HP9: Infectious
Waste holding live micro-organisms, or their toxins, known to cause disease in people or animals.
What HP9 means
HP9 covers waste holding live micro-organisms, or their toxins, known or reliably believed to cause disease in people or animals. Dead micro-organisms aren't infectious, but a toxin can make waste infectious even after the organism has gone.
It has no concentration limits of its own and no test. It's mostly decided by where the waste came from and a clinical judgement.
How WM3 decides a waste is HP9
| Route | When it applies |
|---|---|
| Healthcare waste | When it needs special handling to prevent infection: the patient is known or suspected to have an infection, the waste is or holds a culture, or it may infect anyone who touches it. It's then 18 01 03* (human) or 18 02 02* (animal). |
| Other waste | A waste holding a microbial toxin at a level that would make it HP5 or HP6. |
Whether healthcare waste is infectious is a clinical decision for a healthcare professional, and infectious waste has to be kept apart from other waste. Healthcare waste that isn't infectious is 18 01 04 or 18 02 03.
Where you're likely to meet it
- Infectious clinical waste in orange or yellow bags, and infectious anatomical waste.
- Sharps not contaminated with medicines (18 01 03*).
- Dredgings or skimmings from a watercourse after a blue-green algae bloom (the toxin route).
- Not usually: nappies, sanitary waste and dog waste from outside healthcare (20 01 99), unless a healthcare professional's risk assessment finds them infectious.
What it changes when the waste moves
A waste needs only one hazardous property to be hazardous waste. In England and Wales it then moves on a hazardous waste consignment note in place of a waste transfer note, and the note goes with the load to the site that receives it.
On Digital Waste Tracking, the site that receives a hazardous load records its HP codes alongside the EWC code (the six-digit code from the List of Wastes that says what a waste is).
Sources
- WM3: Waste classification technical guidance (v1.2.GB): Appendix C9, pages C33 to C35; offensive waste, page A42
- GOV.UK: Healthcare and related wastes, how to classify
- Annex III to the Waste Framework Directive (HP1 to HP15)
- GOV.UK: Hazardous waste consignment notes
- The Digital Waste Tracking (England) Regulations 2026: the paragraphs on hazardous properties and POPs, 15 and 16
This page explains the rules. Check the waste itself against WM3 before it moves.
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CarrierNote is on the GOV.UK software provider list, connected to DEFRA's Digital Waste Tracking service. Receiving sites are in scope from October 2026 and carriers from October 2027, and you can be recording to DEFRA's standard from your first load, whenever you start.