EWC chapter 12: metalworking and machining waste codes explained

Engineering workshops, fabrication shops, CNC machining centres and surface-treatment facilities generate some of the most commonly misclassified industrial waste in the UK. Metal swarf looks like scrap metal but falls under the European Waste Catalogue; used cutting fluid is hazardous — always — yet many producers still send it on a standard waste transfer note. Here is the complete chapter 12 breakdown, the machining oil decision tree, and the records each code requires.

What is EWC chapter 12?

The chapter spans the full range of waste streams from metalworking and machining: turnings and filings from lathes, mills and drills; the cutting fluids and coolants that lubricate them; grinding and lapping sludge; welding and shot-blasting residues; and the degreasing baths and steam-cleaning waste used to clean finished components. Note that edible oils and cooking fats are not chapter 12 waste, and general waste oil from vehicles and plant that is not machining-specific falls under chapter 13.

What subcategories and codes does chapter 12 contain?

Chapter 12 has two subcategories — 12 01 and 12 03. There is no subcategory 12 02. Within 12 01, there is no code 12 01 11; the list jumps from 12 01 10 to 12 01 12.

All 13 hazardous codes in EWC chapter 12 require a hazardous waste consignment note (not a standard waste transfer note), an upper-tier registered waste carrier, and records kept for at least 3 years.

What are the most commonly used EWC chapter 12 codes?

How do I classify machining oils and cutting fluids?

Step 1 — Is the fluid a neat (undiluted) oil, or a water-mixed emulsion/solution?

• →Neat (straight) oil, not water-diluted — the fluid comes directly from the drum without adding water → 12 01 06* or 12 01 07*
• →Emulsion or solution (water-mixed) — soluble oil, semi-synthetic or full-synthetic fluid that is mixed with water to form a coolant → 12 01 08* or 12 01 09*

Step 2 — Does the formulation contain halogens (chlorine, fluorine, bromine or iodine)?

• →Contains halogens — oils with chlorinated extreme-pressure (EP) additives, used for heavy-duty turning, tapping, or threading of stainless steel or titanium → 12 01 06* (neat) or 12 01 08* (water-mixed)
• →Free of halogens — most modern general-purpose coolants contain no halogenated compounds → 12 01 07* (neat) or 12 01 09* (water-mixed)

Is metal swarf and machining sludge hazardous?

The critical distinction is between dry metal chips (swarf) and the metal-plus-fluid slurry produced during grinding, honing or lapping:

• →Metal filings, turnings, dust (12 01 01 – 12 01 04) — non-hazardous absolute entries. Even if produced during a machining operation that uses hazardous cutting fluid, the solid metal chips themselves are not hazardous — provided they are separated from the fluid before classification. Oil-contaminated swarf that cannot be separated would be reclassified to the relevant oil code or a mirror sludge entry.
• →Metallic sludge containing oil (12 01 18*) — fine metal particles that are saturated with cutting oil, as produced by honing, super-finishing or similar operations. This is always hazardous. There is no mirror non-hazardous pair — if the sludge contains oil, 12 01 18* is the mandatory code.
• →Machining sludges (12 01 14* / 12 01 15) — a mirror pair. If the sludge contains dangerous substances (heavy metals in the metallic content, or hazardous fluid), use 12 01 14*. If the waste can be shown not to exhibit hazardous properties, use 12 01 15. Blasting material (12 01 16* / 12 01 17) and spent grinding bodies (12 01 20* / 12 01 21) follow the same mirror logic.

What records does chapter 12 waste require?

Only upper-tier registered waste carriers can transport hazardous chapter 12 waste. Lower-tier registration covers certain non-hazardous waste movements but does not extend to codes marked with an asterisk. Businesses producing waste that falls under a hazardous code must check their contractor holds a current upper-tier registration — handing hazardous waste to an unregistered carrier is a breach of the duty of care under s.34 Environmental Protection Act 1990.

This guide is general information about EWC waste codes, not legal advice. Check your specific obligations against the primary sources below and, if in doubt, contact the Environment Agency, SEPA, NRW or NIEA for your nation.