Water hygiene within a healthcare facility is paramount to protecting both patients and staff. This blog explains the key points of the Health Technical Memorandum HTM 04-01, which outlines the legal requirements, design applications, and maintenance needed to ensure safe water in hospitals, care homes, and other healthcare facilities.
What is HTM 04-01?
HTM 04-01 is a Health Technical Memorandum from the Department of Health that provides guidance the management of hot and cold water systems in healthcare settings. It focuses on controlling waterborne pathogens within a healthcare setting, including Legionella, to protect the health of patients and staff.
Who is HTM 04-01 For?
If you work in healthcare or manage facilities, compliance, or patient safety, it’s your job to prevent Legionella in water systems. This applies to healthcare facility managers, maintenance staff, safety officers, and administrative leaders responsible for health and safety compliance.
- Healthcare management
- Water safety group
- Design engineer
- Estate manager
- Operations manager
- Contractor
- Supply chain business
What Does the Health Technical Memorandum 04-01 Cover?
The document provides clear guidance on the legal requirements, design, maintenance, and operation of hot and cold water systems in hospital and other healthcare facilities. It also covers storage and distribution systems. It is divided into three parts:
- Part A: Design, installation, and commissioning of healthcare water systems
- Part B: Operational management of healthcare water systems
- Part C: Measures to control and reduce Legionella and other waterborne pathogens in augmented care units
HTM 04-01 Part A
Part A focuses on devising a water safety plan for hot and cold water systems in healthcare. It highlights the importance of carefully assessing the water supply and choosing construction materials. Materials like natural rubber and linseed oil-based joint compounds are flagged as risky. It also outlines challenges like water filtering, storage, and softening.
HTM 04-01 Part B
Part B covers managing healthcare water systems to control Legionella bacteria. This pathogen is common in water systems but becomes a problem when it multiplies and spreads through aerosols. This section explains how to reduce risks, including keeping water storage temperatures outside the 20-45°C range where Legionella thrives, limiting aerosol release from taps or air conditioning, and preventing stagnant water by regularly flushing unused outlets.
Legionella and Healthcare Environments
Legionella is a severe risk in healthcare settings, especially for specific groups. People over 45, those with weakened immune systems, heavy smokers or drinkers, and individuals with lung, kidney, or heart conditions are more vulnerable. When inhaled in large amounts, Legionella bacteria can cause severe lung infections like Legionnaires’ disease, a dangerous type of pneumonia.
HTM 04-01 Part C
Part C focuses on controlling the Pseudomonas aeruginosa pathogen, especially in environments requiring higher levels of care. The guidelines stress the importance of good water system hygiene and regular monitoring to stop the spread of this pathogen. It also covers designing and maintaining plumbing systems to reduce contamination risks in critical care areas, protecting patients and healthcare workers.
How to Comply With HTM 04-01 Legionella
To meet HTM 04-01 standards, focus on the design and management of water systems. A Legionella risk assessment is key, involving physical inspections and a review of your facility’s hot and cold water systems.
Hiring a specialist ensures nothing gets missed. Legionella experts can help pinpoint risks and implement effective measures for Legionella control.
How We Can Help With HTM 04-01 Legionella Compliance
At Comfort Services Group, we carry out Legionella risk assessments to help businesses and properties stay compliant and keep water systems safe. Our work follows HTM 04-01 guidelines, the Approved Code of Practice L8 (ACOP L8), and Safe Water in Healthcare Premises.
Our technicians inspect your entire water system, testing equipment like thermostatic mixing valves and key water supply points. You’ll get a clear report with test results and practical recommendations for water treatment.
Ensure HTM 04-01 Legionella Compliance by Booking Comfort Services Group
Keep your water systems safe and compliant with Comfort Services Group. Our trained technicians carry out Legionella risk assessments to protect your staff and patients from health risks.
Get in touch today for an evaluation of your healthcare facility.
FAQs
Is HTM a legal requirement?
HTM (Health Technical Memorandum) documents, like HTM 04-01, are not legally required but provide clear guidance on managing water systems in UK healthcare facilities. They are often used in legal cases to define the expected standard of care. Following HTM guidelines helps manage health risks, such as Legionella and demonstrates responsibility for maintaining safe water systems.
What is the acceptable level of Pseudomonas in water?
The acceptable level of Pseudomonas aeruginosa in healthcare water systems depends on the setting and risk involved. In critical areas like operating rooms or spaces for immunocompromised patients, no Pseudomonas aeruginosa should be found in 100 ml of water. UK guidelines recommend aiming for zero detectable levels to reduce infection risks in high-risk healthcare settings. Regular testing is key to maintaining safe conditions for vulnerable patients.
What is the ISO for Pseudomonas aeruginosa in water?
The International Organization for Standardization (ISO) outlines methods for detecting and counting Pseudomonas aeruginosa in water. ISO 16266, “Water quality — Detection and enumeration of Pseudomonas aeruginosa — Method by membrane filtration,” describes how to isolate and identify the bacteria using membrane filtration. This ensures consistent and accurate testing across labs. Following ISO 16266 helps assess Pseudomonas aeruginosa levels in water systems, supporting safe water quality and reducing health risks in healthcare and other environments.
We are proud to share our experience and knowledge and take pride in offering this to all clients when required. If I, or one of the team can help then please schedule a meeting via the office or get in touch via one of our social media platforms.
- Top 10 Best Legionella Risk Assessment Companies in the UK (2026) - June 24, 2026
- Coagulation and Flocculation in Water Treatment: What’s the Difference? - April 7, 2026
- What is the Chain of Infection and How to Break It? - March 27, 2026
