HSG274 Guidelines

What are HSG274 guidelines?

HSG274 is the official guidance published by the Health and Safety Executive to help businesses and landlords carry out effective landlords legionella risk assessments and control the risk of Legionnaires’ disease.

It sits alongside the legal framework set out in ACOP L8, but where L8 explains your legal duties, HSG274 shows you how to actually meet them in real-world situations.

In simple terms, if you are responsible for a building that is connected to mains water, HSG274 is your practical handbook.

Why HSG274 matters

Legionella bacteria can develop in man-made water systems if conditions are right. Warm, stagnant water with a source of nutrients creates the perfect environment.

The risk is not theoretical. Poorly managed systems can lead to serious illness and even fatalities. That is why compliance is not optional.

HSG274 matters because it translates legal responsibility into clear actions. It gives duty holders confidence that they are managing risk properly and protecting people who use their buildings.

What systems does HSG274 cover?

HSG274 is split into three main parts, each focusing on different types of water systems.

Part 1: Evaporative cooling systems

Cooling towers and evaporative condensers are considered high risk due to the potential for aerosol release.

Part 2: Hot and cold water systems

This is the most relevant section for most businesses. It covers everything from domestic-style plumbing to complex commercial systems.

Part 3: Other risk systems

This includes spa pools, humidifiers, vehicle wash systems, and anything else that can create water droplets.

If your system stores, recirculates, or sprays water, there is a strong chance HSG274 applies.

How HSG274 works in practice

HSG274 is not about ticking boxes. It is about creating a structured approach to managing risk.

Risk assessment comes first

Every system must be assessed to identify where legionella could grow and spread. This includes looking at temperatures, storage, usage patterns, and system design.

The outcome of this assessment shapes everything that follows.

Control measures must be in place

Typical control measures include maintaining correct water temperatures, avoiding stagnation, and keeping systems clean.

For example:

• Hot water should typically be stored above 60°C
• Cold water should be kept below 20°C

These are not arbitrary numbers. They are based on the conditions in which bacteria struggle to survive.

Monitoring keeps things on track

Once controls are in place, they must be checked regularly.

This includes temperature checks, inspection of tanks, and ensuring outlets are being used or flushed.

Monitoring provides evidence that your system is under control.

Records prove compliance

HSG274 places strong emphasis on record keeping.

You need to document:

• Risk assessments
• Maintenance activity
• Monitoring results
• Any corrective actions

If something goes wrong, these records are what demonstrate that you have taken your responsibilities seriously.

Who is responsible?

Under UK law, there must be a clearly defined “duty holder”.

This is usually:

• An employer
• A landlord
• A facilities manager
• Or anyone in control of the premises

The duty holder is responsible for ensuring that risks are assessed and managed properly.

In many cases, this responsibility is supported by a “responsible person” or specialist contractor, but accountability still sits with the duty holder.

Common mistakes businesses make

A lot of issues come from misunderstanding what compliance actually means.

One of the biggest mistakes is treating legionella control as a one-off task. A risk assessment alone is not enough. It must lead to ongoing management.

Another common issue is poor documentation. Work may be carried out, but without records, there is no proof.

Temperature control is also frequently overlooked. Systems drift out of range over time, especially in older buildings.

Finally, many businesses rely on outdated assessments that no longer reflect how the building is used.

Best practices for staying compliant

The most effective approach is simple and consistent.

• Start with a thorough risk assessment carried out by a competent professional.
• Make sure your control measures are practical and suited to your building, not copied from a template.
• Build routine monitoring into your operations so it becomes part of normal maintenance rather than an afterthought.
• Review your system regularly, especially after changes to layout, usage, or occupancy.

And most importantly, keep clear records. If it is not written down, it has not happened.

How you benefit from following HSG274

Compliance is not just about avoiding risk. It also improves how your building operates.

Well-managed water systems are more efficient, more reliable, and less likely to cause disruption.

You also protect your reputation. A legionella issue can have serious consequences for businesses, particularly in sectors like healthcare, hospitality, and property management.

Following HSG274 shows that you take safety seriously and that you are running your site responsibly.

How we can help

Understanding HSG274 is one thing. Applying it properly is another.

We support businesses with:

• Legionella risk assessments
• Monitoring and testing
• Ongoing compliance support
• System reviews and improvements

Whether you manage a single property or a large portfolio, we help you stay compliant without overcomplicating the process.

FAQs

Is HSG274 a legal requirement?

HSG274 itself is guidance, but it supports compliance with legal duties under ACOP L8 and health and safety law.

How often should a risk assessment be reviewed?

Typically every two years, or sooner if there are changes to the system or building use.

Do small businesses need to follow HSG274?

Yes. Any business with a water system has a responsibility to manage legionella risk.

What happens if you do not comply?

Failure to manage risk can lead to enforcement action, fines, and serious health consequences.

Next steps

If you are unsure whether your current setup meets HSG274 standards, now is the time to review it.

A simple assessment can highlight risks and give you a clear plan of action.

Get in touch to arrange a review and make sure your system is safe, compliant, and under control.