HP8: Corrosive
Waste that can burn or destroy skin on contact.
What HP8 means
HP8 covers waste that can burn or destroy skin on contact. Any skin-corrosive substances (H314, categories 1A, 1B and 1C) that reach 5% together make a waste HP8; category 1A alone makes it HP4 from 1%.
The HP8 threshold
| Hazard statement | Makes the waste HP |
|---|---|
| H314 (skin corrosion, categories 1A, 1B and 1C) | 5% or more in total |
Any one substance below 1% is left out of the total.
Where not every component of the waste is known, a pH of 2 or lower, or 11.5 or higher, makes it HP8. It can only come down if an acid or alkali reserve test and an in vitro test both support it, and the reserve test can't clear a waste on its own.
Where you're likely to meet it
- Filter cake from waste treatment holding metal hydroxides, at pH 11.6 to 13.1, which WM3 treats as corrosive unless its make-up is fully known or it's tested.
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 C8, pages C29 to C31; filter cake example, page C19
- 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.