Skip to content

Chemical collection and stock control for UK schools, universities and hospitals

Copper metal (CAS 7440-50-8): storage and disposal

Copper turnings, foil and powder are common in school, college and university science stores, and a tub of bright metal looks unremarkable. Copper powder can carry an aquatic toxicity classification, but solid copper foil and turnings do not automatically have the same classification. The waste classification depends on the material's form, condition and composition. Its reactions with a few specific neighbours decide where it is shelved.

CAS number
7440-50-8
Form
Solid
Storage class
General
Signal word
Warning
Usual EWC code
16 05 06*
  • Hazardous to the environment pictogramHazardous to the environment

What to do this week

  1. Check the label is readable and write down the opened date if it is not already there.
  2. Check it is stored as general stock and apart from the items listed under "Do not store with".
  3. If you no longer need it, add it to your disposal list so it goes on the next collection.

Safe storage in a school or lab

Check the cap and the shelf beneath the tub: green or blue staining there means damp has reached the copper. Turnings, foil and powder belong in a dry, labelled general store, dated on arrival, with a tray under them because of the aquatic hazard, and it must never go down a drain. Keep copper away from hydrogen peroxide, since metals speed its breakdown and release oxygen and pressure, and away from ammonium nitrate. Picric acid, Bouin's fluid and ammonium picrate form shock sensitive picrates with metals, and sodium azide forms shock sensitive copper azide, so none of them should share a shelf with copper. Food grade supplies must not sit beside laboratory stock.

How to tell it has deteriorated

Brown, then darker tarnish is the ordinary change: bright turnings and foil dull to a brown or deeper surface in air. A green or blue-green crust points to damp and is usually seen on foil edges, on turnings and around the cap. Powder may darken and clump. Neither change is a sudden danger on its own, but green deposits can spread to labels and shelving and are worth a note in the stock record. Look at the container too: a corroded cap, a faded label, staining around the lid, a failed seal and any loss of the stock record. Because of the aquatic hazard, a tub that has leaked grit or crust must not be rinsed in a sink.

How it must be disposed of

By specialist collection only. It never goes down the drain or into general waste. It is normally packed in a non-regulated or low hazard laboratory pack with compatible chemicals.

The waste code and hazardous classification of copper turnings, foil and powder must be established from the actual material and its condition. Code 16 05 06* applies where the laboratory chemical waste contains hazardous substances. Metal that looks unremarkable still has to be described accurately on the paperwork. The only route is specialist collection: no sink, no drain, no general waste bin, no skip, and no attempt to treat it first. Say which form is held and which neighbours it shared a cupboard with, because collectors group by what could react. It is packed in compatible groups, away from hydrogen peroxide, sodium azide and picric acid products.

Waste codes and transport details for Copper metal
EWC code, laboratory chemicals16 05 06*
Discarded inorganic chemical, not a laboratory pack16 05 07*
Hazardous wasteYes

The code depends on where the waste came from and what it is mixed with. Use the waste code finder to see why.

Do not store with

Named chemicals to keep apart

  • Ammonium nitrateAmmonium nitrate forms mixtures with these materials that can detonate.
  • Ammonium picratePicric acid forms shock sensitive metal picrates with metals.
  • Hydrogen peroxideMetals speed the breakdown of hydrogen peroxide, releasing oxygen and pressure.
  • Picric acidPicric acid forms shock sensitive metal picrates with metals.
  • Sodium azideAzides form shock sensitive metal azides with lead, copper, brass and similar metals.

Common quantities we collect

Usually held as: turnings, foil, powder.

Part-used bottles and full containers are both fine. Tell us the size and how many, and an estimate is enough for a first price.

Where it is commonly held

Hazard statements

  • H410 Very toxic to aquatic life with long lasting effects.
Precautionary statements
  • P273 Avoid release to the environment.
  • P391 Collect spillage.
  • P501 Dispose of contents and container in accordance with local, regional, national and international regulations.

Substance as classified, dilutions may differ.

Questions

Is copper metal really hazardous waste?

It is classified as very toxic to aquatic life with long lasting effects, and it is entered as hazardous waste. A tub of turnings looks unremarkable, but it still needs a hazardous waste consignment note and specialist collection, not general waste or a drain.

Why must copper not be kept near sodium azide?

Azides form shock sensitive metal azides with lead, copper, brass and similar metals. Any stored sodium azide is therefore a reason to check that no copper, or brass fittings, share its shelf or cupboard.

Does green staining on old copper foil mean it has gone off?

Green or blue-green staining shows that damp has reached the metal. It does not change how the foil is described for collection, but it should lead to a check of the container, the label and neighbouring stock. Do not wash or treat it, simply record it.

Guidance only. Check your own risk assessment and your supplier's safety data sheet.

Hazard data source: PubChem GHS Classification, retrieved 31 Oct 2026. Formula Cu. EC number 231-159-6.

Request collection Add to register
Search the chemical database