The Safeguard Gap
Every one of the 3,228 notices comes down to one of two things.
- The guard was never good enough. The machine had no guard, or one you could reach around. The fix is an engineering job, and just over half of these notices give the employer a deadline to do it.
- The guard was there and wasn't working. Someone had wired the interlock out. The guard had been left off after a job. It had been broken for weeks and nobody noticed. Seven in ten of these get the machine shut down immediately.
The second kind is the more serious of the two. Inspectors treat it as the most urgent, as it is the hardest for a site to catch because, on paper, the guarding appears to be there. This is what the report focuses on.
What Inspectors Found
Half of these notices shut the machine down immediately. In 814 of the 3,228 notices, the inspector recorded what was wrong, and those 814 are the basis of Figure 1. The red bars are the cases where a guard existed but had been bypassed, taken off, broken, left unset or never checked.
The chart splits into two groups:
- Grey bars (451 notices): machines that never had proper guarding. Just over half were given an improvement notice with a deadline to fix it.
- Red bars (363 notices): machines that had a guard, but it had been bypassed, taken off, broken, left unset or never checked. Inspectors shut these down between 62% and 83% of the time, depending on the failure.
The takeaway: a guard that was never fitted is an engineering gap. A guard that was fitted and then defeated or left broken tells the inspector that safety on the site is not being managed.
The machines named in the notices:
- Lathes, milling machines and drills: 945 notices, usually a missing chuck guard.
- Woodworking machines: 425.
- Presses and guillotines: 316.
- Saws: 227. Conveyors: 226.
- Tractor power take-off shafts: only 82, but three in four were shut down immediately.
Manufacturing accounts for 83% of the notices. Metal fabrication and machining tops the list, usually a lathe or a mill in a small workshop, with woodworking second. Construction and farming get few notices, but when they do, the machine is nearly always shut down.
The regions have much the same mix of industries, so industry does not explain why a notice in the East and South East shuts the machine down 60% of the time and one in the North West 29%. If every region shut machines down at the national rate for its industries, all of them would sit between 43% and 47%. The difference lies in how inspectors work in each region, or which sites they visit, rather than in the machines.
What It Costs
A typical machine guarding conviction costs £40,000, and the serious ones cost £300,000 or more. HSE's prosecutions register holds 2,417 convictions from the last ten years, the period the current sentencing guideline has been in force, and in 155 of them the machine guarding rule was charged [2]. HSE fines are set by the court, not by HSE itself, under the Sentencing Council's health and safety guideline, which since 2016 has scaled them to the company's turnover as well as to what happened [3]. The same failure can therefore cost a small firm £10,000 and a large one £1 million, which is why the middle of the range tells you more than the total.
| Machine guarding convictions, 2016 to 2026 | |
|---|---|
| Convictions | 155 |
| Fines, all together | £16.9 million |
| Typical fine (the median) | £40,000 |
| Half of all fines fell between | £14,000 and £100,000 |
| Fines of £500,000 or more | 9 |
| Largest fine | £1.9 million |
| HSE's legal costs on top, typical | £4,000 |
More than half the cases were fined under £50,000, and 41 were fined £100,000 or more. The 11 serious enough to go to the higher court had a typical fine of £297,000, nine times the rest.
The sectors with the most notices are not the ones that pay the most in court. Metal fabrication has the most notices and the lowest typical fine, because the typical case is a manual lathe in a small workshop. Food and drink has a tenth as many notices but the most convictions of any sector, and they involve conveyors, mixers and packaging lines on larger sites, where both the injuries and the turnover are bigger.
| Sector | Convictions | Typical fine |
|---|---|---|
| Plastics and rubber | 14 | £80,000 |
| Food and drink | 26 | £75,000 |
| Other manufacturing | 14 | £55,522 |
| Services and other | 23 | £32,000 |
| Wood, joinery and furniture | 18 | £23,750 |
| Fabricated metal and machining | 15 | £20,000 |
Sectors with ten or more convictions. Typical fine is the median.
The worst cases are not recorded as guarding cases. HSE often prosecutes under the general duty to protect employees, section 2 of the Health and Safety at Work Act, rather than under the guarding rule. Of the 34 recent machinery prosecutions HSE describes, only 10 were charged under Regulation 11. The other 24 were charged under section 2, and those were the ones with the deaths (six) and the six-figure fines. The 155 is therefore a floor: the true number of machinery prosecutions is higher, and so is the true cost.
The notice often comes first. Forty-five convictions on the register followed a machine guarding notice served at the same site, usually during the investigation of the accident that went to court. Nine of those employers had been told before the offence began.
From Guarding to Isolation
Unlike the United States, Great Britain has no lockout/tagout (LOTO) law. OSHA has one standard for it, 29 CFR 1910.147, and one line of enforcement under it [4]. Britain has the same obligation, spread across four sets of rules:
- the Health and Safety at Work Act (the general duty to keep people safe at work)
- PUWER Regulation 19 (safe isolation: every machine must have a way to cut it off from its energy)
- PUWER Regulation 22 (maintenance is done with the machine stopped)
- the Electricity at Work Regulations (electrical equipment is made dead before anyone works on it)
So there is no single rule an inspector reaches for when a machine has not been isolated. Of the 30,226 notices on the register, 357 mention isolation or locking off, about 1%, and not one conviction in ten years was charged under Regulation 19.
Lockout failures are recorded as guarding failures instead. Inspectors use the guarding rule, Regulation 11. An interlock wired out so the door opens with the machine running, a guard taken off while the machine can still start, an interlock that fails to stop the machine when it should: all of these go on the register as guarding failures. Bypassed interlocks alone account for 115 notices, and 83% of them had the machine shut down. The failures an inspector cannot see on the day, such as a blockage cleared on a running machine or a guard left off after a job, surface later, in court.
The Five Checks
The fix does not require new machinery. It requires treating a guard as something that is checked rather than something that was installed. The notices point to five checks, each of which closes off a failure that appears on the register, and all five can start tomorrow.
Walk every machine and check it has a guard, and the right kind. A fixed guard where possible, an interlocked guard or light curtain where not. Record which one each machine has. (451 notices: no guard, or one you could reach round.)
Check the adjustable guards are set for the job. Crown guards, riving knives, bridge guards and push-sticks only work when set for the cut. Put the setting on the job sheet. (62 notices. Three in four were shut down immediately.)
Open the door with the machine running. If it doesn't stop, the interlock has failed. Test every interlock on a schedule and write down the result. (143 notices: faulty interlocks, guards not maintained, nobody checking.)
Find out who can bypass an interlock, and who checks the guard went back. Decide who may, and for which jobs. Keep the override keys under control, and sign off that every guard is back before the machine restarts. (150 notices. Bypassed interlocks got the machine shut down 83% of the time.)
Isolate before anyone reaches in. Clearing a blockage, cleaning and setting are the jobs that end up in court. Each machine needs an isolation procedure, each job a record that it was applied, and each restart a sign-off. That record is what lockout/tagout software is for. (357 notices across the register, and three of the four isolation prosecutions.)
Do all five and you can show the guard was there and working on the day someone reached in. That is what both registers turn on.
The Research
Zentri read both of HSE's public registers in full: every notice on the HSE enforcement notices register, 30,226 of them, from August 2021 to July 2026 [1], and every case on the HSE prosecutions register, its public register of convictions, 2,417 of them, from the 2016 sentencing guideline to October 2026 [2].
How we counted. A notice is included if it cites the machine guarding rule, Regulation 11 of the Provision and Use of Work Equipment Regulations 1998 (PUWER) [5]: 3,228 notices. A conviction is included if Regulation 11 was among the charges (155 convictions). We count notices rather than visits, since one visit can produce several.
How we classified. Each notice was sorted by the machine involved and by what the inspector said was wrong, using one fixed set of rules applied to the inspector's own words. A suggested fix ("for example, by fitting an interlocked guard") does not count as a failure. For the convictions, we read the 213 cases HSE describes and identified the machinery ones.
The full method, the validation and the tables cut from this page are in the download pack.
References
- HSE enforcement notices register, notices.hse.gov.uk. Notices issued August 2021 to July 2026.
- HSE public register of convictions, convictions.hse.gov.uk. Hearings 2016 to October 2026.
- Sentencing Council. Health and Safety Offences, Corporate Manslaughter and Food Safety and Hygiene Offences: Definitive Guideline. In force from 1 February 2016.
- Nugent, S. and Nugent, M. The LOTO Evidence Gap: 2025 OSHA Lockout/Tagout Citation Analysis. Zentri, 2026. zentri.cc/resources/osha-lockout-tagout-citation-analysis
- The Provision and Use of Work Equipment Regulations 1998, SI 1998/2306, Regulation 11.
This is not a regional ranking or a safety ranking. Nothing here says one region is safer than another. Northern Ireland is excluded, as it has its own regulator. No employer or individual is named in this research.
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About Zentri
Zentri is a permit to work, digital lockout/tagout and safety observation platform that builds the record of safety-critical work as it happens on the floor. It connects machine-specific isolation procedures, permits to work, training and sign-on records, verification, periodic inspection and closeout into a single auditable record, so the proof an inspector asks for is captured as the work happens, not reconstructed afterward.
The HSE registers point to the same problem from a different direction. A guard or an interlock is only as good as the last time someone checked it, and the moment it gets bypassed is usually the moment someone needs to get into the machine to clear it, clean it or set it. Controlling that access and recording those checks is what Zentri is built for.
See how Zentri records isolation, permits, sign-on and periodic inspection for every machine.
Book a walkthrough and see how Zentri records every guard check, isolation and sign-off as the work happens.
About the Authors
Sam Nugent, a co-founder of Zentri, is a chemical engineer who has worked across a range of industrial settings. He led the research behind this report.
Matthew Nugent, also a co-founder of Zentri, is a chemical engineer who works across multiple industries. He led the analysis behind the findings presented here.
"We published this because the data answers the question safety leaders actually ask: what was wrong on the day? More often than you would expect, the guard was there. It just wasn't working."
Frequently Asked Questions
Frequently asked questions
No single one. The duty is spread across section 2 of the Health and Safety at Work etc. Act 1974, PUWER 1998 Regulations 19 and 22 (isolation from energy sources and maintenance with equipment stopped) and the Electricity at Work Regulations 1989. In practice HSE enforces the lockout moment through machine guarding law: of 30,226 notices on its register, 357 mention isolation or lock-off, while 3,228 cite PUWER Regulation 11.
Regulation 11 of the Provision and Use of Work Equipment Regulations 1998 requires employers to take effective measures to prevent access to any dangerous part of machinery, or to stop its movement before any part of a person enters the danger zone. It sets an order of protection: fixed guards where practicable, then other guards or protection devices such as interlocks and light curtains, then protection appliances such as jigs and push-sticks, then information, instruction, training and supervision. It is the regulation most often cited in HSE machine guarding enforcement.
3,228 notices on HSE's enforcement notices register, issued between 30 August 2021 and 25 July 2026.
An improvement notice requires the employer to put a breach right by a set date. A prohibition notice stops an activity that the inspector believes carries a risk of serious personal injury, usually with immediate effect. 44% of Regulation 11 notices were prohibition notices, compared with 25% across all notices on the register.
Metalworking machines (lathes, milling machines and drills), followed by woodworking machines and presses, press brakes and guillotines.
The law sets no upper limit. The court, not HSE, sets the fine under the Sentencing Council's guideline for health and safety offences, by the offender's turnover, culpability and the harm risked. On HSE's register, the 155 convictions with a Regulation 11 charge had a median fine of £40,000, with half of all fines between £14,000 and £100,000. Cases heard in the Crown Court had a median fine of £297,120, and the largest Regulation 11 fine was £1.9 million. Prosecution costs, typically about £4,000, are awarded on top.
Yes. Since February 2016 the Sentencing Council's guideline has set fines by reference to the offender's turnover, in four bands: micro (under £2 million), small (£2 million to £10 million), medium (£10 million to £50 million) and large (over £50 million), adjusted for culpability and harm. Two employers convicted of the same failure can therefore receive very different fines.
Prosecution is reserved for the most serious cases, usually after an injury. Many machinery prosecutions are also charged under section 2 of the Health and Safety at Work etc. Act rather than Regulation 11, so the 155 is a minimum.
HSE publishes both. The enforcement notices register (notices.hse.gov.uk) lists improvement and prohibition notices for about five years after they are served. The public register of convictions (convictions.hse.gov.uk) lists prosecutions that ended in a conviction, nine weeks after the hearing, for about ten years. This report is built from snapshots of both.
The distance between a machine that was guarded when it was installed and a machine that is guarded at the moment someone reaches into it.
Citation
To cite this report:
Nugent, S. and Nugent, M. (2026). The Safeguard Gap: UK Machinery Safety Report. Zentri. zentri.cc/resources/hse-machine-guarding-enforcement-analysis
To quote the headline figure:
Zentri analysed 3,228 HSE enforcement notices (August 2021 to July 2026) and 155 convictions (2016 to 2026) citing PUWER Regulation 11 in Great Britain.