What is this document?
INDG458 is a brief introductory leaflet published by the Health and Safety Executive (HSE) in 2012. It provides a straightforward overview of legionella risks and the basic duties of those responsible for premises with water systems.
This is often the first document people encounter when learning about legionella control. It explains what legionella is, why it matters, and points duty holders toward more detailed guidance.
Who needs to read this?
This document is relevant to anyone who has control over premises with man-made water systems:
- Landlords with rental properties that have hot and cold water systems
- Property managers responsible for building water services
- Care home operators with vulnerable residents
- Employers with workplace water systems (showers, cooling towers, etc.)
- Building owners with responsibility for water services
If you are unsure whether legionella control applies to you, this leaflet is a good starting point.
Key points covered
The leaflet explains:
- What legionellosis is — The group of diseases caused by legionella bacteria, including Legionnaires' disease (a serious form of pneumonia) and milder conditions like Pontiac fever
- How infection occurs — Through breathing in water droplets (aerosols) from contaminated water systems
- Who is at risk — Particularly older people, smokers, and those with weakened immune systems
- Legal duties — Employers and those in control of premises must assess and control legionella risk
- Where to find more guidance — References to ACOP L8 and technical guidance HSG274
How this applies to you
If you control premises with water systems, you have a legal duty to:
- Identify and assess potential sources of legionella risk
- Prepare a written scheme to prevent or control the risk
- Implement and monitor your control measures
- Keep records of your precautions and checks
- Appoint someone competent to take responsibility for water safety
INDG458 is an introduction only. For detailed guidance on how to comply, you should also read:
- ACOP L8 — The Approved Code of Practice with full legal requirements
- HSG274 — Technical guidance on specific water systems
Related Safety Clarity content
- Legionella Control and Water Safety — Our complete guide to legionella compliance
- Do I need a legionella assessment? — Check if legionella controls apply to you
- Landlord's guide to legionella — Specific guidance for residential landlords
Read the official document: INDG458 on HSE website
Disclaimer: This summary is for general information only. Always refer to the official HSE publication for authoritative guidance. If you are unsure about your duties, seek professional advice from a competent legionella specialist.