By David Healey, Senior Solicitor · Carter & Carter Solicitors · March 2026

He was a mechanical fitter, 59 years old, contracted to carry out planned maintenance at a large chemical plant in Huddersfield. Not their employee. Not on their books. Working under their supervision, on their site, using their equipment — but technically employed by someone else.

On 6 November 2023, an isolation valve failed during the work. A sudden, uncontrolled release of high-pressure steam narrowly avoided causing him serious injury. The HSE investigation found that the valve — and the flange bolts he had been cutting through — were corroded and in poor condition. The risk assessment the company had on paper didn’t reflect the real risk on the ground. A safe system of work should have been in place. It wasn’t.

At Leeds Magistrates’ Court on 28 January 2026, the company was fined £400,000. The contractor was the victim. The company paid the price. And the legal principle at the heart of the case is one that thousands of contractors across England and Wales don’t know applies to them.

What duty does a company owe to contractors working on its site?

Most people assume that health and safety law only protects employees — people who are directly employed by the company that owns the site. That assumption is wrong, and it means a significant number of contractors, subcontractors, and self-employed workers miss out on compensation they’re legally entitled to.

Section 3(1) of the Health and Safety at Work etc. Act 1974 imposes a duty on every employer to ensure, so far as is reasonably practicable, that persons not in their employment who may be affected by their work activities are not exposed to risks to their health and safety. That covers contractors, agency workers, subcontractors, and anyone else working under a company’s control and direction — even if they’re on a different payroll.

In the Huddersfield case, the HSE found that the contractor was working “under the control and direction” of the site occupier. That phrase is the legal test. It doesn’t matter whose payslip you’re on. What matters is who was directing your work — and whether they had proper systems in place to protect you.

What went wrong — and what should have been in place?

The HSE investigation identified two distinct failures. First, the work equipment itself — specifically the isolation valve and flange bolts — had been allowed to deteriorate through corrosion to the point where it was no longer in an efficient state, in efficient working order, or in good repair. That is a specific breach of Regulation 5(1) of the Provision and Use of Work Equipment Regulations 1998 (PUWER).

Second, the risk assessment the company had on paper was inadequate. Widespread corrosion of the flange bolts meant it had become routine to cut them rather than unscrew them — but this practice reduces the ability to control any unexpected pressure remaining in the pipework. The risk assessment failed to reflect that. It also failed to incorporate HSE’s own published guidance, which recommends double isolation for this type of maintenance work rather than the single isolation method that had become standard practice at the site.

HSE Inspector David Welsh described the combination as “a dangerous accident waiting to happen.” The corroded equipment and the paper risk assessment that didn’t reflect real-world conditions — taken together — created an unacceptable risk for the contractor who had no control over either.

Why do so many contractors assume they can’t claim?

The most common barrier is the nature of contracting itself. When you work across multiple sites, often through an agency or as a self-employed tradesperson, the assumption is that you’ve accepted a certain level of risk as part of the arrangement. That instinct is understandable — but it isn’t the law.

The second barrier is uncertainty about who to claim against. If you’re injured while working for a contractor firm on a client’s site, the question of liability can feel impossibly complicated — is it your employer, the client, or someone else? In practice, the answer often involves more than one party. The site occupier may be liable under Section 3(1) of HSWA 1974. Your direct employer may be liable under Section 2(1). In some cases, both are liable. A solicitor who understands this area can establish which duties were owed and breached — that’s not something you need to work out yourself before calling.

The third barrier is the reluctance to rock the boat. Contractors often rely on repeat work from the same clients, and the concern about damaging that relationship is real. But under the Employers’ Liability (Compulsory Insurance) Act 1969, employers are legally required to hold insurance for exactly these claims. The claim goes against the insurer — not the company’s operating budget, and not the individuals you worked alongside.

What does a contractor injury claim actually involve?

A contractor injury claim is an employer liability claim — or more accurately, a site occupier liability claim — under the Health and Safety at Work etc. Act 1974 and the relevant specific regulations, such as PUWER. The claim goes against the responsible party’s insurer. It does not go against the individual site workers or managers you dealt with day-to-day.

What needs to be established is straightforward in principle: that the site occupier owed you a duty of care, that they breached it, and that the breach caused your injury. Evidence that supports this includes the RIDDOR report your employer or the site occupier was required to file, any HSE investigation materials if the incident was reported, the site’s risk assessment documentation — or the absence of it — and any records showing the condition of the work equipment involved.

Under the Limitation Act 1980, you have three years from the date of injury to bring a claim. The clear advice is to act as early as possible — evidence is easier to obtain, witnesses are easier to locate, and documentation is less likely to have been lost or archived.

What should I do if I was injured as a contractor?

Report the injury to both your direct employer and the site occupier — and make sure it goes in the accident book. Under the Reporting of Injuries, Diseases and Dangerous Occurrences Regulations 2013 (RIDDOR), serious injuries and dangerous occurrences must be reported to the HSE. If neither your employer nor the site occupier has done this, that failure is itself relevant to a claim.

Photograph the scene if you can — the equipment involved, the area where the incident happened, any hazards or defects that were present. Keep any documentation you were given about the work: method statements, permits to work, risk assessments. Note the names of anyone who witnessed the incident or who was involved in directing your work on the day.

Then take legal advice. The question of who owes you a duty of care — and whether it was breached — is one a specialist solicitor can establish from the facts of your situation. You don’t need to work it out in advance. You just need to make the call.