based on the work our students are carrying out (assignments and research). Some are quite stellar!

The PSPLA decision is quite cleverly balanced. Now it is up to HASANZ and its member organisations to ensure that anyone on the register is competent to, among other things, investigate incidents.
At Victoria University of Wellington we are developing a new Master's level paper on incident investigations and hope to offer it at the end of 2023. The plan is for the paper to be available as a standalone paper (subject to entry requirements).
As a footnote, I searched the HSWA for "investig" and found that safety reps can investigate worker complaints. What if the complaints were about workplace incidents? Would there be a conflict between our Act and the Private Security Personnel and Private Investigators Act?

Peter Drucker wrote about the "worker's letter". This was written by a senior manager (preferably the CEO) to recognise something above and beyond expectations. The senior manager would call out the recipient during a tea break or similar and present the letter. Done well everyone knew what "good" looked like and the file copy came out during the annual performance review.

Why not amend section 383 of the Companies Act to include offences under the HSWA and so enable regulatory agencies to apply to the court to disqualify a director for a period of time? This might stop an SME from trading and would hurt directors of large PCBUs. This is occasionally done in the UK.
Not a perfect solution but it would be another tool in the regulatory kit.
As a further thought, Gisborne District Council just got convictions of two forestry companies under the RMA. Those companies had been previously convicted of HSWA breaches. Officers/directors of recidivist PCBUs need to know they can lose their jobs

I also agree with Ian.
Applying rigorous research will yield evidence to inform policy but, as an academic, I admit a conflict of interest!
Some of my wish-list research titles follow.
How can small and medium-sized businesses be helped to integrate better business practices with effective OHS?
How can messages about OHS and productivity reach the PCBUs that are hard to reach?
Contracting with large PCBUs to manage OHS in their suppliers and customers: possibilities, costs and benefits.
Helping sector groups to develop their own OHS standards: possibilities, costs and benefits.
Worker fatigue at the margins of the economy: who pays, who should pay?
Are there common factors that link victims of workplace harm? [NB: this is not the same as so-called accident-prone people]

I recall a UK client whose sites were so large that cycling was the only safe way to get around. There were strict controls on ignition sources that all but prohibited the use of vehicles with internal combustion engines.

This was an awful story. Drowning in liquid waste was a ghastly way to die.
It's worth reading the UK Confined Spaces Regulations 1997 (attached) to see a variation on the hierarchy of control. I'll place it in my teaching alongside the NZ legislation, ISO31000 and Haddon barrier approaches.
Essentially, the Regulations prohibit entry unless there is no other way of carrying out a task but then explicitly requires an emergency plan.

Hi Sheri
You have raised some very good issues here that I suspect will be worse on some sites where there are non-workers who often will have no training in evacuation. Under the old "normal" the wardens would ensure evacuation but now? I am thinking of retail shop customers, students on a large campus, etc.
There was a fire in a Littlewoods department store in the UK in the 1980s when a couple who had bought their lunch in the cafeteria sat eating despite the alarm and then smoke. They died.
While the main legal requirement for evacuation is under the Fire and Emergency New Zealand Act 2017 and Regulations I think we also need to pay attention to sections 36 and 37 HSWA. What would it practicable to do and would that be reasonable?
Thank you!
Chris

Hi Aaron
Some brief thoughts.
You must comply with the Privacy Act (ie, not disclose any personal information). If the filming shows 'workers' at work they may need to give their consent, even if they are carrying out business as usual activities.
If a camera is fitted to allow filming outside a helicopter or other vehicle this might prohibit sharing film showing a third party without the consent of the third party. However, filming in a public space seems to be legally acceptable.
Maybe fit plain English notices where they can be seen that tell workers, passengers, etc, that they may be filmed in the course of this journey.
Take care to not disclose any commercially sensitive information unwittingly, for example voice over when someone describes a planned property transaction.
A regulatory agency may have the power to require production of recordings and you may want to comply with such a request via your lawyer.
I suggest you draft a plain English policy in consultation with your own workers and then ask your lawyer to tidy up with 'shall', 'must', 'must not', etc where appropriate. But keep it plain English!
Sorry this is a bit terse.
Chris

The numbers of deaths are not just 50-60 per year. New Zealand is killing 900-1000 people at or because of work each year. About 50-60 are due to trauma but, historically, most deaths were due to disease (eg, asbestosis) but I think an emerging issue may now be fatigue.
Port workers work shifts 24/7, 365 days per year. Some are (or have been) on zero hours contracts. Add to the mix vehicles (fork lift trucks, straddle cranes, heavy goods vehicles, etc) moving shipping containers in, into and out of ports and there may be a lethal cocktail.
Deaths in the Ports will be the subject of the next NZISM webinar when we may also have a guest speaker.

Hi Riki
Your question begs questions.
Do you mean you are completing the diploma at undergraduate or postgraduate level?
Do you want to study at undergraduate level or postgraduate level?
Do you want to study face-to-face or online?
Some thoughts.
At Victoria University of Wellington one of our postgraduate students researched OHS decisions in the District Court over a 10-year period comparing prosecutions for traumatic injury with prosecutions for occupational health/disease. She added to a database of cases we have been developing and that needs completion. This was her research report for completion of part B of her Masters.
Another student has completed part A of the Master's programme (= the postgraduate diploma) and, instead of carrying out a research report, is working on a Master's by thesis researching aspects of OHS law in NZ. He will also draw on the now-expanded database.
A year ago we started exploring an option for a postgraduate paper to be developed jointly with the Law School for lawyers, managers and OHS practitioners to be run as a “summer school”. However, the project must wait until we have the staff, funding, and demand. Does this sound like what you want?
Happy to talk on the phone (0274713723) or by Zoom
Chris
Lecturer in Occupational Health and Safety

Working as an academic, no, not at a personal level.
But as a long-time OHS consultant and academic, each newspaper report of a workplace fatality, and each court case following a traumatic death grieves me. Each means that whanau have lost someone they loved. Children may grow up not knowing a father or sibling; parents may bury a child.
Pike River still makes me downright angry. We the country accepted poor legislation, and an underfunded regulator. It took 29 deaths to make the major changes and we still have a journey to travel.
And well done Michael! That is an excellent result. Can you share your critical success factors? What can others learn from you?

Hi all
Nobody else has mentioned section 28 of the Health and Safety at Work Act.

Sarah started this conversation with a question about "events", not risk. If we must discuss risk, use the ISO definition of risk: "effect of uncertainty on objectives". Ask how uncertain someone is. Or how certain they are. Or use a simple word, how sure are you? This does wonders for nailing down how uncertain people are - how little they actually know.
Learn to use probability. Ask for a consensus view about ranges. "Are you 90-95% sure this tank will fail in the next 10 years?"
Gather data about similar events of concern. Why did they happen? What's different.
Don't use likelihood words. They mean whatever a reader wants them to mean. Or as Lewis Carroll wrote:
“When I use a word”, Humpty Dumpty said, in rather a scornful tone, “it means just what I choose it to mean – neither more nor less.” (p 196, Through the Looking-Glass).

I'm very glad the construction industry doesn't worry about the triangles.
Yes, Heinrich (and Bird) worked in the insurance industry and got their data from reports filed by clients.
It is easy to overlook the difference that technology has made to our lives. In the 1930-1990 period computerisation of OHS data was generally not practicable. Computers did not exist or were too expensive and mostly used for the "important" financial analyses. Things are different now. The computer I'm writing this on may have more power than NASA had for the whole space programme in the 1960s.
But one problem remains - the willingness of workers to report incidents, regardless of their outcomes. That is exacerbated by subsequent access to the "data capture system" and limitations imposed by the categories it uses that we (the authors of the system) impose on the reporters. The longer the time between event and reporting, the more the event will have become "unforeseeable" leading to the need to adjust the facts. That can also be exacerbated by fear of the event being investigated. And that the reporter may be a manager, not the victim. Whose story is correct?
Last night I started updating my teaching materials for 2022 and read chapter 4 in Sydney Dekker's book "Foundations of Safety Science". The chapter is worth a read. It nicely skewers ideas about ratios.
PS: Critical risks often get so much attention that minor risks can eventuate and cause major damage.